Merged
authorLaurent Bessard
Mon, 09 Sep 2013 00:48:34 +0200
changeset 1307 26e8b99bc2c3
parent 1289 1d221eda1e42 (current diff)
parent 1306 1ff1cdf6c318 (diff)
child 1308 ad61268dbdb6
Merged
plcopen/plcopen.py
--- a/IDEFrame.py	Wed Sep 04 00:06:44 2013 +0200
+++ b/IDEFrame.py	Mon Sep 09 00:48:34 2013 +0200
@@ -2302,7 +2302,6 @@
         if tagname is not None:
             self._Refresh(TITLE, FILEMENU, EDITMENU, PROJECTTREE, POUINSTANCEVARIABLESPANEL)
             self.EditProjectElement(ITEM_CONFIGURATION, tagname)
-        dialog.Destroy()
 
     def GenerateAddResourceFunction(self, config_name):
         def OnAddResourceMenu(event):
--- a/PLCControler.py	Wed Sep 04 00:06:44 2013 +0200
+++ b/PLCControler.py	Mon Sep 09 00:48:34 2013 +0200
@@ -24,13 +24,12 @@
 
 from xml.dom import minidom
 from types import StringType, UnicodeType, TupleType
-import cPickle
+from copy import deepcopy
 import os,sys,re
 import datetime
 from time import localtime
 
-from plcopen import plcopen
-from plcopen.structures import *
+from plcopen import*
 from graphics.GraphicCommons import *
 from PLCGenerator import *
 
@@ -66,14 +65,14 @@
                   ITEM_VAR_INOUT
                  ] = range(17, 24)
 
-VAR_CLASS_INFOS = {"Local" :    (plcopen.interface_localVars,    ITEM_VAR_LOCAL),
-                   "Global" :   (plcopen.interface_globalVars,   ITEM_VAR_GLOBAL),
-                   "External" : (plcopen.interface_externalVars, ITEM_VAR_EXTERNAL),
-                   "Temp" :     (plcopen.interface_tempVars,     ITEM_VAR_TEMP),
-                   "Input" :    (plcopen.interface_inputVars,    ITEM_VAR_INPUT),
-                   "Output" :   (plcopen.interface_outputVars,   ITEM_VAR_OUTPUT),
-                   "InOut" :    (plcopen.interface_inOutVars,    ITEM_VAR_INOUT)
-                  }
+VAR_CLASS_INFOS = {
+    "Local":    ("localVars",    ITEM_VAR_LOCAL),
+    "Global":   ("globalVars",   ITEM_VAR_GLOBAL),
+    "External": ("externalVars", ITEM_VAR_EXTERNAL),
+    "Temp":     ("tempVars",     ITEM_VAR_TEMP),
+    "Input":    ("inputVars",    ITEM_VAR_INPUT),
+    "Output":   ("outputVars",   ITEM_VAR_OUTPUT),
+    "InOut":    ("inOutVars",    ITEM_VAR_INOUT)}
 
 POU_TYPES = {"program": ITEM_PROGRAM,
              "functionBlock": ITEM_FUNCTIONBLOCK,
@@ -215,7 +214,7 @@
         self.ProgramFilePath = ""
             
     def GetQualifierTypes(self):
-        return plcopen.QualifierList
+        return QualifierList
 
     def GetProject(self, debug = False):
         if debug and self.CurrentCompiledProject is not None:
@@ -234,11 +233,12 @@
     # Create a new project by replacing the current one
     def CreateNewProject(self, properties):
         # Create the project
-        self.Project = plcopen.project()
+        self.Project = PLCOpenParser.CreateRoot()
         properties["creationDateTime"] = datetime.datetime(*localtime()[:6])
         self.Project.setfileHeader(properties)
         self.Project.setcontentHeader(properties)
         self.SetFilePath("")
+        
         # Initialize the project buffer
         self.CreateProjectBuffer(False)
         self.ProgramChunks = []
@@ -390,8 +390,9 @@
 
     def GetPouVariableInfos(self, project, variable, var_class, debug=False):
         vartype_content = variable.gettype().getcontent()
-        if vartype_content["name"] == "derived":
-            var_type = vartype_content["value"].getname()
+        vartype_content_type = vartype_content.getLocalTag()
+        if vartype_content_type == "derived":
+            var_type = vartype_content.getname()
             pou_type = None
             pou = project.getpou(var_type)
             if pou is not None:
@@ -419,15 +420,15 @@
                         "class": var_class,
                         "edit": False,
                         "debug": False}
-        elif vartype_content["name"] in ["string", "wstring"]:
+        elif vartype_content_type in ["string", "wstring"]:
             return {"name": variable.getname(), 
-                    "type": vartype_content["name"].upper(), 
+                    "type": vartype_content_type.upper(), 
                     "class": var_class,
                     "edit": False,
                     "debug": True}
         else:
             return {"name": variable.getname(),
-                    "type": vartype_content["name"], 
+                    "type": vartype_content_type, 
                     "class": var_class,
                     "edit": False,
                     "debug": True}
@@ -556,14 +557,14 @@
         for varlist in varlists:
             for variable in varlist.getvariable():
                 vartype_content = variable.gettype().getcontent()
-                if vartype_content["name"] == "derived":
+                if vartype_content.getLocalTag() == "derived":
                     var_path = "%s.%s" % (parent_path, variable.getname())
-                    var_type = vartype_content["value"].getname()
+                    var_type = vartype_content.getname()
                     if var_type == pou_type:
                         instances.append(var_path)
                     else:
                         pou = project.getpou(var_type)
-                        if pou is not None and project.ElementIsUsedBy(pou_type, var_type):
+                        if pou is not None:# and project.ElementIsUsedBy(pou_type, var_type):
                             instances.extend(
                                 self.RecursiveSearchPouInstances(
                                     project, pou_type, var_path, 
@@ -598,7 +599,7 @@
                             if pou_type == words[1]:
                                 instances.append(pou_path)
                             pou = project.getpou(pou_type)
-                            if pou is not None and project.ElementIsUsedBy(words[1], pou_type):
+                            if pou is not None:# and project.ElementIsUsedBy(words[1], pou_type):
                                 instances.extend(
                                     self.RecursiveSearchPouInstances(
                                         project, words[1], pou_path, 
@@ -625,7 +626,7 @@
                 for variable in varlist.getvariable():
                     if variable.getname() == parts[0]:
                         vartype_content = variable.gettype().getcontent()
-                        if vartype_content["name"] == "derived":
+                        if vartype_content.getLocalTag() == "derived":
                             return self.RecursiveGetPouInstanceTagName(
                                             project, 
                                             vartype_content["value"].getname(),
@@ -656,14 +657,14 @@
             for variable in varlist.getvariable():
                 if variable.getname() == parts[0]:
                     vartype_content = variable.gettype().getcontent()
-                    if vartype_content["name"] == "derived":                        
+                    if vartype_content.getLocalTag() == "derived":                        
                         if len(parts) == 1:
                             return self.ComputePouName(
-                                        vartype_content["value"].getname())
+                                        vartype_content.getname())
                         else:
                             return self.RecursiveGetPouInstanceTagName(
                                         project, 
-                                        vartype_content["value"].getname(),
+                                        vartype_content.getname(),
                                         parts[1:], debug)
         return None
     
@@ -728,23 +729,23 @@
     
     # Return if data type given by name is used by another data type or pou
     def DataTypeIsUsed(self, name, debug = False):
-        project = self.GetProject(debug)
-        if project is not None:
-            return project.ElementIsUsed(name) or project.DataTypeIsDerived(name)
+        #project = self.GetProject(debug)
+        #if project is not None:
+        #    return project.ElementIsUsed(name)
         return False
 
     # Return if pou given by name is used by another pou
     def PouIsUsed(self, name, debug = False):
-        project = self.GetProject(debug)
-        if project is not None:
-            return project.ElementIsUsed(name)
+        #project = self.GetProject(debug)
+        #if project is not None:
+        #    return project.ElementIsUsed(name)
         return False
 
     # Return if pou given by name is directly or undirectly used by the reference pou
     def PouIsUsedBy(self, name, reference, debug = False):
-        project = self.GetProject(debug)
-        if project is not None:
-            return project.ElementIsUsedBy(name, reference)
+        #project = self.GetProject(debug)
+        #if project is not None:
+        #    return project.ElementIsUsedBy(name, reference)
         return False
 
     def GenerateProgram(self, filepath=None):
@@ -832,14 +833,13 @@
             pou = self.Project.getpou(name)
             if pou is not None:
                 pou.setpouType(pou_type)
-                self.Project.RefreshCustomBlockTypes()
                 self.BufferProject()
                 
     def GetPouXml(self, pou_name):
         if self.Project is not None:
             pou = self.Project.getpou(pou_name)
             if pou is not None:
-                return pou.generateXMLText('pou', 0)
+                return pou.tostring()
         return None
     
     def PastePou(self, pou_type, pou_xml):
@@ -847,47 +847,40 @@
         Adds the POU defined by 'pou_xml' to the current project with type 'pou_type'
         '''
         try:
-            tree = minidom.parseString(pou_xml.encode("utf-8"))
-            root = tree.childNodes[0]
+            new_pou = LoadPou(pou_xml)
         except:
             return _("Couldn't paste non-POU object.")
-
-        if root.nodeName == "pou":
-            new_pou = plcopen.pous_pou()
-            new_pou.loadXMLTree(root)
-
-            name = new_pou.getname()
+        
+        name = new_pou.getname()
+        
+        idx = 0
+        new_name = name
+        while self.Project.getpou(new_name):
+            # a POU with that name already exists.
+            # make a new name and test if a POU with that name exists.
+            # append an incrementing numeric suffix to the POU name.
+            idx += 1
+            new_name = "%s%d" % (name, idx)
             
-            idx = 0
-            new_name = name
-            while self.Project.getpou(new_name):
-                # a POU with that name already exists.
-                # make a new name and test if a POU with that name exists.
-                # append an incrementing numeric suffix to the POU name.
-                idx += 1
-                new_name = "%s%d" % (name, idx)
-                
-            # we've found a name that does not already exist, use it
-            new_pou.setname(new_name)
+        # we've found a name that does not already exist, use it
+        new_pou.setname(new_name)
+        
+        if pou_type is not None:
+            orig_type = new_pou.getpouType()
+
+            # prevent violations of POU content restrictions:
+            # function blocks cannot be pasted as functions,
+            # programs cannot be pasted as functions or function blocks
+            if orig_type == 'functionBlock' and pou_type == 'function' or \
+               orig_type == 'program' and pou_type in ['function', 'functionBlock']:
+                return _('''%s "%s" can't be pasted as a %s.''') % (orig_type, name, pou_type)
             
-            if pou_type is not None:
-                orig_type = new_pou.getpouType()
-    
-                # prevent violations of POU content restrictions:
-                # function blocks cannot be pasted as functions,
-                # programs cannot be pasted as functions or function blocks
-                if orig_type == 'functionBlock' and pou_type == 'function' or \
-                   orig_type == 'program' and pou_type in ['function', 'functionBlock']:
-                    return _('''%s "%s" can't be pasted as a %s.''') % (orig_type, name, pou_type)
-                
-                new_pou.setpouType(pou_type)
-
-            self.Project.insertpou(-1, new_pou)
-            self.BufferProject()
-            
-            return self.ComputePouName(new_name),
-        else:
-            return _("Couldn't paste non-POU object.")
+            new_pou.setpouType(pou_type)
+
+        self.Project.insertpou(-1, new_pou)
+        self.BufferProject()
+        
+        return self.ComputePouName(new_name),
 
     # Remove a Pou from project
     def ProjectRemovePou(self, pou_name):
@@ -982,8 +975,6 @@
             if datatype is not None:
                 datatype.setname(new_name)
                 self.Project.updateElementName(old_name, new_name)
-                self.Project.RefreshElementUsingTree()
-                self.Project.RefreshDataTypeHierarchy()
                 self.BufferProject()
     
     # Change the name of a pou
@@ -994,8 +985,6 @@
             if pou is not None:
                 pou.setname(new_name)
                 self.Project.updateElementName(old_name, new_name)
-                self.Project.RefreshElementUsingTree()
-                self.Project.RefreshCustomBlockTypes()
                 self.BufferProject()
     
     # Change the name of a pou transition
@@ -1032,7 +1021,6 @@
                     for var in varlist.getvariable():
                         if var.getname() == old_name:
                             var.setname(new_name)
-                self.Project.RefreshCustomBlockTypes()
                 self.BufferProject()
         
     # Change the name of a configuration
@@ -1071,7 +1059,6 @@
             pou = project.getpou(name)
             if pou is not None:
                 pou.setdescription(description)
-                project.RefreshCustomBlockTypes()
                 self.BufferProject()
     
     # Return the type of the pou given by its name
@@ -1170,9 +1157,9 @@
                 current_type = next_type
                 infos = VAR_CLASS_INFOS.get(var["Class"], None)
                 if infos is not None:
-                    current_varlist = infos[0]()
+                    current_varlist = PLCOpenParser.CreateElement(infos[0], "interface")
                 else:
-                    current_varlist = plcopen.varList()
+                    current_varlist = PLCOpenParser.CreateElement("varList")
                 varlist_list.append((var["Class"], current_varlist))
                 if var["Option"] == "Constant":
                     current_varlist.setconstant(True)
@@ -1181,49 +1168,47 @@
                 elif var["Option"] == "Non-Retain":
                     current_varlist.setnonretain(True)
             # Create variable and change its properties
-            tempvar = plcopen.varListPlain_variable()
+            tempvar = PLCOpenParser.CreateElement("variable", "varListPlain")
             tempvar.setname(var["Name"])
             
-            var_type = plcopen.dataType()
+            var_type = PLCOpenParser.CreateElement("type", "variable")
             if isinstance(var["Type"], TupleType):
                 if var["Type"][0] == "array":
                     array_type, base_type_name, dimensions = var["Type"]
-                    array = plcopen.derivedTypes_array()
+                    array = PLCOpenParser.CreateElement("array", "dataType")
+                    baseType = PLCOpenParser.CreateElement("baseType", "array")
+                    array.setbaseType(baseType)
                     for i, dimension in enumerate(dimensions):
-                        dimension_range = plcopen.rangeSigned()
-                        dimension_range.setlower(dimension[0])
-                        dimension_range.setupper(dimension[1])
+                        dimension_range = PLCOpenParser.CreateElement("dimension", "array")
                         if i == 0:
                             array.setdimension([dimension_range])
                         else:
                             array.appenddimension(dimension_range)
+                        dimension_range.setlower(dimension[0])
+                        dimension_range.setupper(dimension[1])
                     if base_type_name in self.GetBaseTypes():
-                        if base_type_name == "STRING":
-                            array.baseType.setcontent({"name" : "string", "value" : plcopen.elementaryTypes_string()})
-                        elif base_type_name == "WSTRING":
-                            array.baseType.setcontent({"name" : "wstring", "value" : plcopen.wstring()})
-                        else:
-                            array.baseType.setcontent({"name" : base_type_name, "value" : None})
+                        baseType.setcontent(PLCOpenParser.CreateElement(
+                            base_type_name.lower()
+                            if base_type_name in ["STRING", "WSTRING"]
+                            else base_type_name, "dataType"))
                     else:
-                        derived_datatype = plcopen.derivedTypes_derived()
+                        derived_datatype = PLCOpenParser.CreateElement("derived", "dataType")
                         derived_datatype.setname(base_type_name)
-                        array.baseType.setcontent({"name" : "derived", "value" : derived_datatype})
-                    var_type.setcontent({"name" : "array", "value" : array})
+                        baseType.setcontent(derived_datatype)
+                    var_type.setcontent(array)
             elif var["Type"] in self.GetBaseTypes():
-                if var["Type"] == "STRING":
-                    var_type.setcontent({"name" : "string", "value" : plcopen.elementaryTypes_string()})
-                elif var["Type"] == "WSTRING":
-                    var_type.setcontent({"name" : "wstring", "value" : plcopen.elementaryTypes_wstring()})
-                else:
-                    var_type.setcontent({"name" : var["Type"], "value" : None})
+                var_type.setcontent(PLCOpenParser.CreateElement(
+                    var["Type"].lower()
+                    if var["Type"] in ["STRING", "WSTRING"]
+                    else var["Type"], "dataType"))
             else:
-                derived_type = plcopen.derivedTypes_derived()
+                derived_type = PLCOpenParser.CreateElement("derived", "dataType")
                 derived_type.setname(var["Type"])
-                var_type.setcontent({"name" : "derived", "value" : derived_type})
+                var_type.setcontent(derived_type)
             tempvar.settype(var_type)
 
             if var["Initial Value"] != "":
-                value = plcopen.value()
+                value = PLCOpenParser.CreateElement("initialValue", "variable")
                 value.setvalue(var["Initial Value"])
                 tempvar.setinitialValue(value)
             if var["Location"] != "":
@@ -1231,8 +1216,8 @@
             else:
                 tempvar.setaddress(None)
             if var['Documentation'] != "":
-                ft = plcopen.formattedText()
-                ft.settext(var['Documentation'])
+                ft = PLCOpenParser.CreateElement("documentation", "variable")
+                ft.setanyText(var['Documentation'])
                 tempvar.setdocumentation(ft)
 
             # Add variable to varList
@@ -1248,27 +1233,27 @@
         tempvar = {"Name": var.getname()}
 
         vartype_content = var.gettype().getcontent()
-        if vartype_content["name"] == "derived":
-            tempvar["Type"] = vartype_content["value"].getname()
-        elif vartype_content["name"] == "array":
+        vartype_content_type = vartype_content.getLocalTag()
+        if vartype_content_type == "derived":
+            tempvar["Type"] = vartype_content.getname()
+        elif vartype_content_type == "array":
             dimensions = []
-            for dimension in vartype_content["value"].getdimension():
+            for dimension in vartype_content.getdimension():
                 dimensions.append((dimension.getlower(), dimension.getupper()))
-            base_type = vartype_content["value"].baseType.getcontent()
-            if base_type["value"] is None or base_type["name"] in ["string", "wstring"]:
-                base_type_name = base_type["name"].upper()
+            base_type = vartype_content.baseType.getcontent()
+            base_type_type = base_type.getLocalTag()
+            if base_type_type == "derived":
+                base_type_name = base_type.getname()
             else:
-                base_type_name = base_type["value"].getname()
+                base_type_name = base_type_type.upper()
             tempvar["Type"] = ("array", base_type_name, dimensions)
-        elif vartype_content["name"] in ["string", "wstring"]:
-            tempvar["Type"] = vartype_content["name"].upper()
         else:
-            tempvar["Type"] = vartype_content["name"]
-
+            tempvar["Type"] = vartype_content_type.upper()
+        
         tempvar["Edit"] = True
-
+        
         initial = var.getinitialValue()
-        if initial:
+        if initial is not None:
             tempvar["Initial Value"] = initial.getvalue()
         else:
             tempvar["Initial Value"] = ""
@@ -1289,8 +1274,8 @@
             tempvar["Option"] = ""
 
         doc = var.getdocumentation()
-        if doc:
-            tempvar["Documentation"] = doc.gettext()
+        if doc is not None:
+            tempvar["Documentation"] = doc.getanyText()
         else:
             tempvar["Documentation"] = ""
 
@@ -1313,9 +1298,9 @@
             configuration = self.Project.getconfiguration(name)
             if configuration is not None:
                 # Set configuration global vars
-                configuration.setglobalVars([])
-                for vartype, varlist in self.ExtractVarLists(vars):
-                    configuration.globalVars.append(varlist)
+                configuration.setglobalVars([
+                    varlist for vartype, varlist
+                    in self.ExtractVarLists(vars)])
     
     # Return the configuration globalvars
     def GetConfigurationGlobalVars(self, name, debug = False):
@@ -1354,9 +1339,9 @@
             resource = self.Project.getconfigurationResource(config_name, name)
             # Set resource global vars
             if resource is not None:
-                resource.setglobalVars([])
-                for vartype, varlist in self.ExtractVarLists(vars):
-                    resource.globalVars.append(varlist)
+                resource.setglobalVars([
+                    varlist for vartype, varlist
+                    in self.ExtractVarLists(vars)])
     
     # Return the resource globalvars
     def GetConfigurationResourceGlobalVars(self, config_name, name, debug = False):
@@ -1365,7 +1350,7 @@
         if project is not None:
             # Found the resource corresponding to name
             resource = project.getconfigurationResource(config_name, name)
-            if resource:
+            if resource is not None:
                 # Extract variables from every varLists
                 for varlist in resource.getglobalVars():
                     for var in varlist.getvariable():
@@ -1409,31 +1394,31 @@
                 if not en:
                     tree.insert(0, ("EN", "BOOL", ([], [])))
                 return tree, []
-            datatype = project.getdataType(typename)
-            if datatype is None:
-                datatype = self.GetConfNodeDataType(typename)
+            datatype = self.GetDataType(typename)
             if datatype is not None:
                 tree = []
                 basetype_content = datatype.baseType.getcontent()
-                if basetype_content["name"] == "derived":
-                    return self.GenerateVarTree(basetype_content["value"].getname())
-                elif basetype_content["name"] == "array":
+                basetype_content_type = basetype_content.getLocalTag()
+                if basetype_content_type == "derived":
+                    return self.GenerateVarTree(basetype_content.getname())
+                elif basetype_content_type == "array":
                     dimensions = []
-                    base_type = basetype_content["value"].baseType.getcontent()
-                    if base_type["name"] == "derived":
-                        tree = self.GenerateVarTree(base_type["value"].getname())
+                    base_type = basetype_content.baseType.getcontent()
+                    if base_type.getLocalTag() == "derived":
+                        tree = self.GenerateVarTree(base_type.getname())
                         if len(tree[1]) == 0:
                             tree = tree[0]
-                        for dimension in basetype_content["value"].getdimension():
+                        for dimension in basetype_content.getdimension():
                             dimensions.append((dimension.getlower(), dimension.getupper()))
                     return tree, dimensions
-                elif basetype_content["name"] == "struct":
-                    for element in basetype_content["value"].getvariable():
+                elif basetype_content_type == "struct":
+                    for element in basetype_content.getvariable():
                         element_type = element.type.getcontent()
-                        if element_type["name"] == "derived":
-                            tree.append((element.getname(), element_type["value"].getname(), self.GenerateVarTree(element_type["value"].getname())))
+                        element_type_type = element_type.getLocalTag()
+                        if element_type_type == "derived":
+                            tree.append((element.getname(), element_type.getname(), self.GenerateVarTree(element_type.getname())))
                         else:
-                            tree.append((element.getname(), element_type["name"], ([], [])))
+                            tree.append((element.getname(), element_type_type, ([], [])))
                     return tree, []
         return [], []
 
@@ -1451,7 +1436,7 @@
                     tempvar["Tree"] = ([], [])
 
                     vartype_content = var.gettype().getcontent()
-                    if vartype_content["name"] == "derived":
+                    if vartype_content.getLocalTag() == "derived":
                         tempvar["Edit"] = not pou.hasblock(tempvar["Name"])
                         tempvar["Tree"] = self.GenerateVarTree(tempvar["Type"], debug)
 
@@ -1465,46 +1450,40 @@
             pou = self.Project.getpou(name)
             if pou is not None:
                 if pou.interface is None:
-                    pou.interface = plcopen.pou_interface()
+                    pou.interface = PLCOpenParser.CreateElement("interface", "pou")
                 # Set Pou interface
-                pou.setvars(self.ExtractVarLists(vars))
-                self.Project.RefreshElementUsingTree()
-                self.Project.RefreshCustomBlockTypes()
-    
+                pou.setvars([varlist for varlist_type, varlist in self.ExtractVarLists(vars)])
+                
     # Replace the return type of the pou given by its name (only for functions)
-    def SetPouInterfaceReturnType(self, name, type):
+    def SetPouInterfaceReturnType(self, name, return_type):
         if self.Project is not None:
             pou = self.Project.getpou(name)
             if pou is not None:
                 if pou.interface is None:
-                    pou.interface = plcopen.pou_interface()
+                    pou.interface = PLCOpenParser.CreateElement("interface", "pou")
                 # If there isn't any return type yet, add it
-                return_type = pou.interface.getreturnType()
-                if not return_type:
-                    return_type = plcopen.dataType()
-                    pou.interface.setreturnType(return_type)
+                return_type_obj = pou.interface.getreturnType()
+                if return_type_obj is None:
+                    return_type_obj = PLCOpenParser.CreateElement("returnType", "interface")
+                    pou.interface.setreturnType(return_type_obj)
                 # Change return type
-                if type in self.GetBaseTypes():
-                    if type == "STRING":
-                        return_type.setcontent({"name" : "string", "value" : plcopen.elementaryTypes_string()})
-                    elif type == "WSTRING":
-                        return_type.setcontent({"name" : "wstring", "value" : plcopen.elementaryTypes_wstring()})
-                    else:
-                        return_type.setcontent({"name" : type, "value" : None})
+                if return_type in self.GetBaseTypes():
+                    return_type_obj.setcontent(PLCOpenParser.CreateElement(
+                        return_type.lower()
+                        if return_type in ["STRING", "WSTRING"]
+                        else return_type, "dataType"))
                 else:
-                    derived_type = plcopen.derivedTypes_derived()
-                    derived_type.setname(type)
-                    return_type.setcontent({"name" : "derived", "value" : derived_type})
-                self.Project.RefreshElementUsingTree()
-                self.Project.RefreshCustomBlockTypes()
-    
+                    derived_type = PLCOpenParser.CreateElement("derived", "dataType")
+                    derived_type.setname(return_type)
+                    return_type.setcontent(derived_type)
+                
     def UpdateProjectUsedPous(self, old_name, new_name):
-        if self.Project:
+        if self.Project is not None:
             self.Project.updateElementName(old_name, new_name)
     
     def UpdateEditedElementUsedVariable(self, tagname, old_name, new_name):
         pou = self.GetEditedElement(tagname)
-        if pou:
+        if pou is not None:
             pou.updateElementName(old_name, new_name)
     
     # Return the return type of the pou given by its name
@@ -1523,21 +1502,21 @@
         if pou.interface is not None:
             # Return the return type if there is one
             return_type = pou.interface.getreturnType()
-            if return_type:
+            if return_type is not None:
                 returntype_content = return_type.getcontent()
-                if returntype_content["name"] == "derived":
-                    return returntype_content["value"].getname()
-                elif returntype_content["name"] in ["string", "wstring"]:
-                    return returntype_content["name"].upper()
+                returntype_content_type = returntype_content.getLocalTag()
+                if returntype_content_type == "derived":
+                    return returntype_content.getname()
                 else:
-                    return returntype_content["name"]
+                    return returntype_content_type.upper()
         return None
 
     # Function that add a new confnode to the confnode list
     def AddConfNodeTypesList(self, typeslist):
         self.ConfNodeTypes.extend(typeslist)
         addedcat = [{"name": _("%s POUs") % confnodetypes["name"],
-                     "list": confnodetypes["types"].GetCustomBlockTypes()}
+                     "list": [pou.getblockInfos()
+                              for pou in confnodetypes["types"].getpous()]}
                      for confnodetypes in typeslist]
         self.TotalTypes.extend(addedcat)
         for cat in addedcat:
@@ -1551,23 +1530,14 @@
         self.TotalTypesDict = StdBlckDct.copy()
         self.TotalTypes = StdBlckLst[:]
 
-    def GetConfNodeBlockTypes(self):
-        return [{"name": _("%s POUs") % confnodetypes["name"],
-                 "list": confnodetypes["types"].GetCustomBlockTypes()}
-                for confnodetypes in self.ConfNodeTypes]
-        
     def GetConfNodeDataTypes(self, exclude = None, only_locatables = False):
         return [{"name": _("%s Data Types") % confnodetypes["name"],
-                 "list": [datatype["name"] for datatype in confnodetypes["types"].GetCustomDataTypes(exclude, only_locatables)]}
+                 "list": [
+                    datatype.getname() 
+                    for datatype in confnodetypes["types"].getdataTypes()
+                    if not only_locatables or self.IsLocatableDataType(datatype, debug)]}
                 for confnodetypes in self.ConfNodeTypes]
     
-    def GetConfNodeDataType(self, typename):
-        for confnodetype in self.ConfNodeTypes:
-            datatype = confnodetype["types"].getdataType(typename)
-            if datatype is not None:
-                return datatype
-        return None
-    
     def GetVariableLocationTree(self):
         return []
 
@@ -1577,25 +1547,23 @@
     def GetConfigurationExtraVariables(self):
         global_vars = []
         for var_name, var_type, var_initial in self.GetConfNodeGlobalInstances():
-            tempvar = plcopen.varListPlain_variable()
+            tempvar = PLCOpenParser.CreateElement("variable", "globalVars")
             tempvar.setname(var_name)
             
-            tempvartype = plcopen.dataType()
+            tempvartype = PLCOpenParser.CreateElement("dataType", "variable")
             if var_type in self.GetBaseTypes():
-                if var_type == "STRING":
-                    tempvartype.setcontent({"name" : "string", "value" : plcopen.elementaryTypes_string()})
-                elif var_type == "WSTRING":
-                    tempvartype.setcontent({"name" : "wstring", "value" : plcopen.elementaryTypes_wstring()})
-                else:
-                    tempvartype.setcontent({"name" : var_type, "value" : None})
+                tempvar.setcontent(PLCOpenParser.CreateElement(
+                    var_type.lower()
+                    if var_type in ["STRING", "WSTRING"]
+                    else var_type, "dataType"))
             else:
-                tempderivedtype = plcopen.derivedTypes_derived()
+                tempderivedtype = PLCOpenParser.CreateElement("derived", "dataType")
                 tempderivedtype.setname(var_type)
-                tempvartype.setcontent({"name" : "derived", "value" : tempderivedtype})
+                tempvartype.setcontent(tempderivedtype)
             tempvar.settype(tempvartype)
             
             if var_initial != "":
-                value = plcopen.value()
+                value = PLCOpenParser.CreateElement("initialValue", "variable")
                 value.setvalue(var_initial)
                 tempvar.setinitialValue(value)
             
@@ -1623,7 +1591,16 @@
             return result_blocktype
         project = self.GetProject(debug)
         if project is not None:
-            return project.GetCustomBlockType(typename, inputs)
+            blocktype = project.getpou(typename)
+            if blocktype is not None:
+                blocktype_infos = blocktype.getblockInfos()
+                if inputs in [None, "undefined"]:
+                    return blocktype_infos
+            
+                if inputs == tuple([var_type 
+                    for name, var_type, modifier in blocktype_infos["inputs"]]):
+                    return blocktype_infos
+        
         return None
 
     # Return Block types checking for recursion
@@ -1635,22 +1612,19 @@
         if project is not None:
             pou_type = None
             if words[0] in ["P","T","A"]:
-                blocktypes = []
                 name = words[1]
                 pou_type = self.GetPouType(name, debug)
-            if pou_type == "function":
-                for category in self.TotalTypes:
-                    cat = {"name" : category["name"], "list" : []}
-                    for block in category["list"]:
-                        if block["type"] == "function":
-                            cat["list"].append(block)
-                    if len(cat["list"]) > 0:
-                        blocktypes.append(cat)
-            else:
-                blocktypes = [category for category in self.TotalTypes]
+            filter = (["function"] 
+                      if pou_type == "function" or words[0] == "T" 
+                      else ["functionBlock", "function"])
+            blocktypes = [
+                {"name": category["name"],
+                 "list": [block for block in category["list"]
+                          if block["type"] in filter]}
+                for category in self.TotalTypes]
             blocktypes.append({"name" : USER_DEFINED_POUS, 
-                "list": project.GetCustomBlockTypes(name, 
-                    pou_type == "function" or words[0] == "T")})
+                "list": [pou.getblockInfos()
+                         for pou in project.getpous(name, filter)]})
             return blocktypes
         return self.TotalTypes
 
@@ -1663,11 +1637,11 @@
                     blocktypes.append(block["name"])
         project = self.GetProject(debug)
         if project is not None:
-            name = ""
             words = tagname.split("::")
-            if words[0] in ["P","T","A"]:
-                name = words[1]
-            blocktypes.extend(project.GetCustomFunctionBlockTypes(name))
+            blocktypes.extend([pou.getname()
+                for pou in project.getpous(
+                    words[1] if words[0] in ["P","T","A"] else None,
+                    ["functionBlock"])])
         return blocktypes
 
     # Return Block types checking for recursion
@@ -1679,7 +1653,9 @@
                     blocktypes.append(blocktype["name"])
         project = self.GetProject(debug)
         if project is not None:
-            blocktypes.extend(project.GetCustomBlockResource())
+            blocktypes.extend(
+                [pou.getblockInfos()
+                 for pou in project.getpous(filter=["program"])])
         return blocktypes
 
     # Return Data Types checking for recursion
@@ -1694,25 +1670,55 @@
             words = tagname.split("::")
             if words[0] in ["D"]:
                 name = words[1]
-            datatypes.extend([datatype["name"] for datatype in project.GetCustomDataTypes(name, only_locatables)])
+            datatypes.extend([
+                datatype.getname() 
+                for datatype in project.getdataTypes(name)
+                if not only_locatables or self.IsLocatableDataType(datatype, debug)])
         if confnodetypes:
             for category in self.GetConfNodeDataTypes(name, only_locatables):
                 datatypes.extend(category["list"])
         return datatypes
 
-    # Return Base Type of given possible derived type
-    def GetBaseType(self, type, debug = False):
-        project = self.GetProject(debug)
-        if project is not None:
-            result = project.GetBaseType(type)
+    # Return Data Type Object
+    def GetDataType(self, typename, debug = False):
+        project = self.GetProject(debug)
+        if project is not None:
+            result = project.getdataType(typename)
             if result is not None:
                 return result
         for confnodetype in self.ConfNodeTypes:
-            result = confnodetype["types"].GetBaseType(type)
+            result = confnodetype["types"].getdataType(typename)
             if result is not None:
                 return result
         return None
 
+    # Return Data Type Object Base Type
+    def GetDataTypeBaseType(self, datatype):
+        basetype_content = datatype.baseType.getcontent()
+        basetype_content_type = basetype_content.getLocalTag()
+        if basetype_content_type in ["array", "subrangeSigned", "subrangeUnsigned"]:
+            basetype = basetype_content.baseType.getcontent()
+            basetype_type = basetype.getLocalTag()
+            return (basetype.getname() if basetype_type == "derived"
+                    else basetype_type.upper())
+        elif basetype_content_type == "derived":
+            return basetype_content_type.getname()
+        return None
+
+    # Return Base Type of given possible derived type
+    def GetBaseType(self, typename, debug = False):
+        if TypeHierarchy.has_key(typename):
+            return typename
+        
+        datatype = self.GetDataType(typename, debug)
+        if datatype is not None:
+            basetype = self.GetDataTypeBaseType(datatype)
+            if basetype is not None:
+                return self.GetBaseType(basetype, debug)
+            return typename
+        
+        return None
+
     def GetBaseTypes(self):
         '''
         return the list of datatypes defined in IEC 61131-3.
@@ -1721,93 +1727,131 @@
         '''
         return [x for x,y in TypeHierarchy_list if not x.startswith("ANY")]
 
-    def IsOfType(self, type, reference, debug = False):
-        if reference is None:
+    def IsOfType(self, typename, reference, debug = False):
+        if reference is None or typename == reference:
             return True
-        elif type == reference:
-            return True
-        elif type in TypeHierarchy:
-            return self.IsOfType(TypeHierarchy[type], reference)
-        else:
-            project = self.GetProject(debug)
-            if project is not None and project.IsOfType(type, reference):
-                return True
-            for confnodetype in self.ConfNodeTypes:
-                if confnodetype["types"].IsOfType(type, reference):
-                    return True
+        
+        basetype = TypeHierarchy.get(typename)
+        if basetype is not None:
+            return self.IsOfType(basetype, reference)
+        
+        datatype = self.GetDataType(typename, debug)
+        if datatype is not None:
+            basetype = self.GetDataTypeBaseType(datatype)
+            if basetype is not None:
+                return self.IsOfType(basetype, reference, debug)
+        
         return False
     
-    def IsEndType(self, type):
-        if type is not None:
-            return not type.startswith("ANY")
+    def IsEndType(self, typename):
+        if typename is not None:
+            return not typename.startswith("ANY")
         return True
 
-    def IsLocatableType(self, type, debug = False):
-        if isinstance(type, TupleType):
-            return False 
-        if self.GetBlockType(type) is not None:
+    def IsLocatableDataType(self, datatype, debug = False):
+        basetype_content = datatype.baseType.getcontent()
+        basetype_content_type = basetype_content.getLocalTag()
+        if basetype_content_type in ["enum", "struct"]:
             return False
-        project = self.GetProject(debug)
-        if project is not None:
-            datatype = project.getdataType(type)
-            if datatype is None:
-                datatype = self.GetConfNodeDataType(type)
-            if datatype is not None:
-                return project.IsLocatableType(datatype)
+        elif basetype_content_type == "derived":
+            return self.IsLocatableType(basetype_content.getname())
+        elif basetype_content_name == "array":
+            array_base_type = basetype_content.baseType.getcontent()
+            if array_base_type.getLocalTag() == "derived":
+                return self.IsLocatableType(array_base_type.getname(), debug)
         return True
-    
-    def IsEnumeratedType(self, type, debug = False):
-        project = self.GetProject(debug)
-        if project is not None:
-            datatype = project.getdataType(type)
-            if datatype is None:
-                datatype = self.GetConfNodeDataType(type)
-            if datatype is not None:
-                basetype_content = datatype.baseType.getcontent()
-                return basetype_content["name"] == "enum"
+        
+    def IsLocatableType(self, typename, debug = False):
+        if isinstance(typename, TupleType) or self.GetBlockType(typename) is not None:
+            return False
+        
+        datatype = self.GetDataType(typename, debug)
+        if datatype is not None:
+            return self.IsLocatableDataType(datatype)
+        return True
+    
+    def IsEnumeratedType(self, typename, debug = False):
+        if isinstance(typename, TupleType):
+            typename = typename[1]
+        datatype = self.GetDataType(typename, debug)
+        if datatype is not None:
+            basetype_content = datatype.baseType.getcontent()
+            basetype_content_type = basetype_content.getLocalTag()
+            if basetype_content_type == "derived":
+                return self.IsEnumeratedType(basetype_content_type, debug)
+            return basetype_content_type == "enum"
         return False
 
-    def IsNumType(self, type, debug = False):
-        return self.IsOfType(type, "ANY_NUM", debug) or\
-               self.IsOfType(type, "ANY_BIT", debug)
+    def IsSubrangeType(self, typename, exclude=None, debug = False):
+        if typename == exclude:
+            return False
+        if isinstance(typename, TupleType):
+            typename = typename[1]
+        datatype = self.GetDataType(typename, debug)
+        if datatype is not None:
+            basetype_content = datatype.baseType.getcontent()
+            basetype_content_type = basetype_content.getLocalTag()
+            if basetype_content_type == "derived":
+                return self.IsSubrangeType(basetype_content_type, exclude, debug)
+            elif basetype_content_type in ["subrangeSigned", "subrangeUnsigned"]:
+                return not self.IsOfType(
+                    self.GetDataTypeBaseType(datatype), exclude)
+        return False
+
+    def IsNumType(self, typename, debug = False):
+        return self.IsOfType(typename, "ANY_NUM", debug) or\
+               self.IsOfType(typename, "ANY_BIT", debug)
             
-    def GetDataTypeRange(self, type, debug = False):
-        if type in DataTypeRange:
-            return DataTypeRange[type]
+    def GetDataTypeRange(self, typename, debug = False):
+        range = DataTypeRange.get(typename)
+        if range is not None:
+            return range
+        datatype = self.GetDataType(typename, debug)
+        if datatype is not None:
+            basetype_content = datatype.baseType.getcontent()
+            basetype_content_type = basetype_content.getLocalTag()
+            if basetype_content_type in ["subrangeSigned", "subrangeUnsigned"]:
+                return (basetype_content.range.getlower(),
+                        basetype_content.range.getupper())
+            elif basetype_content_type == "derived":
+                return self.GetDataTypeRange(basetype_content.getname(), debug)
+        return None
+    
+    # Return Subrange types
+    def GetSubrangeBaseTypes(self, exclude, debug = False):
+        subrange_basetypes = DataTypeRange.keys()
+        project = self.GetProject(debug)
+        if project is not None:
+            subrange_basetypes.extend(
+                [datatype.getname() for datatype in project.getdataTypes()
+                 if self.IsSubrangeType(datatype.getname(), exclude, debug)])
+        for confnodetype in self.ConfNodeTypes:
+            subrange_basetypes.extend(
+                [datatype.getname() for datatype in confnodetype["types"].getdataTypes()
+                 if self.IsSubrangeType(datatype.getname(), exclude, debug)])
+        return subrange_basetypes
+    
+    # Return Enumerated Values
+    def GetEnumeratedDataValues(self, typename = None, debug = False):
+        values = []
+        if typename is not None:
+            datatype_obj = self.GetDataType(typename, debug)
+            if datatype_obj is not None:
+                basetype_content = datatype_obj.baseType.getcontent()
+                basetype_content_type = basetype_content.getLocalTag()
+                if basetype_content_type == "enum":
+                    return [value.getname() 
+                            for value in basetype_content.xpath(
+                                "ppx:values/ppx:value",
+                                namespaces=PLCOpenParser.NSMAP)]
+                elif basetype_content_type == "derived":
+                    return self.GetEnumeratedDataValues(basetype_content.getname(), debug)
         else:
             project = self.GetProject(debug)
             if project is not None:
-                result = project.GetDataTypeRange(type)
-                if result is not None:
-                    return result
+                values.extend(project.GetEnumeratedDataTypeValues())
             for confnodetype in self.ConfNodeTypes:
-                result = confnodetype["types"].GetDataTypeRange(type)
-                if result is not None:
-                    return result
-        return None
-    
-    # Return Subrange types
-    def GetSubrangeBaseTypes(self, exclude, debug = False):
-        subrange_basetypes = []
-        project = self.GetProject(debug)
-        if project is not None:
-            subrange_basetypes.extend(project.GetSubrangeBaseTypes(exclude))
-        for confnodetype in self.ConfNodeTypes:
-            subrange_basetypes.extend(confnodetype["types"].GetSubrangeBaseTypes(exclude))
-        return DataTypeRange.keys() + subrange_basetypes
-    
-    # Return Enumerated Values
-    def GetEnumeratedDataValues(self, type = None, debug = False):
-        values = []
-        project = self.GetProject(debug)
-        if project is not None:
-            values.extend(project.GetEnumeratedDataTypeValues(type))
-            if type is None and len(values) > 0:
-                return values
-        for confnodetype in self.ConfNodeTypes:
-            values.extend(confnodetype["types"].GetEnumeratedDataTypeValues(type))
-            if type is None and len(values) > 0:
-                return values
+                values.extend(confnodetype["types"].GetEnumeratedDataTypeValues())
         return values
 
 #-------------------------------------------------------------------------------
@@ -1859,62 +1903,64 @@
                 if datatype is None:
                     return None
                 basetype_content = datatype.baseType.getcontent()
-                if basetype_content["value"] is None or basetype_content["name"] in ["string", "wstring"]:
-                    infos["type"] = "Directly"
-                    infos["base_type"] = basetype_content["name"].upper()
-                elif basetype_content["name"] == "derived":
-                    infos["type"] = "Directly"
-                    infos["base_type"] = basetype_content["value"].getname()
-                elif basetype_content["name"] in ["subrangeSigned", "subrangeUnsigned"]:
+                basetype_content_type = basetype_content.getLocalTag()
+                if basetype_content_type in ["subrangeSigned", "subrangeUnsigned"]:
                     infos["type"] = "Subrange"
-                    infos["min"] = basetype_content["value"].range.getlower()
-                    infos["max"] = basetype_content["value"].range.getupper()
-                    base_type = basetype_content["value"].baseType.getcontent()
-                    if base_type["value"] is None:
-                        infos["base_type"] = base_type["name"]
-                    else:
-                        infos["base_type"] = base_type["value"].getname()
-                elif basetype_content["name"] == "enum":
+                    infos["min"] = basetype_content.range.getlower()
+                    infos["max"] = basetype_content.range.getupper()
+                    base_type = basetype_content.baseType.getcontent()
+                    base_type_type = base_type.getLocalTag()
+                    infos["base_type"] = (base_type.getname()
+                        if base_type_type == "derived"
+                        else base_type_type)
+                elif basetype_content_type == "enum":
                     infos["type"] = "Enumerated"
                     infos["values"] = []
-                    for value in basetype_content["value"].values.getvalue():
+                    for value in basetype_content.xpath("ppx:values/ppx:value", namespaces=PLCOpenParser.NSMAP):
                         infos["values"].append(value.getname())
-                elif basetype_content["name"] == "array":
+                elif basetype_content_type == "array":
                     infos["type"] = "Array"
                     infos["dimensions"] = []
-                    for dimension in basetype_content["value"].getdimension():
+                    for dimension in basetype_content.getdimension():
                         infos["dimensions"].append((dimension.getlower(), dimension.getupper()))
-                    base_type = basetype_content["value"].baseType.getcontent()
-                    if base_type["value"] is None or base_type["name"] in ["string", "wstring"]:
-                        infos["base_type"] = base_type["name"].upper()
-                    else:
-                        infos["base_type"] = base_type["value"].getname()
-                elif basetype_content["name"] == "struct":
+                    base_type = basetype_content.baseType.getcontent()
+                    base_type_type = base_type.getLocalTag()
+                    infos["base_type"] = (base_type.getname()
+                        if base_type_type == "derived"
+                        else base_type_type.upper())
+                elif basetype_content_type == "struct":
                     infos["type"] = "Structure"
                     infos["elements"] = []
-                    for element in basetype_content["value"].getvariable():
+                    for element in basetype_content.getvariable():
                         element_infos = {}
                         element_infos["Name"] = element.getname()
                         element_type = element.type.getcontent()
-                        if element_type["value"] is None or element_type["name"] in ["string", "wstring"]:
-                            element_infos["Type"] = element_type["name"].upper()
-                        elif element_type["name"] == "array":
+                        element_type_type = element_type.getLocalTag()
+                        if element_type_type == "array":
                             dimensions = []
-                            for dimension in element_type["value"].getdimension():
+                            for dimension in element_type.getdimension():
                                 dimensions.append((dimension.getlower(), dimension.getupper()))
-                            base_type = element_type["value"].baseType.getcontent()
-                            if base_type["value"] is None or base_type["name"] in ["string", "wstring"]:
-                                base_type_name = base_type["name"].upper()
-                            else:
-                                base_type_name = base_type["value"].getname()
-                            element_infos["Type"] = ("array", base_type_name, dimensions)
+                            base_type = element_type.baseType.getcontent()
+                            base_type_type = element_type.getLocalTag()
+                            element_infos["Type"] = ("array", 
+                                base_type.getname()
+                                if base_type_type == "derived"
+                                else base_type_type.upper(), dimensions)
+                        elif element_type_type == "derived":
+                            element_infos["Type"] = element_type.getname()
                         else:
-                            element_infos["Type"] = element_type["value"].getname()
+                            element_infos["Type"] = element_type_type.upper()
                         if element.initialValue is not None:
                             element_infos["Initial Value"] = str(element.initialValue.getvalue())
                         else:
                             element_infos["Initial Value"] = ""
                         infos["elements"].append(element_infos)
+                else:
+                    infos["type"] = "Directly"
+                    infos["base_type"] = (basetype_content.getname()
+                        if basetype_content_type == "derived"
+                        else basetype_content_type.upper())
+                
                 if datatype.initialValue is not None:
                     infos["initial"] = str(datatype.initialValue.getvalue())
                 else:
@@ -1929,45 +1975,46 @@
             datatype = self.Project.getdataType(words[1])
             if infos["type"] == "Directly":
                 if infos["base_type"] in self.GetBaseTypes():
-                    if infos["base_type"] == "STRING":
-                        datatype.baseType.setcontent({"name" : "string", "value" : plcopen.elementaryTypes_string()})
-                    elif infos["base_type"] == "WSTRING":
-                        datatype.baseType.setcontent({"name" : "wstring", "value" : plcopen.elementaryTypes_wstring()})
-                    else:
-                        datatype.baseType.setcontent({"name" : infos["base_type"], "value" : None})
+                    datatype.baseType.setcontent(PLCOpenParser.CreateElement(
+                        infos["base_type"].lower()
+                        if infos["base_type"] in ["STRING", "WSTRING"]
+                        else infos["base_type"], "dataType"))
                 else:
-                    derived_datatype = plcopen.derivedTypes_derived()
+                    derived_datatype = PLCOpenParser.CreateElement("derived", "dataType")
                     derived_datatype.setname(infos["base_type"])
-                    datatype.baseType.setcontent({"name" : "derived", "value" : derived_datatype})
+                    datatype.baseType.setcontent(derived_datatype)
             elif infos["type"] == "Subrange":
-                if infos["base_type"] in GetSubTypes("ANY_UINT"):
-                    subrange = plcopen.derivedTypes_subrangeUnsigned()
-                    datatype.baseType.setcontent({"name" : "subrangeUnsigned", "value" : subrange})
-                else:
-                    subrange = plcopen.derivedTypes_subrangeSigned()
-                    datatype.baseType.setcontent({"name" : "subrangeSigned", "value" : subrange})
+                subrange = PLCOpenParser.CreateElement(
+                    "subrangeUnsigned" 
+                    if infos["base_type"] in GetSubTypes("ANY_UINT")
+                    else "subrangeSigned", "dataType")
+                datatype.baseType.setcontent(subrange)
                 subrange.range.setlower(infos["min"])
                 subrange.range.setupper(infos["max"])
                 if infos["base_type"] in self.GetBaseTypes():
-                    subrange.baseType.setcontent({"name" : infos["base_type"], "value" : None})
+                    subrange.baseType.setcontent(
+                        PLCOpenParser.CreateElement(infos["base_type"], "dataType"))
                 else:
-                    derived_datatype = plcopen.derivedTypes_derived()
+                    derived_datatype = PLCOpenParser.CreateElement("derived", "dataType")
                     derived_datatype.setname(infos["base_type"])
-                    subrange.baseType.setcontent({"name" : "derived", "value" : derived_datatype})
+                    subrange.baseType.setcontent(derived_datatype)
             elif infos["type"] == "Enumerated":
-                enumerated = plcopen.derivedTypes_enum()
+                enumerated = PLCOpenParser.CreateElement("enum", "dataType")
+                datatype.baseType.setcontent(enumerated)
+                values = PLCOpenParser.CreateElement("values", "enum")
+                enumerated.setvalues(values)
                 for i, enum_value in enumerate(infos["values"]):
-                    value = plcopen.values_value()
+                    value = PLCOpenParser.CreateElement("value", "values")
                     value.setname(enum_value)
                     if i == 0:
-                        enumerated.values.setvalue([value])
+                        values.setvalue([value])
                     else:
-                        enumerated.values.appendvalue(value)
-                datatype.baseType.setcontent({"name" : "enum", "value" : enumerated})
+                        values.appendvalue(value)
             elif infos["type"] == "Array":
-                array = plcopen.derivedTypes_array()
+                array = PLCOpenParser.CreateElement("array", "dataType")
+                datatype.baseType.setcontent(array)
                 for i, dimension in enumerate(infos["dimensions"]):
-                    dimension_range = plcopen.rangeSigned()
+                    dimension_range = PLCOpenParser.CreateElement("dimension", "array")
                     dimension_range.setlower(dimension[0])
                     dimension_range.setupper(dimension[1])
                     if i == 0:
@@ -1975,28 +2022,28 @@
                     else:
                         array.appenddimension(dimension_range)
                 if infos["base_type"] in self.GetBaseTypes():
-                    if infos["base_type"] == "STRING":
-                        array.baseType.setcontent({"name" : "string", "value" : plcopen.elementaryTypes_string()})
-                    elif infos["base_type"] == "WSTRING":
-                        array.baseType.setcontent({"name" : "wstring", "value" : plcopen.wstring()})
-                    else:
-                        array.baseType.setcontent({"name" : infos["base_type"], "value" : None})
+                    array.baseType.setcontent(PLCOpenParser.CreateElement(
+                        infos["base_type"].lower()
+                        if infos["base_type"] in ["STRING", "WSTRING"]
+                        else infos["base_type"], "dataType"))
                 else:
-                    derived_datatype = plcopen.derivedTypes_derived()
+                    derived_datatype = PLCOpenParser.CreateElement("derived", "dataType")
                     derived_datatype.setname(infos["base_type"])
-                    array.baseType.setcontent({"name" : "derived", "value" : derived_datatype})
-                datatype.baseType.setcontent({"name" : "array", "value" : array})
+                    array.baseType.setcontent(derived_datatype)
             elif infos["type"] == "Structure":
-                struct = plcopen.varListPlain()
+                struct = PLCOpenParser.CreateElement("struct", "dataType")
+                datatype.baseType.setcontent(struct)
                 for i, element_infos in enumerate(infos["elements"]):
-                    element = plcopen.varListPlain_variable()
+                    element = PLCOpenParser.CreateElement("variable", "struct")
                     element.setname(element_infos["Name"])
+                    element_type = PLCOpenParser.CreateElement("type", "variable")
                     if isinstance(element_infos["Type"], TupleType):
                         if element_infos["Type"][0] == "array":
                             array_type, base_type_name, dimensions = element_infos["Type"]
-                            array = plcopen.derivedTypes_array()
+                            array = PLCOpenParser.CreateElement("array", "dataType")
+                            element_type.setcontent(array)
                             for j, dimension in enumerate(dimensions):
-                                dimension_range = plcopen.rangeSigned()
+                                dimension_range = PLCOpenParser.CreateElement("dimension", "array")
                                 dimension_range.setlower(dimension[0])
                                 dimension_range.setupper(dimension[1])
                                 if j == 0:
@@ -2004,45 +2051,39 @@
                                 else:
                                     array.appenddimension(dimension_range)
                             if base_type_name in self.GetBaseTypes():
-                                if base_type_name == "STRING":
-                                    array.baseType.setcontent({"name" : "string", "value" : plcopen.elementaryTypes_string()})
-                                elif base_type_name == "WSTRING":
-                                    array.baseType.setcontent({"name" : "wstring", "value" : plcopen.wstring()})
-                                else:
-                                    array.baseType.setcontent({"name" : base_type_name, "value" : None})
+                                array.baseType.setcontent(PLCOpenParser.CreateElement(
+                                    base_type_name.lower()
+                                    if base_type_name in ["STRING", "WSTRING"]
+                                    else base_type_name, "dataType"))
                             else:
-                                derived_datatype = plcopen.derivedTypes_derived()
+                                derived_datatype = PLCOpenParser.CreateElement("derived", "dataType")
                                 derived_datatype.setname(base_type_name)
-                                array.baseType.setcontent({"name" : "derived", "value" : derived_datatype})
-                            element.type.setcontent({"name" : "array", "value" : array})
+                                array.baseType.setcontent(derived_datatype)
                     elif element_infos["Type"] in self.GetBaseTypes():
-                        if element_infos["Type"] == "STRING":
-                            element.type.setcontent({"name" : "string", "value" : plcopen.elementaryTypes_string()})
-                        elif element_infos["Type"] == "WSTRING":
-                            element.type.setcontent({"name" : "wstring", "value" : plcopen.wstring()})
-                        else:
-                            element.type.setcontent({"name" : element_infos["Type"], "value" : None})
+                        element_type.setcontent(
+                            PLCOpenParser.CreateElement(
+                                element_infos["Type"].lower()
+                                if element_infos["Type"] in ["STRING", "WSTRING"]
+                                else element_infos["Type"], "dataType"))
                     else:
-                        derived_datatype = plcopen.derivedTypes_derived()
+                        derived_datatype = PLCOpenParser.CreateElement("derived", "dataType")
                         derived_datatype.setname(element_infos["Type"])
-                        element.type.setcontent({"name" : "derived", "value" : derived_datatype})
+                        element_type.setcontent(derived_datatype)
+                    element.settype(element_type)
                     if element_infos["Initial Value"] != "":
-                        value = plcopen.value()
+                        value = PLCOpenParser.CreateElement("initialValue", "variable")
                         value.setvalue(element_infos["Initial Value"])
                         element.setinitialValue(value)
                     if i == 0:
                         struct.setvariable([element])
                     else:
                         struct.appendvariable(element)
-                datatype.baseType.setcontent({"name" : "struct", "value" : struct})
             if infos["initial"] != "":
                 if datatype.initialValue is None:
-                    datatype.initialValue = plcopen.value()
+                    datatype.initialValue = PLCOpenParser.CreateElement("initialValue", "dataType")
                 datatype.initialValue.setvalue(infos["initial"])
             else:
                 datatype.initialValue = None
-            self.Project.RefreshDataTypeHierarchy()
-            self.Project.RefreshElementUsingTree()
             self.BufferProject()
     
 #-------------------------------------------------------------------------------
@@ -2128,7 +2169,6 @@
             element = self.GetEditedElement(tagname)
             if element is not None:
                 element.settext(text)
-                self.Project.RefreshElementUsingTree()
     
     # Return the edited element text
     def GetEditedElementText(self, tagname, debug = False):
@@ -2173,22 +2213,28 @@
     def GetEditedElementCopy(self, tagname, debug = False):
         element = self.GetEditedElement(tagname, debug)
         if element is not None:
-            name = element.__class__.__name__
-            return element.generateXMLText(name.split("_")[-1], 0)
+            return element.tostring()
         return ""
         
     def GetEditedElementInstancesCopy(self, tagname, blocks_id = None, wires = None, debug = False):
         element = self.GetEditedElement(tagname, debug)
         text = ""
         if element is not None:
-            wires = dict([(wire, True) for wire in wires if wire[0] in blocks_id and wire[1] in blocks_id])
+            wires = dict([(wire, True) 
+                          for wire in wires 
+                          if wire[0] in blocks_id and wire[1] in blocks_id])
+            copy_body = PLCOpenParser.CreateElement("body", "pou")
+            element.append(copy_body)
+            copy_body.setcontent(
+                PLCOpenParser.CreateElement(element.getbodyType(), "body"))
             for id in blocks_id:
                 instance = element.getinstance(id)
                 if instance is not None:
-                    instance_copy = self.Copy(instance)
+                    copy_body.appendcontentInstance(self.Copy(instance))
+                    instance_copy = copy_body.getcontentInstance(id)
                     instance_copy.filterConnections(wires)
-                    name = instance_copy.__class__.__name__
-                    text += instance_copy.generateXMLText(name.split("_")[-1], 0)
+                    text += instance_copy.tostring()
+            element.remove(copy_body)
         return text
     
     def GenerateNewName(self, tagname, name, format, start_idx=0, exclude={}, debug=False):
@@ -2201,9 +2247,10 @@
                 element = self.GetEditedElement(tagname, debug)
                 if element is not None and element.getbodyType() not in ["ST", "IL"]:
                     for instance in element.getinstances():
-                        if isinstance(instance, (plcopen.sfcObjects_step, 
-                                                 plcopen.commonObjects_connector, 
-                                                 plcopen.commonObjects_continuation)):
+                        if isinstance(instance, 
+                            (PLCOpenParser.GetElementClass("step", "sfcObjects"), 
+                             PLCOpenParser.GetElementClass("connector", "commonObjects"), 
+                             PLCOpenParser.GetElementClass("continuation", "commonObjects"))):
                             names[instance.getname().upper()] = True
         else:
             project = self.GetProject(debug)
@@ -2229,10 +2276,6 @@
             i += 1
         return name
     
-    CheckPasteCompatibility = {"SFC": lambda name: True,
-                               "LD": lambda name: not name.startswith("sfcObjects"),
-                               "FBD": lambda name: name.startswith("fbdObjects") or name.startswith("commonObjects")}
-    
     def PasteEditedElementInstances(self, tagname, text, new_pos, middle=False, debug=False):
         element = self.GetEditedElement(tagname, debug)
         element_name, element_type = self.GetEditedElementType(tagname, debug)
@@ -2250,62 +2293,46 @@
             used_id = dict([(instance.getlocalId(), True) for instance in element.getinstances()])
             new_id = {}
             
-            text = "<paste>%s</paste>"%text
-            
             try:
-                tree = minidom.parseString(text.encode("utf-8"))
+                instances = LoadPouInstances(text.encode("utf-8"), bodytype)
+                if len(instances) == 0:
+                    raise ValueError
             except:
                 return _("Invalid plcopen element(s)!!!")
-            instances = []
+            
             exclude = {}
-            for root in tree.childNodes:
-                if root.nodeType == tree.ELEMENT_NODE and root.nodeName == "paste":
-                    for child in root.childNodes:
-                        if child.nodeType == tree.ELEMENT_NODE:
-                            if not child.nodeName in plcopen.ElementNameToClass:
-                                return _("\"%s\" element can't be pasted here!!!")%child.nodeName
-
-                            classname = plcopen.ElementNameToClass[child.nodeName]
-                            if not self.CheckPasteCompatibility[bodytype](classname):
-                                return _("\"%s\" element can't be pasted here!!!")%child.nodeName
-
-                            classobj = getattr(plcopen, classname, None)
-                            if classobj is not None:
-                                instance = classobj()
-                                instance.loadXMLTree(child)
-                                if child.nodeName == "block":
-                                    blockname = instance.getinstanceName()
-                                    if blockname is not None:
-                                        blocktype = instance.gettypeName()
-                                        if element_type == "function":
-                                            return _("FunctionBlock \"%s\" can't be pasted in a Function!!!")%blocktype
-                                        blockname = self.GenerateNewName(tagname, 
-                                                                         blockname, 
-                                                                         "%s%%d"%blocktype, 
-                                                                         debug=debug)
-                                        exclude[blockname] = True
-                                        instance.setinstanceName(blockname)
-                                        self.AddEditedElementPouVar(tagname, blocktype, blockname)
-                                elif child.nodeName == "step":
-                                    stepname = self.GenerateNewName(tagname, 
-                                                                    instance.getname(), 
-                                                                    "Step%d", 
-                                                                    exclude=exclude, 
-                                                                    debug=debug)
-                                    exclude[stepname] = True
-                                    instance.setname(stepname)
-                                localid = instance.getlocalId()
-                                if not used_id.has_key(localid):
-                                    new_id[localid] = True
-                                instances.append((child.nodeName, instance))
-            
-            if len(instances) == 0:
-                return _("Invalid plcopen element(s)!!!")
+            for instance in instances:
+                element.addinstance(instance)
+                instance_type = instance.getLocalTag()
+                if instance_type == "block":
+                    blockname = instance.getinstanceName()
+                    if blockname is not None:
+                        blocktype = instance.gettypeName()
+                        if element_type == "function":
+                            return _("FunctionBlock \"%s\" can't be pasted in a Function!!!")%blocktype
+                        blockname = self.GenerateNewName(tagname, 
+                                                         blockname, 
+                                                         "%s%%d"%blocktype, 
+                                                         debug=debug)
+                        exclude[blockname] = True
+                        instance.setinstanceName(blockname)
+                        self.AddEditedElementPouVar(tagname, blocktype, blockname)
+                elif instance_type == "step":
+                    stepname = self.GenerateNewName(tagname, 
+                                                    instance.getname(), 
+                                                    "Step%d", 
+                                                    exclude=exclude, 
+                                                    debug=debug)
+                    exclude[stepname] = True
+                    instance.setname(stepname)
+                localid = instance.getlocalId()
+                if not used_id.has_key(localid):
+                    new_id[localid] = True
             
             idx = 1
             translate_id = {}
-            bbox = plcopen.rect()
-            for name, instance in instances:
+            bbox = rect()
+            for instance in instances:
                 localId = instance.getlocalId()
                 bbox.union(instance.getBoundingBox())
                 if used_id.has_key(localId):
@@ -2338,12 +2365,11 @@
             diff = (new_pos[0] - x, new_pos[1] - y)
             
             connections = {}
-            for name, instance in instances:
+            for instance in instances:
                 connections.update(instance.updateConnectionsId(translate_id))
                 if getattr(instance, "setexecutionOrderId", None) is not None:
                     instance.setexecutionOrderId(0)
                 instance.translate(*diff)
-                element.addinstance(name, instance)
             
             return new_id, connections
                 
@@ -2392,12 +2418,11 @@
                         for var in varlist.getvariable():
                             if var.getname() == varname:
                                 vartype_content = var.gettype().getcontent()
-                                if vartype_content["name"] == "derived":
-                                    return vartype_content["value"].getname()
-                                elif vartype_content["name"] in ["string", "wstring"]:
-                                    return vartype_content["name"].upper()
+                                vartype_content_type = vartype_content.getLocalTag()
+                                if vartype_content_type == "derived":
+                                    return vartype_content.getname()
                                 else:
-                                    return vartype_content["name"]
+                                    return vartype_content_type.upper()
         return None
     
     def SetConnectionWires(self, connection, connector):
@@ -2457,15 +2482,14 @@
     def AddEditedElementBlock(self, tagname, id, blocktype, blockname = None):
         element = self.GetEditedElement(tagname)
         if element is not None:
-            block = plcopen.fbdObjects_block()
+            block = PLCOpenParser.CreateElement("block", "fbdObjects")
             block.setlocalId(id)
             block.settypeName(blocktype)
             blocktype_infos = self.GetBlockType(blocktype)
             if blocktype_infos["type"] != "function" and blockname is not None:
                 block.setinstanceName(blockname)
                 self.AddEditedElementPouVar(tagname, blocktype, blockname)
-            element.addinstance("block", block)
-            self.Project.RefreshElementUsingTree()
+            element.addinstance(block)
     
     def SetEditedElementBlockInfos(self, tagname, id, infos):
         element = self.GetEditedElement(tagname)
@@ -2510,7 +2534,8 @@
                     block.inputVariables.setvariable([])
                     block.outputVariables.setvariable([])
                     for connector in value["inputs"]:
-                        variable = plcopen.inputVariables_variable()
+                        variable = PLCOpenParser.CreateElement("variable", "inputVariables")
+                        block.inputVariables.appendvariable(variable)
                         variable.setformalParameter(connector.GetName())
                         if connector.IsNegated():
                             variable.setnegated(True)
@@ -2519,9 +2544,9 @@
                         position = connector.GetRelPosition()
                         variable.connectionPointIn.setrelPositionXY(position.x, position.y)
                         self.SetConnectionWires(variable.connectionPointIn, connector)
-                        block.inputVariables.appendvariable(variable)
                     for connector in value["outputs"]:
-                        variable = plcopen.outputVariables_variable()
+                        variable = PLCOpenParser.CreateElement("variable", "outputVariables")
+                        block.outputVariables.appendvariable(variable)
                         variable.setformalParameter(connector.GetName())
                         if connector.IsNegated():
                             variable.setnegated(True)
@@ -2530,23 +2555,17 @@
                         position = connector.GetRelPosition()
                         variable.addconnectionPointOut()
                         variable.connectionPointOut.setrelPositionXY(position.x, position.y)
-                        block.outputVariables.appendvariable(variable)
-            self.Project.RefreshElementUsingTree()
+            block.tostring()
         
-    def AddEditedElementVariable(self, tagname, id, type):
+    def AddEditedElementVariable(self, tagname, id, var_type):
         element = self.GetEditedElement(tagname)
-        if element is not None:            
-            if type == INPUT:
-                name = "inVariable"
-                variable = plcopen.fbdObjects_inVariable()
-            elif type == OUTPUT:
-                name = "outVariable"
-                variable = plcopen.fbdObjects_outVariable()
-            elif type == INOUT:
-                name = "inOutVariable"
-                variable = plcopen.fbdObjects_inOutVariable()
+        if element is not None:
+            variable = PLCOpenParser.CreateElement(
+                {INPUT: "inVariable",
+                 OUTPUT: "outVariable",
+                 INOUT: "inOutVariable"}[var_type], "fbdObjects")
             variable.setlocalId(id)
-            element.addinstance(name, variable)
+            element.addinstance(variable)
         
     def SetEditedElementVariableInfos(self, tagname, id, infos):
         element = self.GetEditedElement(tagname)
@@ -2556,7 +2575,9 @@
                 return 
             for param, value in infos.items():
                 if param == "name":
-                    variable.setexpression(value)    
+                    expression = PLCOpenParser.CreateElement("expression", variable.getLocalTag())
+                    expression.text = value
+                    variable.setexpression(expression)
                 elif param == "executionOrder" and variable.getexecutionOrderId() != value:
                     element.setelementExecutionOrder(variable, value)
                 elif param == "height":
@@ -2592,17 +2613,14 @@
                         variable.connectionPointIn.setrelPositionXY(position.x, position.y)
                         self.SetConnectionWires(variable.connectionPointIn, input)
 
-    def AddEditedElementConnection(self, tagname, id, type):
+    def AddEditedElementConnection(self, tagname, id, connection_type):
         element = self.GetEditedElement(tagname)
         if element is not None:
-            if type == CONNECTOR:
-                name = "connector"
-                connection = plcopen.commonObjects_connector()
-            elif type == CONTINUATION:
-                name = "continuation"
-                connection = plcopen.commonObjects_continuation()
+            connection = PLCOpenParser.CreateElement(
+                {CONNECTOR: "connector",
+                 CONTINUATION: "continuation"}[connection_type], "commonObjects")
             connection.setlocalId(id)
-            element.addinstance(name, connection)
+            element.addinstance(connection)
         
     def SetEditedElementConnectionInfos(self, tagname, id, infos):
         element = self.GetEditedElement(tagname)
@@ -2623,10 +2641,10 @@
                     connection.sety(value)
                 elif param == "connector":
                     position = value.GetRelPosition()
-                    if isinstance(connection, plcopen.commonObjects_continuation):
+                    if isinstance(connection, PLCOpenParser.GetElementClass("continuation", "commonObjects")):
                         connection.addconnectionPointOut()
                         connection.connectionPointOut.setrelPositionXY(position.x, position.y)
-                    elif isinstance(connection, plcopen.commonObjects_connector):
+                    elif isinstance(connection, PLCOpenParser.GetElementClass("connector", "commonObjects")):
                         connection.addconnectionPointIn()
                         connection.connectionPointIn.setrelPositionXY(position.x, position.y)
                         self.SetConnectionWires(connection.connectionPointIn, value)
@@ -2634,9 +2652,9 @@
     def AddEditedElementComment(self, tagname, id):
         element = self.GetEditedElement(tagname)
         if element is not None:
-            comment = plcopen.commonObjects_comment()
+            comment = PLCOpenParser.CreateElement("comment", "commonObjects")
             comment.setlocalId(id)
-            element.addinstance("comment", comment)
+            element.addinstance(comment)
     
     def SetEditedElementCommentInfos(self, tagname, id, infos):
         element = self.GetEditedElement(tagname)
@@ -2654,17 +2672,14 @@
                 elif param == "y":
                     comment.sety(value)
 
-    def AddEditedElementPowerRail(self, tagname, id, type):
+    def AddEditedElementPowerRail(self, tagname, id, powerrail_type):
         element = self.GetEditedElement(tagname)
         if element is not None:
-            if type == LEFTRAIL:
-                name = "leftPowerRail"
-                powerrail = plcopen.ldObjects_leftPowerRail()
-            elif type == RIGHTRAIL:
-                name = "rightPowerRail"
-                powerrail = plcopen.ldObjects_rightPowerRail()
+            powerrail = PLCOpenParser.CreateElement(
+                {LEFTRAIL: "leftPowerRail",
+                 RIGHTRAIL: "rightPowerRail"}[powerrail_type], "ldObjects")
             powerrail.setlocalId(id)
-            element.addinstance(name, powerrail)
+            element.addinstance(powerrail)
     
     def SetEditedElementPowerRailInfos(self, tagname, id, infos):
         element = self.GetEditedElement(tagname)
@@ -2682,28 +2697,28 @@
                 elif param == "y":
                     powerrail.sety(value)
                 elif param == "connectors":
-                    if isinstance(powerrail, plcopen.ldObjects_leftPowerRail):
+                    if isinstance(powerrail, PLCOpenParser.GetElementClass("leftPowerRail", "ldObjects")):
                         powerrail.setconnectionPointOut([])
                         for connector in value["outputs"]:
                             position = connector.GetRelPosition()
-                            connection = plcopen.leftPowerRail_connectionPointOut()
+                            connection = PLCOpenParser.CreateElement("connectionPointOut", "leftPowerRail")
+                            powerrail.appendconnectionPointOut(connection)
                             connection.setrelPositionXY(position.x, position.y)
-                            powerrail.connectionPointOut.append(connection)
-                    elif isinstance(powerrail, plcopen.ldObjects_rightPowerRail):
+                    elif isinstance(powerrail, PLCOpenParser.GetElementClass("rightPowerRail", "ldObjects")):
                         powerrail.setconnectionPointIn([])
                         for connector in value["inputs"]:
                             position = connector.GetRelPosition()
-                            connection = plcopen.connectionPointIn()
+                            connection = PLCOpenParser.CreateElement("connectionPointIn", "rightPowerRail")
+                            powerrail.appendconnectionPointIn(connection)
                             connection.setrelPositionXY(position.x, position.y)
                             self.SetConnectionWires(connection, connector)
-                            powerrail.connectionPointIn.append(connection)
-
+                            
     def AddEditedElementContact(self, tagname, id):
         element = self.GetEditedElement(tagname)
         if element is not None:
-            contact = plcopen.ldObjects_contact()
+            contact = PLCOpenParser.CreateElement("contact", "ldObjects")
             contact.setlocalId(id)
-            element.addinstance("contact", contact)
+            element.addinstance(contact)
 
     def SetEditedElementContactInfos(self, tagname, id, infos):
         element = self.GetEditedElement(tagname)
@@ -2713,20 +2728,17 @@
                 return
             for param, value in infos.items():
                 if param == "name":
-                    contact.setvariable(value)
+                    variable = PLCOpenParser.CreateElement("variable", "contact")
+                    variable.text = value
+                    contact.setvariable(variable)
                 elif param == "type":
-                    if value == CONTACT_NORMAL:
-                        contact.setnegated(False)
-                        contact.setedge("none")
-                    elif value == CONTACT_REVERSE:
-                        contact.setnegated(True)
-                        contact.setedge("none")
-                    elif value == CONTACT_RISING:
-                        contact.setnegated(False)
-                        contact.setedge("rising")
-                    elif value == CONTACT_FALLING:
-                        contact.setnegated(False)
-                        contact.setedge("falling")
+                    negated, edge = {
+                        CONTACT_NORMAL: (False, "none"),
+                        CONTACT_REVERSE: (True, "none"),
+                        CONTACT_RISING: (False, "rising"),
+                        CONTACT_FALLING: (False, "falling")}[value]
+                    contact.setnegated(negated)
+                    contact.setedge(edge)
                 elif param == "height":
                     contact.setheight(value)
                 elif param == "width":
@@ -2749,9 +2761,9 @@
     def AddEditedElementCoil(self, tagname, id):
         element = self.GetEditedElement(tagname)
         if element is not None:
-            coil = plcopen.ldObjects_coil()
+            coil = PLCOpenParser.CreateElement("coil", "ldObjects")
             coil.setlocalId(id)
-            element.addinstance("coil", coil)
+            element.addinstance(coil)
 
     def SetEditedElementCoilInfos(self, tagname, id, infos):
         element = self.GetEditedElement(tagname)
@@ -2761,32 +2773,20 @@
                 return
             for param, value in infos.items():
                 if param == "name":
-                    coil.setvariable(value)
+                    variable = PLCOpenParser.CreateElement("variable", "coil")
+                    variable.text = value
+                    coil.setvariable(variable)
                 elif param == "type":
-                    if value == COIL_NORMAL:
-                        coil.setnegated(False)
-                        coil.setstorage("none")
-                        coil.setedge("none")
-                    elif value == COIL_REVERSE:
-                        coil.setnegated(True)
-                        coil.setstorage("none")
-                        coil.setedge("none")
-                    elif value == COIL_SET:
-                        coil.setnegated(False)
-                        coil.setstorage("set")
-                        coil.setedge("none")
-                    elif value == COIL_RESET:
-                        coil.setnegated(False)
-                        coil.setstorage("reset")
-                        coil.setedge("none")
-                    elif value == COIL_RISING:
-                        coil.setnegated(False)
-                        coil.setstorage("none")
-                        coil.setedge("rising")
-                    elif value == COIL_FALLING:
-                        coil.setnegated(False)
-                        coil.setstorage("none")
-                        coil.setedge("falling")
+                    negated, storage, edge = {
+                        COIL_NORMAL: (False, "none", "none"),
+                        COIL_REVERSE: (True, "none", "none"),
+                        COIL_SET: (False, "set", "none"),
+                        COIL_RESET: (False, "reset", "none"),
+                        COIL_RISING: (False, "none", "rising"),
+                        COIL_FALLING: (False, "none", "falling")}[value]
+                    coil.setnegated(negated)
+                    coil.setstorage(storage)
+                    coil.setedge(edge)
                 elif param == "height":
                     coil.setheight(value)
                 elif param == "width":
@@ -2809,9 +2809,9 @@
     def AddEditedElementStep(self, tagname, id):
         element = self.GetEditedElement(tagname)
         if element is not None:
-            step = plcopen.sfcObjects_step()
+            step = PLCOpenParser.CreateElement("step", "sfcObjects")
             step.setlocalId(id)
-            element.addinstance("step", step)
+            element.addinstance(step)
     
     def SetEditedElementStepInfos(self, tagname, id, infos):
         element = self.GetEditedElement(tagname)
@@ -2859,9 +2859,9 @@
     def AddEditedElementTransition(self, tagname, id):
         element = self.GetEditedElement(tagname)
         if element is not None:
-            transition = plcopen.sfcObjects_transition()
+            transition = PLCOpenParser.CreateElement("transition", "sfcObjects")
             transition.setlocalId(id)
-            element.addinstance("transition", transition)
+            element.addinstance(transition)
     
     def SetEditedElementTransitionInfos(self, tagname, id, infos):
         element = self.GetEditedElement(tagname)
@@ -2897,25 +2897,31 @@
                     transition.connectionPointOut.setrelPositionXY(position.x, position.y)
                 elif infos.get("type", None) == "connection" and param == "connection" and value:
                     transition.setconditionContent("connection", None)
-                    self.SetConnectionWires(transition.condition.content["value"], value)
-    
-    def AddEditedElementDivergence(self, tagname, id, type):
+                    self.SetConnectionWires(transition.condition.content, value)
+    
+    def AddEditedElementDivergence(self, tagname, id, divergence_type):
         element = self.GetEditedElement(tagname)
         if element is not None:
-            if type == SELECTION_DIVERGENCE:
-                name = "selectionDivergence"
-                divergence = plcopen.sfcObjects_selectionDivergence()
-            elif type == SELECTION_CONVERGENCE:
-                name = "selectionConvergence"
-                divergence = plcopen.sfcObjects_selectionConvergence()
-            elif type == SIMULTANEOUS_DIVERGENCE:
-                name = "simultaneousDivergence"
-                divergence = plcopen.sfcObjects_simultaneousDivergence()
-            elif type == SIMULTANEOUS_CONVERGENCE:
-                name = "simultaneousConvergence"
-                divergence = plcopen.sfcObjects_simultaneousConvergence()
+            divergence = PLCOpenParser.CreateElement(
+                {SELECTION_DIVERGENCE: "selectionDivergence",
+                 SELECTION_CONVERGENCE: "selectionConvergence",
+                 SIMULTANEOUS_DIVERGENCE: "simultaneousDivergence",
+                 SIMULTANEOUS_CONVERGENCE: "simultaneousConvergence"}.get(
+                    divergence_type), "sfcObjects")
             divergence.setlocalId(id)
-            element.addinstance(name, divergence)
+            element.addinstance(divergence)
+    
+    DivergenceTypes = [
+        (divergence_type, 
+         PLCOpenParser.GetElementClass(divergence_type, "sfcObjects"))
+        for divergence_type in ["selectionDivergence", "simultaneousDivergence",
+                                "selectionConvergence", "simultaneousConvergence"]]
+    
+    def GetDivergenceType(self, divergence):
+        for divergence_type, divergence_class in self.DivergenceTypes:
+            if isinstance(divergence, divergence_class):
+                return divergence_type
+        return None
     
     def SetEditedElementDivergenceInfos(self, tagname, id, infos):
         element = self.GetEditedElement(tagname)
@@ -2934,7 +2940,8 @@
                     divergence.sety(value)
                 elif param == "connectors":
                     input_connectors = value["inputs"]
-                    if isinstance(divergence, (plcopen.sfcObjects_selectionDivergence, plcopen.sfcObjects_simultaneousDivergence)):
+                    divergence_type = self.GetDivergenceType(divergence)
+                    if divergence_type in ["selectionDivergence", "simultaneousDivergence"]:
                         position = input_connectors[0].GetRelPosition()
                         divergence.addconnectionPointIn()
                         divergence.connectionPointIn.setrelPositionXY(position.x, position.y)
@@ -2943,15 +2950,12 @@
                         divergence.setconnectionPointIn([])
                         for input_connector in input_connectors:
                             position = input_connector.GetRelPosition()
-                            if isinstance(divergence, plcopen.sfcObjects_selectionConvergence):
-                                connection = plcopen.selectionConvergence_connectionPointIn()
-                            else:
-                                connection = plcopen.connectionPointIn()
+                            connection = PLCOpenParser.CreateElement("connectionPointIn", divergence_type)
+                            divergence.appendconnectionPointIn(connection)
                             connection.setrelPositionXY(position.x, position.y)
                             self.SetConnectionWires(connection, input_connector)
-                            divergence.appendconnectionPointIn(connection)
                     output_connectors = value["outputs"]
-                    if isinstance(divergence, (plcopen.sfcObjects_selectionConvergence, plcopen.sfcObjects_simultaneousConvergence)):
+                    if divergence_type in ["selectionConvergence", "simultaneousConvergence"]:
                         position = output_connectors[0].GetRelPosition()
                         divergence.addconnectionPointOut()
                         divergence.connectionPointOut.setrelPositionXY(position.x, position.y)
@@ -2959,19 +2963,16 @@
                         divergence.setconnectionPointOut([])
                         for output_connector in output_connectors:
                             position = output_connector.GetRelPosition()
-                            if isinstance(divergence, plcopen.sfcObjects_selectionDivergence):
-                                connection = plcopen.selectionDivergence_connectionPointOut()
-                            else:
-                                connection = plcopen.simultaneousDivergence_connectionPointOut()
+                            connection = PLCOpenParser.CreateElement("connectionPointOut", divergence_type)
+                            divergence.appendconnectionPointOut(connection)
                             connection.setrelPositionXY(position.x, position.y)
-                            divergence.appendconnectionPointOut(connection)
-    
+                            
     def AddEditedElementJump(self, tagname, id):
         element = self.GetEditedElement(tagname)
         if element is not None:
-            jump = plcopen.sfcObjects_jumpStep()
+            jump = PLCOpenParser.CreateElement("jumpStep", "sfcObjects")
             jump.setlocalId(id)
-            element.addinstance("jumpStep", jump)
+            element.addinstance(jump)
     
     def SetEditedElementJumpInfos(self, tagname, id, infos):
         element = self.GetEditedElement(tagname)
@@ -2999,9 +3000,9 @@
     def AddEditedElementActionBlock(self, tagname, id):
         element = self.GetEditedElement(tagname)
         if element is not None:
-            actionBlock = plcopen.commonObjects_actionBlock()
+            actionBlock = PLCOpenParser.CreateElement("actionBlock", "commonObjects")
             actionBlock.setlocalId(id)
-            element.addinstance("actionBlock", actionBlock)
+            element.addinstance(actionBlock)
     
     def SetEditedElementActionBlockInfos(self, tagname, id, infos):
         element = self.GetEditedElement(tagname)
@@ -3030,10 +3031,9 @@
         element = self.GetEditedElement(tagname)
         if element is not None:
             instance = element.getinstance(id)
-            if isinstance(instance, plcopen.fbdObjects_block):
+            if isinstance(instance, PLCOpenParser.GetElementClass("block", "fbdObjects")):
                 self.RemoveEditedElementPouVar(tagname, instance.gettypeName(), instance.getinstanceName())
             element.removeinstance(id)
-            self.Project.RefreshElementUsingTree()
 
     def GetEditedResourceVariables(self, tagname, debug = False):
         varlist = []
@@ -3053,7 +3053,8 @@
             resource.setpouInstance([])
             task_list = {}
             for task in tasks:
-                new_task = plcopen.resource_task()
+                new_task = PLCOpenParser.CreateElement("task", "resource")
+                resource.appendtask(new_task)
                 new_task.setname(task["Name"])
                 if task["Triggering"] == "Interrupt":
                     new_task.setsingle(task["Single"])
@@ -3073,12 +3074,16 @@
                 new_task.setpriority(int(task["Priority"]))
                 if task["Name"] != "":
                     task_list[task["Name"]] = new_task
-                resource.appendtask(new_task)
             for instance in instances:
-                new_instance = plcopen.pouInstance()
+                task = task_list.get(instance["Task"])
+                if task is not None:
+                    new_instance = PLCOpenParser.CreateElement("pouInstance", "task")
+                    task.appendpouInstance(new_instance)
+                else:
+                    new_instance = PLCOpenParser.CreateElement("pouInstance", "resource")
+                    resource.appendpouInstance(new_instance)
                 new_instance.setname(instance["Name"])
                 new_instance.settypeName(instance["Type"])
-                task_list.get(instance["Task"], resource).appendpouInstance(new_instance)
 
     def GetEditedResourceInfos(self, tagname, debug = False):
         resource = self.GetEditedElement(tagname, debug)
@@ -3136,31 +3141,20 @@
             return tasks_data, instances_data
 
     def OpenXMLFile(self, filepath):
-        xmlfile = open(filepath, 'r')
-        tree = minidom.parse(xmlfile)
-        xmlfile.close()
+        try:
+            self.Project = LoadProject(filepath)
+        except Exception, e:
+            return _("Project file syntax error:\n\n") + str(e)
+        self.SetFilePath(filepath)
+        self.CreateProjectBuffer(True)
+        self.ProgramChunks = []
+        self.ProgramOffset = 0
+        self.NextCompiledProject = self.Copy(self.Project)
+        self.CurrentCompiledProject = None
+        self.Buffering = False
+        self.CurrentElementEditing = None
+        return None
         
-        self.Project = plcopen.project()
-        for child in tree.childNodes:
-            if child.nodeType == tree.ELEMENT_NODE and child.nodeName == "project":
-                try:
-                    result = self.Project.loadXMLTree(child)
-                except ValueError, e:
-                    return _("Project file syntax error:\n\n") + str(e)
-                self.SetFilePath(filepath)
-                self.Project.RefreshElementUsingTree()
-                self.Project.RefreshDataTypeHierarchy()
-                self.Project.RefreshCustomBlockTypes()
-                self.CreateProjectBuffer(True)
-                self.ProgramChunks = []
-                self.ProgramOffset = 0
-                self.NextCompiledProject = self.Copy(self.Project)
-                self.CurrentCompiledProject = None
-                self.Buffering = False
-                self.CurrentElementEditing = None
-                return None
-        return _("No PLC project found")
-
     def SaveXMLFile(self, filepath = None):
         if not filepath and self.FilePath == "":
             return False
@@ -3168,19 +3162,11 @@
             contentheader = {"modificationDateTime": datetime.datetime(*localtime()[:6])}
             self.Project.setcontentHeader(contentheader)
             
-            text = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
-            extras = {"xmlns" : "http://www.plcopen.org/xml/tc6.xsd",
-                      "xmlns:xhtml" : "http://www.w3.org/1999/xhtml",
-                      "xmlns:xsi" : "http://www.w3.org/2001/XMLSchema-instance",
-                      "xsi:schemaLocation" : "http://www.plcopen.org/xml/tc6.xsd"}
-            text += self.Project.generateXMLText("project", 0, extras)
+            if filepath:
+                SaveProject(self.Project, filepath)
+            else:
+                SaveProject(self.Project, self.FilePath)
             
-            if filepath:
-                xmlfile = open(filepath,"w")
-            else:
-                xmlfile = open(self.FilePath,"w")
-            xmlfile.write(text.encode("utf-8"))
-            xmlfile.close()
             self.MarkProjectAsSaved()
             if filepath:
                 self.SetFilePath(filepath)
@@ -3207,11 +3193,11 @@
     Return a copy of the project
     """
     def Copy(self, model):
-        return cPickle.loads(cPickle.dumps(model))
+        return deepcopy(model)
 
     def CreateProjectBuffer(self, saved):
         if self.ProjectBufferEnabled:
-            self.ProjectBuffer = UndoBuffer(cPickle.dumps(self.Project), saved)
+            self.ProjectBuffer = UndoBuffer(PLCOpenParser.Dumps(self.Project), saved)
         else:
             self.ProjectBuffer = None
             self.ProjectSaved = saved
@@ -3230,7 +3216,7 @@
 
     def BufferProject(self):
         if self.ProjectBuffer is not None:
-            self.ProjectBuffer.Buffering(cPickle.dumps(self.Project))
+            self.ProjectBuffer.Buffering(PLCOpenParser.Dumps(self.Project))
         else:
             self.ProjectSaved = False
 
@@ -3242,7 +3228,7 @@
         
     def EndBuffering(self):
         if self.ProjectBuffer is not None and self.Buffering:
-            self.ProjectBuffer.Buffering(cPickle.dumps(self.Project))
+            self.ProjectBuffer.Buffering(PLCOpenParser.Dumps(self.Project))
             self.Buffering = False
 
     def MarkProjectAsSaved(self):
@@ -3262,11 +3248,11 @@
     def LoadPrevious(self):
         self.EndBuffering()
         if self.ProjectBuffer is not None:
-            self.Project = cPickle.loads(self.ProjectBuffer.Previous())
+            self.Project = PLCOpenParser.Loads(self.ProjectBuffer.Previous())
     
     def LoadNext(self):
         if self.ProjectBuffer is not None:
-            self.Project = cPickle.loads(self.ProjectBuffer.Next())
+            self.Project = PLCOpenParser.Loads(self.ProjectBuffer.Next())
     
     def GetBufferState(self):
         if self.ProjectBuffer is not None:
--- a/PLCGenerator.py	Wed Sep 04 00:06:44 2013 +0200
+++ b/PLCGenerator.py	Mon Sep 09 00:48:34 2013 +0200
@@ -22,7 +22,7 @@
 #License along with this library; if not, write to the Free Software
 #Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
-from plcopen import plcopen
+from plcopen import PLCOpenParser
 from plcopen.structures import *
 from types import *
 import re
@@ -126,26 +126,25 @@
                             (datatype.getname(), (tagname, "name")),
                             (" : ", ())]
             basetype_content = datatype.baseType.getcontent()
-            # Data type derived directly from a string type 
-            if basetype_content["name"] in ["string", "wstring"]:
-                datatype_def += [(basetype_content["name"].upper(), (tagname, "base"))]
+            basetype_content_type = basetype_content.getLocalTag()
             # Data type derived directly from a user defined type 
-            elif basetype_content["name"] == "derived":
-                basetype_name = basetype_content["value"].getname()
+            if basetype_content_type == "derived":
+                basetype_name = basetype_content.getname()
                 self.GenerateDataType(basetype_name)
                 datatype_def += [(basetype_name, (tagname, "base"))]
             # Data type is a subrange
-            elif basetype_content["name"] in ["subrangeSigned", "subrangeUnsigned"]:
-                base_type = basetype_content["value"].baseType.getcontent()
+            elif basetype_content_type in ["subrangeSigned", "subrangeUnsigned"]:
+                base_type = basetype_content.baseType.getcontent()
+                base_type_type = base_type.getLocalTag()
                 # Subrange derived directly from a user defined type 
-                if base_type["name"] == "derived":
-                    basetype_name = base_type["value"].getname()
+                if base_type_type == "derived":
+                    basetype_name = base_type_type.getname()
                     self.GenerateDataType(basetype_name)
                 # Subrange derived directly from an elementary type 
                 else:
-                    basetype_name = base_type["name"]
-                min_value = basetype_content["value"].range.getlower()
-                max_value = basetype_content["value"].range.getupper()
+                    basetype_name = base_type_type
+                min_value = basetype_content.range.getlower()
+                max_value = basetype_content.range.getupper()
                 datatype_def += [(basetype_name, (tagname, "base")),
                                  (" (", ()),
                                  ("%s"%min_value, (tagname, "lower")),
@@ -153,63 +152,59 @@
                                  ("%s"%max_value, (tagname, "upper")),
                                  (")",())]
             # Data type is an enumerated type
-            elif basetype_content["name"] == "enum":
+            elif basetype_content_type == "enum":
                 values = [[(value.getname(), (tagname, "value", i))]
-                          for i, value in enumerate(basetype_content["value"].values.getvalue())]
+                          for i, value in enumerate(
+                              basetype_content.xpath("ppx:values/ppx:value", 
+                                  namespaces=PLCOpenParser.NSMAP))]
                 datatype_def += [("(", ())]
                 datatype_def += JoinList([(", ", ())], values)
                 datatype_def += [(")", ())]
             # Data type is an array
-            elif basetype_content["name"] == "array":
-                base_type = basetype_content["value"].baseType.getcontent()
+            elif basetype_content_type == "array":
+                base_type = basetype_content.baseType.getcontent()
+                base_type_type = base_type.getLocalTag()
                 # Array derived directly from a user defined type 
-                if base_type["name"] == "derived":
-                    basetype_name = base_type["value"].getname()
+                if base_type_type == "derived":
+                    basetype_name = base_type.getname()
                     self.GenerateDataType(basetype_name)
-                # Array derived directly from a string type 
-                elif base_type["name"] in ["string", "wstring"]:
-                    basetype_name = base_type["name"].upper()
                 # Array derived directly from an elementary type 
                 else:
-                    basetype_name = base_type["name"]
+                    basetype_name = base_type_type.upper()
                 dimensions = [[("%s"%dimension.getlower(), (tagname, "range", i, "lower")),
                                ("..", ()),
                                ("%s"%dimension.getupper(), (tagname, "range", i, "upper"))] 
-                              for i, dimension in enumerate(basetype_content["value"].getdimension())]
+                              for i, dimension in enumerate(basetype_content.getdimension())]
                 datatype_def += [("ARRAY [", ())]
                 datatype_def += JoinList([(",", ())], dimensions)
                 datatype_def += [("] OF " , ()),
                                  (basetype_name, (tagname, "base"))]
             # Data type is a structure
-            elif basetype_content["name"] == "struct":
+            elif basetype_content_type == "struct":
                 elements = []
-                for i, element in enumerate(basetype_content["value"].getvariable()):
+                for i, element in enumerate(basetype_content.getvariable()):
                     element_type = element.type.getcontent()
+                    element_type_type = element_type.getLocalTag()
                     # Structure element derived directly from a user defined type 
-                    if element_type["name"] == "derived":
-                        elementtype_name = element_type["value"].getname()
+                    if element_type_type == "derived":
+                        elementtype_name = element_type.getname()
                         self.GenerateDataType(elementtype_name)
-                    elif element_type["name"] == "array":
-                        base_type = element_type["value"].baseType.getcontent()
+                    elif element_type_type == "array":
+                        base_type = element_type.baseType.getcontent()
+                        base_type_type = base_type.getLocalTag()
                         # Array derived directly from a user defined type 
-                        if base_type["name"] == "derived":
-                            basetype_name = base_type["value"].getname()
+                        if base_type_type == "derived":
+                            basetype_name = base_type.getname()
                             self.GenerateDataType(basetype_name)
-                        # Array derived directly from a string type 
-                        elif base_type["name"] in ["string", "wstring"]:
-                            basetype_name = base_type["name"].upper()
                         # Array derived directly from an elementary type 
                         else:
-                            basetype_name = base_type["name"]
+                            basetype_name = base_type_type.upper()
                         dimensions = ["%s..%s" % (dimension.getlower(), dimension.getupper())
-                                      for dimension in element_type["value"].getdimension()]
+                                      for dimension in element_type.getdimension()]
                         elementtype_name = "ARRAY [%s] OF %s" % (",".join(dimensions), basetype_name)
-                    # Structure element derived directly from a string type 
-                    elif element_type["name"] in ["string", "wstring"]:
-                        elementtype_name = element_type["name"].upper()
                     # Structure element derived directly from an elementary type 
                     else:
-                        elementtype_name = element_type["name"]
+                        elementtype_name = element_type_type.upper()
                     element_text = [("\n    ", ()),
                                     (element.getname(), (tagname, "struct", i, "name")),
                                     (" : ", ()),
@@ -224,7 +219,7 @@
                 datatype_def += [("\n  END_STRUCT", ())]
             # Data type derived directly from a elementary type 
             else:
-                datatype_def += [(basetype_content["name"], (tagname, "base"))]
+                datatype_def += [(basetype_content_type.upper(), (tagname, "base"))]
             # Data type has an initial value
             if datatype.initialValue is not None:
                 datatype_def += [(" := ", ()),
@@ -271,7 +266,7 @@
         extra_variables = self.Controler.GetConfigurationExtraVariables()
         if len(extra_variables) > 0:
             if len(varlists) == 0:
-                varlists = [(plcopen.interface_globalVars(), [])]
+                varlists = [(PLCOpenParser.CreateElement("globalVars", "interface"), [])]
             varlists[-1][1].extend(extra_variables)
             
         # Generate any global variable in configuration
@@ -289,8 +284,8 @@
             # Generate any variable of this block
             for var in varlist_variables:
                 vartype_content = var.gettype().getcontent()
-                if vartype_content["name"] == "derived":
-                    var_type = vartype_content["value"].getname()
+                if vartype_content.getLocalTag() == "derived":
+                    var_type = vartype_content.getname()
                     self.GenerateDataType(var_type)
                 else:
                     var_type = var.gettypeAsText()
@@ -342,8 +337,8 @@
             # Generate any variable of this block
             for var in varlist.getvariable():
                 vartype_content = var.gettype().getcontent()
-                if vartype_content["name"] == "derived":
-                    var_type = vartype_content["value"].getname()
+                if vartype_content.getLocalTag() == "derived":
+                    var_type = vartype_content.getname()
                     self.GenerateDataType(var_type)
                 else:
                     var_type = var.gettypeAsText()
@@ -458,6 +453,24 @@
 #                           Generator of POU programs
 #-------------------------------------------------------------------------------
 
+[ConnectorClass, ContinuationClass, ActionBlockClass] = [
+    PLCOpenParser.GetElementClass(instance_name, "commonObjects")
+    for instance_name in ["connector", "continuation", "actionBlock"]]
+[InVariableClass, InOutVariableClass, OutVariableClass, BlockClass] = [
+    PLCOpenParser.GetElementClass(instance_name, "fbdObjects")
+    for instance_name in ["inVariable", "inOutVariable", "outVariable", "block"]]
+[ContactClass, CoilClass, LeftPowerRailClass, RightPowerRailClass] = [
+    PLCOpenParser.GetElementClass(instance_name, "ldObjects")
+    for instance_name in ["contact", "coil", "leftPowerRail", "rightPowerRail"]]
+[StepClass, TransitionClass, JumpStepClass, 
+ SelectionConvergenceClass, SelectionDivergenceClass,
+ SimultaneousConvergenceClass, SimultaneousDivergenceClass] = [
+    PLCOpenParser.GetElementClass(instance_name, "sfcObjects")
+    for instance_name in ["step", "transition", "jumpStep", 
+        "selectionConvergence", "selectionDivergence",
+        "simultaneousConvergence", "simultaneousDivergence"]]
+TransitionObjClass = PLCOpenParser.GetElementClass("transition", "transitions")
+ActionObjClass = PLCOpenParser.GetElementClass("action", "actions")
 
 class PouProgramGenerator:
     
@@ -541,16 +554,17 @@
     # Return connectors linked by a connection to the given connector
     def GetConnectedConnector(self, connector, body):
         links = connector.getconnections()
-        if links and len(links) == 1:
+        if links is not None and len(links) == 1:
             return self.GetLinkedConnector(links[0], body)
         return None        
 
     def GetLinkedConnector(self, link, body):
         parameter = link.getformalParameter()
         instance = body.getcontentInstance(link.getrefLocalId())
-        if isinstance(instance, (plcopen.fbdObjects_inVariable, plcopen.fbdObjects_inOutVariable, plcopen.commonObjects_continuation, plcopen.ldObjects_contact, plcopen.ldObjects_coil)):
+        if isinstance(instance, (InVariableClass, InOutVariableClass, 
+             ContinuationClass, ContactClass, CoilClass)):
             return instance.connectionPointOut
-        elif isinstance(instance, plcopen.fbdObjects_block):
+        elif isinstance(instance, BlockClass):
             outputvariables = instance.outputVariables.getvariable()
             if len(outputvariables) == 1:
                 return outputvariables[0].connectionPointOut
@@ -565,7 +579,7 @@
                     blockposition = instance.getposition()
                     if point.x == blockposition.x + relposition[0] and point.y == blockposition.y + relposition[1]:
                         return variable.connectionPointOut
-        elif isinstance(instance, plcopen.ldObjects_leftPowerRail):
+        elif isinstance(instance, LeftPowerRailClass):
             outputconnections = instance.getconnectionPointOut()
             if len(outputconnections) == 1:
                 return outputconnections[0]
@@ -591,25 +605,26 @@
             if isinstance(body, ListType):
                 body = body[0]
             body_content = body.getcontent()
+            body_type = body_content.getLocalTag()
             if self.Type == "FUNCTION":
                 returntype_content = interface.getreturnType().getcontent()
-                if returntype_content["name"] == "derived":
-                    self.ReturnType = returntype_content["value"].getname()
-                elif returntype_content["name"] in ["string", "wstring"]:
-                    self.ReturnType = returntype_content["name"].upper()
-                else:
-                    self.ReturnType = returntype_content["name"]
+                returntype_content_type = returntype_content.getLocalTag()
+                if returntype_content_type == "derived":
+                    self.ReturnType = returntype_content.getname()
+                else:
+                    self.ReturnType = returntype_content_type.upper()
             for varlist in interface.getcontent():
                 variables = []
                 located = []
-                for var in varlist["value"].getvariable():
+                varlist_type = varlist.getLocalTag()
+                for var in varlist.getvariable():
                     vartype_content = var.gettype().getcontent()
-                    if vartype_content["name"] == "derived":
-                        var_type = vartype_content["value"].getname()
+                    if vartype_content.getLocalTag() == "derived":
+                        var_type = vartype_content.getname()
                         blocktype = self.GetBlockType(var_type)
                         if blocktype is not None:
                             self.ParentGenerator.GeneratePouProgram(var_type)
-                            if body_content["name"] in ["FBD", "LD", "SFC"]:
+                            if body_type in ["FBD", "LD", "SFC"]:
                                 block = pou.getinstanceByName(var.getname())
                             else:
                                 block = None
@@ -627,9 +642,9 @@
                                 initial_value = None
                             address = var.getaddress()
                             if address is not None:
-                                located.append((vartype_content["value"].getname(), var.getname(), address, initial_value))
+                                located.append((vartype_content.getname(), var.getname(), address, initial_value))
                             else:
-                                variables.append((vartype_content["value"].getname(), var.getname(), None, initial_value))
+                                variables.append((vartype_content.getname(), var.getname(), None, initial_value))
                     else:
                         var_type = var.gettypeAsText()
                         initial = var.getinitialValue()
@@ -642,18 +657,18 @@
                             located.append((var_type, var.getname(), address, initial_value))
                         else:
                             variables.append((var_type, var.getname(), None, initial_value))
-                if varlist["value"].getconstant():
+                if varlist.getconstant():
                     option = "CONSTANT"
-                elif varlist["value"].getretain():
+                elif varlist.getretain():
                     option = "RETAIN"
-                elif varlist["value"].getnonretain():
+                elif varlist.getnonretain():
                     option = "NON_RETAIN"
                 else:
                     option = None
                 if len(variables) > 0:
-                    self.Interface.append((varTypeNames[varlist["name"]], option, False, variables))
+                    self.Interface.append((varTypeNames[varlist_type], option, False, variables))
                 if len(located) > 0:
-                    self.Interface.append((varTypeNames[varlist["name"]], option, True, located))
+                    self.Interface.append((varTypeNames[varlist_type], option, True, located))
     
     LITERAL_TYPES = {
         "T": "TIME",
@@ -669,24 +684,25 @@
         if isinstance(body, ListType):
             body = body[0]
         body_content = body.getcontent()
-        body_type = body_content["name"]
+        body_type = body_content.getLocalTag()
         if body_type in ["FBD", "LD", "SFC"]:
             undefined_blocks = []
             for instance in body.getcontentInstances():
-                if isinstance(instance, (plcopen.fbdObjects_inVariable, plcopen.fbdObjects_outVariable, plcopen.fbdObjects_inOutVariable)):
-                    expression = instance.getexpression()
+                if isinstance(instance, (InVariableClass, OutVariableClass, 
+                                         InOutVariableClass)):
+                    expression = instance.getexpression().text
                     var_type = self.GetVariableType(expression)
-                    if isinstance(pou, plcopen.transitions_transition) and expression == pou.getname():
+                    if (isinstance(pou, TransitionObjClass) 
+                        and expression == pou.getname()):
                         var_type = "BOOL"
-                    elif (not isinstance(pou, (plcopen.transitions_transition, plcopen.actions_action)) and
+                    elif (not isinstance(pou, (TransitionObjClass, ActionObjClass)) and
                           pou.getpouType() == "function" and expression == pou.getname()):
                         returntype_content = pou.interface.getreturnType().getcontent()
-                        if returntype_content["name"] == "derived":
-                            var_type = returntype_content["value"].getname()
-                        elif returntype_content["name"] in ["string", "wstring"]:
-                            var_type = returntype_content["name"].upper()
+                        returntype_content_type = returntype_content.getLocalTag()
+                        if returntype_content_type == "derived":
+                            var_type = returntype_content.getname()
                         else:
-                            var_type = returntype_content["name"]
+                            var_type = returntype_content_type.upper()
                     elif var_type is None:
                         parts = expression.split("#")
                         if len(parts) > 1:
@@ -698,54 +714,58 @@
                         elif expression.startswith('"'):
                             var_type = "WSTRING"
                     if var_type is not None:
-                        if isinstance(instance, (plcopen.fbdObjects_inVariable, plcopen.fbdObjects_inOutVariable)):
+                        if isinstance(instance, (InVariableClass, InOutVariableClass)):
                             for connection in self.ExtractRelatedConnections(instance.connectionPointOut):
                                 self.ConnectionTypes[connection] = var_type
-                        if isinstance(instance, (plcopen.fbdObjects_outVariable, plcopen.fbdObjects_inOutVariable)):
+                        if isinstance(instance, (OutVariableClass, InOutVariableClass)):
                             self.ConnectionTypes[instance.connectionPointIn] = var_type
                             connected = self.GetConnectedConnector(instance.connectionPointIn, body)
-                            if connected and not self.ConnectionTypes.has_key(connected):
-                                for connection in self.ExtractRelatedConnections(connected):
-                                    self.ConnectionTypes[connection] = var_type
-                elif isinstance(instance, (plcopen.ldObjects_contact, plcopen.ldObjects_coil)):
+                            if connected is not None and not self.ConnectionTypes.has_key(connected):
+                                for related in self.ExtractRelatedConnections(connected):
+                                    self.ConnectionTypes[related] = var_type
+                elif isinstance(instance, (ContactClass, CoilClass)):
                     for connection in self.ExtractRelatedConnections(instance.connectionPointOut):
                         self.ConnectionTypes[connection] = "BOOL"
                     self.ConnectionTypes[instance.connectionPointIn] = "BOOL"
-                    connected = self.GetConnectedConnector(instance.connectionPointIn, body)
-                    if connected and not self.ConnectionTypes.has_key(connected):
-                        for connection in self.ExtractRelatedConnections(connected):
-                            self.ConnectionTypes[connection] = "BOOL"
-                elif isinstance(instance, plcopen.ldObjects_leftPowerRail):
+                    for link in instance.connectionPointIn.getconnections():
+                        connected = self.GetLinkedConnector(link, body)
+                        if connected is not None and not self.ConnectionTypes.has_key(connected):
+                            for related in self.ExtractRelatedConnections(connected):
+                                self.ConnectionTypes[related] = "BOOL"
+                elif isinstance(instance, LeftPowerRailClass):
                     for connection in instance.getconnectionPointOut():
                         for related in self.ExtractRelatedConnections(connection):
                             self.ConnectionTypes[related] = "BOOL"
-                elif isinstance(instance, plcopen.ldObjects_rightPowerRail):
+                elif isinstance(instance, RightPowerRailClass):
                     for connection in instance.getconnectionPointIn():
                         self.ConnectionTypes[connection] = "BOOL"
-                        connected = self.GetConnectedConnector(connection, body)
-                        if connected and not self.ConnectionTypes.has_key(connected):
-                            for connection in self.ExtractRelatedConnections(connected):
-                                self.ConnectionTypes[connection] = "BOOL"
-                elif isinstance(instance, plcopen.sfcObjects_transition):
-                    content = instance.condition.getcontent()
-                    if content["name"] == "connection" and len(content["value"]) == 1:
-                        connected = self.GetLinkedConnector(content["value"][0], body)
-                        if connected and not self.ConnectionTypes.has_key(connected):
-                            for connection in self.ExtractRelatedConnections(connected):
-                                self.ConnectionTypes[connection] = "BOOL"
-                elif isinstance(instance, plcopen.commonObjects_continuation):
+                        for link in connection.getconnections():
+                            connected = self.GetLinkedConnector(link, body)
+                            if connected is not None and not self.ConnectionTypes.has_key(connected):
+                                for related in self.ExtractRelatedConnections(connected):
+                                    self.ConnectionTypes[related] = "BOOL"
+                elif isinstance(instance, TransitionClass):
+                    content = instance.getconditionContent()
+                    if content["type"] == "connection":
+                        self.ConnectionTypes[content["value"]] = "BOOL"
+                        for link in content["value"].getconnections():
+                            connected = self.GetLinkedConnector(link, body)
+                            if connected is not None and not self.ConnectionTypes.has_key(connected):
+                                for related in self.ExtractRelatedConnections(connected):
+                                    self.ConnectionTypes[related] = "BOOL"
+                elif isinstance(instance, ContinuationClass):
                     name = instance.getname()
                     connector = None
                     var_type = "ANY"
                     for element in body.getcontentInstances():
-                        if isinstance(element, plcopen.commonObjects_connector) and element.getname() == name:
+                        if isinstance(element, ConnectorClass) and element.getname() == name:
                             if connector is not None:
                                 raise PLCGenException, _("More than one connector found corresponding to \"%s\" continuation in \"%s\" POU")%(name, self.Name)
                             connector = element
                     if connector is not None:
                         undefined = [instance.connectionPointOut, connector.connectionPointIn]
                         connected = self.GetConnectedConnector(connector.connectionPointIn, body)
-                        if connected:
+                        if connected is not None:
                             undefined.append(connected)
                         related = []
                         for connection in undefined:
@@ -760,7 +780,7 @@
                                 self.ConnectionTypes[connection] = var_type
                     else:
                         raise PLCGenException, _("No connector found corresponding to \"%s\" continuation in \"%s\" POU")%(name, self.Name)
-                elif isinstance(instance, plcopen.fbdObjects_block):
+                elif isinstance(instance, BlockClass):
                     block_infos = self.GetBlockType(instance.gettypeName(), "undefined")
                     if block_infos is not None:
                         self.ComputeBlockInputTypes(instance, block_infos, body)
@@ -822,11 +842,11 @@
                             if not undefined.has_key(itype):
                                 undefined[itype] = []
                             undefined[itype].append(variable.connectionPointIn)
-                            if connected:
+                            if connected is not None:
                                 undefined[itype].append(connected)
                         else:
                             self.ConnectionTypes[variable.connectionPointIn] = itype
-                            if connected and not self.ConnectionTypes.has_key(connected):
+                            if connected is not None and not self.ConnectionTypes.has_key(connected):
                                 for connection in self.ExtractRelatedConnections(connected):
                                     self.ConnectionTypes[connection] = itype
         for var_type, connections in undefined.items():
@@ -848,22 +868,22 @@
         if isinstance(body, ListType):
             body = body[0]
         body_content = body.getcontent()
-        body_type = body_content["name"]
+        body_type = body_content.getLocalTag()
         if body_type in ["IL","ST"]:
-            text = body_content["value"].gettext()
+            text = body_content.getanyText()
             self.ParentGenerator.GeneratePouProgramInText(text.upper())
             self.Program = [(ReIndentText(text, len(self.CurrentIndent)), 
                             (self.TagName, "body", len(self.CurrentIndent)))]
         elif body_type == "SFC":
             self.IndentRight()
             for instance in body.getcontentInstances():
-                if isinstance(instance, plcopen.sfcObjects_step):
+                if isinstance(instance, StepClass):
                     self.GenerateSFCStep(instance, pou)
-                elif isinstance(instance, plcopen.commonObjects_actionBlock):
+                elif isinstance(instance, ActionBlockClass):
                     self.GenerateSFCStepActions(instance, pou)
-                elif isinstance(instance, plcopen.sfcObjects_transition):
+                elif isinstance(instance, TransitionClass):
                     self.GenerateSFCTransition(instance, pou)
-                elif isinstance(instance, plcopen.sfcObjects_jumpStep):
+                elif isinstance(instance, JumpStepClass):
                     self.GenerateSFCJump(instance, pou)
             if len(self.InitialSteps) > 0 and len(self.SFCComputedBlocks) > 0:
                 action_name = "COMPUTE_FUNCTION_BLOCKS"
@@ -878,17 +898,17 @@
             otherInstances = {"outVariables&coils" : [], "blocks" : [], "connectors" : []}
             orderedInstances = []
             for instance in body.getcontentInstances():
-                if isinstance(instance, (plcopen.fbdObjects_outVariable, plcopen.fbdObjects_inOutVariable, plcopen.fbdObjects_block)):
+                if isinstance(instance, (OutVariableClass, InOutVariableClass, BlockClass)):
                     executionOrderId = instance.getexecutionOrderId()
                     if executionOrderId > 0:
                         orderedInstances.append((executionOrderId, instance))
-                    elif isinstance(instance, (plcopen.fbdObjects_outVariable, plcopen.fbdObjects_inOutVariable)):
+                    elif isinstance(instance, (OutVariableClass, InOutVariableClass)):
                         otherInstances["outVariables&coils"].append(instance)
-                    elif isinstance(instance, plcopen.fbdObjects_block):
+                    elif isinstance(instance, BlockClass):
                         otherInstances["blocks"].append(instance)
-                elif isinstance(instance, plcopen.commonObjects_connector):
+                elif isinstance(instance, ConnectorClass):
                     otherInstances["connectors"].append(instance)
-                elif isinstance(instance, plcopen.ldObjects_coil):
+                elif isinstance(instance, CoilClass):
                     otherInstances["outVariables&coils"].append(instance)
             orderedInstances.sort()
             otherInstances["outVariables&coils"].sort(SortInstances)
@@ -896,17 +916,17 @@
             instances = [instance for (executionOrderId, instance) in orderedInstances]
             instances.extend(otherInstances["outVariables&coils"] + otherInstances["blocks"] + otherInstances["connectors"])
             for instance in instances:
-                if isinstance(instance, (plcopen.fbdObjects_outVariable, plcopen.fbdObjects_inOutVariable)):
+                if isinstance(instance, (OutVariableClass, InOutVariableClass)):
                     connections = instance.connectionPointIn.getconnections()
                     if connections is not None:
                         expression = self.ComputeExpression(body, connections)
                         if expression is not None:
                             self.Program += [(self.CurrentIndent, ()),
-                                             (instance.getexpression(), (self.TagName, "io_variable", instance.getlocalId(), "expression")),
+                                             (instance.getexpression().text, (self.TagName, "io_variable", instance.getlocalId(), "expression")),
                                              (" := ", ())]
                             self.Program += expression
                             self.Program += [(";\n", ())]
-                elif isinstance(instance, plcopen.fbdObjects_block):
+                elif isinstance(instance, BlockClass):
                     block_type = instance.gettypeName()
                     self.ParentGenerator.GeneratePouProgram(block_type)
                     block_infos = self.GetBlockType(block_type, tuple([self.ConnectionTypes.get(variable.connectionPointIn, "ANY") for variable in instance.inputVariables.getvariable() if variable.getformalParameter() != "EN"]))
@@ -918,14 +938,14 @@
                         block_infos["generate"](self, instance, block_infos, body, None)
                     except ValueError, e:
                         raise PLCGenException, e.message
-                elif isinstance(instance, plcopen.commonObjects_connector):
+                elif isinstance(instance, ConnectorClass):
                     connector = instance.getname()
                     if self.ComputedConnectors.get(connector, None):
                         continue
                     expression = self.ComputeExpression(body, instance.connectionPointIn.getconnections())
                     if expression is not None:
                         self.ComputedConnectors[connector] = expression
-                elif isinstance(instance, plcopen.ldObjects_coil):
+                elif isinstance(instance, CoilClass):
                     connections = instance.connectionPointIn.getconnections()
                     if connections is not None:
                         coil_info = (self.TagName, "coil", instance.getlocalId())
@@ -933,7 +953,7 @@
                         if expression is not None:
                             expression = self.ExtractModifier(instance, expression, coil_info)
                             self.Program += [(self.CurrentIndent, ())]
-                            self.Program += [(instance.getvariable(), coil_info + ("reference",))]
+                            self.Program += [(instance.getvariable().text, coil_info + ("reference",))]
                             self.Program += [(" := ", ())] + expression + [(";\n", ())]
                         
     def FactorizePaths(self, paths):
@@ -968,11 +988,11 @@
         for connection in connections:
             localId = connection.getrefLocalId()
             next = body.getcontentInstance(localId)
-            if isinstance(next, plcopen.ldObjects_leftPowerRail):
+            if isinstance(next, LeftPowerRailClass):
                 paths.append(None)
-            elif isinstance(next, (plcopen.fbdObjects_inVariable, plcopen.fbdObjects_inOutVariable)):
-                paths.append(str([(next.getexpression(), (self.TagName, "io_variable", localId, "expression"))]))
-            elif isinstance(next, plcopen.fbdObjects_block):
+            elif isinstance(next, (InVariableClass, InOutVariableClass)):
+                paths.append(str([(next.getexpression().text, (self.TagName, "io_variable", localId, "expression"))]))
+            elif isinstance(next, BlockClass):
                 block_type = next.gettypeName()
                 self.ParentGenerator.GeneratePouProgram(block_type)
                 block_infos = self.GetBlockType(block_type, tuple([self.ConnectionTypes.get(variable.connectionPointIn, "ANY") for variable in next.inputVariables.getvariable() if variable.getformalParameter() != "EN"]))
@@ -984,7 +1004,7 @@
                     paths.append(str(block_infos["generate"](self, next, block_infos, body, connection, order, to_inout)))
                 except ValueError, e:
                     raise PLCGenException, e.message
-            elif isinstance(next, plcopen.commonObjects_continuation):
+            elif isinstance(next, ContinuationClass):
                 name = next.getname()
                 computed_value = self.ComputedConnectors.get(name, None)
                 if computed_value != None:
@@ -992,7 +1012,7 @@
                 else:
                     connector = None
                     for instance in body.getcontentInstances():
-                        if isinstance(instance, plcopen.commonObjects_connector) and instance.getname() == name:
+                        if isinstance(instance, ConnectorClass) and instance.getname() == name:
                             if connector is not None:
                                 raise PLCGenException, _("More than one connector found corresponding to \"%s\" continuation in \"%s\" POU")%(name, self.Name)
                             connector = instance
@@ -1005,9 +1025,9 @@
                                 paths.append(str(expression))
                     else:
                         raise PLCGenException, _("No connector found corresponding to \"%s\" continuation in \"%s\" POU")%(name, self.Name)
-            elif isinstance(next, plcopen.ldObjects_contact):
+            elif isinstance(next, ContactClass):
                 contact_info = (self.TagName, "contact", next.getlocalId())
-                variable = str(self.ExtractModifier(next, [(next.getvariable(), contact_info + ("reference",))], contact_info))
+                variable = str(self.ExtractModifier(next, [(next.getvariable().text, contact_info + ("reference",))], contact_info))
                 result = self.GeneratePaths(next.connectionPointIn.getconnections(), body, order)
                 if len(result) > 1:
                     factorized_paths = self.FactorizePaths(result)
@@ -1021,7 +1041,7 @@
                     paths.append([variable, result[0]])
                 else:
                     paths.append(variable)
-            elif isinstance(next, plcopen.ldObjects_coil):
+            elif isinstance(next, CoilClass):
                 paths.append(str(self.GeneratePaths(next.connectionPointIn.getconnections(), body, order)))
         return paths
 
@@ -1092,7 +1112,7 @@
     
     def ExtractDivergenceInput(self, divergence, pou):
         connectionPointIn = divergence.getconnectionPointIn()
-        if connectionPointIn:
+        if connectionPointIn is not None:
             connections = connectionPointIn.getconnections()
             if connections is not None and len(connections) == 1:
                 instanceLocalId = connections[0].getrefLocalId()
@@ -1124,7 +1144,7 @@
                           "transitions" : [], 
                           "actions" : []}
             self.SFCNetworks["Steps"][step_name] = step_infos
-            if step.connectionPointIn:
+            if step.connectionPointIn is not None:
                 instances = []
                 connections = step.connectionPointIn.getconnections()
                 if connections is not None and len(connections) == 1:
@@ -1133,16 +1153,16 @@
                     if isinstance(body, ListType):
                         body = body[0]
                     instance = body.getcontentInstance(instanceLocalId)
-                    if isinstance(instance, plcopen.sfcObjects_transition):
+                    if isinstance(instance, TransitionClass):
                         instances.append(instance)
-                    elif isinstance(instance, plcopen.sfcObjects_selectionConvergence):
+                    elif isinstance(instance, SelectionConvergenceClass):
                         instances.extend(self.ExtractConvergenceInputs(instance, pou))
-                    elif isinstance(instance, plcopen.sfcObjects_simultaneousDivergence):
+                    elif isinstance(instance, SimultaneousDivergenceClass):
                         transition = self.ExtractDivergenceInput(instance, pou)
-                        if transition:
-                            if isinstance(transition, plcopen.sfcObjects_transition):
+                        if transition is not None:
+                            if isinstance(transition, TransitionClass):
                                 instances.append(transition)
-                            elif isinstance(transition, plcopen.sfcObjects_selectionConvergence):
+                            elif isinstance(transition, SelectionConvergenceClass):
                                 instances.extend(self.ExtractConvergenceInputs(transition, pou))
                 for instance in instances:
                     self.GenerateSFCTransition(instance, pou)
@@ -1152,7 +1172,7 @@
     
     def GenerateSFCJump(self, jump, pou):
         jump_target = jump.gettargetName()
-        if jump.connectionPointIn:
+        if jump.connectionPointIn is not None:
             instances = []
             connections = jump.connectionPointIn.getconnections()
             if connections is not None and len(connections) == 1:
@@ -1161,16 +1181,16 @@
                 if isinstance(body, ListType):
                     body = body[0]
                 instance = body.getcontentInstance(instanceLocalId)
-                if isinstance(instance, plcopen.sfcObjects_transition):
+                if isinstance(instance, TransitionClass):
                     instances.append(instance)
-                elif isinstance(instance, plcopen.sfcObjects_selectionConvergence):
+                elif isinstance(instance, SelectionConvergenceClass):
                     instances.extend(self.ExtractConvergenceInputs(instance, pou))
-                elif isinstance(instance, plcopen.sfcObjects_simultaneousDivergence):
+                elif isinstance(instance, SimultaneousDivergenceClass):
                     transition = self.ExtractDivergenceInput(instance, pou)
-                    if transition:
-                        if isinstance(transition, plcopen.sfcObjects_transition):
+                    if transition is not None:
+                        if isinstance(transition, TransitionClass):
                             instances.append(transition)
-                        elif isinstance(transition, plcopen.sfcObjects_selectionConvergence):
+                        elif isinstance(transition, SelectionConvergenceClass):
                             instances.extend(self.ExtractConvergenceInputs(transition, pou))
             for instance in instances:
                 self.GenerateSFCTransition(instance, pou)
@@ -1212,7 +1232,7 @@
     def GenerateSFCAction(self, action_name, pou):
         if action_name not in self.SFCNetworks["Actions"].keys():
             actionContent = pou.getaction(action_name)
-            if actionContent:
+            if actionContent is not None:
                 previous_tagname = self.TagName
                 self.TagName = self.ParentGenerator.Controler.ComputePouActionName(self.Name, action_name)
                 self.ComputeProgram(actionContent)
@@ -1230,21 +1250,22 @@
                 if isinstance(body, ListType):
                     body = body[0]
                 instance = body.getcontentInstance(instanceLocalId)
-                if isinstance(instance, plcopen.sfcObjects_step):
+                if isinstance(instance, StepClass):
                     steps.append(instance)
-                elif isinstance(instance, plcopen.sfcObjects_selectionDivergence):
+                elif isinstance(instance, SelectionDivergenceClass):
                     step = self.ExtractDivergenceInput(instance, pou)
-                    if step:
-                        if isinstance(step, plcopen.sfcObjects_step):
+                    if step is not None:
+                        if isinstance(step, StepClass):
                             steps.append(step)
-                        elif isinstance(step, plcopen.sfcObjects_simultaneousConvergence):
+                        elif isinstance(step, SimultaneousConvergenceClass):
                             steps.extend(self.ExtractConvergenceInputs(step, pou))
-                elif isinstance(instance, plcopen.sfcObjects_simultaneousConvergence):
+                elif isinstance(instance, SimultaneousConvergenceClass):
                     steps.extend(self.ExtractConvergenceInputs(instance, pou))
             transition_infos = {"id" : transition.getlocalId(), 
                                 "priority": transition.getpriority(), 
                                 "from": [], 
-                                "to" : []}
+                                "to" : [],
+                                "content": []}
             self.SFCNetworks["Transitions"][transition] = transition_infos
             transitionValues = transition.getconditionContent()
             if transitionValues["type"] == "inline":
@@ -1259,14 +1280,14 @@
                 self.TagName = self.ParentGenerator.Controler.ComputePouTransitionName(self.Name, transitionValues["value"])
                 if transitionType == "IL":
                     transition_infos["content"] = [(":\n", ()),
-                                                   (ReIndentText(transitionBody.gettext(), len(self.CurrentIndent)), (self.TagName, "body", len(self.CurrentIndent)))]
+                                                   (ReIndentText(transitionBody.getanyText(), len(self.CurrentIndent)), (self.TagName, "body", len(self.CurrentIndent)))]
                 elif transitionType == "ST":
                     transition_infos["content"] = [("\n", ()),
-                                                   (ReIndentText(transitionBody.gettext(), len(self.CurrentIndent)), (self.TagName, "body", len(self.CurrentIndent)))]
+                                                   (ReIndentText(transitionBody.getanyText(), len(self.CurrentIndent)), (self.TagName, "body", len(self.CurrentIndent)))]
                 else:
                     for instance in transitionBody.getcontentInstances():
-                        if isinstance(instance, plcopen.fbdObjects_outVariable) and instance.getexpression() == transitionValues["value"]\
-                            or isinstance(instance, plcopen.ldObjects_coil) and instance.getvariable() == transitionValues["value"]:
+                        if isinstance(instance, OutVariableClass) and instance.getexpression().text == transitionValues["value"]\
+                            or isinstance(instance, CoilClass) and instance.getvariable().text == transitionValues["value"]:
                             connections = instance.connectionPointIn.getconnections()
                             if connections is not None:
                                 expression = self.ComputeExpression(transitionBody, connections)
@@ -1281,7 +1302,7 @@
                 body = pou.getbody()
                 if isinstance(body, ListType):
                     body = body[0]
-                connections = transition.getconnections()
+                connections = transitionValues["value"].getconnections()
                 if connections is not None:
                     expression = self.ComputeExpression(body, connections)
                     if expression is not None:
@@ -1335,7 +1356,7 @@
             action_content, action_info = self.SFCNetworks["Actions"].pop(action_name)
             self.Program += [("%sACTION "%self.CurrentIndent, ()),
                              (action_name, action_info),
-                             (" :\n", ())]
+                             (":\n", ())]
             self.Program += action_content
             self.Program += [("%sEND_ACTION\n\n"%self.CurrentIndent, ())]
     
--- a/PLCOpenEditor.py	Wed Sep 04 00:06:44 2013 +0200
+++ b/PLCOpenEditor.py	Mon Sep 09 00:48:34 2013 +0200
@@ -276,6 +276,7 @@
             self.Controler = PLCControler()
             self.Controler.CreateNewProject(properties)
             self.LibraryPanel.SetController(self.Controler)
+            self.ProjectTree.Enable(True)
             self._Refresh(TITLE, FILEMENU, EDITMENU, PROJECTTREE, POUINSTANCEVARIABLESPANEL, 
                           LIBRARYTREE)
 
--- a/editors/Viewer.py	Wed Sep 04 00:06:44 2013 +0200
+++ b/editors/Viewer.py	Mon Sep 09 00:48:34 2013 +0200
@@ -1074,7 +1074,7 @@
     def RefreshView(self, variablepanel=True, selection=None):
         EditorPanel.RefreshView(self, variablepanel)
         
-        if self.TagName.split("::")[0] == "A":
+        if self.TagName.split("::")[0] == "A" and self.Debug:
             self.AddDataConsumer("%s.Q" % self.InstancePath.upper(), self)
         
         if self.ToolTipElement is not None:
--- a/plcopen/__init__.py	Wed Sep 04 00:06:44 2013 +0200
+++ b/plcopen/__init__.py	Mon Sep 09 00:48:34 2013 +0200
@@ -25,9 +25,7 @@
 # Package initialisation
 
 # plcopen module dynamically creates its classes
-import plcopen
-for classname, cls in plcopen.PLCOpenClasses.items():
-    plcopen.__dict__[classname] = cls
-from plcopen import VarOrder, ElementNameToClass, rect
+from plcopen import PLCOpenParser, LoadProject, SaveProject, LoadPou, \
+    LoadPouInstances, VarOrder, QualifierList, rect
 
 from structures import *
--- a/plcopen/plcopen.py	Wed Sep 04 00:06:44 2013 +0200
+++ b/plcopen/plcopen.py	Mon Sep 09 00:48:34 2013 +0200
@@ -26,6 +26,7 @@
 from structures import *
 from types import *
 import os, re
+from lxml import etree
 from collections import OrderedDict
 """
 Dictionary that makes the relation between var names in plcopen and displayed values
@@ -122,14 +123,84 @@
         result = criteria["pattern"].search(text, result.end())
     return test_result
 
-PLCOpenClasses = GenerateClassesFromXSD(os.path.join(os.path.split(__file__)[0], "tc6_xml_v201.xsd"))
-
-ElementNameToClass = {}
-
-cls = PLCOpenClasses.get("formattedText", None)
+PLCOpenParser = GenerateParserFromXSD(os.path.join(os.path.split(__file__)[0], "tc6_xml_v201.xsd"))
+PLCOpen_XPath = lambda xpath: etree.XPath(xpath, namespaces=PLCOpenParser.NSMAP)
+
+LOAD_POU_PROJECT_TEMPLATE = """
+<project xmlns:ns1="http://www.plcopen.org/xml/tc6_0201" 
+         xmlns:xhtml="http://www.w3.org/1999/xhtml" 
+         xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
+         xmlns="http://www.plcopen.org/xml/tc6_0201">
+  <fileHeader companyName="" productName="" productVersion="" 
+              creationDateTime="1970-01-01T00:00:00"/>
+  <contentHeader name="paste_project">
+    <coordinateInfo>
+      <fbd><scaling x="0" y="0"/></fbd>
+      <ld><scaling x="0" y="0"/></ld>
+      <sfc><scaling x="0" y="0"/></sfc>
+    </coordinateInfo>
+  </contentHeader>
+  <types>
+    <dataTypes/>
+    <pous>%s</pous>
+  </types>
+  <instances>
+    <configurations/>
+  </instances>
+</project>
+"""
+
+def LOAD_POU_INSTANCES_PROJECT_TEMPLATE(body_type):
+    return LOAD_POU_PROJECT_TEMPLATE % """
+<pou name="paste_pou" pouType="program">
+  <body>
+    <%(body_type)s>%%s</%(body_type)s>
+  </body>
+</pou>""" % locals()
+
+def LoadProject(filepath):
+    project_file = open(filepath)
+    project_xml = project_file.read().replace(
+        "http://www.plcopen.org/xml/tc6.xsd", 
+        "http://www.plcopen.org/xml/tc6_0201")
+    for cre, repl in [
+        (re.compile("(?<!<xhtml:p>)(?:<!\[CDATA\[)"), "<xhtml:p><![CDATA["),
+        (re.compile("(?:]]>)(?!</xhtml:p>)"), "]]></xhtml:p>")]:
+        project_xml = cre.sub(repl, project_xml)
+    project_file.close()
+    
+    return etree.fromstring(project_xml, PLCOpenParser)
+
+project_pou_xpath = PLCOpen_XPath("/ppx:project/ppx:types/ppx:pous/ppx:pou")
+def LoadPou(xml_string):
+    root = etree.fromstring(
+        LOAD_POU_PROJECT_TEMPLATE % xml_string, 
+        PLCOpenParser)
+    return project_pou_xpath(root)[0]
+
+project_pou_instances_xpath = {
+    body_type: PLCOpen_XPath(
+        "/ppx:project/ppx:types/ppx:pous/ppx:pou[@name='paste_pou']/ppx:body/ppx:%s/*" % body_type)
+    for body_type in ["FBD", "LD", "SFC"]}
+def LoadPouInstances(xml_string, body_type):
+    root = etree.fromstring(
+        LOAD_POU_INSTANCES_PROJECT_TEMPLATE(body_type) % xml_string, 
+        PLCOpenParser)
+    return project_pou_instances_xpath[body_type](root)
+
+def SaveProject(project, filepath):
+    project_file = open(filepath, 'w')
+    project_file.write(etree.tostring(
+        project, 
+        pretty_print=True, 
+        xml_declaration=True, 
+        encoding='utf-8'))
+    project_file.close()
+
+cls = PLCOpenParser.GetElementClass("formattedText")
 if cls:
     def updateElementName(self, old_name, new_name):
-        text = self.text
+        text = self.getanyText()
         index = text.find(old_name)
         while index != -1:
             if index > 0 and (text[index - 1].isalnum() or text[index - 1] == "_"):
@@ -139,11 +210,11 @@
             else:
                 text = text[:index] + new_name + text[index + len(old_name):]
                 index = text.find(old_name, index + len(new_name))
-        self.text = text
+        self.setanyText(text)
     setattr(cls, "updateElementName", updateElementName)
     
     def updateElementAddress(self, address_model, new_leading):
-        text = self.text
+        text = self.getanyText()
         startpos = 0
         result = address_model.search(text, startpos)
         while result is not None:
@@ -152,11 +223,11 @@
             text = text[:result.start()] + new_address + text[result.end():]
             startpos = result.start() + len(new_address)
             result = address_model.search(self.text, startpos)
-        self.text = text
+        self.setanyText(text)
     setattr(cls, "updateElementAddress", updateElementAddress)
     
     def hasblock(self, block_type):
-        text = self.text.upper()
+        text = self.getanyText().upper()
         index = text.find(block_type.upper())
         while index != -1:
             if (not (index > 0 and (text[index - 1].isalnum() or text[index - 1] == "_")) and 
@@ -167,17 +238,11 @@
     setattr(cls, "hasblock", hasblock)
     
     def Search(self, criteria, parent_infos):
-        return [(tuple(parent_infos),) + result for result in TestTextElement(self.gettext(), criteria)]
+        return [(tuple(parent_infos),) + result for result in TestTextElement(self.getanyText(), criteria)]
     setattr(cls, "Search", Search)
     
-cls = PLCOpenClasses.get("project", None)
-if cls:
-    cls.singleLineAttributes = False
-    cls.EnumeratedDataTypeValues = {}
-    cls.CustomDataTypeRange = {}
-    cls.CustomTypeHierarchy = {}
-    cls.ElementUsingTree = {}
-    cls.CustomBlockTypes = OrderedDict()
+cls = PLCOpenParser.GetElementClass("project")
+if cls:
     
     def setname(self, name):
         self.contentHeader.setname(name)
@@ -188,522 +253,216 @@
     setattr(cls, "getname", getname)
     
     def getfileHeader(self):
-        fileheader = {}
-        for name, value in [("companyName", self.fileHeader.getcompanyName()),
-                            ("companyURL", self.fileHeader.getcompanyURL()),
-                            ("productName", self.fileHeader.getproductName()),
-                            ("productVersion", self.fileHeader.getproductVersion()),
-                            ("productRelease", self.fileHeader.getproductRelease()),
-                            ("creationDateTime", self.fileHeader.getcreationDateTime()),
-                            ("contentDescription", self.fileHeader.getcontentDescription())]:
-            if value is not None:
-                fileheader[name] = value
-            else:
-                fileheader[name] = ""
-        return fileheader
+        fileheader_obj = self.fileHeader
+        return {
+            attr: value if value is not None else ""
+            for attr, value in [
+                ("companyName", fileheader_obj.getcompanyName()),
+                ("companyURL", fileheader_obj.getcompanyURL()),
+                ("productName", fileheader_obj.getproductName()),
+                ("productVersion", fileheader_obj.getproductVersion()),
+                ("productRelease", fileheader_obj.getproductRelease()),
+                ("creationDateTime", fileheader_obj.getcreationDateTime()),
+                ("contentDescription", fileheader_obj.getcontentDescription())]
+        }
     setattr(cls, "getfileHeader", getfileHeader)
     
     def setfileHeader(self, fileheader):
-        if fileheader.has_key("companyName"):
-            self.fileHeader.setcompanyName(fileheader["companyName"])
-        if fileheader.has_key("companyURL"):
-            self.fileHeader.setcompanyURL(fileheader["companyURL"])
-        if fileheader.has_key("productName"):
-            self.fileHeader.setproductName(fileheader["productName"])
-        if fileheader.has_key("productVersion"):
-            self.fileHeader.setproductVersion(fileheader["productVersion"])
-        if fileheader.has_key("productRelease"):
-            self.fileHeader.setproductRelease(fileheader["productRelease"])
-        if fileheader.has_key("creationDateTime"):
-            self.fileHeader.setcreationDateTime(fileheader["creationDateTime"])
-        if fileheader.has_key("contentDescription"):
-            self.fileHeader.setcontentDescription(fileheader["contentDescription"])
+        fileheader_obj = self.fileHeader
+        for attr, value in fileheader.iteritems():
+            setattr(fileheader_obj, attr, value)
     setattr(cls, "setfileHeader", setfileHeader)
     
     def getcontentHeader(self):
-        contentheader = {}
-        for name, value in [("projectName", self.contentHeader.getname()),
-                            ("projectVersion", self.contentHeader.getversion()),
-                            ("modificationDateTime", self.contentHeader.getmodificationDateTime()),
-                            ("organization", self.contentHeader.getorganization()),
-                            ("authorName", self.contentHeader.getauthor()),
-                            ("language", self.contentHeader.getlanguage())]:
-            if value is not None:
-                contentheader[name] = value
-            else:
-                contentheader[name] = ""
+        contentheader_obj = self.contentHeader
+        contentheader = {
+            attr: value if value is not None else ""
+            for attr, value in [
+                ("projectName", contentheader_obj.getname()),
+                ("projectVersion", contentheader_obj.getversion()),
+                ("modificationDateTime", contentheader_obj.getmodificationDateTime()),
+                ("organization", contentheader_obj.getorganization()),
+                ("authorName", contentheader_obj.getauthor()),
+                ("language", contentheader_obj.getlanguage())]
+        }
         contentheader["pageSize"] = self.contentHeader.getpageSize()
         contentheader["scaling"] = self.contentHeader.getscaling()
         return contentheader
     setattr(cls, "getcontentHeader", getcontentHeader)
     
     def setcontentHeader(self, contentheader):
-        if contentheader.has_key("projectName"):
-            self.contentHeader.setname(contentheader["projectName"])
-        if contentheader.has_key("projectVersion"):
-            self.contentHeader.setversion(contentheader["projectVersion"])
-        if contentheader.has_key("modificationDateTime"):
-            self.contentHeader.setmodificationDateTime(contentheader["modificationDateTime"])
-        if contentheader.has_key("organization"):
-            self.contentHeader.setorganization(contentheader["organization"])
-        if contentheader.has_key("authorName"):
-            self.contentHeader.setauthor(contentheader["authorName"])
-        if contentheader.has_key("language"):
-            self.contentHeader.setlanguage(contentheader["language"])
-        if contentheader.has_key("pageSize"):
-            self.contentHeader.setpageSize(*contentheader["pageSize"])
-        if contentheader.has_key("scaling"):
-            self.contentHeader.setscaling(contentheader["scaling"])
+        contentheader_obj = self.contentHeader
+        for attr, value in contentheader.iteritems():
+            if attr == "projectName":
+                contentheader_obj.setname(value)
+            elif attr == "projectVersion":
+                contentheader_obj.setversion(value)
+            elif attr == "pageSize":
+                contentheader_obj.setpageSize(*contentheader["pageSize"])
+            elif attr == "scaling":
+                contentheader_obj.setscaling(contentheader["scaling"])
+            else:
+                setattr(contentheader_obj, attr, value)
     setattr(cls, "setcontentHeader", setcontentHeader)
     
-    def getdataTypes(self):
-        return self.types.getdataTypeElements()
+    def gettypeElementFunc(element_type):
+        elements_xpath = PLCOpen_XPath(
+            "ppx:types/ppx:%(element_type)ss/ppx:%(element_type)s[@name=$name]" % locals())
+        def gettypeElement(self, name):
+            elements = elements_xpath(self, name=name)
+            if len(elements) == 1:
+                return elements[0]
+            return None
+        return gettypeElement
+    
+    datatypes_xpath = PLCOpen_XPath("ppx:types/ppx:dataTypes/ppx:dataType")
+    filtered_datatypes_xpath = PLCOpen_XPath(
+        "ppx:types/ppx:dataTypes/ppx:dataType[@name!=$exclude]")
+    def getdataTypes(self, exclude=None):
+        if exclude is not None:
+            return filtered_datatypes_xpath(self, exclude=exclude)
+        return datatypes_xpath(self)
     setattr(cls, "getdataTypes", getdataTypes)
     
-    def getdataType(self, name):
-        return self.types.getdataTypeElement(name)
-    setattr(cls, "getdataType", getdataType)
+    setattr(cls, "getdataType", gettypeElementFunc("dataType"))
     
     def appenddataType(self, name):
-        if self.CustomTypeHierarchy.has_key(name):
+        if self.getdataType(name) is not None:
             raise ValueError, "\"%s\" Data Type already exists !!!"%name
         self.types.appenddataTypeElement(name)
-        self.AddCustomDataType(self.getdataType(name))
     setattr(cls, "appenddataType", appenddataType)
         
     def insertdataType(self, index, datatype):
         self.types.insertdataTypeElement(index, datatype)
-        self.AddCustomDataType(datatype)
     setattr(cls, "insertdataType", insertdataType)
     
     def removedataType(self, name):
         self.types.removedataTypeElement(name)
-        self.RefreshDataTypeHierarchy()
-        self.RefreshElementUsingTree()
     setattr(cls, "removedataType", removedataType)
     
-    def getpous(self):
-        return self.types.getpouElements()
+    def getpous(self, exclude=None, filter=[]):
+        return self.xpath(
+            "ppx:types/ppx:pous/ppx:pou%s%s" % 
+                (("[@name!='%s']" % exclude) if exclude is not None else '',
+                 ("[%s]" % " or ".join(
+                    map(lambda x: "@pouType='%s'" % x, filter)))
+                 if len(filter) > 0 else ""),
+            namespaces=PLCOpenParser.NSMAP)
     setattr(cls, "getpous", getpous)
     
-    def getpou(self, name):
-        return self.types.getpouElement(name)
-    setattr(cls, "getpou", getpou)
+    setattr(cls, "getpou", gettypeElementFunc("pou"))
     
     def appendpou(self, name, pou_type, body_type):
         self.types.appendpouElement(name, pou_type, body_type)
-        self.AddCustomBlockType(self.getpou(name))
     setattr(cls, "appendpou", appendpou)
         
     def insertpou(self, index, pou):
         self.types.insertpouElement(index, pou)
-        self.AddCustomBlockType(pou)
     setattr(cls, "insertpou", insertpou)
     
     def removepou(self, name):
         self.types.removepouElement(name)
-        self.RefreshCustomBlockTypes()
-        self.RefreshElementUsingTree()
     setattr(cls, "removepou", removepou)
 
+    configurations_xpath = PLCOpen_XPath(
+        "ppx:instances/ppx:configurations/ppx:configuration")
     def getconfigurations(self):
-        configurations = self.instances.configurations.getconfiguration()
-        if configurations:
-            return configurations
-        return []
+        return configurations_xpath(self)
     setattr(cls, "getconfigurations", getconfigurations)
 
+    configuration_xpath = PLCOpen_XPath(
+        "ppx:instances/ppx:configurations/ppx:configuration[@name=$name]")
     def getconfiguration(self, name):
-        for configuration in self.instances.configurations.getconfiguration():
-            if configuration.getname() == name:
-                return configuration
+        configurations = configuration_xpath(self, name=name)
+        if len(configurations) == 1:
+            return configurations[0]
         return None
     setattr(cls, "getconfiguration", getconfiguration)
 
     def addconfiguration(self, name):
-        for configuration in self.instances.configurations.getconfiguration():
-            if configuration.getname() == name:
-                raise ValueError, _("\"%s\" configuration already exists !!!")%name
-        new_configuration = PLCOpenClasses["configurations_configuration"]()
+        if self.getconfiguration(name) is not None:
+            raise ValueError, _("\"%s\" configuration already exists !!!") % name
+        new_configuration = PLCOpenParser.CreateElement("configuration", "configurations")
         new_configuration.setname(name)
         self.instances.configurations.appendconfiguration(new_configuration)
     setattr(cls, "addconfiguration", addconfiguration)    
 
     def removeconfiguration(self, name):
-        found = False
-        for idx, configuration in enumerate(self.instances.configurations.getconfiguration()):
-            if configuration.getname() == name:
-                self.instances.configurations.removeconfiguration(idx)
-                found = True
-                break
-        if not found:
-            raise ValueError, ("\"%s\" configuration doesn't exist !!!")%name
+        configuration = self.getconfiguration(name)
+        if configuration is None:
+            raise ValueError, ("\"%s\" configuration doesn't exist !!!") % name
+        self.instances.configurations.remove(configuration)
     setattr(cls, "removeconfiguration", removeconfiguration)
-
+    
+    resources_xpath = PLCOpen_XPath(
+        "ppx:instances/ppx:configurations/ppx:configuration[@name=$configname]/ppx:resource[@name=$name]")
     def getconfigurationResource(self, config_name, name):
-        configuration = self.getconfiguration(config_name)
-        if configuration:
-            for resource in configuration.getresource():
-                if resource.getname() == name:
-                    return resource
+        resources = resources_xpath(self, configname=config_name, name=name)
+        if len(resources) == 1:
+            return resources[0]
         return None
     setattr(cls, "getconfigurationResource", getconfigurationResource)
 
     def addconfigurationResource(self, config_name, name):
+        if self.getconfigurationResource(config_name, name) is not None:
+            raise ValueError, _("\"%s\" resource already exists in \"%s\" configuration !!!") % (name, config_name)
         configuration = self.getconfiguration(config_name)
-        if configuration:
-            for resource in configuration.getresource():
-                if resource.getname() == name:
-                    raise ValueError, _("\"%s\" resource already exists in \"%s\" configuration !!!")%(name, config_name)
-            new_resource = PLCOpenClasses["configuration_resource"]()
+        if configuration is not None:
+            new_resource = PLCOpenParser.CreateElement("resource", "configuration")
             new_resource.setname(name)
             configuration.appendresource(new_resource)
     setattr(cls, "addconfigurationResource", addconfigurationResource)
 
     def removeconfigurationResource(self, config_name, name):
         configuration = self.getconfiguration(config_name)
-        if configuration:
-            found = False
-            for idx, resource in enumerate(configuration.getresource()):
-                if resource.getname() == name:
-                    configuration.removeresource(idx)
-                    found = True
-                    break
-            if not found:
-                raise ValueError, _("\"%s\" resource doesn't exist in \"%s\" configuration !!!")%(name, config_name)
+        found = False
+        if configuration is not None:
+            resource = self.getconfigurationResource(config_name, name)
+            if resource is not None:
+                configuration.remove(resource)
+                found = True
+        if not found:
+            raise ValueError, _("\"%s\" resource doesn't exist in \"%s\" configuration !!!")%(name, config_name)
     setattr(cls, "removeconfigurationResource", removeconfigurationResource)
 
     def updateElementName(self, old_name, new_name):
-        for datatype in self.types.getdataTypeElements():
+        for datatype in self.getdataTypes():
             datatype.updateElementName(old_name, new_name)
-        for pou in self.types.getpouElements():
+        for pou in self.getpous():
             pou.updateElementName(old_name, new_name)
-        for configuration in self.instances.configurations.getconfiguration():
+        for configuration in self.getconfigurations():
             configuration.updateElementName(old_name, new_name)
     setattr(cls, "updateElementName", updateElementName)
 
     def updateElementAddress(self, old_leading, new_leading):
         address_model = re.compile(FILTER_ADDRESS_MODEL % old_leading)
-        for pou in self.types.getpouElements():
+        for pou in self.getpous():
             pou.updateElementAddress(address_model, new_leading)
-        for configuration in self.instances.configurations.getconfiguration():
+        for configuration in self.getconfigurations():
             configuration.updateElementAddress(address_model, new_leading)
     setattr(cls, "updateElementAddress", updateElementAddress)
 
     def removeVariableByAddress(self, address):
-        for pou in self.types.getpouElements():
+        for pou in self.getpous():
             pou.removeVariableByAddress(address)
-        for configuration in self.instances.configurations.getconfiguration():
+        for configuration in self.getconfigurations():
             configuration.removeVariableByAddress(address)
     setattr(cls, "removeVariableByAddress", removeVariableByAddress)
 
     def removeVariableByFilter(self, leading):
         address_model = re.compile(FILTER_ADDRESS_MODEL % leading)
-        for pou in self.types.getpouElements():
+        for pou in self.getpous():
             pou.removeVariableByFilter(address_model)
-        for configuration in self.instances.configurations.getconfiguration():
+        for configuration in self.getconfigurations():
             configuration.removeVariableByFilter(address_model)
     setattr(cls, "removeVariableByFilter", removeVariableByFilter)
 
-    def RefreshDataTypeHierarchy(self):
-        self.EnumeratedDataTypeValues = {}
-        self.CustomDataTypeRange = {}
-        self.CustomTypeHierarchy = {}
-        for datatype in self.getdataTypes():
-            self.AddCustomDataType(datatype)
-    setattr(cls, "RefreshDataTypeHierarchy", RefreshDataTypeHierarchy)
-
-    def AddCustomDataType(self, datatype):
-        name = datatype.getname()
-        basetype_content = datatype.getbaseType().getcontent()
-        if basetype_content["value"] is None:
-            self.CustomTypeHierarchy[name] = basetype_content["name"]
-        elif basetype_content["name"] in ["string", "wstring"]:
-            self.CustomTypeHierarchy[name] = basetype_content["name"].upper()
-        elif basetype_content["name"] == "derived":
-            self.CustomTypeHierarchy[name] = basetype_content["value"].getname()
-        elif basetype_content["name"] in ["subrangeSigned", "subrangeUnsigned"]:
-            range = (basetype_content["value"].range.getlower(), 
-                     basetype_content["value"].range.getupper())
-            self.CustomDataTypeRange[name] = range
-            base_type = basetype_content["value"].baseType.getcontent()
-            if base_type["value"] is None:
-                self.CustomTypeHierarchy[name] = base_type["name"]
-            else:
-                self.CustomTypeHierarchy[name] = base_type["value"].getname()
-        else:
-            if basetype_content["name"] == "enum":
-                values = []
-                for value in basetype_content["value"].values.getvalue():
-                    values.append(value.getname())
-                self.EnumeratedDataTypeValues[name] = values
-            self.CustomTypeHierarchy[name] = "ANY_DERIVED"
-    setattr(cls, "AddCustomDataType", AddCustomDataType)
-
-    # Update Block types with user-defined pou added
-    def RefreshCustomBlockTypes(self):
-        # Reset the tree of user-defined pou cross-use
-        self.CustomBlockTypes = OrderedDict()
-        for pou in self.getpous():
-            self.AddCustomBlockType(pou)
-    setattr(cls, "RefreshCustomBlockTypes", RefreshCustomBlockTypes)
-
-    def AddCustomBlockType(self, pou): 
-        pou_name = pou.getname()
-        pou_type = pou.getpouType()
-        block_infos = {"name" : pou_name, "type" : pou_type, "extensible" : False,
-                       "inputs" : [], "outputs" : [], "comment" : pou.getdescription(),
-                       "generate" : generate_block, "initialise" : initialise_block}
-        if pou.getinterface():
-            return_type = pou.interface.getreturnType()
-            if return_type:
-                var_type = return_type.getcontent()
-                if var_type["name"] == "derived":
-                    block_infos["outputs"].append(("OUT", var_type["value"].getname(), "none"))
-                elif var_type["name"] in ["string", "wstring"]:
-                    block_infos["outputs"].append(("OUT", var_type["name"].upper(), "none"))
-                else:
-                    block_infos["outputs"].append(("OUT", var_type["name"], "none"))
-            for type, varlist in pou.getvars():
-                if type == "InOut":
-                    for var in varlist.getvariable():
-                        var_type = var.type.getcontent()
-                        if var_type["name"] == "derived":
-                            block_infos["inputs"].append((var.getname(), var_type["value"].getname(), "none"))
-                            block_infos["outputs"].append((var.getname(), var_type["value"].getname(), "none"))
-                        elif var_type["name"] in ["string", "wstring"]:
-                            block_infos["inputs"].append((var.getname(), var_type["name"].upper(), "none"))
-                            block_infos["outputs"].append((var.getname(), var_type["name"].upper(), "none"))
-                        else:
-                            block_infos["inputs"].append((var.getname(), var_type["name"], "none"))
-                            block_infos["outputs"].append((var.getname(), var_type["name"], "none"))
-                elif type == "Input":
-                    for var in varlist.getvariable():
-                        var_type = var.type.getcontent()
-                        if var_type["name"] == "derived":
-                            block_infos["inputs"].append((var.getname(), var_type["value"].getname(), "none"))
-                        elif var_type["name"] in ["string", "wstring"]:
-                            block_infos["inputs"].append((var.getname(), var_type["name"].upper(), "none"))
-                        else:
-                            block_infos["inputs"].append((var.getname(), var_type["name"], "none"))
-                elif type == "Output":
-                    for var in varlist.getvariable():
-                        var_type = var.type.getcontent()
-                        if var_type["name"] == "derived":
-                            block_infos["outputs"].append((var.getname(), var_type["value"].getname(), "none"))
-                        elif var_type["name"] in ["string", "wstring"]:
-                            block_infos["outputs"].append((var.getname(), var_type["name"].upper(), "none"))
-                        else:
-                            block_infos["outputs"].append((var.getname(), var_type["name"], "none"))    
-        block_infos["usage"] = "\n (%s) => (%s)" % (", ".join(["%s:%s" % (input[1], input[0]) for input in block_infos["inputs"]]),
-                                                    ", ".join(["%s:%s" % (output[1], output[0]) for output in block_infos["outputs"]]))
-        self.CustomBlockTypes[pou_name]=block_infos
-    setattr(cls, "AddCustomBlockType", AddCustomBlockType)
-
-    def AddElementUsingTreeInstance(self, name, type_infos):
-        typename = type_infos.getname()
-        elements = self.ElementUsingTree.setdefault(typename, set())
-        elements.add(name)
-    setattr(cls, "AddElementUsingTreeInstance", AddElementUsingTreeInstance)
-    
-    def RefreshElementUsingTree(self):
-        # Reset the tree of user-defined element cross-use
-        self.ElementUsingTree = {}
-        pous = self.getpous()
-        datatypes = self.getdataTypes()
-        # Analyze each datatype
-        for datatype in datatypes:
-            name = datatype.getname()
-            basetype_content = datatype.baseType.getcontent()
-            if basetype_content["name"] == "derived":
-                self.AddElementUsingTreeInstance(name,
-                                                 basetype_content["value"])
-            elif basetype_content["name"] in ["subrangeSigned", "subrangeUnsigned", "array"]:
-                base_type = basetype_content["value"].baseType.getcontent()
-                if base_type["name"] == "derived":
-                    self.AddElementUsingTreeInstance(name, base_type["value"])
-            elif basetype_content["name"] == "struct":
-                for element in basetype_content["value"].getvariable():
-                    type_content = element.type.getcontent()
-                    if type_content["name"] == "derived":
-                        self.AddElementUsingTreeInstance(name, type_content["value"])
-        # Analyze each pou
-        for pou in pous:
-            name = pou.getname()
-            if pou.interface:
-                # Extract variables from every varLists
-                for type, varlist in pou.getvars():
-                    for var in varlist.getvariable():
-                        vartype_content = var.gettype().getcontent()
-                        if vartype_content["name"] == "derived":
-                            self.AddElementUsingTreeInstance(name, vartype_content["value"])
-        
-    setattr(cls, "RefreshElementUsingTree", RefreshElementUsingTree)
-
-    def GetParentType(self, type):
-        if self.CustomTypeHierarchy.has_key(type):
-            return self.CustomTypeHierarchy[type]
-        elif TypeHierarchy.has_key(type):
-            return TypeHierarchy[type]
-        return None
-    setattr(cls, "GetParentType", GetParentType)
-
-    def GetBaseType(self, type):
-        parent_type = self.GetParentType(type)
-        if parent_type is not None:
-            if parent_type.startswith("ANY"):
-                return type
-            else:
-                return self.GetBaseType(parent_type)
-        return None
-    setattr(cls, "GetBaseType", GetBaseType)
-
-    def GetSubrangeBaseTypes(self, exclude):
-        derived = []
-        for type in self.CustomTypeHierarchy.keys():
-            for base_type in DataTypeRange.keys():
-                if self.IsOfType(type, base_type) and not self.IsOfType(type, exclude):
-                    derived.append(type)
-                    break
-        return derived
-    setattr(cls, "GetSubrangeBaseTypes", GetSubrangeBaseTypes)
-
-    """
-    returns true if the given data type is the same that "reference" meta-type or one of its types.
-    """
-    def IsOfType(self, type, reference):
-        if reference is None:
-            return True
-        elif type == reference:
-            return True
-        else:
-            parent_type = self.GetParentType(type)
-            if parent_type is not None:
-                return self.IsOfType(parent_type, reference)
-        return False
-    setattr(cls, "IsOfType", IsOfType)
-
-    # Return if pou given by name is used by another pou
-    def ElementIsUsed(self, name):
-        elements = self.ElementUsingTree.get(name, None)
-        return elements is not None
-    setattr(cls, "ElementIsUsed", ElementIsUsed)
-
-    def DataTypeIsDerived(self, name):
-        return name in self.CustomTypeHierarchy.values()
-    setattr(cls, "DataTypeIsDerived", DataTypeIsDerived)
-
-    # Return if pou given by name is directly or undirectly used by the reference pou
-    def ElementIsUsedBy(self, name, reference):
-        elements = self.ElementUsingTree.get(name, set())
-        # Test if pou is directly used by reference
-        if reference in elements:
-            return True
-        else:
-            # Test if pou is undirectly used by reference, by testing if pous
-            # that directly use pou is directly or undirectly used by reference
-            selffn = self.ElementIsUsedBy
-            for element in elements:
-                if selffn(element, reference):
-                    return True
-        return False
-    setattr(cls, "ElementIsUsedBy", ElementIsUsedBy)
-
-    def GetDataTypeRange(self, type):
-        if self.CustomDataTypeRange.has_key(type):
-            return self.CustomDataTypeRange[type]
-        elif DataTypeRange.has_key(type):
-            return DataTypeRange[type]
-        else:
-            parent_type = self.GetParentType(type)
-            if parent_type is not None:
-                return self.GetDataTypeRange(parent_type)
-        return None
-    setattr(cls, "GetDataTypeRange", GetDataTypeRange)
-
-    def GetEnumeratedDataTypeValues(self, type = None):
-        if type is None:
-            all_values = []
-            for values in self.EnumeratedDataTypeValues.values():
-                all_values.extend(values)
-            return all_values
-        elif self.EnumeratedDataTypeValues.has_key(type):
-            return self.EnumeratedDataTypeValues[type]
-        return []
+    enumerated_values_xpath = PLCOpen_XPath(
+        "ppx:types/ppx:dataTypes/ppx:dataType/ppx:baseType/ppx:enum/ppx:values/ppx:value")
+    def GetEnumeratedDataTypeValues(self):
+        return [value.getname() for value in enumerated_values_xpath(self)]
     setattr(cls, "GetEnumeratedDataTypeValues", GetEnumeratedDataTypeValues)
 
-    # Function that returns the block definition associated to the block type given
-    def GetCustomBlockType(self, typename, inputs = None):
-        customblocktype = self.CustomBlockTypes.get(typename,None)
-        if customblocktype is not None:
-            if inputs is not None and inputs != "undefined":
-                customblock_inputs = tuple([var_type for name, var_type, modifier in customblocktype["inputs"]])
-                if inputs == customblock_inputs:
-                    return customblocktype
-            else:
-                return customblocktype
-        return None
-    setattr(cls, "GetCustomBlockType", GetCustomBlockType)
-
-    # Return Block types checking for recursion
-    def GetCustomBlockTypes(self, exclude = None, onlyfunctions = False):
-        if exclude is not None:
-            return [customblocktype for name,customblocktype in self.CustomBlockTypes.iteritems()
-                if (customblocktype["type"] != "program"
-                    and name != exclude
-                    and not self.ElementIsUsedBy(exclude, name)
-                    and not (onlyfunctions and customblocktype["type"] != "function"))]
-        return [customblocktype for customblocktype in self.CustomBlockTypes.itervalues()
-            if (customblocktype["type"] != "program"
-                and not (onlyfunctions and customblocktype["type"] != "function"))]
-    setattr(cls, "GetCustomBlockTypes", GetCustomBlockTypes)
-
-    # Return Function Block types checking for recursion
-    def GetCustomFunctionBlockTypes(self, exclude = None):
-        if exclude is not None:
-            return [customblocktype for name,customblocktype in self.CustomBlockTypes.iteritems()
-                if (customblocktype["type"] == "functionBlock" 
-                    and name != exclude 
-                    and not self.ElementIsUsedBy(exclude, name))]
-        return [customblocktype for customblocktype in self.CustomBlockTypes.itervalues()
-            if customblocktype["type"] == "functionBlock"]
-    setattr(cls, "GetCustomFunctionBlockTypes", GetCustomFunctionBlockTypes)
-
-    # Return Block types checking for recursion
-    def GetCustomBlockResource(self):
-        return [customblocktype["name"] for customblocktype in self.CustomBlockTypes.itervalues()
-            if customblocktype["type"] == "program"]
-    setattr(cls, "GetCustomBlockResource", GetCustomBlockResource)
-
-    # Return Data Types checking for recursion
-    def GetCustomDataTypes(self, exclude = "", only_locatable = False):
-        customdatatypes = []
-        for customdatatype in self.getdataTypes():
-            if not only_locatable or self.IsLocatableType(customdatatype):
-                customdatatype_name = customdatatype.getname()
-                if customdatatype_name != exclude and not self.ElementIsUsedBy(exclude, customdatatype_name):
-                    customdatatypes.append({"name": customdatatype_name, "infos": customdatatype})
-        return customdatatypes
-    setattr(cls, "GetCustomDataTypes", GetCustomDataTypes)
-
-    # Return if Data Type can be used for located variables
-    def IsLocatableType(self, datatype):
-        basetype_content = datatype.baseType.getcontent()
-        if basetype_content["name"] in ["enum", "struct"]:
-            return False
-        elif basetype_content["name"] == "derived":
-            base_type = self.getdataType(basetype_content["value"].getname())
-            if base_type is not None:
-                return self.IsLocatableType(base_type)
-        elif basetype_content["name"] == "array":
-            array_base_type = basetype_content["value"].baseType.getcontent()
-            if array_base_type["value"] is not None and array_base_type["name"] not in ["string", "wstring"]:
-                base_type = self.getdataType(array_base_type["value"].getname())
-                if base_type is not None:
-                    return self.IsLocatableType(base_type)
-        return True
-    setattr(cls, "IsLocatableType", IsLocatableType)
-
     def Search(self, criteria, parent_infos=[]):
         result = self.types.Search(criteria, parent_infos)
         for configuration in self.instances.configurations.getconfiguration():
@@ -711,13 +470,8 @@
         return result
     setattr(cls, "Search", Search)
 
-cls = PLCOpenClasses.get("project_fileHeader", None)
-if cls:
-    cls.singleLineAttributes = False
-
-cls = PLCOpenClasses.get("project_contentHeader", None)
-if cls:
-    cls.singleLineAttributes = False
+cls = PLCOpenParser.GetElementClass("contentHeader", "project")
+if cls:
     
     def setpageSize(self, width, height):
         self.coordinateInfo.setpageSize(width, height)
@@ -740,7 +494,7 @@
         return scaling
     setattr(cls, "getscaling", getscaling)
 
-cls = PLCOpenClasses.get("contentHeader_coordinateInfo", None)
+cls = PLCOpenParser.GetElementClass("coordinateInfo", "contentHeader")
 if cls:
     def setpageSize(self, width, height):
         if width == 0 and height == 0:
@@ -809,7 +563,7 @@
         variables = varlist.getvariable()
         for i in xrange(len(variables)-1, -1, -1):
             if variables[i].getaddress() == address:
-                variables.pop(i)
+                variables.remove(variables[i])
 
 def _removeConfigurationResourceVariableByFilter(self, address_model):
     for varlist in self.getglobalVars():
@@ -819,7 +573,7 @@
             if var_address is not None:
                 result = address_model.match(var_address)
                 if result is not None:
-                    variables.pop(i)
+                    variables.remove(variables[i])
 
 def _SearchInConfigurationResource(self, criteria, parent_infos=[]):
     search_result = _Search([("name", self.getname())], criteria, parent_infos)
@@ -839,33 +593,30 @@
             var_number += 1
     return search_result
 
-cls = PLCOpenClasses.get("configurations_configuration", None)
-if cls:
-    
-    def addglobalVar(self, type, name, location="", description=""):
+cls = PLCOpenParser.GetElementClass("configuration", "configurations")
+if cls:
+    
+    def addglobalVar(self, var_type, name, location="", description=""):
         globalvars = self.getglobalVars()
         if len(globalvars) == 0:
-            globalvars.append(PLCOpenClasses["varList"]())
-        var = PLCOpenClasses["varListPlain_variable"]()
+            globalvars.append(PLCOpenParser.CreateElement("varList"))
+        var = PLCOpenParser.CreateElement("variable", "varListPlain")
         var.setname(name)
-        var_type = PLCOpenClasses["dataType"]()
-        if type in [x for x,y in TypeHierarchy_list if not x.startswith("ANY")]:
-            if type == "STRING":
-                var_type.setcontent({"name" : "string", "value" : PLCOpenClasses["elementaryTypes_string"]()})
-            elif type == "WSTRING":
-                var_type.setcontent({"name" : "wstring", "value" : PLCOpenClasses["elementaryTypes_wstring"]()})
-            else:
-                var_type.setcontent({"name" : type, "value" : None})
+        var_type_obj = PLCOpenParser.CreateElement("dataType")
+        if var_type in [x for x,y in TypeHierarchy_list if not x.startswith("ANY")]:
+            var_type_obj.setcontent(PLCOpenParser.CreateElement(
+                var_type.lower() if var_type in ["STRING", "WSTRING"]
+                else vartype, "dataType"))
         else:
-            derived_type = PLCOpenClasses["derivedTypes_derived"]()
-            derived_type.setname(type)
-            var_type.setcontent({"name" : "derived", "value" : derived_type})
-        var.settype(var_type)
+            derived_type = PLCOpenParser.CreateElement("derived", "dataType")
+            derived_type.setname(var_type)
+            var_type_obj.setcontent(derived_type)
+        var.settype(var_type_obj)
         if location != "":
             var.setaddress(location)
         if description != "":
-            ft = PLCOpenClasses["formattedText"]()
-            ft.settext(description)
+            ft = PLCOpenParser.CreateElement("documentation", "variable")
+            ft.setanyText(description)
             var.setdocumentation(ft)
         globalvars[-1].appendvariable(var)
     setattr(cls, "addglobalVar", addglobalVar)
@@ -896,7 +647,7 @@
         return search_result
     setattr(cls, "Search", Search)
     
-cls = PLCOpenClasses.get("configuration_resource", None)
+cls = PLCOpenParser.GetElementClass("resource", "configuration")
 if cls:
     def updateElementName(self, old_name, new_name):
         _updateConfigurationResourceElementName(self, old_name, new_name)
@@ -937,7 +688,7 @@
         return search_result
     setattr(cls, "Search", Search)
 
-cls = PLCOpenClasses.get("resource_task", None)
+cls = PLCOpenParser.GetElementClass("task", "resource")
 if cls:
     def compatibility(self, tree):
         if tree.hasAttribute("interval"):
@@ -986,7 +737,7 @@
                        criteria, parent_infos)
     setattr(cls, "Search", Search)
 
-cls = PLCOpenClasses.get("pouInstance", None)
+cls = PLCOpenParser.GetElementClass("pouInstance")
 if cls:
     def compatibility(self, tree):
         if tree.hasAttribute("type"):
@@ -1004,31 +755,33 @@
                        criteria, parent_infos)
     setattr(cls, "Search", Search)
 
-cls = PLCOpenClasses.get("varListPlain_variable", None)
+cls = PLCOpenParser.GetElementClass("variable", "varListPlain")
 if cls:
     def gettypeAsText(self):
         vartype_content = self.gettype().getcontent()
+        vartype_content_name = vartype_content.getLocalTag()
         # Variable type is a user data type
-        if vartype_content["name"] == "derived":
-            return vartype_content["value"].getname()
+        if vartype_content_name == "derived":
+            return vartype_content.getname()
         # Variable type is a string type
-        elif vartype_content["name"] in ["string", "wstring"]:
-            return vartype_content["name"].upper()
+        elif vartype_content_name in ["string", "wstring"]:
+            return vartype_content_name.upper()
         # Variable type is an array
-        elif vartype_content["name"] == "array":
-            base_type = vartype_content["value"].baseType.getcontent()
+        elif vartype_content_name == "array":
+            base_type = vartype_content.baseType.getcontent()
+            base_type_name = base_type.getLocalTag()
             # Array derived directly from a user defined type 
-            if base_type["name"] == "derived":
-                basetype_name = base_type["value"].getname()
+            if base_type_name == "derived":
+                basetype_name = base_type.getname()
             # Array derived directly from a string type 
-            elif base_type["name"] in ["string", "wstring"]:
-                basetype_name = base_type["name"].upper()
+            elif base_type_name in ["string", "wstring"]:
+                basetype_name = base_type_name.upper()
             # Array derived directly from an elementary type 
             else:
-                basetype_name = base_type["name"]
-            return "ARRAY [%s] OF %s" % (",".join(map(lambda x : "%s..%s" % (x.getlower(), x.getupper()), vartype_content["value"].getdimension())), basetype_name)
+                basetype_name = base_type_name
+            return "ARRAY [%s] OF %s" % (",".join(map(lambda x : "%s..%s" % (x.getlower(), x.getupper()), vartype_content.getdimension())), basetype_name)
         # Variable type is an elementary type
-        return vartype_content["name"]
+        return vartype_content_name
     setattr(cls, "gettypeAsText", gettypeAsText)
     
     def Search(self, criteria, parent_infos=[]):
@@ -1045,7 +798,7 @@
         return search_result
     setattr(cls, "Search", Search)
 
-cls = PLCOpenClasses.get("project_types", None)
+cls = PLCOpenParser.GetElementClass("types", "project")
 if cls:
     def getdataTypeElements(self):
         return self.dataTypes.getdataType()
@@ -1060,10 +813,10 @@
     setattr(cls, "getdataTypeElement", getdataTypeElement)
 
     def appenddataTypeElement(self, name):
-        new_datatype = PLCOpenClasses["dataTypes_dataType"]()
+        new_datatype = PLCOpenParser.CreateElement("dataType", "dataTypes")
+        self.dataTypes.appenddataType(new_datatype)
         new_datatype.setname(name)
-        new_datatype.baseType.setcontent({"name" : "BOOL", "value" : None})
-        self.dataTypes.appenddataType(new_datatype)
+        new_datatype.baseType.setcontent(PLCOpenParser.CreateElement("BOOL", "dataType"))
     setattr(cls, "appenddataTypeElement", appenddataTypeElement)
     
     def insertdataTypeElement(self, index, dataType):
@@ -1072,9 +825,9 @@
     
     def removedataTypeElement(self, name):
         found = False
-        for idx, element in enumerate(self.dataTypes.getdataType()):
+        for element in self.dataTypes.getdataType():
             if element.getname() == name:
-                self.dataTypes.removedataType(idx)
+                self.dataTypes.remove(element)
                 found = True
                 break
         if not found:
@@ -1097,12 +850,12 @@
         for element in self.pous.getpou():
             if element.getname() == name:
                 raise ValueError, _("\"%s\" POU already exists !!!")%name
-        new_pou = PLCOpenClasses["pous_pou"]()
+        new_pou = PLCOpenParser.CreateElement("pou", "pous")
+        self.pous.appendpou(new_pou)
         new_pou.setname(name)
         new_pou.setpouType(pou_type)
-        new_pou.appendbody(PLCOpenClasses["body"]())
+        new_pou.appendbody(PLCOpenParser.CreateElement("body", "pou"))
         new_pou.setbodyType(body_type)
-        self.pous.appendpou(new_pou)
     setattr(cls, "appendpouElement", appendpouElement)
         
     def insertpouElement(self, index, pou):
@@ -1111,9 +864,9 @@
     
     def removepouElement(self, name):
         found = False
-        for idx, element in enumerate(self.pous.getpou()):
+        for element in self.pous.getpou():
             if element.getname() == name:
-                self.pous.removepou(idx)
+                self.pous.remove(element)
                 found = True
                 break
         if not found:
@@ -1133,7 +886,7 @@
 def _updateBaseTypeElementName(self, old_name, new_name):
     self.baseType.updateElementName(old_name, new_name)
 
-cls = PLCOpenClasses.get("dataTypes_dataType", None)
+cls = PLCOpenParser.GetElementClass("dataType", "dataTypes")
 if cls:
     setattr(cls, "updateElementName", _updateBaseTypeElementName)
     
@@ -1149,33 +902,45 @@
         return search_result
     setattr(cls, "Search", Search)
 
-cls = PLCOpenClasses.get("dataType", None)
+cls = PLCOpenParser.GetElementClass("dataType")
 if cls:
     
     def updateElementName(self, old_name, new_name):
-        if self.content["name"] in ["derived", "array", "subrangeSigned", "subrangeUnsigned"]:
-            self.content["value"].updateElementName(old_name, new_name)
-        elif self.content["name"] == "struct":
-            for element in self.content["value"].getvariable():
+        content_name = self.content.getLocalTag()
+        if content_name in ["derived", "array", "subrangeSigned", "subrangeUnsigned"]:
+            self.content.updateElementName(old_name, new_name)
+        elif content_name == "struct":
+            for element in self.content.getvariable():
                 element_type = element.type.updateElementName(old_name, new_name)
     setattr(cls, "updateElementName", updateElementName)
 
     def Search(self, criteria, parent_infos=[]):
         search_result = []
-        if self.content["name"] in ["derived", "array", "enum", "subrangeSigned", "subrangeUnsigned"]:
-            search_result.extend(self.content["value"].Search(criteria, parent_infos))
-        elif self.content["name"] == "struct":
-            for i, element in enumerate(self.content["value"].getvariable()):
+        content_name = self.content.getLocalTag()
+        if content_name in ["derived", "array", "enum", "subrangeSigned", "subrangeUnsigned"]:
+            search_result.extend(self.content.Search(criteria, parent_infos + ["base"]))
+        elif content_name == "struct":
+            for i, element in enumerate(self.content.getvariable()):
                 search_result.extend(element.Search(criteria, parent_infos + ["struct", i]))
         else:
-            basetype = self.content["name"]
-            if basetype in ["string", "wstring"]:
-                basetype = basetype.upper()
-            search_result.extend(_Search([("base", basetype)], criteria, parent_infos))
+            if content_name in ["string", "wstring"]:
+                content_name = content_name.upper()
+            search_result.extend(_Search([("base", content_name)], criteria, parent_infos))
         return search_result
     setattr(cls, "Search", Search)
 
-cls = PLCOpenClasses.get("derivedTypes_array", None)
+cls = PLCOpenParser.GetElementClass("derived", "dataType")
+if cls:
+    def updateElementName(self, old_name, new_name):
+        if self.name == old_name:
+            self.name = new_name
+    setattr(cls, "updateElementName", updateElementName)
+    
+    def Search(self, criteria, parent_infos=[]):
+        return [(tuple(parent_infos),) + result for result in TestTextElement(self.name, criteria)]
+    setattr(cls, "Search", Search)
+
+cls = PLCOpenParser.GetElementClass("array", "dataType")
 if cls:
     setattr(cls, "updateElementName", _updateBaseTypeElementName)
     
@@ -1195,68 +960,102 @@
                                  criteria, parent_infos))
     return search_result
 
-cls = PLCOpenClasses.get("derivedTypes_subrangeSigned", None)
+cls = PLCOpenParser.GetElementClass("subrangeSigned", "dataType")
 if cls:
     setattr(cls, "updateElementName", _updateBaseTypeElementName)
     setattr(cls, "Search", _SearchInSubrange)
 
-cls = PLCOpenClasses.get("derivedTypes_subrangeUnsigned", None)
+cls = PLCOpenParser.GetElementClass("subrangeUnsigned", "dataType")
 if cls:
     setattr(cls, "updateElementName", _updateBaseTypeElementName)
     setattr(cls, "Search", _SearchInSubrange)
 
-cls = PLCOpenClasses.get("derivedTypes_enum", None)
+cls = PLCOpenParser.GetElementClass("enum", "dataType")
 if cls:
     
     def updateElementName(self, old_name, new_name):
         pass
     setattr(cls, "updateElementName", updateElementName)
     
+    enumerated_datatype_values_xpath = PLCOpen_XPath("ppx:values/ppx:value")
     def Search(self, criteria, parent_infos=[]):
         search_result = []
-        for i, value in enumerate(self.values.getvalue()):
+        for i, value in enumerate(enumerated_datatype_values_xpath(self)):
             for result in TestTextElement(value.getname(), criteria):
                 search_result.append((tuple(parent_infos + ["value", i]),) + result)
         return search_result
     setattr(cls, "Search", Search)
 
-cls = PLCOpenClasses.get("pous_pou", None)
-if cls:
+def _getvariableTypeinfos(variable_type):
+    type_content = variable_type.getcontent()
+    type_content_type = type_content.getLocalTag()
+    if type_content_type == "derived":
+        return type_content.getname()
+    return type_content_type.upper()
+    
+cls = PLCOpenParser.GetElementClass("pou", "pous")
+if cls:
+    
+    block_inputs_xpath = PLCOpen_XPath(
+        "ppx:interface/*[self::ppx:inputVars or self::ppx:inOutVars]/ppx:variable")
+    block_outputs_xpath = PLCOpen_XPath(
+        "ppx:interface/*[self::ppx:outputVars or self::ppx:inOutVars]/ppx:variable")
+    def getblockInfos(self): 
+        block_infos = {
+            "name" : self.getname(), 
+            "type" : self.getpouType(), 
+            "extensible" : False,
+            "inputs" : [], 
+            "outputs" : [], 
+            "comment" : self.getdescription(),
+            "generate" : generate_block, 
+            "initialise" : initialise_block}
+        if self.interface is not None:
+            return_type = self.interface.getreturnType()
+            if return_type is not None:
+                block_infos["outputs"].append(
+                    ("OUT", _getvariableTypeinfos(return_type), "none"))
+            block_infos["inputs"].extend(
+                [(var.getname(), _getvariableTypeinfos(var.type), "none")
+                 for var in block_inputs_xpath(self)])
+            block_infos["outputs"].extend(
+                [(var.getname(), _getvariableTypeinfos(var.type), "none")
+                 for var in block_outputs_xpath(self)])
+            
+        block_infos["usage"] = ("\n (%s) => (%s)" % 
+            (", ".join(["%s:%s" % (input[1], input[0]) 
+                        for input in block_infos["inputs"]]),
+             ", ".join(["%s:%s" % (output[1], output[0]) 
+                        for output in block_infos["outputs"]])))
+        return block_infos
+    setattr(cls, "getblockInfos", getblockInfos)
     
     def setdescription(self, description):
         doc = self.getdocumentation()
         if doc is None:
-            doc = PLCOpenClasses["formattedText"]()
+            doc = PLCOpenParser.CreateElement("documentation", "pou")
             self.setdocumentation(doc)
-        doc.settext(description)
+        doc.setanyText(description)
     setattr(cls, "setdescription", setdescription)
     
     def getdescription(self):
         doc = self.getdocumentation()
         if doc is not None:
-            return doc.gettext()
+            return doc.getanyText()
         return ""
     setattr(cls, "getdescription", getdescription)
     
-    def setbodyType(self, type):
+    def setbodyType(self, body_type):
         if len(self.body) > 0:
-            if type == "IL":
-                self.body[0].setcontent({"name" : "IL", "value" : PLCOpenClasses["formattedText"]()})
-            elif type == "ST":
-                self.body[0].setcontent({"name" : "ST", "value" : PLCOpenClasses["formattedText"]()})
-            elif type == "LD":
-                self.body[0].setcontent({"name" : "LD", "value" : PLCOpenClasses["body_LD"]()})
-            elif type == "FBD":
-                self.body[0].setcontent({"name" : "FBD", "value" : PLCOpenClasses["body_FBD"]()})
-            elif type == "SFC":
-                self.body[0].setcontent({"name" : "SFC", "value" : PLCOpenClasses["body_SFC"]()})
+            if body_type in ["IL", "ST", "LD", "FBD", "SFC"]:
+                self.body[0].setcontent(PLCOpenParser.CreateElement(body_type, "body"))
             else:
                 raise ValueError, "%s isn't a valid body type!"%type
     setattr(cls, "setbodyType", setbodyType)
     
     def getbodyType(self):
         if len(self.body) > 0:
-            return self.body[0].getcontent()["name"]
+            return self.body[0].getcontent().getLocalTag()
     setattr(cls, "getbodyType", getbodyType)
     
     def resetexecutionOrder(self):
@@ -1274,9 +1073,9 @@
             self.body[0].setelementExecutionOrder(instance, new_executionOrder)
     setattr(cls, "setelementExecutionOrder", setelementExecutionOrder)
     
-    def addinstance(self, name, instance):
+    def addinstance(self, instance):
         if len(self.body) > 0:
-            self.body[0].appendcontentInstance(name, instance)
+            self.body[0].appendcontentInstance(instance)
     setattr(cls, "addinstance", addinstance)
     
     def getinstances(self):
@@ -1326,88 +1125,87 @@
             for name, value in VarTypes.items():
                 reverse_types[value] = name
             for varlist in self.interface.getcontent():
-                vars.append((reverse_types[varlist["name"]], varlist["value"]))
+                vars.append((reverse_types[varlist.getLocalTag()], varlist))
         return vars
     setattr(cls, "getvars", getvars)
     
     def setvars(self, vars):
         if self.interface is None:
-            self.interface = PLCOpenClasses["pou_interface"]()
-        self.interface.setcontent([])
-        for vartype, varlist in vars:
-            self.interface.appendcontent({"name" : VarTypes[vartype], "value" : varlist})
+            self.interface = PLCOpenParser.CreateElement("interface", "pou")
+        self.interface.setcontent(vars)
     setattr(cls, "setvars", setvars)
     
-    def addpouLocalVar(self, type, name, location="", description=""):
-        self.addpouVar(type, name, location=location, description=description)
+    def addpouLocalVar(self, var_type, name, location="", description=""):
+        self.addpouVar(var_type, name, location=location, description=description)
     setattr(cls, "addpouLocalVar", addpouLocalVar)
         
-    def addpouExternalVar(self, type, name):
+    def addpouExternalVar(self, var_type, name):
         self.addpouVar(type, name, "externalVars")
     setattr(cls, "addpouExternalVar", addpouExternalVar)
     
-    def addpouVar(self, type, name, var_class="localVars", location="", description=""):
+    def addpouVar(self, var_type, name, var_class="localVars", location="", description=""):
         if self.interface is None:
-            self.interface = PLCOpenClasses["pou_interface"]()
+            self.interface = PLCOpenParser.CreateElement("interface", "pou")
         content = self.interface.getcontent()
-        if len(content) == 0 or content[-1]["name"] != var_class:
-            content.append({"name" : var_class, "value" : PLCOpenClasses["interface_%s" % var_class]()})
+        if len(content) == 0:
+            varlist = PLCOpenParser.CreateElement(var_class, "interface")
+            self.interface.setcontent([varlist])
+        elif content[-1] != var_class:
+            varlist = PLCOpenParser.CreateElement(var_class, "interface")
+            content[-1].addnext(varlist)
         else:
-            varlist = content[-1]["value"]
+            varlist = content[-1]
             variables = varlist.getvariable()
             if varlist.getconstant() or varlist.getretain() or len(variables) > 0 and variables[0].getaddress():
-                content.append({"name" : var_class, "value" : PLCOpenClasses["interface_%s" % var_class]()})
-        var = PLCOpenClasses["varListPlain_variable"]()
+                varlist = PLCOpenParser.CreateElement(var_class, "interface")
+                content[-1].addnext(varlist)
+        var = PLCOpenParser.CreateElement("variable", "varListPlain")
         var.setname(name)
-        var_type = PLCOpenClasses["dataType"]()
-        if type in [x for x,y in TypeHierarchy_list if not x.startswith("ANY")]:
-            if type == "STRING":
-                var_type.setcontent({"name" : "string", "value" : PLCOpenClasses["elementaryTypes_string"]()})
-            elif type == "WSTRING":
-                var_type.setcontent({"name" : "wstring", "value" : PLCOpenClasses["elementaryTypes_wstring"]()})
-            else:
-                var_type.setcontent({"name" : type, "value" : None})
+        var_type_obj = PLCOpenParser.CreateElement("type", "variable")
+        if var_type in [x for x,y in TypeHierarchy_list if not x.startswith("ANY")]:
+            var_type_obj.setcontent(PLCOpenParser.CreateElement(
+                var_type.lower() if var_type in ["STRING", "WSTRING"]
+                else var_type, "dataType"))
         else:
-            derived_type = PLCOpenClasses["derivedTypes_derived"]()
-            derived_type.setname(type)
-            var_type.setcontent({"name" : "derived", "value" : derived_type})
-        var.settype(var_type)
+            derived_type = PLCOpenParser.CreateElement("derived", "dataType")
+            derived_type.setname(var_type)
+            var_type_obj.setcontent(derived_type)
+        var.settype(var_type_obj)
         if location != "":
             var.setaddress(location)
         if description != "":
-            ft = PLCOpenClasses["formattedText"]()
-            ft.settext(description)
+            ft = PLCOpenParser.CreateElement("documentation", "variable")
+            ft.setanyText(description)
             var.setdocumentation(ft)
         
-        content[-1]["value"].appendvariable(var)
+        varlist.appendvariable(var)
     setattr(cls, "addpouVar", addpouVar)
     
     def changepouVar(self, old_type, old_name, new_type, new_name):
         if self.interface is not None:
             content = self.interface.getcontent()
             for varlist in content:
-                variables = varlist["value"].getvariable()
+                variables = varlist.getvariable()
                 for var in variables:
                     if var.getname() == old_name:
                         vartype_content = var.gettype().getcontent()
-                        if vartype_content["name"] == "derived" and vartype_content["value"].getname() == old_type:
+                        if vartype_content.getLocalTag() == "derived" and vartype_content.getname() == old_type:
                             var.setname(new_name)
-                            vartype_content["value"].setname(new_type)
+                            vartype_content.setname(new_type)
                             return
     setattr(cls, "changepouVar", changepouVar)
     
-    def removepouVar(self, type, name):
+    def removepouVar(self, var_type, name):
         if self.interface is not None:
             content = self.interface.getcontent()
             for varlist in content:
-                variables = varlist["value"].getvariable()
-                for var in variables:
+                for var in varlist.getvariable():
                     if var.getname() == name:
                         vartype_content = var.gettype().getcontent()
-                        if vartype_content["name"] == "derived" and vartype_content["value"].getname() == type:
-                            variables.remove(var)
+                        if vartype_content.getLocalTag() == "derived" and vartype_content.getname() == var_type:
+                            varlist.remove(var)
                             break
-                if len(varlist["value"].getvariable()) == 0:
+                if len(varlist.getvariable()) == 0:
                     content.remove(varlist)
                     break
     setattr(cls, "removepouVar", removepouVar)
@@ -1415,7 +1213,7 @@
     def hasblock(self, name=None, block_type=None):
         if self.getbodyType() in ["FBD", "LD", "SFC"]:
             for instance in self.getinstances():
-                if (isinstance(instance, PLCOpenClasses["fbdObjects_block"]) and 
+                if (isinstance(instance, PLCOpenParser.GetElementClass("block", "fbdObjects")) and 
                     (name and instance.getinstanceName() == name or
                      block_type and instance.gettypeName() == block_type)):
                     return True
@@ -1434,22 +1232,22 @@
         return False
     setattr(cls, "hasblock", hasblock)
     
-    def addtransition(self, name, type):
-        if not self.transitions:
+    def addtransition(self, name, body_type):
+        if self.transitions is None:
             self.addtransitions()
             self.transitions.settransition([])
-        transition = PLCOpenClasses["transitions_transition"]()
+        transition = PLCOpenParser.CreateElement("transition", "transitions")
+        self.transitions.appendtransition(transition)
         transition.setname(name)
-        transition.setbodyType(type)
-        if type == "ST":
-            transition.settext(":= ;")
-        elif type == "IL":
-            transition.settext("\tST\t%s"%name)
-        self.transitions.appendtransition(transition)
+        transition.setbodyType(body_type)
+        if body_type == "ST":
+            transition.setanyText(":= ;")
+        elif body_type == "IL":
+            transition.setanyText("\tST\t%s"%name)
     setattr(cls, "addtransition", addtransition)
     
     def gettransition(self, name):
-        if self.transitions:
+        if self.transitions is not None:
             for transition in self.transitions.gettransition():
                 if transition.getname() == name:
                     return transition
@@ -1457,42 +1255,40 @@
     setattr(cls, "gettransition", gettransition)
         
     def gettransitionList(self):
-        if self.transitions:
+        if self.transitions is not None:
             return self.transitions.gettransition()
         return []
     setattr(cls, "gettransitionList", gettransitionList)
     
     def removetransition(self, name):
-        if self.transitions:
-            transitions = self.transitions.gettransition()
-            i = 0
+        if self.transitions is not None:
             removed = False
-            while i < len(transitions) and not removed:
-                if transitions[i].getname() == name:
-                    if transitions[i].getbodyType() in ["FBD", "LD", "SFC"]:
-                        for instance in transitions[i].getinstances():
-                            if isinstance(instance, PLCOpenClasses["fbdObjects_block"]):
+            for transition in self.transitions.gettransition():
+                if transition.getname() == name:
+                    if transition.getbodyType() in ["FBD", "LD", "SFC"]:
+                        for instance in transition.getinstances():
+                            if isinstance(instance, PLCOpenParser.GetElementClass("block", "fbdObjects")):
                                 self.removepouVar(instance.gettypeName(), 
                                                   instance.getinstanceName())
-                    transitions.pop(i)
+                    self.transitions.remove(transition)
                     removed = True
-                i += 1
+                    break
             if not removed:
                 raise ValueError, _("Transition with name %s doesn't exist!")%name
     setattr(cls, "removetransition", removetransition)
 
-    def addaction(self, name, type):
-        if not self.actions:
+    def addaction(self, name, body_type):
+        if self.actions is None:
             self.addactions()
             self.actions.setaction([])
-        action = PLCOpenClasses["actions_action"]()
+        action = PLCOpenParser.CreateElement("action", "actions")
+        self.actions.appendaction(action)
         action.setname(name)
-        action.setbodyType(type)
-        self.actions.appendaction(action)
+        action.setbodyType(body_type)
     setattr(cls, "addaction", addaction)
     
     def getaction(self, name):
-        if self.actions:
+        if self.actions is not None:
             for action in self.actions.getaction():
                 if action.getname() == name:
                     return action
@@ -1506,28 +1302,26 @@
     setattr(cls, "getactionList", getactionList)
     
     def removeaction(self, name):
-        if self.actions:
-            actions = self.actions.getaction()
-            i = 0
+        if self.actions is not None:
             removed = False
-            while i < len(actions) and not removed:
-                if actions[i].getname() == name:
-                    if actions[i].getbodyType() in ["FBD", "LD", "SFC"]:
-                        for instance in actions[i].getinstances():
-                            if isinstance(instance, PLCOpenClasses["fbdObjects_block"]):
+            for action in self.actions.getaction():
+                if action.getname() == name:
+                    if action.getbodyType() in ["FBD", "LD", "SFC"]:
+                        for instance in action.getinstances():
+                            if isinstance(instance, PLCOpenParser.GetElementClass("block", "fbdObjects")):
                                 self.removepouVar(instance.gettypeName(), 
                                                   instance.getinstanceName())
-                    actions.pop(i)
+                    self.actions.remove(action)
                     removed = True
-                i += 1
+                    break
             if not removed:
                 raise ValueError, _("Action with name %s doesn't exist!")%name
     setattr(cls, "removeaction", removeaction)
 
     def updateElementName(self, old_name, new_name):
-        if self.interface:
+        if self.interface is not None:
             for content in self.interface.getcontent():
-                for var in content["value"].getvariable():
+                for var in content.getvariable():
                     var_address = var.getaddress()
                     if var_address is not None:
                         if var_address == old_name:
@@ -1535,9 +1329,9 @@
                         if var.getname() == old_name:
                             var.setname(new_name)
                     var_type_content = var.gettype().getcontent()
-                    if var_type_content["name"] == "derived":
-                        if var_type_content["value"].getname() == old_name:
-                            var_type_content["value"].setname(new_name)
+                    if var_type_content.getLocalTag() == "derived":
+                        if var_type_content.getname() == old_name:
+                            var_type_content.setname(new_name)
         self.body[0].updateElementName(old_name, new_name)
         for action in self.getactionList():
             action.updateElementName(old_name, new_name)
@@ -1546,9 +1340,9 @@
     setattr(cls, "updateElementName", updateElementName)
 
     def updateElementAddress(self, address_model, new_leading):
-        if self.interface:
+        if self.interface is not None:
             for content in self.interface.getcontent():
-                for var in content["value"].getvariable():
+                for var in content.getvariable():
                     var_address = var.getaddress()
                     if var_address is not None:
                         var.setaddress(update_address(var_address, address_model, new_leading))
@@ -1560,24 +1354,22 @@
     setattr(cls, "updateElementAddress", updateElementAddress)
 
     def removeVariableByAddress(self, address):
-        if self.interface:
+        if self.interface is not None:
             for content in self.interface.getcontent():
-                variables = content["value"].getvariable()
-                for i in xrange(len(variables)-1, -1, -1):
-                    if variables[i].getaddress() == address:
-                        variables.pop(i)
+                for variable in content.getvariable():
+                    if variable.getaddress() == address:
+                        content.remove(variable)
     setattr(cls, "removeVariableByAddress", removeVariableByAddress)
 
     def removeVariableByFilter(self, address_model):
-        if self.interface:
+        if self.interface is not None:
             for content in self.interface.getcontent():
-                variables = content["value"].getvariable()
-                for i in xrange(len(variables)-1, -1, -1):
-                    var_address = variables[i].getaddress()
+                for variable in content.getvariable():
+                    var_address = variable.getaddress()
                     if var_address is not None:
                         result = address_model.match(var_address)
                         if result is not None:
-                            variables.pop(i)
+                            content.remove(variable)
     setattr(cls, "removeVariableByFilter", removeVariableByFilter)
     
     def Search(self, criteria, parent_infos=[]):
@@ -1589,11 +1381,11 @@
             if self.interface is not None:
                 var_number = 0
                 for content in self.interface.getcontent():
-                    variable_type = searchResultVarTypes.get(content["value"], "var_local")
-                    variables = content["value"].getvariable()
-                    for modifier, has_modifier in [("constant", content["value"].getconstant()),
-                                                   ("retain", content["value"].getretain()),
-                                                   ("non_retain", content["value"].getnonretain())]:
+                    variable_type = searchResultVarTypes.get(content, "var_local")
+                    variables = content.getvariable()
+                    for modifier, has_modifier in [("constant", content.getconstant()),
+                                                   ("retain", content.getretain()),
+                                                   ("non_retain", content.getnonretain())]:
                         if has_modifier:
                             for result in TestTextElement(modifier, criteria):
                                 search_result.append((tuple(parent_infos + [variable_type, (var_number, var_number + len(variables)), modifier]),) + result)
@@ -1610,22 +1402,14 @@
         return search_result
     setattr(cls, "Search", Search)
 
-def setbodyType(self, type):
-    if type == "IL":
-        self.body.setcontent({"name" : "IL", "value" : PLCOpenClasses["formattedText"]()})
-    elif type == "ST":
-        self.body.setcontent({"name" : "ST", "value" : PLCOpenClasses["formattedText"]()})
-    elif type == "LD":
-        self.body.setcontent({"name" : "LD", "value" : PLCOpenClasses["body_LD"]()})
-    elif type == "FBD":
-        self.body.setcontent({"name" : "FBD", "value" : PLCOpenClasses["body_FBD"]()})
-    elif type == "SFC":
-        self.body.setcontent({"name" : "SFC", "value" : PLCOpenClasses["body_SFC"]()})
+def setbodyType(self, body_type):
+    if body_type in ["IL", "ST", "LD", "FBD", "SFC"]:
+        self.body.setcontent(PLCOpenParser.CreateElement(body_type, "body"))
     else:
         raise ValueError, "%s isn't a valid body type!"%type
 
 def getbodyType(self):
-    return self.body.getcontent()["name"]
+    return self.body.getcontent().getLocalTag()
 
 def resetexecutionOrder(self):
     self.body.resetexecutionOrder()
@@ -1636,8 +1420,8 @@
 def setelementExecutionOrder(self, instance, new_executionOrder):
     self.body.setelementExecutionOrder(instance, new_executionOrder)
 
-def addinstance(self, name, instance):
-    self.body.appendcontentInstance(name, instance)
+def addinstance(self, instance):
+    self.body.appendcontentInstance(instance)
 
 def getinstances(self):
     return self.body.getcontentInstances()
@@ -1663,7 +1447,7 @@
 def hasblock(self, name=None, block_type=None):
     if self.getbodyType() in ["FBD", "LD", "SFC"]:
         for instance in self.getinstances():
-            if (isinstance(instance, PLCOpenClasses["fbdObjects_block"]) and 
+            if (isinstance(instance, PLCOpenParser.GetElementClass("block", "fbdObjects")) and 
                 (name and instance.getinstanceName() == name or
                  block_type and instance.gettypeName() == block_type)):
                 return True
@@ -1678,7 +1462,7 @@
     self.body.updateElementAddress(address_model, new_leading)
     
 
-cls = PLCOpenClasses.get("transitions_transition", None)
+cls = PLCOpenParser.GetElementClass("transition", "transitions")
 if cls:
     setattr(cls, "setbodyType", setbodyType)
     setattr(cls, "getbodyType", getbodyType)
@@ -1706,7 +1490,7 @@
         return search_result
     setattr(cls, "Search", Search)
 
-cls = PLCOpenClasses.get("actions_action", None)
+cls = PLCOpenParser.GetElementClass("action", "actions")
 if cls:
     setattr(cls, "setbodyType", setbodyType)
     setattr(cls, "getbodyType", getbodyType)
@@ -1734,27 +1518,9 @@
         return search_result
     setattr(cls, "Search", Search)
 
-cls = PLCOpenClasses.get("body", None)
+cls = PLCOpenParser.GetElementClass("body")
 if cls:
     cls.currentExecutionOrderId = 0
-    cls.instances_dict = {}
-    
-    setattr(cls, "_init_", getattr(cls, "__init__"))
-    
-    def __init__(self, *args, **kwargs):
-        self._init_(*args, **kwargs)
-        self.instances_dict = {}
-    setattr(cls, "__init__", __init__)
-    
-    setattr(cls, "_loadXMLTree", getattr(cls, "loadXMLTree"))
-    
-    def loadXMLTree(self, *args, **kwargs):
-        self._loadXMLTree(*args, **kwargs)
-        if self.content["name"] in ["LD","FBD","SFC"]:
-            self.instances_dict = dict(
-                [(element["value"].getlocalId(), element)
-                 for element in self.content["value"].getcontent()])
-    setattr(cls, "loadXMLTree", loadXMLTree)
     
     def resetcurrentExecutionOrderId(self):
         object.__setattr__(self, "currentExecutionOrderId", 0)
@@ -1766,44 +1532,44 @@
     setattr(cls, "getnewExecutionOrderId", getnewExecutionOrderId)
     
     def resetexecutionOrder(self):
-        if self.content["name"] == "FBD":
-            for element in self.content["value"].getcontent():
-                if not isinstance(element["value"], (PLCOpenClasses.get("commonObjects_comment", None), 
-                                                     PLCOpenClasses.get("commonObjects_connector", None), 
-                                                     PLCOpenClasses.get("commonObjects_continuation", None))):
-                    element["value"].setexecutionOrderId(0)
+        if self.content.getLocalTag() == "FBD":
+            for element in self.content.getcontent():
+                if not isinstance(element, (PLCOpenParser.GetElementClass("comment", "commonObjects"), 
+                                            PLCOpenParser.GetElementClass("connector", "commonObjects"), 
+                                            PLCOpenParser.GetElementClass("continuation", "commonObjects"))):
+                    element.setexecutionOrderId(0)
         else:
             raise TypeError, _("Can only generate execution order on FBD networks!")
     setattr(cls, "resetexecutionOrder", resetexecutionOrder)
     
     def compileexecutionOrder(self):
-        if self.content["name"] == "FBD":
+        if self.content.getLocalTag() == "FBD":
             self.resetexecutionOrder()
             self.resetcurrentExecutionOrderId()
-            for element in self.content["value"].getcontent():
-                if isinstance(element["value"], PLCOpenClasses.get("fbdObjects_outVariable", None)) and element["value"].getexecutionOrderId() == 0:
-                    connections = element["value"].connectionPointIn.getconnections()
+            for element in self.content.getcontent():
+                if isinstance(element, PLCOpenParser.GetElementClass("outVariable", "fbdObjects")) and element.getexecutionOrderId() == 0:
+                    connections = element.connectionPointIn.getconnections()
                     if connections and len(connections) == 1:
                         self.compileelementExecutionOrder(connections[0])
-                    element["value"].setexecutionOrderId(self.getnewExecutionOrderId())
+                    element.setexecutionOrderId(self.getnewExecutionOrderId())
         else:
             raise TypeError, _("Can only generate execution order on FBD networks!")
     setattr(cls, "compileexecutionOrder", compileexecutionOrder)
     
     def compileelementExecutionOrder(self, link):
-        if self.content["name"] == "FBD":
+        if self.content.getLocalTag() == "FBD":
             localid = link.getrefLocalId()
             instance = self.getcontentInstance(localid)
-            if isinstance(instance, PLCOpenClasses.get("fbdObjects_block", None)) and instance.getexecutionOrderId() == 0:
+            if isinstance(instance, PLCOpenParser.GetElementClass("block", "fbdObjects")) and instance.getexecutionOrderId() == 0:
                 for variable in instance.inputVariables.getvariable():
                     connections = variable.connectionPointIn.getconnections()
                     if connections and len(connections) == 1:
                         self.compileelementExecutionOrder(connections[0])
                 instance.setexecutionOrderId(self.getnewExecutionOrderId())
-            elif isinstance(instance, PLCOpenClasses.get("commonObjects_continuation", None)) and instance.getexecutionOrderId() == 0:
+            elif isinstance(instance, PLCOpenParser.GetElementClass("continuation", "commonObjects")) and instance.getexecutionOrderId() == 0:
                 name = instance.getname()
                 for tmp_instance in self.getcontentInstances():
-                    if isinstance(tmp_instance, PLCOpenClasses.get("commonObjects_connector", None)) and tmp_instance.getname() == name and tmp_instance.getexecutionOrderId() == 0:
+                    if isinstance(tmp_instance, PLCOpenParser.GetElementClass("connector", "commonObjects")) and tmp_instance.getname() == name and tmp_instance.getexecutionOrderId() == 0:
                         connections = tmp_instance.connectionPointIn.getconnections()
                         if connections and len(connections) == 1:
                             self.compileelementExecutionOrder(connections[0])
@@ -1812,124 +1578,125 @@
     setattr(cls, "compileelementExecutionOrder", compileelementExecutionOrder)
     
     def setelementExecutionOrder(self, instance, new_executionOrder):
-        if self.content["name"] == "FBD":
+        if self.content.getLocalTag() == "FBD":
             old_executionOrder = instance.getexecutionOrderId()
             if old_executionOrder is not None and old_executionOrder != 0 and new_executionOrder != 0:
-                for element in self.content["value"].getcontent():
-                    if element["value"] != instance and not isinstance(element["value"], PLCOpenClasses.get("commonObjects_comment", None)):
-                        element_executionOrder = element["value"].getexecutionOrderId()
+                for element in self.content.getcontent():
+                    if element != instance and not isinstance(element, PLCOpenParser.GetElementClass("comment", "commonObjects")):
+                        element_executionOrder = element.getexecutionOrderId()
                         if old_executionOrder <= element_executionOrder <= new_executionOrder:
-                            element["value"].setexecutionOrderId(element_executionOrder - 1)
+                            element.setexecutionOrderId(element_executionOrder - 1)
                         if new_executionOrder <= element_executionOrder <= old_executionOrder:
-                            element["value"].setexecutionOrderId(element_executionOrder + 1)
+                            element.setexecutionOrderId(element_executionOrder + 1)
             instance.setexecutionOrderId(new_executionOrder)
         else:
             raise TypeError, _("Can only generate execution order on FBD networks!")
     setattr(cls, "setelementExecutionOrder", setelementExecutionOrder)
     
-    def appendcontentInstance(self, name, instance):
-        if self.content["name"] in ["LD","FBD","SFC"]:
-            element = {"name" : name, "value" : instance}
-            self.content["value"].appendcontent(element)
-            self.instances_dict[instance.getlocalId()] = element
+    def appendcontentInstance(self, instance):
+        if self.content.getLocalTag() in ["LD","FBD","SFC"]:
+            self.content.appendcontent(instance)
         else:
-            raise TypeError, _("%s body don't have instances!")%self.content["name"]
+            raise TypeError, _("%s body don't have instances!")%self.content.getLocalTag()
     setattr(cls, "appendcontentInstance", appendcontentInstance)
     
     def getcontentInstances(self):
-        if self.content["name"] in ["LD","FBD","SFC"]:
-            instances = []
-            for element in self.content["value"].getcontent():
-                instances.append(element["value"])
-            return instances
+        if self.content.getLocalTag() in ["LD","FBD","SFC"]:
+            return self.content.getcontent()
         else:
-            raise TypeError, _("%s body don't have instances!")%self.content["name"]
+            raise TypeError, _("%s body don't have instances!")%self.content.getLocalTag()
     setattr(cls, "getcontentInstances", getcontentInstances)
-
-    def getcontentInstance(self, id):
-        if self.content["name"] in ["LD","FBD","SFC"]:
-            instance = self.instances_dict.get(id, None)
-            if instance is not None:
-                return instance["value"]
+    
+    instance_by_id_xpath = PLCOpen_XPath("*[@localId=$localId]")
+    instance_by_name_xpath = PLCOpen_XPath("ppx:block[@instanceName=$name]")
+    def getcontentInstance(self, local_id):
+        if self.content.getLocalTag() in ["LD","FBD","SFC"]:
+            instance = instance_by_id_xpath(self.content, localId=local_id)
+            if len(instance) > 0:
+                return instance[0]
             return None
         else:
-            raise TypeError, _("%s body don't have instances!")%self.content["name"]
+            raise TypeError, _("%s body don't have instances!")%self.content.getLocalTag()
     setattr(cls, "getcontentInstance", getcontentInstance)
     
     def getcontentRandomInstance(self, exclude):
-        if self.content["name"] in ["LD","FBD","SFC"]:
-            ids = self.instances_dict.viewkeys() - exclude
-            if len(ids) > 0:
-                return self.instances_dict[ids.pop()]["value"]
+        if self.content.getLocalTag() in ["LD","FBD","SFC"]:
+            instance = self.content.xpath("*%s[position()=1]" %  
+                ("[not(%s)]" % " or ".join(
+                    map(lambda x: "@localId=%d" % x, exclude))
+                if len(exclude) > 0 else ""))
+            if len(instance) > 0:
+                return instance[0]
             return None
         else:
-            raise TypeError, _("%s body don't have instances!")%self.content["name"]
+            raise TypeError, _("%s body don't have instances!")%self.content.getLocalTag()
     setattr(cls, "getcontentRandomInstance", getcontentRandomInstance)
     
     def getcontentInstanceByName(self, name):
-        if self.content["name"] in ["LD","FBD","SFC"]:
-            for element in self.content["value"].getcontent():
-                if isinstance(element["value"], PLCOpenClasses.get("fbdObjects_block", None)) and element["value"].getinstanceName() == name:
-                    return element["value"]
+        if self.content.getLocalTag() in ["LD","FBD","SFC"]:
+            instance = instance_by_name_xpath(self.content)
+            if len(instance) > 0:
+                return instance[0]
+            return None
         else:
-            raise TypeError, _("%s body don't have instances!")%self.content["name"]
+            raise TypeError, _("%s body don't have instances!")%self.content.getLocalTag()
     setattr(cls, "getcontentInstanceByName", getcontentInstanceByName)
     
-    def removecontentInstance(self, id):
-        if self.content["name"] in ["LD","FBD","SFC"]:
-            element = self.instances_dict.pop(id, None)
-            if element is not None:
-                self.content["value"].getcontent().remove(element)
+    def removecontentInstance(self, local_id):
+        if self.content.getLocalTag() in ["LD","FBD","SFC"]:
+            instance = instance_by_id_xpath(self.content)
+            if len(instance) > 0:
+                self.content.remove(instance[0])
             else:
                 raise ValueError, _("Instance with id %d doesn't exist!")%id
         else:
-            raise TypeError, "%s body don't have instances!"%self.content["name"]
+            raise TypeError, "%s body don't have instances!"%self.content.getLocalTag()
     setattr(cls, "removecontentInstance", removecontentInstance)
     
     def settext(self, text):
-        if self.content["name"] in ["IL","ST"]:
-            self.content["value"].settext(text)
+        if self.content.getLocalTag() in ["IL","ST"]:
+            self.content.setanyText(text)
         else:
-            raise TypeError, _("%s body don't have text!")%self.content["name"]
+            raise TypeError, _("%s body don't have text!")%self.content.getLocalTag()
     setattr(cls, "settext", settext)
 
     def gettext(self):
-        if self.content["name"] in ["IL","ST"]:
-            return self.content["value"].gettext()
+        if self.content.getLocalTag() in ["IL","ST"]:
+            return self.content.getanyText()
         else:
-            raise TypeError, _("%s body don't have text!")%self.content["name"]
+            raise TypeError, _("%s body don't have text!")%self.content.getLocalTag()
     setattr(cls, "gettext", gettext)
     
     def hasblock(self, block_type):
-        if self.content["name"] in ["IL","ST"]:
-            return self.content["value"].hasblock(block_type)
+        if self.content.getLocalTag() in ["IL","ST"]:
+            return self.content.hasblock(block_type)
         else:
-            raise TypeError, _("%s body don't have text!")%self.content["name"]
+            raise TypeError, _("%s body don't have text!")%self.content.getLocalTag()
     setattr(cls, "hasblock", hasblock)
     
     def updateElementName(self, old_name, new_name):
-        if self.content["name"] in ["IL", "ST"]:
-            self.content["value"].updateElementName(old_name, new_name)
+        if self.content.getLocalTag() in ["IL", "ST"]:
+            self.content.updateElementName(old_name, new_name)
         else:
-            for element in self.content["value"].getcontent():
-                element["value"].updateElementName(old_name, new_name)
+            for element in self.content.getcontent():
+                element.updateElementName(old_name, new_name)
     setattr(cls, "updateElementName", updateElementName)
 
     def updateElementAddress(self, address_model, new_leading):
-        if self.content["name"] in ["IL", "ST"]:
-            self.content["value"].updateElementAddress(address_model, new_leading)
+        if self.content.getLocalTag() in ["IL", "ST"]:
+            self.content.updateElementAddress(address_model, new_leading)
         else:
-            for element in self.content["value"].getcontent():
-                element["value"].updateElementAddress(address_model, new_leading)
+            for element in self.content.getcontent():
+                element.updateElementAddress(address_model, new_leading)
     setattr(cls, "updateElementAddress", updateElementAddress)
 
     def Search(self, criteria, parent_infos=[]):
-        if self.content["name"] in ["IL", "ST"]:
-            search_result = self.content["value"].Search(criteria, parent_infos + ["body", 0])
+        if self.content.getLocalTag() in ["IL", "ST"]:
+            search_result = self.content.Search(criteria, parent_infos + ["body", 0])
         else:
             search_result = []
-            for element in self.content["value"].getcontent():
-                search_result.extend(element["value"].Search(criteria, parent_infos))
+            for element in self.content.getcontent():
+                search_result.extend(element.Search(criteria, parent_infos))
         return search_result
     setattr(cls, "Search", Search)
 
@@ -1972,15 +1739,11 @@
 def _filterConnections(connectionPointIn, localId, connections):
     in_connections = connectionPointIn.getconnections()
     if in_connections is not None:
-        to_delete = []
-        for i, connection in enumerate(in_connections):
+        for connection in in_connections:
             connected = connection.getrefLocalId()
             if not connections.has_key((localId, connected)) and \
                not connections.has_key((connected, localId)):
-                to_delete.append(i)
-        to_delete.reverse()
-        for i in to_delete:
-            connectionPointIn.removeconnection(i)
+                connectionPointIn.remove(connection)
 
 def _filterConnectionsSingle(self, connections):
     if self.connectionPointIn is not None:
@@ -1991,8 +1754,8 @@
         _filterConnections(connectionPointIn, self.localId, connections)
 
 def _getconnectionsdefinition(instance, connections_end):
-    id = instance.getlocalId()
-    return dict([((id, end), True) for end in connections_end])
+    local_id = instance.getlocalId()
+    return dict([((local_id, end), True) for end in connections_end])
 
 def _updateConnectionsId(connectionPointIn, translation):
     connections_end = []
@@ -2063,9 +1826,8 @@
                "multiple": _updateConnectionsIdMultiple},
 }
 
-def _initElementClass(name, classname, connectionPointInType="none"):
-    ElementNameToClass[name] = classname
-    cls = PLCOpenClasses.get(classname, None)
+def _initElementClass(name, parent, connectionPointInType="none"):
+    cls = PLCOpenParser.GetElementClass(name, parent)
     if cls:
         setattr(cls, "getx", getx)
         setattr(cls, "gety", gety)
@@ -2133,7 +1895,7 @@
         infos = _getelementinfos(self)
         infos["type"] = type
         specific_values = infos["specific_values"]
-        specific_values["name"] = self.getexpression()
+        specific_values["name"] = self.getexpression().text
         _getexecutionOrder(self, specific_values)
         if input and output:
             infos["inputs"].append(_getconnectioninfos(self, self.connectionPointIn, True, "input"))
@@ -2146,7 +1908,7 @@
     return getvariableinfos
 
 def _getconnectorinfosFunction(type):
-    def getvariableinfos(self):
+    def getconnectorinfos(self):
         infos = _getelementinfos(self)
         infos["type"] = type
         infos["specific_values"]["name"] = self.getname()
@@ -2155,7 +1917,7 @@
         elif type == "continuation":
             infos["outputs"].append(_getconnectioninfos(self, self.connectionPointOut))
         return infos
-    return getvariableinfos
+    return getconnectorinfos
 
 def _getpowerrailinfosFunction(type):
     def getpowerrailinfos(self):
@@ -2172,16 +1934,16 @@
         return infos
     return getpowerrailinfos
 
-def _getldelementinfosFunction(type):
+def _getldelementinfosFunction(ld_element_type):
     def getldelementinfos(self):
         infos = _getelementinfos(self)
-        infos["type"] = type
+        infos["type"] = ld_element_type
         specific_values = infos["specific_values"]
-        specific_values["name"] = self.getvariable()
+        specific_values["name"] = self.getvariable().text
         _getexecutionOrder(self, specific_values)
         specific_values["negated"] = self.getnegated()
         specific_values["edge"] = self.getedge()
-        if type == "coil":
+        if ld_element_type == "coil":
             specific_values["storage"] = self.getstorage()
         infos["inputs"].append(_getconnectioninfos(self, self.connectionPointIn, True))
         infos["outputs"].append(_getconnectioninfos(self, self.connectionPointOut))
@@ -2210,7 +1972,7 @@
         return infos
     return getdivergenceinfos
 
-cls = _initElementClass("comment", "commonObjects_comment")
+cls = _initElementClass("comment", "commonObjects")
 if cls:
     def getinfos(self):
         infos = _getelementinfos(self)
@@ -2220,11 +1982,11 @@
     setattr(cls, "getinfos", getinfos)
     
     def setcontentText(self, text):
-        self.content.settext(text)
+        self.content.setanyText(text)
     setattr(cls, "setcontentText", setcontentText)
         
     def getcontentText(self):
-        return self.content.gettext()
+        return self.content.getanyText()
     setattr(cls, "getcontentText", getcontentText)
     
     def updateElementName(self, old_name, new_name):
@@ -2239,7 +2001,7 @@
         return self.content.Search(criteria, parent_infos + ["comment", self.getlocalId(), "content"])
     setattr(cls, "Search", Search)
 
-cls = _initElementClass("block", "fbdObjects_block")
+cls = _initElementClass("block", "fbdObjects")
 if cls:
     def getBoundingBox(self):
         bbox = _getBoundingBox(self)
@@ -2298,49 +2060,41 @@
         return search_result
     setattr(cls, "Search", Search)
 
-cls = _initElementClass("leftPowerRail", "ldObjects_leftPowerRail")
+cls = _initElementClass("leftPowerRail", "ldObjects")
 if cls:
     setattr(cls, "getinfos", _getpowerrailinfosFunction("leftPowerRail"))
 
-cls = _initElementClass("rightPowerRail", "ldObjects_rightPowerRail", "multiple")
+cls = _initElementClass("rightPowerRail", "ldObjects", "multiple")
 if cls:
     setattr(cls, "getinfos", _getpowerrailinfosFunction("rightPowerRail"))
 
-cls = _initElementClass("contact", "ldObjects_contact", "single")
+def _UpdateLDElementName(self, old_name, new_name):
+    if self.variable.text == old_name:
+        self.variable.text = new_name
+
+def _UpdateLDElementAddress(self, address_model, new_leading):
+    self.variable.text = update_address(self.variable.text, address_model, new_leading)
+
+def _getSearchInLDElement(ld_element_type):
+    def SearchInLDElement(self, criteria, parent_infos=[]):
+        return _Search([("reference", self.variable.text)], criteria, parent_infos + [ld_element_type, self.getlocalId()])
+    return SearchInLDElement
+
+cls = _initElementClass("contact", "ldObjects", "single")
 if cls:
     setattr(cls, "getinfos", _getldelementinfosFunction("contact"))
-    
-    def updateElementName(self, old_name, new_name):
-        if self.variable == old_name:
-            self.variable = new_name
-    setattr(cls, "updateElementName", updateElementName)
-    
-    def updateElementAddress(self, address_model, new_leading):
-        self.variable = update_address(self.variable, address_model, new_leading)
-    setattr(cls, "updateElementAddress", updateElementAddress)
-    
-    def Search(self, criteria, parent_infos=[]):
-        return _Search([("reference", self.getvariable())], criteria, parent_infos + ["contact", self.getlocalId()])
-    setattr(cls, "Search", Search)
-
-cls = _initElementClass("coil", "ldObjects_coil", "single")
+    setattr(cls, "updateElementName", _UpdateLDElementName)
+    setattr(cls, "updateElementAddress", _UpdateLDElementAddress)
+    setattr(cls, "Search", _getSearchInLDElement("contact"))
+
+cls = _initElementClass("coil", "ldObjects", "single")
 if cls:
     setattr(cls, "getinfos", _getldelementinfosFunction("coil"))
-    
-    def updateElementName(self, old_name, new_name):
-        if self.variable == old_name:
-            self.variable = new_name
-    setattr(cls, "updateElementName", updateElementName)
-
-    def updateElementAddress(self, address_model, new_leading):
-        self.variable = update_address(self.variable, address_model, new_leading)
-    setattr(cls, "updateElementAddress", updateElementAddress)
-
-    def Search(self, criteria, parent_infos=[]):
-        return _Search([("reference", self.getvariable())], criteria, parent_infos + ["coil", self.getlocalId()])
-    setattr(cls, "Search", Search)
-
-cls = _initElementClass("step", "sfcObjects_step", "single")
+    setattr(cls, "updateElementName", _UpdateLDElementName)
+    setattr(cls, "updateElementAddress", _UpdateLDElementAddress)
+    setattr(cls, "Search", _getSearchInLDElement("coil"))
+
+cls = _initElementClass("step", "sfcObjects", "single")
 if cls:
     def getinfos(self):
         infos = _getelementinfos(self)
@@ -2348,11 +2102,11 @@
         specific_values = infos["specific_values"]
         specific_values["name"] = self.getname()
         specific_values["initial"] = self.getinitialStep()
-        if self.connectionPointIn:
+        if self.connectionPointIn is not None:
             infos["inputs"].append(_getconnectioninfos(self, self.connectionPointIn, True))
-        if self.connectionPointOut:
+        if self.connectionPointOut is not None:
             infos["outputs"].append(_getconnectioninfos(self, self.connectionPointOut))
-        if self.connectionPointOutAction:
+        if self.connectionPointOutAction is not None:
             specific_values["action"] = _getconnectioninfos(self, self.connectionPointOutAction)
         return infos
     setattr(cls, "getinfos", getinfos)
@@ -2361,7 +2115,7 @@
         return _Search([("name", self.getname())], criteria, parent_infos + ["step", self.getlocalId()])
     setattr(cls, "Search", Search)
 
-cls = PLCOpenClasses.get("transition_condition", None)
+cls = PLCOpenParser.GetElementClass("condition", "transition")
 if cls:
     def compatibility(self, tree):
         connections = []
@@ -2378,7 +2132,7 @@
             tree.childNodes = [node]
     setattr(cls, "compatibility", compatibility)
 
-cls = _initElementClass("transition", "sfcObjects_transition")
+cls = _initElementClass("transition", "sfcObjects")
 if cls:
     def getinfos(self):
         infos = _getelementinfos(self)
@@ -2399,49 +2153,48 @@
         return infos
     setattr(cls, "getinfos", getinfos)
 
-    def setconditionContent(self, type, value):
-        if not self.condition:
+    def setconditionContent(self, condition_type, value):
+        if self.condition is None:
             self.addcondition()
-        if type == "reference":
-            condition = PLCOpenClasses["condition_reference"]()
+        if condition_type == "connection":
+            condition = PLCOpenParser.CreateElement("connectionPointIn", "condition")
+        else:
+            condition = PLCOpenParser.CreateElement(condition_type, "condition")
+        self.condition.setcontent(condition)
+        if condition_type == "reference":
             condition.setname(value)
-        elif type == "inline":
-            condition = PLCOpenClasses["condition_inline"]()
-            condition.setcontent({"name" : "ST", "value" : PLCOpenClasses["formattedText"]()})
+        elif condition_type == "inline":
+            condition.setcontent(PLCOpenParser.CreateElement("ST", "inline"))
             condition.settext(value)
-        elif type == "connection":
-            type = "connectionPointIn"
-            condition = PLCOpenClasses["connectionPointIn"]()
-        self.condition.setcontent({"name" : type, "value" : condition})
     setattr(cls, "setconditionContent", setconditionContent)
         
     def getconditionContent(self):
-        if self.condition:
+        if self.condition is not None:
             content = self.condition.getcontent()
-            values = {"type" : content["name"]}
+            values = {"type" : content.getLocalTag()}
             if values["type"] == "reference":
-                values["value"] = content["value"].getname()
+                values["value"] = content.getname()
             elif values["type"] == "inline":
-                values["value"] = content["value"].gettext()
+                values["value"] = content.gettext()
             elif values["type"] == "connectionPointIn":
                 values["type"] = "connection"
-                values["value"] = content["value"]
+                values["value"] = content
             return values
         return ""
     setattr(cls, "getconditionContent", getconditionContent)
 
     def getconditionConnection(self):
-        if self.condition:
+        if self.condition is not None:
             content = self.condition.getcontent()
-            if content["name"] == "connectionPointIn":
-                return content["value"]
+            if content.getLocalTag() == "connectionPointIn":
+                return content
         return None
     setattr(cls, "getconditionConnection", getconditionConnection)
 
     def getBoundingBox(self):
         bbox = _getBoundingBoxSingle(self)
         condition_connection = self.getconditionConnection()
-        if condition_connection:
+        if condition_connection is not None:
             bbox.union(_getConnectionsBoundingBox(condition_connection))
         return bbox
     setattr(cls, "getBoundingBox", getBoundingBox)
@@ -2449,14 +2202,14 @@
     def translate(self, dx, dy):
         _translateSingle(self, dx, dy)
         condition_connection = self.getconditionConnection()
-        if condition_connection:
+        if condition_connection is not None:
             _translateConnections(condition_connection, dx, dy)
     setattr(cls, "translate", translate)
     
     def filterConnections(self, connections):
         _filterConnectionsSingle(self, connections)
         condition_connection = self.getconditionConnection()
-        if condition_connection:
+        if condition_connection is not None:
             _filterConnections(condition_connection, self.localId, connections)
     setattr(cls, "filterConnections", filterConnections)
     
@@ -2465,33 +2218,35 @@
         if self.connectionPointIn is not None:
             connections_end = _updateConnectionsId(self.connectionPointIn, translation)
         condition_connection = self.getconditionConnection()
-        if condition_connection:
+        if condition_connection is not None:
             connections_end.extend(_updateConnectionsId(condition_connection, translation))
         return _getconnectionsdefinition(self, connections_end)
     setattr(cls, "updateConnectionsId", updateConnectionsId)
 
     def updateElementName(self, old_name, new_name):
-        if self.condition:
+        if self.condition is not None:
             content = self.condition.getcontent()
-            if content["name"] == "reference":
-                if content["value"].getname() == old_name:
-                    content["value"].setname(new_name)
-            elif content["name"] == "inline":
-                content["value"].updateElementName(old_name, new_name)
+            content_name = content.getLocalTag()
+            if content_name == "reference":
+                if content.getname() == old_name:
+                    content.setname(new_name)
+            elif content_name == "inline":
+                content.updateElementName(old_name, new_name)
     setattr(cls, "updateElementName", updateElementName)
 
     def updateElementAddress(self, address_model, new_leading):
-        if self.condition:
+        if self.condition is not None:
             content = self.condition.getcontent()
-            if content["name"] == "reference":
-                content["value"].setname(update_address(content["value"].getname(), address_model, new_leading))
-            elif content["name"] == "inline":
-                content["value"].updateElementAddress(address_model, new_leading)
+            content_name = content.getLocalTag()
+            if content_name == "reference":
+                content.setname(update_address(content.getname(), address_model, new_leading))
+            elif content_name == "inline":
+                content.updateElementAddress(address_model, new_leading)
     setattr(cls, "updateElementAddress", updateElementAddress)
 
     def getconnections(self):
         condition_connection = self.getconditionConnection()
-        if condition_connection:
+        if condition_connection is not None:
             return condition_connection.getconnections()
         return None
     setattr(cls, "getconnections", getconnections)
@@ -2500,30 +2255,31 @@
         parent_infos = parent_infos + ["transition", self.getlocalId()]
         search_result = []
         content = self.condition.getcontent()
-        if content["name"] == "reference":
-            search_result.extend(_Search([("reference", content["value"].getname())], criteria, parent_infos))
-        elif content["name"] == "inline":
-            search_result.extend(content["value"].Search(criteria, parent_infos + ["inline"]))
+        content_name = content.getLocalTag()
+        if content_name == "reference":
+            search_result.extend(_Search([("reference", content.getname())], criteria, parent_infos))
+        elif content_name == "inline":
+            search_result.extend(content.Search(criteria, parent_infos + ["inline"]))
         return search_result
     setattr(cls, "Search", Search)
     
-cls = _initElementClass("selectionDivergence", "sfcObjects_selectionDivergence", "single")
+cls = _initElementClass("selectionDivergence", "sfcObjects", "single")
 if cls:
     setattr(cls, "getinfos", _getdivergenceinfosFunction(True, False))
 
-cls = _initElementClass("selectionConvergence", "sfcObjects_selectionConvergence", "multiple")
+cls = _initElementClass("selectionConvergence", "sfcObjects", "multiple")
 if cls:
     setattr(cls, "getinfos", _getdivergenceinfosFunction(False, False))
 
-cls = _initElementClass("simultaneousDivergence", "sfcObjects_simultaneousDivergence", "single")
+cls = _initElementClass("simultaneousDivergence", "sfcObjects", "single")
 if cls:
     setattr(cls, "getinfos", _getdivergenceinfosFunction(True, True))
 
-cls = _initElementClass("simultaneousConvergence", "sfcObjects_simultaneousConvergence", "multiple")
+cls = _initElementClass("simultaneousConvergence", "sfcObjects", "multiple")
 if cls:
     setattr(cls, "getinfos", _getdivergenceinfosFunction(False, True))
 
-cls = _initElementClass("jumpStep", "sfcObjects_jumpStep", "single")
+cls = _initElementClass("jumpStep", "sfcObjects", "single")
 if cls:
     def getinfos(self):
         infos = _getelementinfos(self)
@@ -2537,7 +2293,7 @@
         return _Search([("target", self.gettargetName())], criteria, parent_infos + ["jump", self.getlocalId()])
     setattr(cls, "Search", Search)
 
-cls = PLCOpenClasses.get("actionBlock_action", None)
+cls = PLCOpenParser.GetElementClass("action", "actionBlock")
 if cls:
     def compatibility(self, tree):
         relPosition = reduce(lambda x, y: x | (y.nodeName == "relPosition"), tree.childNodes, False)
@@ -2551,39 +2307,39 @@
     setattr(cls, "compatibility", compatibility)
     
     def setreferenceName(self, name):
-        if self.reference:
+        if self.reference is not None:
             self.reference.setname(name)
     setattr(cls, "setreferenceName", setreferenceName)
     
     def getreferenceName(self):
-        if self.reference:
+        if self.reference is not None:
             return self.reference.getname()
         return None
     setattr(cls, "getreferenceName", getreferenceName)
 
     def setinlineContent(self, content):
-        if self.inline:
-            self.inline.setcontent({"name" : "ST", "value" : PLCOpenClasses["formattedText"]()})
+        if self.inline is not None:
+            self.inline.setcontent(PLCOpenParser.CreateElement("ST", "inline"))
             self.inline.settext(content)
     setattr(cls, "setinlineContent", setinlineContent)
     
     def getinlineContent(self):
-        if self.inline:
+        if self.inline is not None:
             return self.inline.gettext()
         return None
     setattr(cls, "getinlineContent", getinlineContent)
 
     def updateElementName(self, old_name, new_name):
-        if self.reference and self.reference.getname() == old_name:
+        if self.reference is not None and self.reference.getname() == old_name:
             self.reference.setname(new_name)
-        if self.inline:
+        if self.inline is not None:
             self.inline.updateElementName(old_name, new_name)
     setattr(cls, "updateElementName", updateElementName)
 
     def updateElementAddress(self, address_model, new_leading):
-        if self.reference:
+        if self.reference is not None:
             self.reference.setname(update_address(self.reference.getname(), address_model, new_leading))
-        if self.inline:
+        if self.inline is not None:
             self.inline.updateElementAddress(address_model, new_leading)
     setattr(cls, "updateElementAddress", updateElementAddress)
 
@@ -2599,7 +2355,7 @@
                        criteria, parent_infos)
     setattr(cls, "Search", Search)
 
-cls = _initElementClass("actionBlock", "commonObjects_actionBlock", "single")
+cls = _initElementClass("actionBlock", "commonObjects", "single")
 if cls:
     def compatibility(self, tree):
         for child in tree.childNodes[:]:
@@ -2618,7 +2374,8 @@
     def setactions(self, actions):
         self.action = []
         for params in actions:
-            action = PLCOpenClasses["actionBlock_action"]()
+            action = PLCOpenParser.CreateElement("action", "actionBlock")
+            self.appendaction(action)
             action.setqualifier(params["qualifier"])
             if params["type"] == "reference":
                 action.addreference()
@@ -2630,7 +2387,6 @@
                 action.setduration(params["duration"])
             if params.has_key("indicator"):
                 action.setindicator(params["indicator"])
-            self.action.append(action)
     setattr(cls, "setactions", setactions)
 
     def getactions(self):
@@ -2640,17 +2396,17 @@
             params["qualifier"] = action.getqualifier()
             if params["qualifier"] is None:
                 params["qualifier"] = "N"
-            if action.getreference():
+            if action.getreference() is not None:
                 params["type"] = "reference"
                 params["value"] = action.getreferenceName()
-            elif action.getinline():
+            elif action.getinline() is not None:
                 params["type"] = "inline"
                 params["value"] = action.getinlineContent()
             duration = action.getduration()
             if duration:
                 params["duration"] = duration
             indicator = action.getindicator()
-            if indicator:
+            if indicator is not None:
                 params["indicator"] = indicator
             actions.append(params)
         return actions
@@ -2675,58 +2431,41 @@
     setattr(cls, "Search", Search)
 
 def _SearchInIOVariable(self, criteria, parent_infos=[]):
-    return _Search([("expression", self.getexpression())], criteria, parent_infos + ["io_variable", self.getlocalId()])
-
-cls = _initElementClass("inVariable", "fbdObjects_inVariable")
+    return _Search([("expression", self.expression.text)], criteria, parent_infos + ["io_variable", self.getlocalId()])
+
+def _UpdateIOElementName(self, old_name, new_name):
+    if self.expression.text == old_name:
+        self.expression.text = new_name
+
+def _UpdateIOElementAddress(self, old_name, new_name):
+    self.expression.text = update_address(self.expression.text, address_model, new_leading)
+
+cls = _initElementClass("inVariable", "fbdObjects")
 if cls:
     setattr(cls, "getinfos", _getvariableinfosFunction("input", False, True))
-    
-    def updateElementName(self, old_name, new_name):
-        if self.expression == old_name:
-            self.expression = new_name
-    setattr(cls, "updateElementName", updateElementName)
-
-    def updateElementAddress(self, address_model, new_leading):
-        self.expression = update_address(self.expression, address_model, new_leading)
-    setattr(cls, "updateElementAddress", updateElementAddress)
-
+    setattr(cls, "updateElementName", _UpdateIOElementName)
+    setattr(cls, "updateElementAddress", _UpdateIOElementAddress)
     setattr(cls, "Search", _SearchInIOVariable)
 
-cls = _initElementClass("outVariable", "fbdObjects_outVariable", "single")
+cls = _initElementClass("outVariable", "fbdObjects", "single")
 if cls:
     setattr(cls, "getinfos", _getvariableinfosFunction("output", True, False))
-    
-    def updateElementName(self, old_name, new_name):
-        if self.expression == old_name:
-            self.expression = new_name
-    setattr(cls, "updateElementName", updateElementName)
-
-    def updateElementAddress(self, address_model, new_leading):
-        self.expression = update_address(self.expression, address_model, new_leading)
-    setattr(cls, "updateElementAddress", updateElementAddress)
-
+    setattr(cls, "updateElementName", _UpdateIOElementName)
+    setattr(cls, "updateElementAddress", _UpdateIOElementAddress)
     setattr(cls, "Search", _SearchInIOVariable)
 
-cls = _initElementClass("inOutVariable", "fbdObjects_inOutVariable", "single")
+cls = _initElementClass("inOutVariable", "fbdObjects", "single")
 if cls:
     setattr(cls, "getinfos", _getvariableinfosFunction("inout", True, True))
-    
-    def updateElementName(self, old_name, new_name):
-        if self.expression == old_name:
-            self.expression = new_name
-    setattr(cls, "updateElementName", updateElementName)
-
-    def updateElementAddress(self, address_model, new_leading):
-        self.expression = update_address(self.expression, address_model, new_leading)
-    setattr(cls, "updateElementAddress", updateElementAddress)
-
+    setattr(cls, "updateElementName", _UpdateIOElementName)
+    setattr(cls, "updateElementAddress", _UpdateIOElementAddress)
     setattr(cls, "Search", _SearchInIOVariable)
 
 
 def _SearchInConnector(self, criteria, parent_infos=[]):
     return _Search([("name", self.getname())], criteria, parent_infos + ["connector", self.getlocalId()])
 
-cls = _initElementClass("continuation", "commonObjects_continuation")
+cls = _initElementClass("continuation", "commonObjects")
 if cls:
     setattr(cls, "getinfos", _getconnectorinfosFunction("continuation"))
     setattr(cls, "Search", _SearchInConnector)
@@ -2736,7 +2475,7 @@
             self.name = new_name
     setattr(cls, "updateElementName", updateElementName)
 
-cls = _initElementClass("connector", "commonObjects_connector", "single")
+cls = _initElementClass("connector", "commonObjects", "single")
 if cls:
     setattr(cls, "getinfos", _getconnectorinfosFunction("connector"))
     setattr(cls, "Search", _SearchInConnector)
@@ -2746,15 +2485,16 @@
             self.name = new_name
     setattr(cls, "updateElementName", updateElementName)
 
-cls = PLCOpenClasses.get("connection", None)
+cls = PLCOpenParser.GetElementClass("connection")
 if cls:
     def setpoints(self, points):
-        self.position = []
+        positions = []
         for point in points:
-            position = PLCOpenClasses["position"]()
+            position = PLCOpenParser.CreateElement("position", "connection")
             position.setx(point.x)
             position.sety(point.y)
-            self.position.append(position)
+            positions.append(position)
+        self.position = positions
     setattr(cls, "setpoints", setpoints)
 
     def getpoints(self):
@@ -2764,111 +2504,115 @@
         return points
     setattr(cls, "getpoints", getpoints)
 
-cls = PLCOpenClasses.get("connectionPointIn", None)
+cls = PLCOpenParser.GetElementClass("connectionPointIn")
 if cls:
     def setrelPositionXY(self, x, y):
-        self.relPosition = PLCOpenClasses["position"]()
+        self.relPosition = PLCOpenParser.CreateElement("relPosition", "connectionPointIn")
         self.relPosition.setx(x)
         self.relPosition.sety(y)
     setattr(cls, "setrelPositionXY", setrelPositionXY)
 
     def getrelPositionXY(self):
-        if self.relPosition:
+        if self.relPosition is not None:
             return self.relPosition.getx(), self.relPosition.gety()
-        else:
-            return self.relPosition
+        return self.relPosition
     setattr(cls, "getrelPositionXY", getrelPositionXY)
 
     def addconnection(self):
-        if not self.content:
-            self.content = {"name" : "connection", "value" : [PLCOpenClasses["connection"]()]}
-        else:
-            self.content["value"].append(PLCOpenClasses["connection"]())
+        self.append(PLCOpenParser.CreateElement("connection", "connectionPointIn"))
     setattr(cls, "addconnection", addconnection)
 
     def removeconnection(self, idx):
-        if self.content:
-            self.content["value"].pop(idx)
-        if len(self.content["value"]) == 0:
-            self.content = None
+        if len(self.content) > idx:
+            self.remove(self.content[idx])
     setattr(cls, "removeconnection", removeconnection)
 
     def removeconnections(self):
-        if self.content:
-            self.content = None
+        self.content = None
     setattr(cls, "removeconnections", removeconnections)
     
+    connection_xpath = PLCOpen_XPath("ppx:connection")
+    connection_by_position_xpath = PLCOpen_XPath("ppx:connection[position()=$pos]")
     def getconnections(self):
-        if self.content:
-            return self.content["value"]
-        return []
+        return connection_xpath(self)
     setattr(cls, "getconnections", getconnections)
     
-    def setconnectionId(self, idx, id):
-        if self.content:
-            self.content["value"][idx].setrefLocalId(id)
+    def getconnection(self, idx):
+        connection = connection_by_position_xpath(self, pos=idx+1)
+        if len(connection) > 0:
+            return connection[0]
+        return None
+    setattr(cls, "getconnection", getconnection)
+    
+    def setconnectionId(self, idx, local_id):
+        connection = self.getconnection(idx)
+        if connection is not None:
+            connection.setrefLocalId(local_id)
     setattr(cls, "setconnectionId", setconnectionId)
     
     def getconnectionId(self, idx):
-        if self.content:
-            return self.content["value"][idx].getrefLocalId()
+        connection = self.getconnection(idx)
+        if connection is not None:
+            return connection.getrefLocalId()
         return None
     setattr(cls, "getconnectionId", getconnectionId)
     
     def setconnectionPoints(self, idx, points):
-        if self.content:
-            self.content["value"][idx].setpoints(points)
+        connection = self.getconnection(idx)
+        if connection is not None:
+            connection.setpoints(points)
     setattr(cls, "setconnectionPoints", setconnectionPoints)
 
     def getconnectionPoints(self, idx):
-        if self.content:
-            return self.content["value"][idx].getpoints()
+        connection = self.getconnection(idx)
+        if connection is not None:
+            return connection.getpoints()
         return []
     setattr(cls, "getconnectionPoints", getconnectionPoints)
 
     def setconnectionParameter(self, idx, parameter):
-        if self.content:
-            self.content["value"][idx].setformalParameter(parameter)
+        connection = self.getconnection(idx)
+        if connection is not None:
+            connection.setformalParameter(parameter)
     setattr(cls, "setconnectionParameter", setconnectionParameter)
     
     def getconnectionParameter(self, idx):
-        if self.content:
-            return self.content["value"][idx].getformalParameter()
+        connection = self.getconnection(idx)
+        if connection is not None:
+            return connection.getformalParameter()
         return None
     setattr(cls, "getconnectionParameter", getconnectionParameter)
 
-cls = PLCOpenClasses.get("connectionPointOut", None)
+cls = PLCOpenParser.GetElementClass("connectionPointOut")
 if cls:
     def setrelPositionXY(self, x, y):
-        self.relPosition = PLCOpenClasses["position"]()
+        self.relPosition = PLCOpenParser.CreateElement("relPosition", "connectionPointOut")
         self.relPosition.setx(x)
         self.relPosition.sety(y)
     setattr(cls, "setrelPositionXY", setrelPositionXY)
 
     def getrelPositionXY(self):
-        if self.relPosition:
+        if self.relPosition is not None:
             return self.relPosition.getx(), self.relPosition.gety()
         return self.relPosition
     setattr(cls, "getrelPositionXY", getrelPositionXY)
 
-cls = PLCOpenClasses.get("value", None)
+cls = PLCOpenParser.GetElementClass("value")
 if cls:
     def setvalue(self, value):
         value = value.strip()
         if value.startswith("[") and value.endswith("]"):
-            arrayValue = PLCOpenClasses["value_arrayValue"]()
-            self.content = {"name" : "arrayValue", "value" : arrayValue}
+            content = PLCOpenParser.CreateElement("arrayValue", "value")
         elif value.startswith("(") and value.endswith(")"):
-            structValue = PLCOpenClasses["value_structValue"]()
-            self.content = {"name" : "structValue", "value" : structValue}
+            content = PLCOpenParser.CreateElement("structValue", "value")
         else:
-            simpleValue = PLCOpenClasses["value_simpleValue"]()
-            self.content = {"name" : "simpleValue", "value": simpleValue}
-        self.content["value"].setvalue(value)
+            content = PLCOpenParser.CreateElement("simpleValue", "value")
+        content.setvalue(value)
+        self.setcontent(content)
     setattr(cls, "setvalue", setvalue)
     
     def getvalue(self):
-        return self.content["value"].getvalue()
+        return self.content.getvalue()
     setattr(cls, "getvalue", getvalue)
 
 def extractValues(values):
@@ -2885,15 +2629,15 @@
             raise ValueError, _("\"%s\" is an invalid value!")%value
     return items
 
-cls = PLCOpenClasses.get("value_arrayValue", None)
+cls = PLCOpenParser.GetElementClass("arrayValue", "value")
 if cls:
     arrayValue_model = re.compile("([0-9]*)\((.*)\)$")
     
     def setvalue(self, value):
-        self.value = []
+        elements = []
         for item in extractValues(value[1:-1]):
             item = item.strip()
-            element = PLCOpenClasses["arrayValue_value"]()
+            element = PLCOpenParser.CreateElement("value", "arrayValue")
             result = arrayValue_model.match(item)
             if result is not None:
                 groups = result.groups()
@@ -2901,14 +2645,18 @@
                 element.setvalue(groups[1].strip())
             else:
                 element.setvalue(item)
-            self.value.append(element)
+            elements.append(element)
+        self.value = elements
     setattr(cls, "setvalue", setvalue)
     
     def getvalue(self):
         values = []
         for element in self.value:
-            repetition = element.getrepetitionValue()
-            if repetition is not None and int(repetition) > 1:
+            try:
+                repetition = int(element.getrepetitionValue())
+            except:
+                repetition = 1
+            if repetition > 1:
                 value = element.getvalue()
                 if value is None:
                     value = ""
@@ -2918,20 +2666,21 @@
         return "[%s]"%", ".join(values)
     setattr(cls, "getvalue", getvalue)
 
-cls = PLCOpenClasses.get("value_structValue", None)
+cls = PLCOpenParser.GetElementClass("structValue", "value")
 if cls:
     structValue_model = re.compile("(.*):=(.*)")
     
     def setvalue(self, value):
-        self.value = []
+        elements = []
         for item in extractValues(value[1:-1]):
             result = structValue_model.match(item)
             if result is not None:
                 groups = result.groups()
-                element = PLCOpenClasses["structValue_value"]()
+                element = PLCOpenParser.CreateElement("value", "structValue")
                 element.setmember(groups[0].strip())
                 element.setvalue(groups[1].strip())
-                self.value.append(element)
+                elements.append(element)
+        self.value = elements
     setattr(cls, "setvalue", setvalue)
     
     def getvalue(self):
@@ -2940,3 +2689,4 @@
             values.append("%s := %s"%(element.getmember(), element.getvalue()))
         return "(%s)"%", ".join(values)
     setattr(cls, "getvalue", getvalue)
+
--- a/plcopen/structures.py	Wed Sep 04 00:06:44 2013 +0200
+++ b/plcopen/structures.py	Mon Sep 09 00:48:34 2013 +0200
@@ -42,7 +42,7 @@
         return mylist
 
 def generate_block(generator, block, block_infos, body, link, order=False, to_inout=False):
-    body_type = body.getcontent()["name"]
+    body_type = body.getcontent().getLocalTag()
     name = block.getinstanceName()
     type = block.gettypeName()
     executionOrderId = block.getexecutionOrderId()
@@ -158,7 +158,7 @@
             generator.Program += JoinList([(", ", ())], vars)
             generator.Program += [(");\n", ())]
     
-    if link:
+    if link is not None:
         connectionPoint = link.getposition()[-1]
         output_parameter = link.getformalParameter()
     else:
@@ -177,7 +177,7 @@
     else:
         for i, variable in enumerate(output_variables):
             blockPointx, blockPointy = variable.connectionPointOut.getrelPositionXY()
-            if (not connectionPoint or 
+            if (connectionPoint is None or 
                 block.getx() + blockPointx == connectionPoint.getx() and 
                 block.gety() + blockPointy == connectionPoint.gety()):
                 output_variable = variable
--- a/xmlclass/__init__.py	Wed Sep 04 00:06:44 2013 +0200
+++ b/xmlclass/__init__.py	Mon Sep 09 00:48:34 2013 +0200
@@ -24,5 +24,5 @@
 
 # Package initialisation
 
-from xmlclass import ClassFactory, GenerateClasses, GetAttributeValue, time_model, CreateNode, NodeSetAttr, NodeRenameAttr, UpdateXMLClassGlobals
-from xsdschema import XSDClassFactory, GenerateClassesFromXSD, GenerateClassesFromXSDstring
+from xmlclass import ClassFactory, GenerateParser, DefaultElementClass, GetAttributeValue, time_model, CreateNode, NodeSetAttr, NodeRenameAttr
+from xsdschema import XSDClassFactory, GenerateParserFromXSD, GenerateParserFromXSDstring
--- a/xmlclass/xmlclass.py	Wed Sep 04 00:06:44 2013 +0200
+++ b/xmlclass/xmlclass.py	Mon Sep 09 00:48:34 2013 +0200
@@ -28,7 +28,9 @@
 from types import *
 from xml.dom import minidom
 from xml.sax.saxutils import escape, unescape, quoteattr
+from lxml import etree
 from new import classobj
+from collections import OrderedDict
 
 def CreateNode(name):
     node = minidom.Node()
@@ -533,28 +535,33 @@
     return GetModelNameList
 
 def GenerateAnyInfos(infos):
+    
+    def GetTextElement(tree):
+        if infos["namespace"][0] == "##any":
+            return tree.xpath("p")[0]
+        return tree.xpath("ns:p", namespaces={"ns": infos["namespace"][0]})[0]
+    
     def ExtractAny(tree):
-        if tree.nodeName in ["#text", "#cdata-section"]:
-            return unicode(unescape(tree.data))
-        else:
-            return tree
-    
-    def GenerateAny(value, name=None, indent=0):
-        if isinstance(value, (StringType, UnicodeType)):
-            try:
-                value = value.decode("utf-8")
-            except:
-                pass
-            return u'<![CDATA[%s]]>\n' % value
-        else:
-            return value.toprettyxml(indent=" "*indent, encoding="utf-8")
+        return GetTextElement(tree).text
+    
+    def GenerateAny(tree, value):
+        GetTextElement(tree).text = etree.CDATA(value)
+        
+    def InitialAny():
+        if infos["namespace"][0] == "##any":
+            element_name = "p"
+        else:
+            element_name = "{%s}p" % infos["namespace"][0]
+        p = etree.Element(element_name)
+        p.text = etree.CDATA("")
+        return p
         
     return {
         "type": COMPLEXTYPE, 
         "extract": ExtractAny,
         "generate": GenerateAny,
-        "initial": lambda: "",
-        "check": lambda x: isinstance(x, (StringType, UnicodeType, minidom.Node))
+        "initial": InitialAny,
+        "check": lambda x: isinstance(x, (StringType, UnicodeType, etree.ElementBase))
     }
 
 def GenerateTagInfos(infos):
@@ -591,38 +598,23 @@
     
 def GetElementInitialValue(factory, infos):
     infos["elmt_type"] = FindTypeInfos(factory, infos["elmt_type"])
-    if infos["minOccurs"] == 0 and infos["maxOccurs"] == 1:
-        if infos.has_key("default"):
-            return infos["elmt_type"]["extract"](infos["default"], False)
-        else:
-            return None
-    elif infos["minOccurs"] == 1 and infos["maxOccurs"] == 1:
-        return infos["elmt_type"]["initial"]()
+    if infos["minOccurs"] == 1:
+        element_name = factory.etreeNamespaceFormat % infos["name"]
+        if infos["elmt_type"]["type"] == SIMPLETYPE:
+            def initial_value():
+                value = etree.Element(element_name)
+                value.text = (infos["elmt_type"]["generate"](infos["elmt_type"]["initial"]()))
+                return value
+        else:
+            def initial_value():
+                value = infos["elmt_type"]["initial"]()
+                if infos["type"] != ANY:
+                    DefaultElementClass.__setattr__(value, "tag", element_name)
+                    value.init()
+                return value
+        return [initial_value() for i in xrange(infos["minOccurs"])]
     else:
-        return [infos["elmt_type"]["initial"]() for i in xrange(infos["minOccurs"])]
-
-def HandleError(message, raise_exception):
-    if raise_exception:
-        raise ValueError(message)
-    return False
-
-def CheckElementValue(factory, name, infos, value, raise_exception=True):
-    infos["elmt_type"] = FindTypeInfos(factory, infos["elmt_type"])
-    if value is None and raise_exception:
-        if not (infos["minOccurs"] == 0 and infos["maxOccurs"] == 1):
-            return HandleError("Attribute '%s' isn't optional." % name, raise_exception)
-    elif infos["maxOccurs"] == "unbounded" or infos["maxOccurs"] > 1:
-        if not isinstance(value, ListType):
-            return HandleError("Attribute '%s' must be a list." % name, raise_exception)
-        if len(value) < infos["minOccurs"] or infos["maxOccurs"] != "unbounded" and len(value) > infos["maxOccurs"]:
-            return HandleError("List out of bounds for attribute '%s'." % name, raise_exception)
-        if not reduce(lambda x, y: x and y, map(infos["elmt_type"]["check"], value), True):
-            return HandleError("Attribute '%s' must be a list of valid elements." % name, raise_exception)
-    elif infos.has_key("fixed") and value != infos["fixed"]:
-        return HandleError("Value of attribute '%s' can only be '%s'." % (name, str(infos["fixed"])), raise_exception)
-    else:
-        return infos["elmt_type"]["check"](value)
-    return True
+        return []
 
 def GetContentInfos(name, choices):
     for choice_infos in choices:
@@ -649,6 +641,7 @@
                         sequence_element["elmt_type"] = element_infos
         elif choice["elmt_type"] == "tag":
             choice["elmt_type"] = GenerateTagInfos(choice)
+            factory.AddToLookupClass(choice["name"], name, DefaultElementClass)
         else:
             choice_infos = factory.ExtractTypeInfos(choice["name"], name, choice["elmt_type"])
             if choice_infos is not None:
@@ -656,26 +649,6 @@
         choices.append((choice["name"], choice))
     return choices
 
-def ExtractContentElement(factory, tree, infos, content):
-    infos["elmt_type"] = FindTypeInfos(factory, infos["elmt_type"])
-    if infos["maxOccurs"] == "unbounded" or infos["maxOccurs"] > 1:
-        if isinstance(content, ListType) and len(content) > 0 and \
-           content[-1]["name"] == tree.nodeName:
-            content_item = content.pop(-1)
-            content_item["value"].append(infos["elmt_type"]["extract"](tree))
-            return content_item
-        elif not isinstance(content, ListType) and \
-             content is not None and \
-             content["name"] == tree.nodeName:
-            return {"name": tree.nodeName, 
-                    "value": content["value"] + [infos["elmt_type"]["extract"](tree)]}
-        else:
-            return {"name": tree.nodeName, 
-                    "value": [infos["elmt_type"]["extract"](tree)]}
-    else:
-        return {"name": tree.nodeName, 
-                "value": infos["elmt_type"]["extract"](tree)}
-
 def GenerateContentInfos(factory, name, choices):
     choices_dict = {}
     for choice_name, infos in choices:
@@ -691,6 +664,7 @@
             if choices_dict.has_key(choice_name):
                 raise ValueError("'%s' element defined two times in choice" % choice_name)
             choices_dict[choice_name] = infos
+    choices_xpath = "|".join(map(lambda x: "%s:%s" % (factory.TargetNamespace, x), choices_dict.keys()))
     
     def GetContentInitial():
         content_name, infos = choices[0]
@@ -698,140 +672,15 @@
             content_value = []
             for i in xrange(infos["minOccurs"]):
                 for element_infos in infos["elements"]:
-                    value = GetElementInitialValue(factory, element_infos)
-                    if value is not None:
-                        if element_infos["type"] == CHOICE:
-                            content_value.append(value)
-                        else:
-                            content_value.append({"name": element_infos["name"], "value": value})
+                    content_value.extend(GetElementInitialValue(factory, element_infos))
         else:
             content_value = GetElementInitialValue(factory, infos)
-        return {"name": content_name, "value": content_value}
-        
-    def CheckContent(value):
-        if value["name"] != "sequence":
-            infos = choices_dict.get(value["name"], None)
-            if infos is not None:
-                return CheckElementValue(factory, value["name"], infos, value["value"], False)
-        elif len(value["value"]) > 0:
-            infos = choices_dict.get(value["value"][0]["name"], None)
-            if infos is None:
-                for choice_name, infos in choices:
-                    if infos["type"] == "sequence":
-                        for element_infos in infos["elements"]:
-                            if element_infos["type"] == CHOICE:
-                                infos = GetContentInfos(value["value"][0]["name"], element_infos["choices"])
-            if infos is not None:
-                sequence_number = 0
-                element_idx = 0
-                while element_idx < len(value["value"]):
-                    for element_infos in infos["elements"]:
-                        element_value = None
-                        if element_infos["type"] == CHOICE:
-                            choice_infos = None
-                            if element_idx < len(value["value"]):
-                                for choice in element_infos["choices"]:
-                                    if choice["name"] == value["value"][element_idx]["name"]:
-                                        choice_infos = choice
-                                        element_value = value["value"][element_idx]["value"]
-                                        element_idx += 1
-                                        break
-                            if ((choice_infos is not None and 
-                                 not CheckElementValue(factory, choice_infos["name"], choice_infos, element_value, False)) or
-                                (choice_infos is None and element_infos["minOccurs"] > 0)):
-                                raise ValueError("Invalid sequence value in attribute 'content'")
-                        else:
-                            if element_idx < len(value["value"]) and element_infos["name"] == value["value"][element_idx]["name"]:
-                                element_value = value["value"][element_idx]["value"]
-                                element_idx += 1
-                            if not CheckElementValue(factory, element_infos["name"], element_infos, element_value, False):
-                                raise ValueError("Invalid sequence value in attribute 'content'")
-                    sequence_number += 1
-                if sequence_number < infos["minOccurs"] or infos["maxOccurs"] != "unbounded" and sequence_number > infos["maxOccurs"]:
-                    raise ValueError("Invalid sequence value in attribute 'content'")
-                return True
-        else:
-            for element_name, infos in choices:
-                if element_name == "sequence":
-                    required = 0
-                    for element in infos["elements"]:
-                        if element["minOccurs"] > 0:
-                            required += 1
-                    if required == 0:
-                        return True
-        return False
-    
-    def ExtractContent(tree, content):
-        infos = choices_dict.get(tree.nodeName, None)
-        if infos is not None:
-            if infos["name"] == "sequence":
-                sequence_dict = dict([(element_infos["name"], element_infos) for element_infos in infos["elements"] if element_infos["type"] != CHOICE])
-                element_infos = sequence_dict.get(tree.nodeName)
-                if content is not None and \
-                   content["name"] == "sequence" and \
-                   len(content["value"]) > 0 and \
-                   choices_dict.get(content["value"][-1]["name"]) == infos:
-                    return {"name": "sequence",
-                            "value": content["value"] + [ExtractContentElement(factory, tree, element_infos, content["value"][-1])]}
-                else:
-                    return {"name": "sequence",
-                            "value": [ExtractContentElement(factory, tree, element_infos, None)]}
-            else:
-                return ExtractContentElement(factory, tree, infos, content)
-        else:
-            for choice_name, infos in choices:
-                if infos["type"] == "sequence":
-                    for element_infos in infos["elements"]:
-                        if element_infos["type"] == CHOICE:
-                            try:
-                                if content is not None and \
-                                    content["name"] == "sequence" and \
-                                    len(content["value"]) > 0:
-                                    return {"name": "sequence",
-                                            "value": content["value"] + [element_infos["elmt_type"]["extract"](tree, content["value"][-1])]}
-                                else:
-                                    return {"name": "sequence",
-                                            "value": [element_infos["elmt_type"]["extract"](tree, None)]}
-                            except:
-                                pass
-        raise ValueError("Invalid element \"%s\" for content!" % tree.nodeName)
-    
-    def GenerateContent(value, name=None, indent=0):
-        text = ""
-        if value["name"] != "sequence":
-            infos = choices_dict.get(value["name"], None)
-            if infos is not None:
-                infos["elmt_type"] = FindTypeInfos(factory, infos["elmt_type"])
-                if infos["maxOccurs"] == "unbounded" or infos["maxOccurs"] > 1:
-                    for item in value["value"]:
-                        text += infos["elmt_type"]["generate"](item, value["name"], indent)
-                else:
-                    text += infos["elmt_type"]["generate"](value["value"], value["name"], indent)
-        elif len(value["value"]) > 0:
-            infos = choices_dict.get(value["value"][0]["name"], None)
-            if infos is None:
-                for choice_name, infos in choices:
-                    if infos["type"] == "sequence":
-                        for element_infos in infos["elements"]:
-                            if element_infos["type"] == CHOICE:
-                                infos = GetContentInfos(value["value"][0]["name"], element_infos["choices"])
-            if infos is not None:
-                sequence_dict = dict([(element_infos["name"], element_infos) for element_infos in infos["elements"]]) 
-                for element_value in value["value"]:
-                    element_infos = sequence_dict.get(element_value["name"])
-                    if element_infos["maxOccurs"] == "unbounded" or element_infos["maxOccurs"] > 1:
-                        for item in element_value["value"]:
-                            text += element_infos["elmt_type"]["generate"](item, element_value["name"], indent)
-                    else:
-                        text += element_infos["elmt_type"]["generate"](element_value["value"], element_infos["name"], indent)
-        return text
+        return content_value
         
     return {
         "type": COMPLEXTYPE,
+        "choices_xpath": etree.XPath(choices_xpath, namespaces=factory.NSMAP),
         "initial": GetContentInitial,
-        "check": CheckContent,
-        "extract": ExtractContent,
-        "generate": GenerateContent
     }
 
 #-------------------------------------------------------------------------------
@@ -901,9 +750,11 @@
         self.XMLClassDefinitions = {}
         
         self.DefinedNamespaces = {}
+        self.NSMAP = {}
         self.Namespaces = {}
         self.SchemaNamespace = None
         self.TargetNamespace = None
+        self.etreeNamespaceFormat = "%s"
         
         self.CurrentCompilations = []
         
@@ -914,6 +765,8 @@
         else:
             self.ComputedClasses = {}
         self.ComputedClassesInfos = {}
+        self.ComputedClassesLookUp = {}
+        self.EquivalentClassesParent = {}
         self.AlreadyComputed = {}
 
     def GetQualifiedNameInfos(self, name, namespace=None, canbenone=False):
@@ -1016,7 +869,9 @@
                     attrs[name] = infos["extract"]["default"](attr)
             elif namespace == "xmlns":
                 infos = self.GetQualifiedNameInfos("anyURI", self.SchemaNamespace)
-                self.DefinedNamespaces[infos["extract"](attr)] = name
+                value = infos["extract"](attr)
+                self.DefinedNamespaces[value] = name
+                self.NSMAP[name] = value
             else:
                 raise ValueError("Invalid attribute \"%s\" for member \"%s\"!" % (qualified_name, node.nodeName))
         for attr in valid_attrs:
@@ -1063,20 +918,48 @@
 
     def ParseSchema(self):
         pass
-
+    
+    def AddEquivalentClass(self, name, base):
+        if name != base:
+            equivalences = self.EquivalentClassesParent.setdefault(self.etreeNamespaceFormat % base, {})
+            equivalences[self.etreeNamespaceFormat % name] = True
+        
+    def AddToLookupClass(self, name, parent, typeinfos):
+        lookup_name = self.etreeNamespaceFormat % name
+        if isinstance(typeinfos, (StringType, UnicodeType)):
+            self.AddEquivalentClass(name, typeinfos)
+            typeinfos = self.etreeNamespaceFormat % typeinfos
+        lookup_classes = self.ComputedClassesLookUp.get(lookup_name)
+        if lookup_classes is None:
+            self.ComputedClassesLookUp[lookup_name] = (typeinfos, parent)
+        elif isinstance(lookup_classes, DictType):
+            lookup_classes[self.etreeNamespaceFormat % parent 
+                           if parent is not None else None] = typeinfos
+        else:
+            lookup_classes = {self.etreeNamespaceFormat % lookup_classes[1]
+                              if lookup_classes[1] is not None else None: lookup_classes[0]}
+            lookup_classes[self.etreeNamespaceFormat % parent
+                           if parent is not None else None] = typeinfos
+            self.ComputedClassesLookUp[lookup_name] = lookup_classes
+    
     def ExtractTypeInfos(self, name, parent, typeinfos):
         if isinstance(typeinfos, (StringType, UnicodeType)):
-            namespace, name = DecomposeQualifiedName(typeinfos)
-            infos = self.GetQualifiedNameInfos(name, namespace)
+            namespace, type_name = DecomposeQualifiedName(typeinfos)
+            infos = self.GetQualifiedNameInfos(type_name, namespace)
+            if name != "base":
+                if infos["type"] == SIMPLETYPE:
+                    self.AddToLookupClass(name, parent, DefaultElementClass)
+                elif namespace == self.TargetNamespace:
+                    self.AddToLookupClass(name, parent, type_name)
             if infos["type"] == COMPLEXTYPE:
-                name, parent = self.SplitQualifiedName(name, namespace)
-                result = self.CreateClass(name, parent, infos)
+                type_name, parent = self.SplitQualifiedName(type_name, namespace)
+                result = self.CreateClass(type_name, parent, infos)
                 if result is not None and not isinstance(result, (UnicodeType, StringType)):
                     self.Namespaces[self.TargetNamespace][result["name"]] = result
                 return result
             elif infos["type"] == ELEMENT and infos["elmt_type"]["type"] == COMPLEXTYPE:
-                name, parent = self.SplitQualifiedName(name, namespace)
-                result = self.CreateClass(name, parent, infos["elmt_type"])
+                type_name, parent = self.SplitQualifiedName(type_name, namespace)
+                result = self.CreateClass(type_name, parent, infos["elmt_type"])
                 if result is not None and not isinstance(result, (UnicodeType, StringType)):
                     self.Namespaces[self.TargetNamespace][result["name"]] = result
                 return result
@@ -1086,7 +969,12 @@
             return self.CreateClass(name, parent, typeinfos)
         elif typeinfos["type"] == SIMPLETYPE:
             return typeinfos
-            
+    
+    def GetEquivalentParents(self, parent):
+        return reduce(lambda x, y: x + y,
+            [[p] + self.GetEquivalentParents(p)
+             for p in self.EquivalentClassesParent.get(parent, {}).keys()], [])
+    
     """
     Methods that generates the classes
     """
@@ -1123,6 +1011,21 @@
                             if result is not None and \
                                not isinstance(result, (UnicodeType, StringType)):
                                 self.Namespaces[self.TargetNamespace][result["name"]] = result
+        
+        for name, parents in self.ComputedClassesLookUp.iteritems():
+            if isinstance(parents, DictType):
+                computed_classes = parents.items()
+            elif parents[1] is not None:
+                computed_classes = [(self.etreeNamespaceFormat % parents[1], parents[0])]
+            else:
+                computed_classes = []
+            for parent, computed_class in computed_classes:
+                for equivalent_parent in self.GetEquivalentParents(parent):
+                    if not isinstance(parents, DictType):
+                        parents = dict(computed_classes)
+                        self.ComputedClassesLookUp[name] = parents
+                    parents[equivalent_parent] = computed_class
+        
         return self.ComputedClasses
 
     def CreateClass(self, name, parent, classinfos, baseclass = False):
@@ -1141,9 +1044,12 @@
         bases = []
         base_infos = classinfos.get("base", None)
         if base_infos is not None:
+            namespace, base_name = DecomposeQualifiedName(base_infos)
+            if namespace == self.TargetNamespace:
+                self.AddEquivalentClass(name, base_name)
             result = self.ExtractTypeInfos("base", name, base_infos)
             if result is None:
-                namespace, base_name = DecomposeQualifiedName(base_infos)                
+                namespace, base_name = DecomposeQualifiedName(base_infos)
                 if self.AlreadyComputed.get(base_name, False):
                     self.ComputeAfter.append((name, parent, classinfos))
                     if self.TargetNamespace is not None:
@@ -1164,7 +1070,7 @@
                 if classinfos["base"] is None:
                     raise ValueError("No class found for base type")
                 bases.append(classinfos["base"])
-        bases.append(object)
+        bases.append(DefaultElementClass)
         bases = tuple(bases)
         classmembers = {"__doc__": classinfos.get("doc", ""), "IsBaseClass": baseclass}
         
@@ -1177,11 +1083,8 @@
                     raise ValueError("\"%s\" type is not a simple type!" % attribute["attr_type"])
                 attrname = attribute["name"]
                 if attribute["use"] == "optional":
-                    classmembers[attrname] = None
                     classmembers["add%s"%attrname] = generateAddMethod(attrname, self, attribute)
                     classmembers["delete%s"%attrname] = generateDeleteMethod(attrname)
-                else:
-                    classmembers[attrname] = infos["initial"]()
                 classmembers["set%s"%attrname] = generateSetMethod(attrname)
                 classmembers["get%s"%attrname] = generateGetMethod(attrname)
             else:
@@ -1200,54 +1103,42 @@
                     classmembers["set%sbytype" % elmtname] = generateSetChoiceByTypeMethod(self, element["choices"])
                 infos = GenerateContentInfos(self, name, choices)
             elif element["type"] == ANY:
-                elmtname = element["name"] = "text"
+                elmtname = element["name"] = "anyText"
                 element["minOccurs"] = element["maxOccurs"] = 1
                 infos = GenerateAnyInfos(element)
             else:
                 elmtname = element["name"]
                 if element["elmt_type"] == "tag":
                     infos = GenerateTagInfos(element)
+                    self.AddToLookupClass(element["name"], name, DefaultElementClass)
                 else:
                     infos = self.ExtractTypeInfos(element["name"], name, element["elmt_type"])
             if infos is not None:
                 element["elmt_type"] = infos
             if element["maxOccurs"] == "unbounded" or element["maxOccurs"] > 1:
-                classmembers[elmtname] = []
                 classmembers["append%s" % elmtname] = generateAppendMethod(elmtname, element["maxOccurs"], self, element)
                 classmembers["insert%s" % elmtname] = generateInsertMethod(elmtname, element["maxOccurs"], self, element)
                 classmembers["remove%s" % elmtname] = generateRemoveMethod(elmtname, element["minOccurs"])
                 classmembers["count%s" % elmtname] = generateCountMethod(elmtname)
             else:
                 if element["minOccurs"] == 0:
-                    classmembers[elmtname] = None
                     classmembers["add%s" % elmtname] = generateAddMethod(elmtname, self, element)
                     classmembers["delete%s" % elmtname] = generateDeleteMethod(elmtname)
-                elif not isinstance(element["elmt_type"], (UnicodeType, StringType)):
-                    classmembers[elmtname] = element["elmt_type"]["initial"]()
-                else:
-                    classmembers[elmtname] = None
             classmembers["set%s" % elmtname] = generateSetMethod(elmtname)
             classmembers["get%s" % elmtname] = generateGetMethod(elmtname)
             
-        classmembers["__init__"] = generateInitMethod(self, classinfos)
-        classmembers["getStructure"] = generateStructureMethod(classinfos)
-        classmembers["loadXMLTree"] = generateLoadXMLTree(self, classinfos)
-        classmembers["generateXMLText"] = generateGenerateXMLText(self, classinfos)
+        classmembers["init"] = generateInitMethod(self, classinfos)
         classmembers["getElementAttributes"] = generateGetElementAttributes(self, classinfos)
         classmembers["getElementInfos"] = generateGetElementInfos(self, classinfos)
         classmembers["setElementValue"] = generateSetElementValue(self, classinfos)
-        classmembers["singleLineAttributes"] = True
-        classmembers["compatibility"] = lambda x, y: None
-        classmembers["extraAttrs"] = {}
         
         class_definition = classobj(str(classname), bases, classmembers)
+        setattr(class_definition, "__getattr__", generateGetattrMethod(self, class_definition, classinfos))
         setattr(class_definition, "__setattr__", generateSetattrMethod(self, class_definition, classinfos))
         class_infos = {"type": COMPILEDCOMPLEXTYPE,
                        "name": classname,
-                       "check": generateClassCheckFunction(class_definition),
                        "initial": generateClassCreateFunction(class_definition),
-                       "extract": generateClassExtractFunction(class_definition),
-                       "generate": class_definition.generateXMLText}
+        }
         
         if self.FileName is not None:
             self.ComputedClasses[self.FileName][classname] = class_definition
@@ -1255,6 +1146,9 @@
             self.ComputedClasses[classname] = class_definition
         self.ComputedClassesInfos[classname] = class_infos
         
+        self.AddToLookupClass(name, parent, class_definition)
+        self.AddToLookupClass(classname, None, class_definition)
+            
         return class_infos
 
     """
@@ -1281,14 +1175,6 @@
             print classname
 
 """
-Method that generate the method for checking a class instance
-"""
-def generateClassCheckFunction(class_definition):
-    def classCheckfunction(instance):
-        return isinstance(instance, class_definition)
-    return classCheckfunction
-
-"""
 Method that generate the method for creating a class instance
 """
 def generateClassCreateFunction(class_definition):
@@ -1296,265 +1182,109 @@
         return class_definition()
     return classCreatefunction
 
-"""
-Method that generate the method for extracting a class instance
-"""
-def generateClassExtractFunction(class_definition):
-    def classExtractfunction(node):
-        instance = class_definition()
-        instance.loadXMLTree(node)
-        return instance
-    return classExtractfunction
-
-"""
-Method that generate the method for loading an xml tree by following the
-attributes list defined
-"""
+def generateGetattrMethod(factory, class_definition, classinfos):
+    attributes = dict([(attr["name"], attr) for attr in classinfos["attributes"] if attr["use"] != "prohibited"])
+    optional_attributes = dict([(attr["name"], True) for attr in classinfos["attributes"] if attr["use"] == "optional"])
+    elements = dict([(element["name"], element) for element in classinfos["elements"]])
+    
+    def getattrMethod(self, name):
+        if attributes.has_key(name):
+            attribute_infos = attributes[name]
+            attribute_infos["attr_type"] = FindTypeInfos(factory, attribute_infos["attr_type"])
+            value = self.get(name)
+            if value is not None:
+                return attribute_infos["attr_type"]["extract"](value, extract=False)
+            elif attribute_infos.has_key("fixed"):
+                return attribute_infos["attr_type"]["extract"](attribute_infos["fixed"], extract=False)
+            elif attribute_infos.has_key("default"):
+                return attribute_infos["attr_type"]["extract"](attribute_infos["default"], extract=False)
+            return None
+        
+        elif elements.has_key(name):
+            element_infos = elements[name]
+            element_infos["elmt_type"] = FindTypeInfos(factory, element_infos["elmt_type"])
+            if element_infos["type"] == CHOICE:
+                content = element_infos["elmt_type"]["choices_xpath"](self)
+                if element_infos["maxOccurs"] == "unbounded" or element_infos["maxOccurs"] > 1:
+                    return content
+                elif len(content) > 0:
+                    return content[0]
+                return None 
+            elif element_infos["type"] == ANY:
+                return element_infos["elmt_type"]["extract"](self)
+            else:
+                element_name = factory.etreeNamespaceFormat % name
+                if element_infos["maxOccurs"] == "unbounded" or element_infos["maxOccurs"] > 1:
+                    return self.findall(element_name)
+                else:
+                    return self.find(element_name)
+            
+        elif classinfos.has_key("base"):
+            return classinfos["base"].__getattr__(self, name)
+        
+        return DefaultElementClass.__getattribute__(self, name)
+    
+    return getattrMethod
+
 def generateSetattrMethod(factory, class_definition, classinfos):
     attributes = dict([(attr["name"], attr) for attr in classinfos["attributes"] if attr["use"] != "prohibited"])
     optional_attributes = dict([(attr["name"], True) for attr in classinfos["attributes"] if attr["use"] == "optional"])
-    elements = dict([(element["name"], element) for element in classinfos["elements"]])
+    elements = OrderedDict([(element["name"], element) for element in classinfos["elements"]])
     
     def setattrMethod(self, name, value):
         if attributes.has_key(name):
-            attributes[name]["attr_type"] = FindTypeInfos(factory, attributes[name]["attr_type"])
-            if value is None:
-                if optional_attributes.get(name, False):
-                    return object.__setattr__(self, name, None)
-                else:
-                    raise ValueError("Attribute '%s' isn't optional." % name)
-            elif attributes[name].has_key("fixed") and value != attributes[name]["fixed"]:
-                raise ValueError, "Value of attribute '%s' can only be '%s'."%(name, str(attributes[name]["fixed"]))
-            elif attributes[name]["attr_type"]["check"](value):
-                return object.__setattr__(self, name, value)
+            attribute_infos = attributes[name]
+            attribute_infos["attr_type"] = FindTypeInfos(factory, attribute_infos["attr_type"])
+            if optional_attributes.get(name, False):
+                default = attribute_infos.get("default", None)
+                if value is None or value == default:
+                    self.attrib.pop(name, None)
+                    return
+            elif attribute_infos.has_key("fixed"):
+                return
+            return self.set(name, attribute_infos["attr_type"]["generate"](value))
+        
+        elif elements.has_key(name):
+            element_infos = elements[name]
+            element_infos["elmt_type"] = FindTypeInfos(factory, element_infos["elmt_type"])
+            if element_infos["type"] == ANY:
+                element_infos["elmt_type"]["generate"](self, value)
+            
             else:
-                raise ValueError("Invalid value for attribute '%s'." % (name))
-        elif elements.has_key(name):
-            if CheckElementValue(factory, name, elements[name], value):
-                return object.__setattr__(self, name, value)
-            else:
-                raise ValueError("Invalid value for attribute '%s'." % (name))
+                element_xpath = ("%s:%s" % (factory.TargetNamespace, name)
+                                 if name != "content"
+                                 else elements["content"]["elmt_type"]["choices_xpath"].path)
+                
+                for element in self.xpath(element_xpath, namespaces=factory.NSMAP):
+                    self.remove(element)
+                
+                if value is not None:
+                    element_idx = elements.keys().index(name)
+                    if element_idx > 0:
+                        previous_elements_xpath = "|".join(map(
+                            lambda x: "%s:%s" % (factory.TargetNamespace, x)
+                                      if x != "content"
+                                      else elements["content"]["elmt_type"]["choices_xpath"].path,
+                            elements.keys()[:element_idx]))
+                        
+                        insertion_point = len(self.xpath(previous_elements_xpath, namespaces=factory.NSMAP))
+                    else:
+                        insertion_point = 0
+                    
+                    if not isinstance(value, ListType):
+                        value = [value]
+                        
+                    for element in reversed(value):
+                        self.insert(insertion_point, element)
+        
         elif classinfos.has_key("base"):
             return classinfos["base"].__setattr__(self, name, value)
-        elif class_definition.__dict__.has_key(name):
-            return object.__setattr__(self, name, value)
+        
         else:
             raise AttributeError("'%s' can't have an attribute '%s'." % (self.__class__.__name__, name))
         
     return setattrMethod
 
-"""
-Method that generate the method for generating the xml tree structure model by 
-following the attributes list defined
-"""
-def ComputeMultiplicity(name, infos):
-    if infos["minOccurs"] == 0:
-        if infos["maxOccurs"] == "unbounded":
-            return "(?:%s)*" % name
-        elif infos["maxOccurs"] == 1:
-            return "(?:%s)?" % name
-        else:
-            return "(?:%s){,%d}" % (name, infos["maxOccurs"])
-    elif infos["minOccurs"] == 1:
-        if infos["maxOccurs"] == "unbounded":
-            return "(?:%s)+" % name
-        elif infos["maxOccurs"] == 1:
-            return "(?:%s)" % name
-        else:
-            return "(?:%s){1,%d}" % (name, infos["maxOccurs"])
-    else:
-        if infos["maxOccurs"] == "unbounded":
-            return "(?:%s){%d,}" % (name, infos["minOccurs"], name)
-        else:
-            return "(?:%s){%d,%d}" % (name, infos["minOccurs"], 
-                                       infos["maxOccurs"])
-
-def GetStructure(classinfos):
-    elements = []
-    for element in classinfos["elements"]:
-        if element["type"] == ANY:
-            infos = element.copy()
-            infos["minOccurs"] = 0
-            elements.append(ComputeMultiplicity("#text |#cdata-section |\w* ", infos))
-        elif element["type"] == CHOICE:
-            choices = []
-            for infos in element["choices"]:
-                if infos["type"] == "sequence":
-                    structure = "(?:%s)" % GetStructure(infos)
-                else:
-                    structure = "%s " % infos["name"]
-                choices.append(ComputeMultiplicity(structure, infos))
-            elements.append(ComputeMultiplicity("|".join(choices), element))
-        elif element["name"] == "content" and element["elmt_type"]["type"] == SIMPLETYPE:
-            elements.append("(?:#text |#cdata-section )?")
-        else:
-            elements.append(ComputeMultiplicity("%s " % element["name"], element))
-    if classinfos.get("order", True) or len(elements) == 0:
-        return "".join(elements)
-    else:
-        raise ValueError("XSD structure not yet supported!")
-
-def generateStructureMethod(classinfos):
-    def getStructureMethod(self):
-        structure = GetStructure(classinfos)
-        if classinfos.has_key("base"):
-            return classinfos["base"].getStructure(self) + structure
-        return structure
-    return getStructureMethod
-
-"""
-Method that generate the method for loading an xml tree by following the
-attributes list defined
-"""
-def generateLoadXMLTree(factory, classinfos):
-    attributes = dict([(attr["name"], attr) for attr in classinfos["attributes"] if attr["use"] != "prohibited"])
-    elements = dict([(element["name"], element) for element in classinfos["elements"]])
-    
-    def loadXMLTreeMethod(self, tree, extras=[], derived=False):
-        self.extraAttrs = {}
-        self.compatibility(tree)
-        if not derived:
-            children_structure = ""
-            for node in tree.childNodes:
-                if not (node.nodeName == "#text" and node.data.strip() == "") and node.nodeName != "#comment":
-                    children_structure += "%s " % node.nodeName
-            structure_pattern = self.getStructure()
-            if structure_pattern != "":
-                structure_model = re.compile("(%s)$" % structure_pattern)
-                result = structure_model.match(children_structure)
-                if not result:
-                    raise ValueError("Invalid structure for \"%s\" children!." % tree.nodeName)
-        required_attributes = dict([(attr["name"], True) for attr in classinfos["attributes"] if attr["use"] == "required"])
-        if classinfos.has_key("base"):
-            extras.extend([attr["name"] for attr in classinfos["attributes"] if attr["use"] != "prohibited"])
-            classinfos["base"].loadXMLTree(self, tree, extras, True)
-        for attrname, attr in tree._attrs.iteritems():
-            if attributes.has_key(attrname):
-                attributes[attrname]["attr_type"] = FindTypeInfos(factory, attributes[attrname]["attr_type"])
-                object.__setattr__(self, attrname, attributes[attrname]["attr_type"]["extract"](attr))
-            elif not classinfos.has_key("base") and not attrname in extras and not self.extraAttrs.has_key(attrname):
-                self.extraAttrs[attrname] = GetAttributeValue(attr)
-            required_attributes.pop(attrname, None)
-        if len(required_attributes) > 0:
-            raise ValueError("Required attributes %s missing for \"%s\" element!" % (", ".join(["\"%s\""%name for name in required_attributes]), tree.nodeName))
-        first = {}
-        for node in tree.childNodes:
-            name = node.nodeName
-            if name == "#text" and node.data.strip() == "" or name == "#comment":
-                continue
-            elif elements.has_key(name):
-                elements[name]["elmt_type"] = FindTypeInfos(factory, elements[name]["elmt_type"])
-                if elements[name]["maxOccurs"] == "unbounded" or elements[name]["maxOccurs"] > 1:
-                    if first.get(name, True):
-                        object.__setattr__(self, name, [elements[name]["elmt_type"]["extract"](node)])
-                        first[name] = False
-                    else:
-                        getattr(self, name).append(elements[name]["elmt_type"]["extract"](node))
-                else:
-                    object.__setattr__(self, name, elements[name]["elmt_type"]["extract"](node))
-            elif elements.has_key("text"):
-                if elements["text"]["maxOccurs"] == "unbounded" or elements["text"]["maxOccurs"] > 1:
-                    if first.get("text", True):
-                        object.__setattr__(self, "text", [elements["text"]["elmt_type"]["extract"](node)])
-                        first["text"] = False
-                    else:
-                        getattr(self, "text").append(elements["text"]["elmt_type"]["extract"](node))
-                else:
-                    object.__setattr__(self, "text", elements["text"]["elmt_type"]["extract"](node))
-            elif elements.has_key("content"):
-                if name in ["#cdata-section", "#text"]:
-                    if elements["content"]["elmt_type"]["type"] == SIMPLETYPE:
-                        object.__setattr__(self, "content", elements["content"]["elmt_type"]["extract"](node.data, False))
-                else:
-                    content = getattr(self, "content")
-                    if elements["content"]["maxOccurs"] == "unbounded" or elements["content"]["maxOccurs"] > 1:
-                        if first.get("content", True):
-                            object.__setattr__(self, "content", [elements["content"]["elmt_type"]["extract"](node, None)])
-                            first["content"] = False
-                        else:
-                            content.append(elements["content"]["elmt_type"]["extract"](node, content))
-                    else:
-                        object.__setattr__(self, "content", elements["content"]["elmt_type"]["extract"](node, content))
-    return loadXMLTreeMethod
-        
-
-"""
-Method that generates the method for generating an xml text by following the
-attributes list defined
-"""
-def generateGenerateXMLText(factory, classinfos):
-    def generateXMLTextMethod(self, name, indent=0, extras={}, derived=False):
-        ind1, ind2 = getIndent(indent, name)
-        if not derived:
-            text = ind1 + u'<%s' % name
-        else:
-            text = u''
-        
-        first = True
-        
-        if not classinfos.has_key("base"):
-            extras.update(self.extraAttrs)
-            for attr, value in extras.iteritems():
-                if not first and not self.singleLineAttributes:
-                    text += u'\n%s' % (ind2)
-                text += u' %s=%s' % (attr, quoteattr(value))
-                first = False
-            extras.clear()
-        for attr in classinfos["attributes"]:
-            if attr["use"] != "prohibited":
-                attr["attr_type"] = FindTypeInfos(factory, attr["attr_type"])
-                value = getattr(self, attr["name"], None)
-                if value != None:
-                    computed_value = attr["attr_type"]["generate"](value)
-                else:
-                    computed_value = None
-                if attr["use"] != "optional" or (value != None and \
-                   computed_value != attr.get("default", attr["attr_type"]["generate"](attr["attr_type"]["initial"]()))):
-                    if classinfos.has_key("base"):
-                        extras[attr["name"]] = computed_value
-                    else:
-                        if not first and not self.singleLineAttributes:
-                            text += u'\n%s' % (ind2)
-                        text += ' %s=%s' % (attr["name"], quoteattr(computed_value))
-                    first = False
-        if classinfos.has_key("base"):
-            first, new_text = classinfos["base"].generateXMLText(self, name, indent, extras, True)
-            text += new_text
-        else:
-            first = True
-        for element in classinfos["elements"]:
-            element["elmt_type"] = FindTypeInfos(factory, element["elmt_type"])
-            value = getattr(self, element["name"], None)
-            if element["minOccurs"] == 0 and element["maxOccurs"] == 1:
-                if value is not None:
-                    if first:
-                        text += u'>\n'
-                        first = False
-                    text += element["elmt_type"]["generate"](value, element["name"], indent + 1)
-            elif element["minOccurs"] == 1 and element["maxOccurs"] == 1:
-                if first:
-                    text += u'>\n'
-                    first = False
-                if element["name"] == "content" and element["elmt_type"]["type"] == SIMPLETYPE:
-                    text += element["elmt_type"]["generate"](value)
-                else:
-                    text += element["elmt_type"]["generate"](value, element["name"], indent + 1)
-            else:
-                if first and len(value) > 0:
-                    text += u'>\n'
-                    first = False
-                for item in value:
-                    text += element["elmt_type"]["generate"](item, element["name"], indent + 1)
-        if not derived:
-            if first:
-                text += u'/>\n'
-            else:
-                text += ind1 + u'</%s>\n' % (name)
-            return text
-        else:
-            return first, text
-    return generateXMLTextMethod
-
 def gettypeinfos(name, facets):
     if facets.has_key("enumeration") and facets["enumeration"][0] is not None:
         return facets["enumeration"][0]
@@ -1723,20 +1453,21 @@
 """
 def generateInitMethod(factory, classinfos):
     def initMethod(self):
-        self.extraAttrs = {}
         if classinfos.has_key("base"):
-            classinfos["base"].__init__(self)
+            classinfos["base"].init(self)
         for attribute in classinfos["attributes"]:
             attribute["attr_type"] = FindTypeInfos(factory, attribute["attr_type"])
             if attribute["use"] == "required":
-                setattr(self, attribute["name"], attribute["attr_type"]["initial"]())
-            elif attribute["use"] == "optional":
-                if attribute.has_key("default"):
-                    setattr(self, attribute["name"], attribute["attr_type"]["extract"](attribute["default"], False))
-                else:
-                    setattr(self, attribute["name"], None)
+                self.set(attribute["name"], attribute["attr_type"]["generate"](attribute["attr_type"]["initial"]()))
         for element in classinfos["elements"]:
-            setattr(self, element["name"], GetElementInitialValue(factory, element))
+            if element["type"] != CHOICE:
+                element_name = (
+                    etree.QName(factory.NSMAP["xhtml"], "p")
+                    if element["type"] == ANY
+                    else factory.etreeNamespaceFormat % element["name"])
+                initial = GetElementInitialValue(factory, element)
+                if initial is not None:
+                    map(self.append, initial)
     return initMethod
 
 def generateSetMethod(attr):
@@ -1753,18 +1484,16 @@
     def addMethod(self):
         if infos["type"] == ATTRIBUTE:
             infos["attr_type"] = FindTypeInfos(factory, infos["attr_type"])
-            initial = infos["attr_type"]["initial"]
-            extract = infos["attr_type"]["extract"]
+            if not infos.has_key("default"):
+                setattr(self, attr, infos["attr_type"]["initial"]())
         elif infos["type"] == ELEMENT:
             infos["elmt_type"] = FindTypeInfos(factory, infos["elmt_type"])
-            initial = infos["elmt_type"]["initial"]
-            extract = infos["elmt_type"]["extract"]
+            value = infos["elmt_type"]["initial"]()
+            DefaultElementClass.__setattr__(value, "tag", factory.etreeNamespaceFormat % attr)
+            setattr(self, attr, value)
+            value.init()
         else:
             raise ValueError("Invalid class attribute!")
-        if infos.has_key("default"):
-            setattr(self, attr, extract(infos["default"], False))
-        else:
-            setattr(self, attr, initial())
     return addMethod
 
 def generateDeleteMethod(attr):
@@ -1777,10 +1506,10 @@
         infos["elmt_type"] = FindTypeInfos(factory, infos["elmt_type"])
         attr_list = getattr(self, attr)
         if maxOccurs == "unbounded" or len(attr_list) < maxOccurs:
-            if infos["elmt_type"]["check"](value):
-                attr_list.append(value)
+            if len(attr_list) == 0:
+                setattr(self, attr, [value])
             else:
-                raise ValueError("\"%s\" value isn't valid!" % attr)
+                attr_list[-1].addnext(value)
         else:
             raise ValueError("There can't be more than %d values in \"%s\"!" % (maxOccurs, attr))
     return appendMethod
@@ -1790,10 +1519,12 @@
         infos["elmt_type"] = FindTypeInfos(factory, infos["elmt_type"])
         attr_list = getattr(self, attr)
         if maxOccurs == "unbounded" or len(attr_list) < maxOccurs:
-            if infos["elmt_type"]["check"](value):
-                attr_list.insert(index, value)
+            if len(attr_list) == 0:
+                setattr(self, attr, [value])
+            elif index == 0:
+                attr_list[0].addprevious(value)
             else:
-                raise ValueError("\"%s\" value isn't valid!" % attr)
+                attr_list[min(index - 1, len(attr_list) - 1)].addnext(value)
         else:
             raise ValueError("There can't be more than %d values in \"%s\"!" % (maxOccurs, attr))
     return insertMethod
@@ -1805,24 +1536,24 @@
 
 def generateSetChoiceByTypeMethod(factory, choice_types):
     choices = dict([(choice["name"], choice) for choice in choice_types])
-    def setChoiceMethod(self, type):
-        if not choices.has_key(type):
-            raise ValueError("Unknown \"%s\" choice type for \"content\"!" % type)
-        choices[type]["elmt_type"] = FindTypeInfos(factory, choices[type]["elmt_type"])
-        new_element = choices[type]["elmt_type"]["initial"]()
-        self.content = {"name": type, "value": new_element}
-        return new_element
+    def setChoiceMethod(self, content_type):
+        if not choices.has_key(content_type):
+            raise ValueError("Unknown \"%s\" choice type for \"content\"!" % content_type)
+        choices[content_type]["elmt_type"] = FindTypeInfos(factory, choices[content_type]["elmt_type"])
+        new_content = choices[content_type]["elmt_type"]["initial"]()
+        self.content = new_content
+        return new_content
     return setChoiceMethod
 
 def generateAppendChoiceByTypeMethod(maxOccurs, factory, choice_types):
     choices = dict([(choice["name"], choice) for choice in choice_types])
-    def appendChoiceMethod(self, type):
-        if not choices.has_key(type):
-            raise ValueError("Unknown \"%s\" choice type for \"content\"!" % type)
-        choices[type]["elmt_type"] = FindTypeInfos(factory, choices[type]["elmt_type"])
+    def appendChoiceMethod(self, content_type):
+        if not choices.has_key(content_type):
+            raise ValueError("Unknown \"%s\" choice type for \"content\"!" % content_type)
+        choices[content_type]["elmt_type"] = FindTypeInfos(factory, choices[content_type]["elmt_type"])
         if maxOccurs == "unbounded" or len(self.content) < maxOccurs:
-            new_element = choices[type]["elmt_type"]["initial"]()
-            self.content.append({"name": type, "value": new_element})
+            new_element = choices[content_type]["elmt_type"]["initial"]()
+            self.appendcontent(new_element)
             return new_element
         else:
             raise ValueError("There can't be more than %d values in \"content\"!" % maxOccurs)
@@ -1830,13 +1561,13 @@
 
 def generateInsertChoiceByTypeMethod(maxOccurs, factory, choice_types):
     choices = dict([(choice["name"], choice) for choice in choice_types])
-    def insertChoiceMethod(self, index, type):
-        if not choices.has_key(type):
-            raise ValueError("Unknown \"%s\" choice type for \"content\"!" % type)
-        choices[type]["elmt_type"] = FindTypeInfos(factory, choices[type]["elmt_type"])
+    def insertChoiceMethod(self, index, content_type):
+        if not choices.has_key(content_type):
+            raise ValueError("Unknown \"%s\" choice type for \"content\"!" % content_type)
+        choices[type]["elmt_type"] = FindTypeInfos(factory, choices[content_type]["elmt_type"])
         if maxOccurs == "unbounded" or len(self.content) < maxOccurs:
-            new_element = choices[type]["elmt_type"]["initial"]()
-            self.content.insert(index, {"name" : type, "value" : new_element})
+            new_element = choices[content_type]["elmt_type"]["initial"]()
+            self.insertcontent(index, new_element)
             return new_element
         else:
             raise ValueError("There can't be more than %d values in \"content\"!" % maxOccurs)
@@ -1846,7 +1577,7 @@
     def removeMethod(self, index):
         attr_list = getattr(self, attr)
         if len(attr_list) > minOccurs:
-            getattr(self, attr).pop(index)
+            self.remove(attr_list[index])
         else:
             raise ValueError("There can't be less than %d values in \"%s\"!" % (minOccurs, attr))
     return removeMethod
@@ -1857,16 +1588,112 @@
     return countMethod
 
 """
-This function generate the classes from a class factory
+This function generate a xml parser from a class factory
 """
-def GenerateClasses(factory):
+
+NAMESPACE_PATTERN = re.compile("xmlns(?:\:[^\=]*)?=\"[^\"]*\" ")
+
+class DefaultElementClass(etree.ElementBase):
+    
+    def init(self):
+        pass
+    
+    def getLocalTag(self):
+        return etree.QName(self.tag).localname
+        
+    def tostring(self):
+        return NAMESPACE_PATTERN.sub("", etree.tostring(self, pretty_print=True))
+
+class XMLElementClassLookUp(etree.PythonElementClassLookup):
+    
+    def __init__(self, classes, *args, **kwargs):
+        etree.PythonElementClassLookup.__init__(self, *args, **kwargs)
+        self.LookUpClasses = classes
+    
+    def GetElementClass(self, element_tag, parent_tag=None, default=DefaultElementClass):
+        element_class = self.LookUpClasses.get(element_tag, (default, None))
+        if not isinstance(element_class, DictType):
+            if isinstance(element_class[0], (StringType, UnicodeType)):
+                return self.GetElementClass(element_class[0], default=default)
+            return element_class[0]
+        
+        element_with_parent_class = element_class.get(parent_tag, default)
+        if isinstance(element_with_parent_class, (StringType, UnicodeType)):
+            return self.GetElementClass(element_with_parent_class, default=default)
+        return element_with_parent_class
+        
+    def lookup(self, document, element):
+        parent = element.getparent()
+        return self.GetElementClass(element.tag, 
+            parent.tag if parent is not None else None)
+
+class XMLClassParser(etree.XMLParser):
+
+    def __init__(self, namespaces, default_namespace_format, base_class, *args, **kwargs):
+        etree.XMLParser.__init__(self, *args, **kwargs)
+        self.DefaultNamespaceFormat = default_namespace_format
+        self.NSMAP = namespaces
+        targetNamespace = etree.QName(default_namespace_format % "d").namespace
+        if targetNamespace is not None:
+            self.RootNSMAP = {
+                name if targetNamespace != uri else None: uri
+                for name, uri in namespaces.iteritems()}
+        else:
+            self.RootNSMAP = namespaces
+        self.BaseClass = base_class
+    
+    def set_element_class_lookup(self, class_lookup):
+        etree.XMLParser.set_element_class_lookup(self, class_lookup)
+        self.ClassLookup = class_lookup
+    
+    def Dumps(self, xml_obj):
+        return etree.tostring(xml_obj)
+    
+    def Loads(self, xml_string):
+        return etree.fromstring(xml_string, self)
+    
+    def CreateRoot(self):
+        if self.BaseClass is not None:
+            root = self.makeelement(
+                self.DefaultNamespaceFormat % self.BaseClass[0],
+                nsmap=self.RootNSMAP)
+            root.init()
+            return root
+        return None
+    
+    def GetElementClass(self, element_tag, parent_tag=None):
+        return self.ClassLookup.GetElementClass(
+            self.DefaultNamespaceFormat % element_tag, 
+            self.DefaultNamespaceFormat % parent_tag 
+            if parent_tag is not None else parent_tag, 
+            None)
+    
+    def CreateElement(self, element_tag, parent_tag=None):
+        new_element = self.GetElementClass(element_tag, parent_tag)()
+        DefaultElementClass.__setattr__(new_element, "tag", self.DefaultNamespaceFormat % element_tag)
+        new_element.init()
+        return new_element
+    
+def GenerateParser(factory, xsdstring):
     ComputedClasses = factory.CreateClasses()
     if factory.FileName is not None and len(ComputedClasses) == 1:
-        UpdateXMLClassGlobals(ComputedClasses[factory.FileName])
-        return ComputedClasses[factory.FileName]
+        ComputedClasses = ComputedClasses[factory.FileName]
+        BaseClass = [(name, XSDclass) for name, XSDclass in ComputedClasses.items() if XSDclass.IsBaseClass]
     else:
-        UpdateXMLClassGlobals(ComputedClasses)
-        return ComputedClasses
+        BaseClass = []
+    UpdateXMLClassGlobals(ComputedClasses)
+    
+    parser = XMLClassParser(
+        factory.NSMAP,
+        factory.etreeNamespaceFormat,
+        BaseClass[0] if len(BaseClass) == 1 else None,
+        schema = etree.XMLSchema(etree.fromstring(xsdstring)),
+        strip_cdata = False, remove_blank_text=True)
+    class_lookup = XMLElementClassLookUp(factory.ComputedClassesLookUp)
+    parser.set_element_class_lookup(class_lookup)
+    
+    return parser
 
 def UpdateXMLClassGlobals(classes):
     globals().update(classes)
+
--- a/xmlclass/xsdschema.py	Wed Sep 04 00:06:44 2013 +0200
+++ b/xmlclass/xsdschema.py	Mon Sep 09 00:48:34 2013 +0200
@@ -939,8 +939,9 @@
     factory.BlockDefault = attributes["blockDefault"]
     factory.FinalDefault = attributes["finalDefault"]
     
-    if attributes.has_key("targetNamespace"):
-        factory.TargetNamespace = factory.DefinedNamespaces.get(attributes["targetNamespace"], None)
+    factory.TargetNamespace = factory.DefinedNamespaces.get(attributes["targetNamespace"], None)
+    if factory.TargetNamespace is not None:
+        factory.etreeNamespaceFormat = "{%s}%%s" % attributes["targetNamespace"]
     factory.Namespaces[factory.TargetNamespace] = {}
     
     annotations, children = factory.ReduceElements(elements, True)
@@ -1030,15 +1031,14 @@
                 schema = child
                 break
         for qualified_name, attr in schema._attrs.items():
-            value = GetAttributeValue(attr)
-            if value == "http://www.w3.org/2001/XMLSchema":
-                namespace, name = DecomposeQualifiedName(qualified_name)
-                if namespace == "xmlns":
-                    self.DefinedNamespaces["http://www.w3.org/2001/XMLSchema"] = name
+            namespace, name = DecomposeQualifiedName(qualified_name)
+            if namespace == "xmlns":
+                value = GetAttributeValue(attr)
+                self.DefinedNamespaces[value] = name
+                self.NSMAP[name] = value
+                if value == "http://www.w3.org/2001/XMLSchema":
                     self.SchemaNamespace = name
-                else:
-                    self.DefinedNamespaces["http://www.w3.org/2001/XMLSchema"] = self.SchemaNamespace
-                self.Namespaces[self.SchemaNamespace] = XSD_NAMESPACE
+                    self.Namespaces[self.SchemaNamespace] = XSD_NAMESPACE
         self.Schema = XSD_NAMESPACE["schema"]["extract"]["default"](self, schema)
         ReduceSchema(self, self.Schema[1], self.Schema[2])
 
@@ -1084,19 +1084,20 @@
         return None
 
 """
-This function opens the xsd file and generate the classes from the xml tree
+This function opens the xsd file and generate a xml parser with class lookup from 
+the xml tree
 """
-def GenerateClassesFromXSD(filepath):
+def GenerateParserFromXSD(filepath):
     xsdfile = open(filepath, 'r')
-    factory = XSDClassFactory(minidom.parse(xsdfile), filepath)
+    xsdstring = xsdfile.read()
     xsdfile.close()
-    return GenerateClasses(factory)
+    return GenerateParser(XSDClassFactory(minidom.parseString(xsdstring), filepath), xsdstring)
 
 """
-This function generate the classes from the xsd given as a string
+This function generate a xml from the xsd given as a string
 """
-def GenerateClassesFromXSDstring(xsdstring):
-    return GenerateClasses(XSDClassFactory(minidom.parseString(xsdstring)))
+def GenerateParserFromXSDstring(xsdstring):
+    return GenerateParser(XSDClassFactory(minidom.parseString(xsdstring)))
 
 
 #-------------------------------------------------------------------------------