xmlclass/xmlclass.py
author lbessard
Tue, 10 Jul 2007 19:19:54 +0200
changeset 34 ad3fa2752106
parent 24 364320323b4d
child 58 39cd981ff242
permissions -rw-r--r--
Bugs on ST generation fixed
#!/usr/bin/env python
# -*- coding: utf-8 -*-

#This file is part of PLCOpenEditor, a library implementing an IEC 61131-3 editor
#based on the plcopen standard. 
#
#Copyright (C): Edouard TISSERANT and Laurent BESSARD
#
#See COPYING file for copyrights details.
#
#This library is free software; you can redistribute it and/or
#modify it under the terms of the GNU General Public
#License as published by the Free Software Foundation; either
#version 2.1 of the License, or (at your option) any later version.
#
#This library is distributed in the hope that it will be useful,
#but WITHOUT ANY WARRANTY; without even the implied warranty of
#MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
#Lesser General Public License for more details.
#
#You should have received a copy of the GNU General Public
#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 xml.dom import minidom
import sys,re
from types import *
from datetime import *

"""
Time and date definitions
"""
TimeType = time(0,0,0).__class__
DateType = date(1,1,1).__class__
DateTimeType = datetime(1,1,1,0,0,0).__class__

"""
Regular expression models for extracting dates and times from a string
"""
time_model = re.compile('([0-9]{2}):([0-9]{2}):([0-9]{2}(?:.[0-9]*)?)')
date_model = re.compile('([0-9]{4})-([0-9]{2})-([0-9]{2})')
datetime_model = re.compile('([0-9]{4})-([0-9]{2})-([0-9]{2})[ T]([0-9]{2}):([0-9]{2}):([0-9]{2}(?:.[0-9]*)?)')

"""
Dictionaries for stocking Classes and Types created from XML
"""
XMLClasses = {}

"""
This function calculates the number of whitespace for indentation
"""
def getIndent(indent, balise):
    first = indent * 2
    second = first + len(balise) + 1
    return "\t".expandtabs(first), "\t".expandtabs(second)

"""
This function opens the xsd file and generate the classes from the xml tree
"""
def GenerateClassesFromXSD(filename):
    xsdfile = open(filename, 'r')
    Generate_xsd_classes(minidom.parse(xsdfile), None)
    xsdfile.close()

"""
This function recursively creates a definition of the classes and their attributes
for plcopen from the xsd file of plcopen opened in a DOM model
"""
def Generate_xsd_classes(tree, parent, sequence = False):
    attributes = {}
    inheritance = []
    if sequence:
        order = []
    # The lists of attributes and inheritance of the node are generated from the childrens 
    for node in tree.childNodes:
        # We make fun of #text elements and all other tags that don't are xsd tags
        if node.nodeName != "#text" and node.nodeName.startswith("xsd:"):
            recursion = False
            name = node.nodeName[4:].encode()
            
            # This tags defines an attribute of the class
            if name in ["element", "attribute"]:
                nodename = GetAttributeValue(node._attrs["name"])
                if "type" in node._attrs:
                    nodetype = GetAttributeValue(node._attrs["type"])
                    if nodetype.startswith("xsd"):
                        nodetype = nodetype.replace("xsd", "bse")
                    elif nodetype.startswith("ppx"):
                        nodetype = nodetype.replace("ppx", "cls")
                else:
                    # The type of attribute is defines in the child tree so we generate a new class
                    # No name is defined so we create one from nodename and parent class name
                    # (because some different nodes can have the same name)
                    if parent:
                        classname = "%s_%s"%(parent, nodename)
                    else:
                        classname = nodename
                    Generate_xsd_classes(node, classname)
                    nodetype = "cls:%s"%classname
                if name == "attribute":
                    if "use" in node._attrs:
                        use = GetAttributeValue(node._attrs["use"])
                    else:
                        use = "optional"
                if name == "element":
                    # If a tag can be written more than one time we define a list attribute
                    if "maxOccurs" in node._attrs and GetAttributeValue(node._attrs["maxOccurs"]) == "unbounded":
                        nodetype = "%s[]"%nodetype
                    if "minOccurs" in node._attrs and GetAttributeValue(node._attrs["minOccurs"]) == "0":
                        use = "optional"
                    else:
                        use = "required"
                attributes[nodename] = (nodetype, name, use)
                if sequence:
                    order.append(nodename)
            
            # This tag defines a new class
            elif name == "complexType" or name == "simpleType":
                if "name" in node._attrs:
                    classname = GetAttributeValue(node._attrs["name"])
                    super, attrs = Generate_xsd_classes(node, classname)
                else:
                    classname = parent
                    super, attrs = Generate_xsd_classes(node, classname.split("_")[-1])
                # When all attributes and inheritances have been extracted, the
                # values are added in the list of classes to create
                if classname not in XMLClasses:
                    XMLClasses[classname] = (super, attrs)
                elif XMLClasses[classname] != (super, attrs):
                    print "A different class has already got %s for name"%classname
            
            # This tag defines an attribute that can have different types
            elif name == "choice":
                super, attrs = Generate_xsd_classes(node, parent)
                if "ref" in attrs.keys():
                    choices = attrs
                else:
                    choices = {}
                    for attr, (attr_type, xml_type, write_type) in attrs.items():
                        choices[attr] = attr_type
                if "maxOccurs" in node._attrs and GetAttributeValue(node._attrs["maxOccurs"]) == "unbounded":
                    attributes["multichoice_content"] = choices
                    if sequence:
                        order.append("multichoice_content")
                else:
                    attributes["choice_content"] = choices
                    if sequence:
                        order.append("choice_content")
            
            # This tag defines the order in which class attributes must be written
            # in plcopen xml file. We have to store this order like an attribute
            elif name in "sequence":
                super, attrs, order = Generate_xsd_classes(node, parent, True)
                if "maxOccurs" in node._attrs and GetAttributeValue(node._attrs["maxOccurs"]) == "unbounded":
                    for attr, (attr_type, xml_type, write_type) in attrs.items():
                        attrs[attr] = ("%s[]"%attr_type, xml_type, write_type)
                if "minOccurs" in node._attrs and GetAttributeValue(node._attrs["minOccurs"]) == "0":
                    for attr, (attr_type, xml_type, write_type) in attrs.items():
                        attrs[attr] = (attr_type, xml_type, "optional")
                inheritance.extend(super)
                attributes.update(attrs)
                attributes["order"] = order
            
            # This tag defines of types
            elif name == "group":
                if "name" in node._attrs:
                    nodename = GetAttributeValue(node._attrs["name"])
                    super, attrs = Generate_xsd_classes(node, None)
                    XMLClasses[nodename] = (super, {"group":attrs["choice_content"]})
                elif "ref" in node._attrs:
                    if "ref" not in attributes:
                        attributes["ref"] = [GetAttributeValue(node._attrs["ref"])]
                    else:
                        attributes["ref"].append(GetAttributeValue(node._attrs["ref"]))
            
            # This tag define a base class for the node
            elif name == "extension":
                super = GetAttributeValue(node._attrs["base"])
                if super.startswith("xsd"):
                    super = super.replace("xsd", "bse")
                elif super.startswith("ppx"):
                    super = super.replace("ppx", "cls")
                inheritance.append(super[4:])
                recursion = True
                
            # This tag defines a restriction on the type of attribute
            elif name == "restriction":
                basetype = GetAttributeValue(node._attrs["base"])
                if basetype.startswith("xsd"):
                    basetype = basetype.replace("xsd", "bse")
                elif basetype.startswith("ppx"):
                    basetype = basetype.replace("ppx", "cls")
                attributes["basetype"] = basetype
                recursion = True
            
            # This tag defines an enumerated type
            elif name == "enumeration":
                if "enum" not in attributes:
                    attributes["enum"] = [GetAttributeValue(node._attrs["value"])]
                else:
                    attributes["enum"].append(GetAttributeValue(node._attrs["value"]))
            
            # This tags defines a restriction on a numerical value
            elif name in ["minInclusive","maxInclusive"]:
                if "limit" not in attributes:
                    attributes["limit"] = {}
                if name == "minInclusive":
                    attributes["limit"]["min"] = eval(GetAttributeValue(node._attrs["value"]))
                elif name == "maxInclusive":
                    attributes["limit"]["max"] = eval(GetAttributeValue(node._attrs["value"]))
            
            # This tag are not important but their childrens are. The childrens are then parsed. 
            elif name in ["complexContent", "schema"]:
                recursion = True
            
            # We make fun of xsd documentation
            elif name in ["annotation"]:
                pass
            
            else:
                #print name
                Generate_xsd_classes(node, parent)
            
            # Parse the childrens of node
            if recursion:
                super, attrs = Generate_xsd_classes(node, parent)
                inheritance.extend(super)
                attributes.update(attrs)
    
    # if sequence tag have been found, order is returned
    if sequence:
        return inheritance, attributes, order
    else:
        return inheritance, attributes
"""
Function that extracts data from a node
"""
def GetAttributeValue(attr):
    if len(attr.childNodes) == 1:
        return attr.childNodes[0].data.encode()
    else:
        return ""

"""
Funtion that returns the Python type and default value for a given type
"""
def GetTypeInitialValue(attr_type):
    type_compute = attr_type[4:].replace("[]", "")
    if attr_type.startswith("bse:"):
        if type_compute == "boolean":
            return BooleanType, "False"
        elif type_compute in ["decimal","unsignedLong","long","integer"]:
            return IntType, "0"
        elif type_compute in ["string","anyURI","NMTOKEN"]:
            return StringType, "\"\""
        elif type_compute == "time":
            return TimeType, "time(0,0,0,0)"
        elif type_compute == "date":
            return DateType, "date(1,1,1)"
        elif type_compute == "dateTime":
            return DateTimeType, "datetime(1,1,1,0,0,0,0)"
        elif type_compute == "language":
            return StringType, "\"en-US\""
        else:
            print "Can't affect: %s"%type_compute
    elif attr_type.startswith("cls:"):
        if type_compute in XMLClasses:
            return XMLClasses[type_compute],"%s()"%type_compute

"""
Function that computes value from a python type (Only Boolean are critical because
there is no uppercase in plcopen)
"""
def ComputeValue(value):
    if type(value) == BooleanType:
        if value:
            return "true"
        else:
            return "false"
    else:
        return str(value)

"""
Function that extracts a value from a string following the xsd type given
"""
def GetComputedValue(attr_type, value):
    type_compute = attr_type[4:].replace("[]", "")
    if type_compute == "boolean":
         if value == "true":
             return True
         elif value == "false":
             return False
         else:
            raise ValueError, "\"%s\" is not a valid boolean!"%value
    elif type_compute in ["decimal","unsignedLong","long","integer"]:
        return int(value)
    elif type_compute in ["string","anyURI","NMTOKEN","language"]:
        return value
    elif type_compute == "time":
        result = time_model.match(value)
        if result:
            values = result.groups()
            time_values = [int(v) for v in values[:2]]
            seconds = float(values[2])
            time_values.extend([int(seconds), int((seconds % 1) * 1000000)])
            return time(*time_values)
        else:
            raise ValueError, "\"%s\" is not a valid time!"%value
    elif type_compute == "date":
        result = date_model.match(value)
        if result:
            date_values = [int(v) for v in result.groups()]
            return date(*date_values)
        else:
            raise ValueError, "\"%s\" is not a valid date!"%value
    elif type_compute == "dateTime":
        result = datetime_model.match(value)
        if result:
            values = result.groups()
            datetime_values = [int(v) for v in values[:5]]
            seconds = float(values[5])
            datetime_values.extend([int(seconds), int((seconds % 1) * 1000000)])
            return datetime(*datetime_values)
        else:
            raise ValueError, "\"%s\" is not a valid datetime!"%value
    else:
        print "Can't affect: %s"%type_compute
        return None

"""
This is the Metaclass for PLCOpen element classes. It generates automatically
the basic useful methods for manipulate the differents attributes of the classes
"""
class MetaClass(type):
    
    def __init__(cls, name, bases, dict, user_classes):
        super(MetaClass, cls).__init__(name, bases, {})
        #print name, bases, dict, "\n"
        initialValues = {}
        for attr, values in dict.items():
            if attr in ["order", "basetype"]:
                pass
            
            # Class is a enumerated type
            elif attr == "enum":
                value_type, initial = GetTypeInitialValue(dict["basetype"])
                initialValues["value"] = "\"%s\""%values[0]
                setattr(cls, "value", values[0])
                setattr(cls, "setValue", MetaClass.generateSetEnumMethod(cls, values, value_type))
                setattr(cls, "getValue", MetaClass.generateGetMethod(cls, "value"))
            
            # Class is a limited type
            elif attr == "limit":
                value_type, initial = GetTypeInitialValue(dict["basetype"])
                initial = 0
                if "min" in values:
                    initial = max(initial, values["min"])
                if "max" in values:
                    initial = min(initial, values["max"])
                initialValues["value"] = "%d"%initial
                setattr(cls, "value", initial)
                setattr(cls, "setValue", MetaClass.generateSetLimitMethod(cls, values, value_type))
                setattr(cls, "getValue", MetaClass.generateGetMethod(cls, "value"))
            
            # Class has an attribute that can have different value types
            elif attr == "choice_content":
                setattr(cls, "content", None)
                initialValues["content"] = "None"
                setattr(cls, "deleteContent", MetaClass.generateDeleteMethod(cls, "content"))
                setattr(cls, "setContent", MetaClass.generateSetChoiceMethod(cls, values))
                setattr(cls, "getContent", MetaClass.generateGetMethod(cls, "content"))
            elif attr == "multichoice_content":
                setattr(cls, "content", [])
                initialValues["content"] = "[]"
                setattr(cls, "appendContent", MetaClass.generateAppendChoiceMethod(cls, values))
                setattr(cls, "insertContent", MetaClass.generateInsertChoiceMethod(cls, values))
                setattr(cls, "removeContent", MetaClass.generateRemoveMethod(cls, "content"))
                setattr(cls, "countContent", MetaClass.generateCountMethod(cls, "content"))
                setattr(cls, "setContent", MetaClass.generateSetMethod(cls, "content", ListType))
                setattr(cls, "getContent", MetaClass.generateGetMethod(cls, "content"))
            
            # It's an attribute of the class
            else:
                attrname = attr[0].upper()+attr[1:]
                attr_type, xml_type, write_type = values
                value_type, initial = GetTypeInitialValue(attr_type)
                # Value of the attribute is a list
                if attr_type.endswith("[]"):
                    setattr(cls, attr, [])
                    initialValues[attr] = "[]"
                    setattr(cls, "append"+attrname, MetaClass.generateAppendMethod(cls, attr, value_type))
                    setattr(cls, "insert"+attrname, MetaClass.generateInsertMethod(cls, attr, value_type))
                    setattr(cls, "remove"+attrname, MetaClass.generateRemoveMethod(cls, attr))
                    setattr(cls, "count"+attrname, MetaClass.generateCountMethod(cls, attr))
                    setattr(cls, "set"+attrname, MetaClass.generateSetMethod(cls, attr, ListType))
                else:
                    if write_type == "optional":
                        setattr(cls, attr, None)
                        initialValues[attr] = "None"
                        setattr(cls, "add"+attrname, MetaClass.generateAddMethod(cls, attr, initial, user_classes))
                        setattr(cls, "delete"+attrname, MetaClass.generateDeleteMethod(cls, attr))
                    else:
                        setattr(cls, attr, initial)
                        initialValues[attr] = initial
                    setattr(cls, "set"+attrname, MetaClass.generateSetMethod(cls, attr, value_type))
                setattr(cls, "get"+attrname, MetaClass.generateGetMethod(cls, attr))
        setattr(cls, "__init__", MetaClass.generateInitMethod(cls, bases, initialValues, user_classes))
        setattr(cls, "loadXMLTree", MetaClass.generateLoadXMLTree(cls, bases, dict, user_classes))
        setattr(cls, "generateXMLText", MetaClass.generateGenerateXMLText(cls, bases, dict))
        setattr(cls, "singleLineAttributes", True)

    """
    Method that generate the method for loading an xml tree by following the
    attributes list defined
    """
    def generateLoadXMLTree(cls, bases, dict, user_classes):
        def loadXMLTreeMethod(self, tree):
            # If class is derived, values of inheritance classes are loaded
            for base in bases:
                base.loadXMLTree(self, tree)
            # Class is a enumerated or limited value
            if "enum" in dict.keys() or "limit" in dict.keys():
                attr_value = GetAttributeValue(tree)
                attr_type = dict["basetype"]
                val = GetComputedValue(attr_type, attr_value)
                self.setValue(val)
            else:
                
                # Load the node attributes if they are defined in the list
                for attrname, attr in tree._attrs.items():
                    if attrname in dict.keys():
                        attr_type, xml_type, write_type = dict[attrname]
                        attr_value = GetAttributeValue(attr)
                        if write_type != "optional" or attr_value != "":
                            # Extracts the value
                            if attr_type.startswith("bse:"):
                                val = GetComputedValue(attr_type, attr_value)
                            elif attr_type.startswith("cls:"):
                                val = eval("%s()"%attr_type[4:], globals().update(user_classes))
                                val.loadXMLTree(attr)
                            setattr(self, attrname, val)
                
                # Load the node childs if they are defined in the list
                for node in tree.childNodes:
                    name = node.nodeName
                    # We make fun of #text elements
                    if name != "#text":
                        
                        # Class has an attribute that can have different value types
                        if "choice_content" in dict.keys() and name in dict["choice_content"].keys():
                            attr_type = dict["choice_content"][name]
                            # Extracts the value
                            if attr_type.startswith("bse:"):
                                attr_value = GetAttributeValue(node)
                                if write_type != "optional" or attr_value != "":
                                    val = GetComputedValue(attr_type.replace("[]",""), attr_value)
                                else:
                                    val = None
                            elif attr_type.startswith("cls:"):
                                val = eval("%s()"%attr_type[4:].replace("[]",""), globals().update(user_classes))
                                val.loadXMLTree(node)
                            # Stock value in content attribute
                            if val:
                                if attr_type.endswith("[]"):
                                    if self.content:
                                        self.content["value"].append(val)
                                    else:
                                        self.content = {"name":name,"value":[val]}
                                else:
                                    self.content = {"name":name,"value":val}
                        
                        # Class has a list of attributes that can have different value types
                        elif "multichoice_content" in dict.keys() and name in dict["multichoice_content"].keys():
                            attr_type = dict["multichoice_content"][name]
                            # Extracts the value
                            if attr_type.startswith("bse:"):
                                attr_value = GetAttributeValue(node)
                                if write_type != "optional" or attr_value != "":
                                    val = GetComputedValue(attr_type, attr_value)
                                else:
                                    val = None
                            elif attr_type.startswith("cls:"):
                                val = eval("%s()"%attr_type[4:], globals().update(user_classes))
                                val.loadXMLTree(node)
                            # Add to content attribute list
                            if val:
                                self.content.append({"name":name,"value":val})
                        
                        # The node child is defined in the list
                        elif name in dict.keys():
                            attr_type, xml_type, write_type = dict[name]
                            # Extracts the value
                            if attr_type.startswith("bse:"):
                                attr_value = GetAttributeValue(node)
                                if write_type != "optional" or attr_value != "":
                                    val = GetComputedValue(attr_type.replace("[]",""), attr_value)
                                else:
                                    val = None
                            elif attr_type.startswith("cls:"):
                                val = eval("%s()"%attr_type[4:].replace("[]",""), globals().update(user_classes))
                                val.loadXMLTree(node)
                            # Stock value in attribute
                            if val:
                                if attr_type.endswith("[]"):
                                    getattr(self, name).append(val)
                                else:
                                    setattr(self, name, val)
        return loadXMLTreeMethod

    """
    Method that generates the method for generating an xml text by following the
    attributes list defined
    """
    def generateGenerateXMLText(cls, bases, dict):
        def generateXMLTextMethod(self, name, indent, extras = {}, derived = False):
            ind1, ind2 = getIndent(indent, name)
            if not derived:
                text = ind1 + "<%s"%name
            else:
                text = ""
            if len(bases) > 0:
                base_extras = {}
            if "order" in dict.keys():
                order = dict["order"]
            else:
                order = []
            if "choice_content" in dict.keys() and "choice_content" not in order:
                order.append("choice_content") 
            if "multichoice_content" in dict.keys() and "multichoice_content" not in order:
                order.append("multichoice_content") 
            size = 0
            first = True
            for attr, value in extras.items():
                if not first and not self.singleLineAttributes:
                    text += "\n%s"%(ind2)
                text += " %s=\"%s\""%(attr, ComputeValue(value))
                first = False
            for attr, values in dict.items():
                if attr in ["order","choice_content","multichoice_content"]:
                    pass
                elif attr in ["enum","limit"]:
                    if not derived:
                        text += ">%s</%s>\n"%(ComputeValue(self.value),name)
                    else:
                        text += ComputeValue(self.value)
                    return text
                elif values[1] == "attribute":
                    value = getattr(self, attr, None)
                    if values[2] != "optional" or value != None:
                        if not first and not self.singleLineAttributes:
                            text += "\n%s"%(ind2)
                        if values[0].startswith("cls"):
                            if len(bases) > 0:
                                base_extras[attr] = value.getValue()
                            else:
                                text += " %s=\"%s\""%(attr, ComputeValue(value.getValue()))
                        else:
                            if len(bases) > 0:
                                base_extras[attr] = value
                            else:
                                text += " %s=\"%s\""%(attr, ComputeValue(value))
                        first = False
            if len(bases) > 0:
                first, new_text = bases[0].generateXMLText(self, name, indent, base_extras, True)
                text += new_text
            else:
                first = True
            ind3, ind4 = getIndent(indent + 1, name)
            for attr in order:
                value = getattr(self, attr, None)
                if attr == "choice_content":
                    if self.content:
                        if first:
                            text += ">\n"
                            first = False
                        value_type = dict[attr][self.content["name"]]
                        if value_type.startswith("bse:"):
                            if value_type.endswith("[]"):
                                for content in self.content["value"]:
                                    text += ind1 + "<%s>%s</%s>\n"%(self.content["name"], ComputeValue(content), self.content["name"])
                            else:
                                text += ind1 + "<%s>%s</%s>\n"%(self.content["name"], ComputeValue(self.content["value"]), self.content["name"])
                        elif value_type.endswith("[]"):
                            for content in self.content["value"]:
                                text += content.generateXMLText(self.content["name"], indent + 1)
                        else:
                            text += self.content["value"].generateXMLText(self.content["name"], indent + 1)
                elif attr == "multichoice_content":
                    if len(self.content) > 0:
                        for element in self.content:
                            if first:
                                text += ">\n"
                                first = False
                            value_type = dict[attr][element["name"]]
                            if value_type.startswith("bse:"):
                                text += ind1 + "<%s>%s</%s>\n"%(element["name"], ComputeValue(element["value"]), element["name"])
                            else:
                                text += element["value"].generateXMLText(element["name"], indent + 1)
                elif dict[attr][2] != "optional" or value != None:
                    if dict[attr][0].endswith("[]"):
                        if first and len(value) > 0:
                            text += ">\n"
                            first = False
                        for element in value:
                            if dict[attr][0].startswith("bse:"):
                                text += ind3 + "<%s>%s</%s>\n"%(attr, ComputeValue(element), attr)
                            else:
                                text += element.generateXMLText(attr, indent + 1)
                    else:
                        if first:
                            text += ">\n"
                            first = False
                        if dict[attr][0].startswith("bse:"):
                            text += ind3 + "<%s>%s</%s>\n"%(attr, ComputeValue(value), attr)
                        else:
                            text += getattr(self, attr).generateXMLText(attr, indent + 1)
            if not derived:
                if first:
                    text += "/>\n"
                else:
                    text += ind1 + "</%s>\n"%(name)
                return text
            else:
                return first, text
        return generateXMLTextMethod
        
    """
    Methods that generates the different methods for setting and getting the attributes
    """
    
    def generateInitMethod(cls, bases, dict, user_classes):
        def initMethod(self):
            for base in bases:
                base.__init__(self)
            for attr, initial in dict.items():
                setattr(self, attr, eval(initial, globals().update(user_classes)))
        return initMethod

    def generateSetMethod(cls, attr, choice_type):
        def setMethod(self, value):
            setattr(self, attr, value)
        return setMethod

    def generateSetChoiceMethod(cls, attr_type):
        def setChoiceMethod(self, name, value):
            self.content = {"name":name,"value":value}
        return setChoiceMethod

    def generateSetEnumMethod(cls, enum, attr_type):
        def setEnumMethod(self, value):
            if value in enum:
                self.value = value
            else:
                raise ValueError, "%s is not a valid value. Must be in %s"%(value, str(enum))
        return setEnumMethod

    def generateSetLimitMethod(cls, limit, attr_type):
        def setMethod(self, value):
            if "min" in limit and value < limit["min"]:
                raise ValueError, "%s is not a valid value. Must be greater than %d"%(value, limit["min"])
            elif "max" in limit and value > limit["max"]:
                raise ValueError, "%s is not a valid value. Must be smaller than %d"%(value, limit["max"])
            else:
                self.value = value
        return setMethod

    def generateGetMethod(cls, attr):
        def getMethod(self):
            return getattr(self, attr, None)
        return getMethod

    def generateAddMethod(cls, attr, initial, user_classes):
        def addMethod(self):
            setattr(self, attr, eval(initial, globals().update(user_classes)))
        return addMethod

    def generateDeleteMethod(cls, attr):
        def deleteMethod(self):
            setattr(self, attr, None)
        return deleteMethod

    def generateAppendMethod(cls, attr, attr_type):
        def appendMethod(self, value):
            getattr(self, attr).append(value)
        return appendMethod

    def generateInsertMethod(cls, attr, attr_type):
        def insertMethod(self, index, value):
            getattr(self, attr).insert(index, value)
        return insertMethod

    def generateAppendChoiceMethod(cls, choice_types):
        def appendMethod(self, name, value):
            self.content.append({"name":name,"value":value})
        return appendMethod

    def generateInsertChoiceMethod(cls, choice_types):
        def insertMethod(self, index, name, value):
            self.content.insert(index, {"name":name,"value":value})
        return insertMethod

    def generateRemoveMethod(cls, attr):
        def removeMethod(self, index):
            getattr(self, attr).pop(index)
        return removeMethod

    def generateCountMethod(cls, attr):
        def countMethod(self):
            return len(getattr(self, attr))
        return countMethod

"""
Methods that generate the classes
"""
def CreateClasses(user_classes, user_types):
    for classname in XMLClasses.keys():
        CreateClass(classname, user_classes, user_types)

def CreateClass(classname, user_classes, user_types):
    # Checks that classe haven't been generated yet
    if classname not in user_classes and classname not in user_types and classname in XMLClasses:
        inheritance, attributes = XMLClasses[classname]
        #print classe, inheritance, attributes
        dict = {}
        bases = []
        
        # If inheritance classes haven't been generated
        for base in inheritance:
            if base not in user_classes:
                CreateClass(base, user_classes, user_types)
            bases.append(user_classes[base])
        
        # Checks that all attribute types are available 
        for attribute, type_attribute in attributes.items():
            if attribute == "group":
                user_types[classname] = type_attribute
            elif attribute == "ref":
                user_types[classname] = {}
                for attr in type_attribute:
                    if attr[4:] not in user_types:
                        CreateClass(attr[4:], user_classes, user_types)
                    user_types[classname].update(user_types[attr[4:]])
            elif attribute in ["choice_content","multichoice_content"]:
                element_types = {}
                for attr, value in type_attribute.items():
                    if attr == "ref":
                        for ref in type_attribute["ref"]:
                            if ref[4:] not in user_types:
                                CreateClass(ref[4:], user_classes, user_types)
                            element_types.update(user_types[ref[4:]])
                    else:
                        element_types[attr] = value
                dict[attribute] = element_types
            else:
                dict[attribute] = type_attribute
                if attribute == "enum":
                    user_types["%s_enum"%classname] = type_attribute
                elif attribute not in ["limit", "order"]:
                    if type_attribute[0].startswith("ppx:"):
                        type_compute = type_attribute[0][4:].replace("[]","")
                        if type_compute not in user_classes:
                            CreateClass(type_compute, user_classes, user_types)
        if "group" not in attributes.keys() and "ref" not in attributes.keys():
            cls = MetaClass.__new__(MetaClass, classname, tuple(bases), dict)
            MetaClass.__init__(cls, classname, tuple(bases), dict, user_classes)
            user_classes[classname] = cls

"""
Methods that print the classes generated
"""
def PrintClasses():
    for classname, xmlclass in XMLClasses.items():
        print "%s : %s\n"%(classname, str(xmlclass))
    
def PrintClassNames():
    classnames = XMLClasses.keys()
    classnames.sort()
    for classname in classnames:
        print classname