minixsv/xsvalBase.py
author etisserant
Fri, 13 Jul 2007 19:21:17 +0200
changeset 39 5b04b4670697
parent 0 b622defdfd98
permissions -rw-r--r--
First working IEC std lib test, actually test from string and to_string functions.
#
# minixsv, Release 0.3
# file: xsvalBase.py
#
# XML schema validator base class
#
# history:
# 2004-10-07 rl   created
#
# Copyright (c) 2004 by Roland Leuthe.  All rights reserved.
#
# --------------------------------------------------------------------
# The minixsv XML schema validator is
#
# Copyright (c) 2004 by Roland Leuthe
#
# By obtaining, using, and/or copying this software and/or its
# associated documentation, you agree that you have read, understood,
# and will comply with the following terms and conditions:
#
# Permission to use, copy, modify, and distribute this software and
# its associated documentation for any purpose and without fee is
# hereby granted, provided that the above copyright notice appears in
# all copies, and that both that copyright notice and this permission
# notice appear in supporting documentation, and that the name of
# the author not be used in advertising or publicity
# pertaining to distribution of the software without specific, written
# prior permission.
#
# THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
# TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANT-
# ABILITY AND FITNESS.  IN NO EVENT SHALL THE AUTHOR
# BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
# OF THIS SOFTWARE.
# --------------------------------------------------------------------

from xsvalErrorHandler import *
import xsvalSimpleTypes

###########################################################
#  Validator class for validating one input file against one XML schema file

class XsValBase:

    def __init__(self, xmlIf, errorHandler):
        self.xmlIf         = xmlIf
        self.errorHandler  = errorHandler

        self._raiseError   = self.errorHandler.raiseError
        self._addError     = self.errorHandler.addError
        self._addWarning   = self.errorHandler.addWarning

        self.checkKeyrefList = []


    ########################################
    # validate inputTree against xsdTree
    #
    def validate (self, inputTree, xsdTree):
        self.inputTree = inputTree
        self.xsdTree   = xsdTree

        self.xsdRoot     = self.xsdTree.getRootNode()
        self.xsdNSAlias  = self.xmlIf.extractNamespaceAlias(self.xsdRoot.getTagName())
        self.inputRoot    = self.inputTree.getRootNode()
        self.inputNSAlias = self.xmlIf.extractNamespaceAlias(self.inputRoot.getTagName())

        self.simpleTypeVal = xsvalSimpleTypes.XsSimpleTypeVal(self)

        self._setupLookupTables()

        inputRootTagName = self.inputRoot.getTagName()
        inputRootLocalName = self.inputRoot.getLocalName()
        if self.xsdElementDict.has_key(inputRootLocalName):
            # start recursive schema validation
            try:
                self._checkElementTag (self.xsdElementDict[inputRootLocalName], inputRootTagName, (self.inputRoot,), 0)
            except TagException, errInst:
                self._addError (errInst.errstr, errInst.node, errInst.endTag)

            # validate keyrefs
            for inputElement, keyrefNode in self.checkKeyrefList:
                self._checkKeyRefConstraint (keyrefNode, inputElement)
        else:
            self._raiseError ("Used root tag %s not found in schema file!" %(inputRootTagName), self.inputRoot)


    ########################################
    # setup lookup dictionaries used during validation
    #
    def _setupLookupTables (self):
        # retrieve all elements
        self.xsdElementDict = {}
        for xsdTypeNode in self.xsdRoot.getChildrenNS(self.xsdNSAlias, "element"):
            self.xsdElementDict[xsdTypeNode.getAttribute("name")] = xsdTypeNode

        # retrieve all type definitions (complex and simple types)
        self.xsdTypeDict = {}
        for xsdTypeNode in self.xsdRoot.getChildrenNS(self.xsdNSAlias, "complexType"):
            self.xsdTypeDict[xsdTypeNode.getAttribute("name")] = xsdTypeNode

        for xsdTypeNode in self.xsdRoot.getChildrenNS(self.xsdNSAlias, "simpleType"):
            self.xsdTypeDict[xsdTypeNode.getAttribute("name")] = xsdTypeNode

        # retrieve all group definitions
        self.xsdGroupDict = {}
        for xsdTypeNode in self.xsdRoot.getChildrenNS(self.xsdNSAlias, "group"):
            self.xsdGroupDict[xsdTypeNode.getAttribute("name")] = xsdTypeNode

        # retrieve all attribute group definitions
        self.xsdAttributeGroupDict = {}
        for xsdTypeNode in self.xsdRoot.getChildrenNS(self.xsdNSAlias, "attributeGroup"):
            self.xsdAttributeGroupDict[xsdTypeNode.getAttribute("name")] = xsdTypeNode

        # retrieve all identity constraints
        self.xsdIdentityConstrDict = {}
        for identConstrTagName in ("unique", "key", "keyref"):
            identConstrNodeList = self.xsdRoot.getElementsByTagNameNS (self.xsdNSAlias, identConstrTagName)
            for identConstrNode in identConstrNodeList:
                identConstrName = identConstrNode.getAttribute("name")
                if not self.xsdIdentityConstrDict.has_key(identConstrName):
                    self.xsdIdentityConstrDict[identConstrName] = {"Node": identConstrNode, "ValueDict":{}}
                else:
                    self._raiseError ("Duplicate identity constraint name '%s' found in schema definition!" %(identConstrName), identConstrNode)


    ########################################
    # validate inputElement against complexType node
    #
    def _checkComplexTypeTag (self, xsdParentElementNode, xsdElement, inputElement, inputElementChildIndex, usedAsBaseType=None):
        baseTypeAttributes = {"__SPECIAL_ATTRS__":{}}
        if xsdParentElementNode.getAttribute ("nillable") == "true":
            baseTypeAttributes["__SPECIAL_ATTRS__"]["nil"] = "xsd:boolean"

        complexContentElement = xsdElement.getFirstChildNS(self.xsdNSAlias, "complexContent")
        if complexContentElement != None:
            inputElementChildIndex, baseTypeAttributes = self._checkComplexContentTag (xsdParentElementNode, complexContentElement, inputElement, inputElementChildIndex, usedAsBaseType, baseTypeAttributes)
        else:
            inputElementChildIndex, baseTypeAttributes = self._checkComplexTypeContent (xsdElement, inputElement, inputElementChildIndex, usedAsBaseType, baseTypeAttributes)
        return inputElementChildIndex, baseTypeAttributes

    def _checkComplexContentTag (self, xsdParentElementNode, xsdElement, inputElement, inputElementChildIndex, usedAsBaseType, baseTypeAttributes):
        extensionElement = xsdElement.getFirstChildNS(self.xsdNSAlias, "extension")
        if extensionElement != None:
            inputElementChildIndex, baseTypeAttributes = self._checkExtensionComplexContent (xsdParentElementNode, extensionElement, inputElement, inputElementChildIndex, usedAsBaseType, baseTypeAttributes)
        else:
            restrictionElement = xsdElement.getFirstChildNS(self.xsdNSAlias, "restriction")
            if restrictionElement != None:
                inputElementChildIndex, baseTypeAttributes = self._checkRestrictionComplexContent (xsdParentElementNode, restrictionElement, inputElement, inputElementChildIndex, usedAsBaseType, baseTypeAttributes)
        return inputElementChildIndex, baseTypeAttributes

    def _checkExtensionComplexContent (self, xsdParentElementNode, xsdElement, inputElement, inputElementChildIndex, usedAsBaseType, baseTypeAttributes):
        baseType = self.xmlIf.extractLocalName(xsdElement.getAttribute("base"))
        inputElementChildIndex, baseTypeAttributes = self._checkComplexTypeTag (xsdParentElementNode, self.xsdTypeDict[baseType], inputElement, inputElementChildIndex, "extension")

        inputElementChildIndex, baseTypeAttributes = self._checkComplexTypeContent (xsdElement, inputElement, inputElementChildIndex, usedAsBaseType, baseTypeAttributes)
        return inputElementChildIndex, baseTypeAttributes

    def _checkRestrictionComplexContent (self, xsdParentElementNode, xsdElement, inputElement, inputElementChildIndex, usedAsBaseType, baseTypeAttributes):
        # first check against base type (retrieve only the base type attributes)
        baseType = self.xmlIf.extractLocalName(xsdElement.getAttribute("base"))
        inputElementChildIndex, baseTypeAttributes = self._checkComplexTypeTag (xsdParentElementNode, self.xsdTypeDict[baseType], inputElement, inputElementChildIndex, "restriction")

        # then check input against derived complex type
        inputElementChildIndex, baseTypeAttributes = self._checkComplexTypeContent (xsdElement, inputElement, inputElementChildIndex, usedAsBaseType, baseTypeAttributes)
        return inputElementChildIndex, baseTypeAttributes

    def _checkComplexTypeContent (self, xsdElement, inputElement, inputElementChildIndex, usedAsBaseType, baseTypeAttributes):
        inputTagName = inputElement.getTagName()
        childTags = inputElement.getChildren()
        if usedAsBaseType in (None, "extension"):
            validChildTags = xsdElement.getChildren()
            for validChildTag in validChildTags:
                if validChildTag.getLocalName() not in ("attribute", "attributeGroup", "anyAttribute"):
                    inputElementChildIndex = self._checkParticle (validChildTag, inputElement, childTags, inputElementChildIndex)

            if usedAsBaseType == None and inputElementChildIndex < len (childTags):
                self._addError ("Unexpected child tag '%s' in tag '%s' found!" %(childTags[inputElementChildIndex].getTagName(), inputTagName), childTags[inputElementChildIndex])

        if usedAsBaseType in (None,):
            self._checkAttributeTags (xsdElement, inputElement, baseTypeAttributes)

        if usedAsBaseType in ("restriction", "extension"):
            validAttributes = xsdElement.getChildrenNS(self.xsdNSAlias, "attribute")
            for validAttrGroup in xsdElement.getChildrenNS(self.xsdNSAlias, "attributeGroup"):
                attributeGroupRef = self.xmlIf.extractLocalName(validAttrGroup.getAttribute("ref"))
                validAttributes.extend (self.xsdAttributeGroupDict[attributeGroupRef].getChildrenNS(self.xsdNSAlias, "attribute"))
            for validAttribute in validAttributes:
                baseTypeAttributes[validAttribute.getAttribute("name")] = validAttribute
        return inputElementChildIndex, baseTypeAttributes


    ########################################
    # validate inputNodeList against xsdNode
    #
    def _checkList (self, elementMethod, xsdNode, inputParentNode, inputNodeList, currIndex):
        if not xsdNode.hasAttribute("minOccurs"):
            xsdNode.setAttribute("minOccurs", "1") # default
        if not xsdNode.hasAttribute("maxOccurs"):
            xsdNode.setAttribute("maxOccurs", "1") # default

        minOccurs = string.atoi(xsdNode.getAttribute("minOccurs"))
        maxOccurs = -1
        if xsdNode.getAttribute("maxOccurs") != "unbounded":
            maxOccurs = string.atoi(xsdNode.getAttribute("maxOccurs"))
        occurs = 0
        while maxOccurs == -1 or occurs < maxOccurs:
            try:
                newIndex = elementMethod (xsdNode, inputParentNode, inputNodeList, currIndex)
                occurs += 1
                if newIndex > currIndex:
                    currIndex = newIndex
                else:
                    break # no suitable element found
            except TagException, errInst:
                break

        if occurs == 0 and minOccurs > 0:
            raise errInst
        elif occurs < minOccurs:
            expInputTagName = xsdNode.getAttribute("name")
            if expInputTagName == None:
                expInputTagName = self.xmlIf.extractLocalName(xsdNode.getAttribute("ref"))

            errInst.errstr = "Minimum number (%d) of child tags '%s' in tag '%s' not available (only %d)!" %(minOccurs, expInputTagName, inputParentNode.getTagName(), occurs)
            raise errInst

        return currIndex

    ########################################
    # validate inputNode against element node
    #
    def _checkElementTag (self, xsdNode, inputParentNode, inputNodeList, currIndex):
        if xsdNode.hasAttribute("ref"):
            refAttr = self.xmlIf.extractLocalName(xsdNode.getAttribute("ref"))
            currIndex = self._checkElementTag (self.xsdElementDict[refAttr], inputParentNode, inputNodeList, currIndex)

        else:
            nameAttr = xsdNode.getAttribute ("name")
            if currIndex >= len (inputNodeList):
                raise TagException ("Missing child tag '%s' in tag '%s'!" %(nameAttr, inputParentNode.getTagName()), inputParentNode, 1)

            inputNode = inputNodeList[currIndex]
            if nameAttr != inputNode.getLocalName():
                raise TagException ("Missing child tag '%s' in tag '%s'!" %(nameAttr, inputParentNode.getTagName()), inputNode, 0)

            simpleType = None
            complexTypeNode = xsdNode.getFirstChildNS (self.xsdNSAlias, "complexType")
            simpleTypeNode  = xsdNode.getFirstChildNS (self.xsdNSAlias, "simpleType")
            if xsdNode.hasAttribute("type"):
                typeAttr = xsdNode.getAttribute ("type")
                localTypeAttr = self.xmlIf.extractLocalName(typeAttr)
                if self.xsdTypeDict.has_key (localTypeAttr) and self.xsdTypeDict[localTypeAttr].getLocalName() == "complexType":
                    complexTypeNode = self.xsdTypeDict[localTypeAttr]
                else:
                    simpleType = typeAttr

            if complexTypeNode != None:
                try:
                    self._checkComplexTypeTag (xsdNode, complexTypeNode, inputNode, 0)
                except TagException, errInst:
                    self._addError (errInst.errstr, errInst.node, errInst.endTag)
            else:
                try:
                    simpleTypeReturnDict = {}
                    if simpleTypeNode != None:
                        self.simpleTypeVal.checkSimpleTypeDef (simpleTypeNode, inputNode.getTagName(), inputNode.getElementValue(), simpleTypeReturnDict)
                    elif simpleType != None:
                        self.simpleTypeVal.checkSimpleType (inputNode.getTagName(), simpleType, inputNode.getElementValue(), simpleTypeReturnDict)
                    # TODO: What to check if np type is specified for the element?

                    if simpleTypeReturnDict.has_key("adaptedAttrValue"):
                        inputNode.setElementValue(simpleTypeReturnDict["adaptedAttrValue"])

                except xsvalSimpleTypes.SimpleTypeError, errstr:
                    self._addError (str(errstr), inputNode)

            currIndex += 1

            # check unique attributes and keys
            childUniqueDefList = xsdNode.getChildrenNS (self.xsdNSAlias, "unique")
            for childUniqueDef in childUniqueDefList:
                self._checkIdentityConstraint (childUniqueDef, inputNode, "unique")

            childKeyDefList = xsdNode.getChildrenNS (self.xsdNSAlias, "key")
            for childKeyDef in childKeyDefList:
                self._checkIdentityConstraint (childKeyDef, inputNode, "key")

            childKeyrefDefList = xsdNode.getChildrenNS (self.xsdNSAlias, "keyref")
            for childKeyrefDef in childKeyrefDefList:
                self.checkKeyrefList.append ((inputNode, childKeyrefDef))

        return currIndex


    ########################################
    # validate inputNode against sequence node
    #
    def _checkSequenceTag (self, xsdNode, inputParentNode, inputNodeList, currIndex):
        for xsdChildNode in xsdNode.getChildren():
            currIndex = self._checkParticle (xsdChildNode, inputParentNode, inputNodeList, currIndex)
        return currIndex

    ########################################
    # validate inputNode against choice node
    #
    def _checkChoiceTag (self, xsdNode, inputParentNode, inputNodeList, currIndex):
        for xsdChildNode in xsdNode.getChildren():
            try:
                currIndex = self._checkParticle (xsdChildNode, inputParentNode, inputNodeList, currIndex)
                break
            except TagException, errInst:
                pass
        else:
            if currIndex < len(inputNodeList):
                currNode = inputNodeList[currIndex]
                endTag = 0
            else:
                currNode = inputParentNode
                endTag = 1
            raise TagException ("No suitable child tag for choice found!", currNode, endTag)

        return currIndex

    ########################################
    # validate inputNode against group node
    #
    def _checkGroupTag (self, xsdNode, inputParentNode, inputNodeList, currIndex):
        if xsdNode.hasAttribute("ref"):
            refAttr = self.xmlIf.extractLocalName(xsdNode.getAttribute("ref"))
            currIndex = self._checkGroupTag (self.xsdGroupDict[refAttr], inputParentNode, inputNodeList, currIndex)
        else:
            for xsdChildNode in xsdNode.getChildren():
                currIndex = self._checkParticle (xsdChildNode, inputParentNode, inputNodeList, currIndex)
        return currIndex

    ########################################
    # validate inputNode against all node
    #
    def _checkAllTag (self, xsdNode, inputParentNode, inputNodeList, currIndex):
        oldIndex = currIndex
        xsdChildDict = {}
        for xsdChildNode in xsdNode.getChildren():
            xsdChildDict[xsdChildNode] = 0
        while currIndex < len(inputNodeList):
            currNode = inputNodeList[currIndex]
            for xsdChildNode in xsdChildDict.keys():
                try:
                    newIndex = self._checkParticle (xsdChildNode, inputParentNode, inputNodeList, currIndex)
                except TagException, errInst:
                    continue

                if xsdChildDict[xsdChildNode] == 0:
                    xsdChildDict[xsdChildNode] = 1
                    currIndex = newIndex
                    break
                else:
                    raise TagException ("Ambiguous child tag '%s' found in all-group!" %(currNode.getTagName()), currNode)
            else:
                raise TagException ("Unexpected child tag '%s' for all-group found!" %(currNode.getTagName()), currNode)

        for xsdChildNode, occurs in xsdChildDict.items():
           if xsdChildNode.getAttribute("minOccurs") != "0" and occurs == 0:
               raise TagException ("Child tag '%s' missing in all-group (%s)" %(xsdChildNode.getAttribute("name"), inputParentNode.getTagName()), inputNodeList[oldIndex])

        return currIndex


    ########################################
    # validate inputNode against any node
    #
    def _checkAnyTag (self, xsdNode, inputParentNode, inputNodeList, currIndex):
        processContents = xsdNode.getAttribute("processContents")
        if processContents == "skip":
            pass
        elif processContents == "lax":
            # TODO: Was muss hier gecheckt werden?
            pass
        elif processContents == "strict":
            # TODO: Was muss hier gecheckt werden?
            pass

        if currIndex < len(inputNodeList):
            currIndex = currIndex + 1

        return currIndex

    ########################################
    # validate inputNode against particle
    #
    def _checkParticle (self, xsdNode, inputParentNode, inputNodeList, currIndex):
        xsdTagName = xsdNode.getTagName()
        if xsdTagName == self.xsdNSAlias + "element":
            currIndex = self._checkList (self._checkElementTag, xsdNode, inputParentNode, inputNodeList, currIndex)
        elif xsdTagName == self.xsdNSAlias + "choice":
            currIndex = self._checkList (self._checkChoiceTag, xsdNode, inputParentNode, inputNodeList, currIndex)
        elif xsdTagName == self.xsdNSAlias + "sequence":
            currIndex = self._checkList (self._checkSequenceTag, xsdNode, inputParentNode, inputNodeList, currIndex)
        elif xsdTagName == self.xsdNSAlias + "group":
            currIndex = self._checkList (self._checkGroupTag, xsdNode, inputParentNode, inputNodeList, currIndex)
        elif xsdTagName == self.xsdNSAlias + "all":
            currIndex = self._checkList (self._checkAllTag, xsdNode, inputParentNode, inputNodeList, currIndex)
        elif xsdTagName == self.xsdNSAlias + "any":
            currIndex = self._checkList (self._checkAnyTag, xsdNode, inputParentNode, inputNodeList, currIndex)
        elif xsdTagName == self.xsdNSAlias + "annotation":
            pass # nothing to check
        else:
            self._addError ("Internal error: Invalid tag %s found!" %(xsdTagName))
        return currIndex


    ########################################
    # validate attributes of inputNode against complexType node
    #
    def _checkAttributeTags (self, xsdNode, inputNode, validAttrDict):
        validAttributes = xsdNode.getChildrenNS(self.xsdNSAlias, "attribute")
        for validAttrGroup in xsdNode.getChildrenNS(self.xsdNSAlias, "attributeGroup"):
            attributeGroupRef = self.xmlIf.extractLocalName(validAttrGroup.getAttribute("ref"))
            validAttributes.extend (self.xsdAttributeGroupDict[attributeGroupRef].getChildrenNS(self.xsdNSAlias, "attribute"))
        for validAttribute in validAttributes:
            if validAttribute.hasAttribute("name"):
                keyAttr = validAttribute.getAttribute("name")
            else:
                keyAttr = self.xmlIf.extractLocalName(validAttribute.getAttribute("ref"))
            validAttrDict[keyAttr] = validAttribute

        inputAttrDict = {}
        for iAttrName, iAttrValue in inputNode.getAttributeDict().items():
            if self.xmlIf.extractNamespaceAlias (iAttrName) != "xmlns:" and iAttrName != "xmlns":
                inputAttrDict[self.xmlIf.extractLocalName(iAttrName)] = iAttrValue

        for attrKey, validAttribute in validAttrDict.items():
            # handle special attributes, e.g. xsi:nil
            if attrKey == "__SPECIAL_ATTRS__":
                for specialAttrName, specialAttrType in validAttribute.items():
                    if inputAttrDict.has_key(specialAttrName):
                        simpleTypeReturnDict = {}
                        try:
                            self.simpleTypeVal.checkSimpleType (specialAttrName, specialAttrType, inputAttrDict[specialAttrName], simpleTypeReturnDict)
                        except xsvalSimpleTypes.SimpleTypeError, errstr:
                            self._addError (str(errstr), inputNode)

                        del inputAttrDict[specialAttrName]
                continue

            attrDict = validAttribute.getAttributeDict()
            if attrDict.has_key("ref"):
                # TODO: What to do here??
                attrRef = self.xmlIf.extractLocalName(attrDict["ref"])
                if inputAttrDict.has_key(attrRef):
                    del inputAttrDict[attrRef]
            else:
                attrName = attrDict["name"]
                if not attrDict.has_key("use"):
                    attrDict["use"] = "optional"

                if inputAttrDict.has_key(attrName):
                    del inputAttrDict[attrName]
                else:
                    if attrDict["use"] == "required":
                        self._addError ("Attribute '%s' is missing for tag %s!" %(attrName, inputNode.getTagName()), inputNode)
                    elif attrDict["use"] == "optional":
                        if attrDict.has_key("default"):
                            inputNode.setAttribute(attrName, attrDict["default"])
                if attrDict.has_key("fixed"):
                    if inputNode.getAttribute(attrName) != attrDict["fixed"]:
                        self._addError ("Attribute '%s' must have fixed value '%s'!" %(attrName, attrDict["fixed"]), inputNode)

                if inputNode.hasAttribute(attrName):
                    if attrDict["use"] == "prohibited":
                        self._addError ("Attribute '%s' is prohibited in this context!" %(attrName), inputNode)
                    else:
                        attributeValue = inputNode.getAttribute(attrName)
                        try:
                            simpleTypeReturnDict = {}
                            if attrDict.has_key("type"):
                                self.simpleTypeVal.checkSimpleType (attrName, attrDict["type"], attributeValue, simpleTypeReturnDict)
                            else:
                                typedefNode = validAttribute.getFirstChildNS(self.xsdNSAlias, "simpleType")
                                if typedefNode != None:
                                    self.simpleTypeVal.checkSimpleTypeDef (typedefNode, attrName, attributeValue, simpleTypeReturnDict)
                                else:
                                    pass    # default if no type attribute is specified

                            if simpleTypeReturnDict.has_key("adaptedAttrValue"):
                                inputNode.setAttribute(attrName, simpleTypeReturnDict["adaptedAttrValue"])

                        except xsvalSimpleTypes.SimpleTypeError, errstr:
                            self._addError (str(errstr), inputNode)

        for inputAttribute in inputAttrDict.keys():
            # TODO: adapt for using namespaces!!
            if self.xmlIf.extractLocalName(inputAttribute) in ("noNamespaceSchemaLocation", "schemaLocation"):
                del inputAttrDict[inputAttribute]

        for inputAttribute in inputAttrDict.keys():
            if inputAttribute == "nil":
                self._addError ("Tag '%s' hasn't been defined as nillable!" %(inputNode.getTagName()), inputNode)
            else:
                self._addError ("Unexpected attribute '%s' in Tag '%s'!" %(inputAttribute, inputNode.getTagName()), inputNode)


    ########################################
    # validate unique and key definition
    #
    def _checkIdentityConstraint (self, identityConstrNode, inputElement, isKey):
        identConstrName = identityConstrNode.getAttribute ("name")
        selectorXPathNode = identityConstrNode.getFirstChildNS (self.xsdNSAlias, "selector")
        selectorNodeList, dummy = self._getXPath (inputElement, selectorXPathNode.getAttribute("xpath"), self.inputNSAlias)

        valueDict = {}
        for selectorNode in selectorNodeList:
            fieldXPathNodeList = identityConstrNode.getChildrenNS (self.xsdNSAlias, "field")
            keyValue = []
            for fieldXPathNode in fieldXPathNodeList:
                fieldXPath = fieldXPathNode.getAttribute("xpath")
                fieldNodeList, fieldAttributeList = self._getXPath (selectorNode, fieldXPath, self.inputNSAlias, isKey)
                if len(fieldNodeList) > 1 or len(fieldAttributeList) > 1:
                    self._addError ("The field xPath of identity constraint '%s' must evaluate to exactly 0 or 1 node!" %(identConstrName), fieldXPathNode)
                    return

                # TODO: unique and key check currently only on string base
                for fieldNode in fieldNodeList:
                    keyValue.append (fieldNode.getElementValue ())

                for attrValue in fieldAttributeList:
                    keyValue.append (attrValue)

            if keyValue != []:
                keyValue = tuple(keyValue)
                if not valueDict.has_key (keyValue):
                    valueDict[keyValue] = 1
                    self.xsdIdentityConstrDict[identConstrName]["ValueDict"][keyValue] = 1
                else:
                    self._addError ("Duplicate identity constraint values '%s' found for identity contraint '%s'!" %(keyValue, identConstrName), selectorNode)

    ########################################
    # validate unique and key definition
    #
    def _checkKeyRefConstraint (self, keyrefNode, inputElement):
        keyRefName = keyrefNode.getAttribute ("name")
        keyReference = keyrefNode.getAttribute ("refer")
        if not self.xsdIdentityConstrDict.has_key (keyReference):
            self._addError ("keyref refers unknown key '%s'!" %(keyReference), keyrefNode)
            return

        selectorXPathNode = keyrefNode.getFirstChildNS (self.xsdNSAlias, "selector")
        selectorNodeList, dummy = self._getXPath (inputElement, selectorXPathNode.getAttribute("xpath"), self.inputNSAlias)

        for selectorNode in selectorNodeList:
            fieldXPathNodeList = keyrefNode.getChildrenNS(self.xsdNSAlias, "field")
            keyValue = []
            for fieldXPathNode in fieldXPathNodeList:
                fieldXPath = fieldXPathNode.getAttribute("xpath")
                fieldNodeList, fieldAttributeList = self._getXPath (selectorNode, fieldXPath, self.inputNSAlias, "keyref")
                if len(fieldNodeList) > 1 or len(fieldAttributeList) > 1:
                    self._addError ("The field xPath of keyref '%s' must evaluate to exactly 0 or 1 node!" %(keyRefName), fieldXPathNode)
                    return

                # TODO: unique and key check currently only on string base
                for fieldNode in fieldNodeList:
                    keyValue.append(fieldNode.getElementValue())

                for attrValue in fieldAttributeList:
                    keyValue.append(attrValue)

            keyValue = tuple(keyValue)
            if not self.xsdIdentityConstrDict[keyReference]["ValueDict"].has_key (keyValue):
                self._addError ("Element value '%s' does not match key type '%s'!" %(keyValue, keyReference), selectorNode)

    ########################################
    # retrieve nodes/attributes specified by given xPath
    #
    def _getXPath (self, node, xPath, defaultNamespace, identityConstraint=None):
        try:
            nodeList, attributeList = node.getXPathList (xPath, defaultNamespace)
        except IOError, errstr:
            self._addError (errstr, node)
            nodeList = attributeList = []

        if nodeList == [] and attributeList == []:
            if identityConstraint == "key":
                self.errorHandler.addError ("Key is missing! XPath = '%s'!" %(xPath), node)
            elif identityConstraint in ("unique", "keyref"):
                self.errorHandler.addWarning ("Identity constraint is missing! XPath = '%s'!" %(xPath), node)

        return nodeList, attributeList


########################################
# define own exception for XML schema validation errors
#
class TagException (StandardError):
    def __init__ (self, errstr="", node=None, endTag=0):
        self.node   = node
        self.errstr = errstr
        self.endTag = endTag
        StandardError.__init__(self)