#---------------------------------------------------------------------------- # Name: xmlmarshaller.py # Purpose: # # Author: John Spurling # # Created: 7/28/04 # CVS-ID: $Id$ # Copyright: (c) 2004-2005 ActiveGrid, Inc. # License: wxWindows License #---------------------------------------------------------------------------- import __builtin__ import sys from types import * import xml.sax import xml.sax.handler from xml.sax import saxutils import objutils MODULE_PATH = "__main__" ### ToDO remove maxOccurs "unbounded" resolves to -1 hacks after bug 177 is fixed """ More documentation later, but here are some special Python attributes that McLane recognizes: name: __xmlname__ type: string description: the name of the xml element for the marshalled object name: __xmlattributes__ type: tuple or list description: the name(s) of the Python string attribute(s) to be marshalled as xml attributes instead of nested xml elements. currently these can only be strings since there's not a way to get the type information back when unmarshalling. name: __xmlexclude__ type: tuple or list description: the name(s) of the python attribute(s) to skip when marshalling. name: __xmlrename__ type: dict description: describes an alternate Python <-> XML name mapping. Normally the name mapping is the identity function. __xmlrename__ overrides that. The keys are the Python names, the values are their associated XML names. name: __xmlflattensequence__ type: dict, tuple, or list description: the name(s) of the Python sequence attribute(s) whose items are to be marshalled as a series of xml elements (with an optional keyword argument that specifies the element name to use) as opposed to containing them in a separate sequence element, e.g.: myseq = (1, 2) 1 2 1 2 name: __xmlnamespaces__ type: dict description: a dict of the namespaces that the object uses. Each item in the dict should consist of a prefix,url combination where the key is the prefix and url is the value, e.g.: __xmlnamespaces__ = { "xsd":"http://www.w3c.org/foo.xsd" } name: __xmldefaultnamespace__ type: String description: the prefix of a namespace defined in __xmlnamespaces__ that should be used as the default namespace for the object. name: __xmlattrnamespaces__ type: dict description: a dict assigning the Python object's attributes to the namespaces defined in __xmlnamespaces__. Each item in the dict should consist of a prefix,attributeList combination where the key is the prefix and the value is a list of the Python attribute names. e.g.: __xmlattrnamespaces__ = { "ag":["firstName", "lastName", "addressLine1", "city"] } name: __xmlattrgroups__ type: dict description: a dict specifying groups of attributes to be wrapped in an enclosing tag. The key is the name of the enclosing tag; the value is a list of attributes to include within it. e.g. __xmlattrgroups__ = {"name": ["firstName", "lastName"], "address": ["addressLine1", "city", "state", "zip"]} """ ################################################################################ # # module exceptions # ################################################################################ class Error(Exception): """Base class for errors in this module.""" pass class UnhandledTypeException(Error): """Exception raised when attempting to marshal an unsupported type. """ def __init__(self, typename): self.typename = typename def __str__(self): return "%s is not supported for marshalling." % str(self.typename) class XMLAttributeIsNotStringType(Error): """Exception raised when an object's attribute is specified to be marshalled as an XML attribute of the enclosing object instead of a nested element. """ def __init__(self, attrname, typename): self.attrname = attrname self.typename = typename def __str__(self): return """%s was set to be marshalled as an XML attribute instead of a nested element, but the object's type is %s, not string.""" % (self.attrname, self.typename) ################################################################################ # # constants and such # ################################################################################ XMLNS = 'xmlns' XMLNS_PREFIX = XMLNS + ':' XMLNS_PREFIX_LENGTH = len(XMLNS_PREFIX) BASETYPE_ELEMENT_NAME = 'item' # This list doesn't seem to be used. # Internal documentation or useless? You make the call! MEMBERS_TO_SKIP = ('__module__', '__doc__', '__xmlname__', '__xmlattributes__', '__xmlexclude__', '__xmlflattensequence__', '__xmlnamespaces__', '__xmldefaultnamespace__', '__xmlattrnamespaces__', '__xmlattrgroups__') ################################################################################ # # classes and functions # ################################################################################ def _objectfactory(objname, objargs=None, xsname=None): '''dynamically create an object based on the objname and return it. look it up in the BASETYPE_ELEMENT_MAP first. ''' # split the objname into the typename and module path, # importing the module if need be. if not isinstance(objargs, list): objargs = [objargs] if (xsname): try: objname = knownGlobalTypes[xsname] except KeyError: pass ## print "[objectfactory] creating an object of type %s and value %s, xsname=%s" % (objname, objargs, xsname) objtype = objname.split('.')[-1] pathlist = objname.split('.') modulename = '.'.join(pathlist[0:-1]) ## print "[objectfactory] object [%s] %s(%r)" % (objname, objtype, objargs) if objname == 'bool': return not objargs[0].lower() == 'false' elif objname == 'str': # don't strip strings - blanks are significant !!! if len(objargs) > 0: return saxutils.unescape(objargs[0]).encode() else: return '' elif objname == 'unicode': # don't strip strings - blanks are significant !!! if len(objargs) > 0: return saxutils.unescape(objargs[0]).encode() else: return '' elif objtype in ('float', 'int', 'str', 'long'): objargs = [x.strip() for x in objargs] try: if __builtin__.__dict__.has_key(objname): module = __builtin__ elif knownGlobalModule: module = knownGlobalModule else: if modulename: module = __import__(modulename) for name in pathlist[1:-1]: module = module.__dict__[name] if objargs: return module.__dict__[objtype](*objargs) else: if objtype == 'None': return None return module.__dict__[objtype]() except KeyError: raise KeyError("Could not find class %s" % objname) class Element: def __init__(self, name, attrs=None): self.name = name self.attrs = attrs self.content = '' self.children = [] def getobjtype(self): if self.attrs.has_key('objtype'): return self.attrs.getValue('objtype') else: return 'str' def toString(self): print " name = ", self.name, "; attrs = ", self.attrs, "number of children = ", len(self.children) i = -1 for child in self.children: i = i + 1 childClass = child.__class__.__name__ print " Child ", i, " class: ",childClass class XMLObjectFactory(xml.sax.ContentHandler): def __init__(self): self.rootelement = None self.elementstack = [] xml.sax.handler.ContentHandler.__init__(self) def toString(self): print "-----XMLObjectFactory Dump-------------------------------" if (self.rootelement == None): print "rootelement is None" else: print "rootelement is an object" i = -1 print "length of elementstack is: ", len(self.elementstack) for e in self.elementstack: i = i + 1 print "elementstack[", i, "]: " e.toString() print "-----end XMLObjectFactory--------------------------------" ## ContentHandler methods def startElement(self, name, attrs): ## print "startElement for name: ", name if name.find(':') > -1: # Strip namespace prefixes for now until actually looking them up in xsd name = name[name.index(':') + 1:] ## for attrname in attrs.getNames(): ## print "%s: %s" % (attrname, attrs.getValue(attrname)) element = Element(name, attrs.copy()) self.elementstack.append(element) ## print self.elementstack def characters(self, content): ## print "got content: %s" % content if content: self.elementstack[-1].content += content def endElement(self, name): ## print "[endElement] name of element we're at the end of: %s" % name xsname = name if name.find(':') > -1: # Strip namespace prefixes for now until actually looking them up in xsd name = name[name.index(':') + 1:] oldChildren = self.elementstack[-1].children element = self.elementstack.pop() if ((len(self.elementstack) > 1) and (self.elementstack[-1].getobjtype() == "None")): parentElement = self.elementstack[-2] ## print "[endElement] %s: found parent with objtype==None: using its grandparent" % name elif (len(self.elementstack) > 0): parentElement = self.elementstack[-1] objtype = element.getobjtype() ## print "element objtype is: ", objtype if (objtype == "None"): ## print "[endElement] %s: skipping a (objtype==None) end tag" % name return constructorarglist = [] if element.content: strippedElementContent = element.content.strip() if strippedElementContent: constructorarglist.append(element.content) ## print "[endElement] calling objectfactory" obj = _objectfactory(objtype, constructorarglist, xsname) complexType = None if hasattr(obj, '__xsdcomplextype__'): complexType = getattr(obj, '__xsdcomplextype__') if (hasattr(obj, '__xmlname__') and getattr(obj, '__xmlname__') == "sequence"): ## print "[endElement] sequence found" ## self.toString() self.elementstack[-1].children = oldChildren ## self.toString() ## print "done moving sequence stuff; returning" return if len(self.elementstack) > 0: ## print "[endElement] appending child with name: ", name, "; objtype: ", objtype parentElement.children.append((name, obj)) ## print "parentElement now has ", len(parentElement.children), " children" else: self.rootelement = obj if element.attrs and not isinstance(obj, list): ## print "[endElement] %s: element has attrs and the obj is not a list" % name for attrname, attr in element.attrs.items(): if attrname == XMLNS or attrname.startswith(XMLNS_PREFIX): if attrname.startswith(XMLNS_PREFIX): ns = attrname[XMLNS_PREFIX_LENGTH:] else: ns = "" if not hasattr(obj, '__xmlnamespaces__'): obj.__xmlnamespaces__ = {ns:attr} elif ns not in obj.__xmlnamespaces__: if (hasattr(obj.__class__, '__xmlnamespaces__') and obj.__xmlnamespaces__ is obj.__class__.__xmlnamespaces__): obj.__xmlnamespaces__ = dict(obj.__xmlnamespaces__) obj.__xmlnamespaces__[ns] = attr elif not attrname == 'objtype': if attrname.find(':') > -1: # Strip namespace prefixes for now until actually looking them up in xsd attrname = attrname[attrname.index(':') + 1:] if complexType: xsdElement = complexType.findElement(attrname) if xsdElement: type = xsdElement.type if type: type = xsdToPythonType(type) ### ToDO remove maxOccurs hack after bug 177 is fixed if attrname == "maxOccurs" and attr == "unbounded": attr = "-1" attr = _objectfactory(type, attr) objutils.setattrignorecase(obj, _toAttrName(obj, attrname), attr) ## obj.__dict__[_toAttrName(obj, attrname)] = attr # stuff any child attributes meant to be in a sequence via the __xmlflattensequence__ flattenDict = {} if hasattr(obj, '__xmlflattensequence__'): ## print "[endElement] %s: obj has __xmlflattensequence__" % name if (isinstance(obj.__xmlflattensequence__,dict)): ## print "[endElement] dict with obj.__xmlflattensequence__.items: ", obj.__xmlflattensequence__.items() for sequencename, xmlnametuple in obj.__xmlflattensequence__.items(): for xmlname in xmlnametuple: ## print "[endElement]: adding flattenDict[%s] = %s" % (xmlname, sequencename) flattenDict[xmlname] = sequencename # handle __xmlflattensequence__ list/tuple (i.e. no element rename) elif (isinstance(obj.__xmlflattensequence__,list) or isinstance(obj.__xmlflattensequence__,tuple)): for sequencename in obj.__xmlflattensequence__: flattenDict[sequencename] = sequencename else: raise "Invalid type for __xmlflattensequence___ : it must be a dict, list, or tuple" # reattach an object's attributes to it for childname, child in element.children: ## print "[endElement] childname is: ", childname, "; child is: ", child if flattenDict.has_key(childname): sequencename = _toAttrName(obj, flattenDict[childname]) ## print "[endElement] sequencename is: ", sequencename try: ## print "[endElement] obj.__dict__ is: ", obj.__dict__ sequencevalue = obj.__dict__[sequencename] except (AttributeError, KeyError): sequencevalue = None if sequencevalue == None: sequencevalue = [] obj.__dict__[sequencename] = sequencevalue sequencevalue.append(child) elif isinstance(obj, list): ## print "appended childname = ", childname obj.append(child) else: ## print "childname = %s, obj = %s, child = %s" % (childname, repr(obj), repr(child)) objutils.setattrignorecase(obj, _toAttrName(obj, childname), child) obj.__dict__[_toAttrName(obj, childname)] = child if complexType: for element in complexType.elements: if element.default: elementName = _toAttrName(obj, element.name) if ((elementName not in obj.__dict__) or (obj.__dict__[elementName] == None)): pythonType = xsdToPythonType(element.type) defaultValue = _objectfactory(pythonType, element.default) obj.__dict__[elementName] = defaultValue def getRootObject(self): return self.rootelement def _toAttrName(obj, name): if (hasattr(obj, "__xmlrename__")): for key, val in obj.__xmlrename__.iteritems(): if (name == val): name = key break ## if (name.startswith("__") and not name.endswith("__")): ## name = "_%s%s" % (obj.__class__.__name__, name) return name __typeMappingXsdToPython = { "string": "str", "char": "str", "varchar": "str", "date": "str", # ToDO Need to work out how to create python date types "boolean": "bool", "decimal": "float", # ToDO Does python have a better fixed point type? "int": "int", "long": "long", "float": "float", "bool": "bool", "str": "str", "unicode": "unicode", "short": "int", "duration": "str", # see above (date) "datetime": "str", # see above (date) "time": "str", # see above (date) "double": "float", } def xsdToPythonType(xsdType): try: return __typeMappingXsdToPython[xsdType] except KeyError: raise Exception("Unknown xsd type %s" % xsdType) def _getXmlValue(pythonValue): if (isinstance(pythonValue, bool)): return str(pythonValue).lower() elif (isinstance(pythonValue, unicode)): return pythonValue.encode() else: return str(pythonValue) def unmarshal(xmlstr, knownTypes=None, knownModule=None): global knownGlobalTypes, knownGlobalModule if (knownTypes == None): knownGlobalTypes = {} else: knownGlobalTypes = knownTypes knownGlobalModule = knownModule objectfactory = XMLObjectFactory() xml.sax.parseString(xmlstr, objectfactory) return objectfactory.getRootObject() def marshal(obj, elementName=None, prettyPrint=False, indent=0, knownTypes=None, withEncoding=True, encoding=None): xmlstr = ''.join(_marshal(obj, elementName, prettyPrint=prettyPrint, indent=indent, knownTypes=knownTypes)) if withEncoding: if encoding is None: return '\n%s' % (sys.getdefaultencoding(), xmlstr) else: return '\n%s' % (encoding, xmlstr.encode(encoding)) else: return xmlstr def _marshal(obj, elementName=None, nameSpacePrefix='', nameSpaces=None, prettyPrint=False, indent=0, knownTypes=None): if prettyPrint or indent: prefix = ' '*indent newline = '\n' increment = 4 else: prefix = '' newline = '' increment = 0 ## Determine the XML element name. If it isn't specified in the ## parameter list, look for it in the __xmlname__ Python ## attribute, else use the default generic BASETYPE_ELEMENT_NAME. if not nameSpaces: nameSpaces = {} # Need to do this since if the {} is a default parameter it gets shared by all calls into the function nameSpaceAttrs = '' if knownTypes == None: knownTypes = {} if hasattr(obj, '__xmlnamespaces__'): for nameSpaceKey, nameSpaceUrl in getattr(obj, '__xmlnamespaces__').items(): if nameSpaceUrl in nameSpaces: nameSpaceKey = nameSpaces[nameSpaceUrl] else: ## # TODO: Wait to do this until there is shared state for use when going through the object graph ## origNameSpaceKey = nameSpaceKey # Make sure there is no key collision, ie: same key referencing two different URL's ## i = 1 ## while nameSpaceKey in nameSpaces.values(): ## nameSpaceKey = origNameSpaceKey + str(i) ## i += 1 nameSpaces[nameSpaceUrl] = nameSpaceKey if nameSpaceKey == '': nameSpaceAttrs += ' xmlns="%s" ' % (nameSpaceUrl) else: nameSpaceAttrs += ' xmlns:%s="%s" ' % (nameSpaceKey, nameSpaceUrl) nameSpaceAttrs = nameSpaceAttrs.rstrip() if hasattr(obj, '__xmldefaultnamespace__'): nameSpacePrefix = getattr(obj, '__xmldefaultnamespace__') + ':' if not elementName: if hasattr(obj, '__xmlname__'): elementName = nameSpacePrefix + obj.__xmlname__ else: elementName = nameSpacePrefix + BASETYPE_ELEMENT_NAME else: elementName = nameSpacePrefix + elementName if hasattr(obj, '__xmlsequencer__'): elementAdd = obj.__xmlsequencer__ else: elementAdd = None ## print "marshal: entered with elementName: ", elementName members_to_skip = [] ## Add more members_to_skip based on ones the user has selected ## via the __xmlexclude__ attribute. if hasattr(obj, '__xmlexclude__'): ## print "marshal: found __xmlexclude__" members_to_skip += list(obj.__xmlexclude__) # Marshal the attributes that are selected to be XML attributes. objattrs = '' className = obj.__class__.__name__ classNamePrefix = "_" + className if hasattr(obj, '__xmlattributes__'): ## print "marshal: found __xmlattributes__" xmlattributes = obj.__xmlattributes__ members_to_skip += xmlattributes for attr in xmlattributes: internalAttrName = attr if (attr.startswith("__") and not attr.endswith("__")): internalAttrName = classNamePrefix + attr # Fail silently if a python attribute is specified to be # an XML attribute but is missing. ## print "marshal: processing attribute ", internalAttrName try: value = obj.__dict__[internalAttrName] except KeyError: continue ## # But, check and see if it is a property first: ## if (objutils.hasPropertyValue(obj, attr)): ## value = getattr(obj, attr) ## else: ## continue xsdElement = None if hasattr(obj, '__xsdcomplextype__'): ## print "marshal: found __xsdcomplextype__" complexType = getattr(obj, '__xsdcomplextype__') xsdElement = complexType.findElement(attr) if xsdElement: default = xsdElement.default if default == value or default == _getXmlValue(value): continue elif value == None: continue # ToDO remove maxOccurs hack after bug 177 is fixed if attr == "maxOccurs" and value == -1: value = "unbounded" if isinstance(value, bool): if value == True: value = "true" else: value = "false" attrNameSpacePrefix = '' if hasattr(obj, '__xmlattrnamespaces__'): ## print "marshal: found __xmlattrnamespaces__" for nameSpaceKey, nameSpaceAttributes in getattr(obj, '__xmlattrnamespaces__').items(): if nameSpaceKey == nameSpacePrefix[:-1]: # Don't need to specify attribute namespace if it is the same as it's element continue if attr in nameSpaceAttributes: attrNameSpacePrefix = nameSpaceKey + ':' break ## if attr.startswith('_'): ## attr = attr[1:] if (hasattr(obj, "__xmlrename__") and attr in obj.__xmlrename__): ## print "marshal: found __xmlrename__ (and its attribute)" attr = obj.__xmlrename__[attr] objattrs += ' %s%s="%s"' % (attrNameSpacePrefix, attr, value) ## print "marshal: new objattrs is: ", objattrs if isinstance(obj, NoneType): return '' elif isinstance(obj, bool): return ['%s<%s objtype="bool">%s%s' % (prefix, elementName, obj, elementName, newline)] elif isinstance(obj, int): return ['''%s<%s objtype="int">%s%s''' % (prefix, elementName, str(obj), elementName, newline)] elif isinstance(obj, long): return ['%s<%s objtype="long">%s%s' % (prefix, elementName, str(obj), elementName, newline)] elif isinstance(obj, float): return ['%s<%s objtype="float">%s%s' % (prefix, elementName, str(obj), elementName, newline)] elif isinstance(obj, unicode): # have to check before basestring - unicode is instance of base string return ['''%s<%s>%s%s''' % (prefix, elementName, saxutils.escape(obj.encode()), elementName, newline)] elif isinstance(obj, basestring): return ['''%s<%s>%s%s''' % (prefix, elementName, saxutils.escape(obj), elementName, newline)] elif isinstance(obj, list): if len(obj) < 1: return '' xmlString = ['%s<%s objtype="list">%s' % (prefix, elementName, newline)] for item in obj: xmlString.extend(_marshal(item, nameSpaces=nameSpaces, indent=indent+increment, knownTypes=knownTypes)) xmlString.append('%s%s' % (prefix, elementName, newline)) return xmlString elif isinstance(obj, tuple): if len(obj) < 1: return '' xmlString = ['%s<%s objtype="list" mutable="false">%s' % (prefix, elementName, newline)] for item in obj: xmlString.extend(_marshal(item, nameSpaces=nameSpaces, indent=indent+increment, knownTypes=knownTypes)) xmlString.append('%s%s' % (prefix, elementName, newline)) return xmlString elif isinstance(obj, dict): xmlString = ['%s<%s objtype="dict">%s' % (prefix, elementName, newline)] subprefix = prefix + ' '*increment subindent = indent + 2*increment for key, val in obj.iteritems(): xmlString.append("%s%s" % (subprefix, newline)) xmlString.extend(_marshal(key, indent=subindent, knownTypes=knownTypes)) xmlString.append("%s%s%s%s" % (subprefix, newline, subprefix, newline)) xmlString.extend(_marshal(val, nameSpaces=nameSpaces, indent=subindent, knownTypes=knownTypes)) xmlString.append("%s%s" % (subprefix, newline)) xmlString.append('%s%s' % (prefix, elementName, newline)) return xmlString else: moduleName = obj.__class__.__module__ if (moduleName == "activegrid.model.schema"): xmlString = ['%s<%s%s%s' % (prefix, elementName, nameSpaceAttrs, objattrs)] else: # Only add the objtype if the element tag is unknown to us. try: objname = knownTypes[elementName] xmlString = ['%s<%s%s%s' % (prefix, elementName, nameSpaceAttrs, objattrs)] except KeyError: xmlString = ['%s<%s%s%s objtype="%s.%s"' % (prefix, elementName, nameSpaceAttrs, objattrs, moduleName, className)] ## print "UnknownTypeException: Unknown type (%s.%s) passed to marshaller" % (moduleName, className) # get the member, value pairs for the object, filtering out the types we don't support if (elementAdd != None): prefix += increment*' ' indent += increment xmlMemberString = [] if hasattr(obj, '__xmlbody__'): xmlbody = getattr(obj, obj.__xmlbody__) if xmlbody != None: xmlMemberString.append(xmlbody) else: entryList = obj.__dict__.items() ## # Add in properties ## for key in obj.__class__.__dict__.iterkeys(): ## if (key not in members_to_skip and key not in obj.__dict__ ## and objutils.hasPropertyValue(obj, key)): ## value = getattr(obj, key) ## entryList.append((key, value)) entryList.sort() if hasattr(obj, '__xmlattrgroups__'): attrGroups = obj.__xmlattrgroups__ if (not isinstance(attrGroups,dict)): raise "__xmlattrgroups__ is not a dict, but must be" for n in attrGroups: v = attrGroups[n] members_to_skip += v else: attrGroups = {} # add the list of all attributes to attrGroups eList = [] for x, z in entryList: eList.append(x) attrGroups['__nogroup__'] = eList for eName in attrGroups: eList = attrGroups[eName] if (eName != '__nogroup__'): prefix += increment*' ' indent += increment xmlMemberString.append('%s<%s objtype="None">%s' % (prefix, eName, newline)) for name in eList: value = obj.__dict__[name] ## print " ", name, " = ", value ## # special name handling for private "__*" attributes: ## # remove the _ added by Python ## if name.startswith(classNamePrefix): name = name[len(classNamePrefix):] if eName == '__nogroup__' and name in members_to_skip: continue if name.startswith('__') and name.endswith('__'): continue ## idx = name.find('__') ## if idx > 0: ## newName = name[idx+2:] ## if newName: ## name = newName ## print "marshal: processing subElement ", name subElementNameSpacePrefix = nameSpacePrefix if hasattr(obj, '__xmlattrnamespaces__'): for nameSpaceKey, nameSpaceValues in getattr(obj, '__xmlattrnamespaces__').items(): if name in nameSpaceValues: subElementNameSpacePrefix = nameSpaceKey + ':' break # handle sequences listed in __xmlflattensequence__ # specially: instead of listing the contained items inside # of a separate list, as god intended, list them inside # the object containing the sequence. if hasattr(obj, '__xmlflattensequence__') and name in obj.__xmlflattensequence__ and value: try: xmlnametuple = obj.__xmlflattensequence__[name] xmlname = None if len(xmlnametuple) == 1: xmlname = xmlnametuple[0] except: xmlname = name ## xmlname = name.lower() for seqitem in value: xmlMemberString.extend(_marshal(seqitem, xmlname, subElementNameSpacePrefix, nameSpaces=nameSpaces, indent=indent+increment, knownTypes=knownTypes)) else: if (hasattr(obj, "__xmlrename__") and name in obj.__xmlrename__): xmlname = obj.__xmlrename__[name] else: xmlname = name ## if (indent > 30): ## print "getting pretty deep, xmlname = ", xmlname xmlMemberString.extend(_marshal(value, xmlname, subElementNameSpacePrefix, nameSpaces=nameSpaces, indent=indent+increment, knownTypes=knownTypes)) if (eName != '__nogroup__'): ## print "marshal: Completing attrGroup ", eName xmlMemberString.append('%s%s' % (prefix, eName, newline)) prefix = prefix[:-increment] indent -= increment # if we have nested elements, add them here, otherwise close the element tag immediately. xmlMemberString = filter(lambda x: len(x)>0, xmlMemberString) if len(xmlMemberString) > 0: xmlString.append('>') if hasattr(obj, '__xmlbody__'): xmlString.extend(xmlMemberString) xmlString.append('%s' % (elementName, newline)) else: xmlString.append(newline) if (elementAdd != None): xmlString.append('%s<%s>%s' % (prefix, elementAdd, newline)) xmlString.extend(xmlMemberString) if (elementAdd != None): xmlString.append('%s%s' % (prefix, elementAdd, newline)) prefix = prefix[:-increment] indent -= increment xmlString.append('%s%s' % (prefix, elementName, newline)) else: xmlString.append('/>%s' % newline) return xmlString