Removed the Requirement to Install Python and NodeJS (Now Bundled with Borealis)

Dependencies/Python/Lib/xml/dom/expatbuilder.py

@@ -0,0 +1,962 @@
+"""Facility to use the Expat parser to load a minidom instance
+from a string or file.
+
+This avoids all the overhead of SAX and pulldom to gain performance.
+"""
+
+# Warning!
+#
+# This module is tightly bound to the implementation details of the
+# minidom DOM and can't be used with other DOM implementations.  This
+# is due, in part, to a lack of appropriate methods in the DOM (there is
+# no way to create Entity and Notation nodes via the DOM Level 2
+# interface), and for performance.  The latter is the cause of some fairly
+# cryptic code.
+#
+# Performance hacks:
+#
+#   -  .character_data_handler() has an extra case in which continuing
+#      data is appended to an existing Text node; this can be a
+#      speedup since pyexpat can break up character data into multiple
+#      callbacks even though we set the buffer_text attribute on the
+#      parser.  This also gives us the advantage that we don't need a
+#      separate normalization pass.
+#
+#   -  Determining that a node exists is done using an identity comparison
+#      with None rather than a truth test; this avoids searching for and
+#      calling any methods on the node object if it exists.  (A rather
+#      nice speedup is achieved this way as well!)
+
+from xml.dom import xmlbuilder, minidom, Node
+from xml.dom import EMPTY_NAMESPACE, EMPTY_PREFIX, XMLNS_NAMESPACE
+from xml.parsers import expat
+from xml.dom.minidom import _append_child, _set_attribute_node
+from xml.dom.NodeFilter import NodeFilter
+
+TEXT_NODE = Node.TEXT_NODE
+CDATA_SECTION_NODE = Node.CDATA_SECTION_NODE
+DOCUMENT_NODE = Node.DOCUMENT_NODE
+
+FILTER_ACCEPT = xmlbuilder.DOMBuilderFilter.FILTER_ACCEPT
+FILTER_REJECT = xmlbuilder.DOMBuilderFilter.FILTER_REJECT
+FILTER_SKIP = xmlbuilder.DOMBuilderFilter.FILTER_SKIP
+FILTER_INTERRUPT = xmlbuilder.DOMBuilderFilter.FILTER_INTERRUPT
+
+theDOMImplementation = minidom.getDOMImplementation()
+
+# Expat typename -> TypeInfo
+_typeinfo_map = {
+    "CDATA":    minidom.TypeInfo(None, "cdata"),
+    "ENUM":     minidom.TypeInfo(None, "enumeration"),
+    "ENTITY":   minidom.TypeInfo(None, "entity"),
+    "ENTITIES": minidom.TypeInfo(None, "entities"),
+    "ID":       minidom.TypeInfo(None, "id"),
+    "IDREF":    minidom.TypeInfo(None, "idref"),
+    "IDREFS":   minidom.TypeInfo(None, "idrefs"),
+    "NMTOKEN":  minidom.TypeInfo(None, "nmtoken"),
+    "NMTOKENS": minidom.TypeInfo(None, "nmtokens"),
+    }
+
+class ElementInfo(object):
+    __slots__ = '_attr_info', '_model', 'tagName'
+
+    def __init__(self, tagName, model=None):
+        self.tagName = tagName
+        self._attr_info = []
+        self._model = model
+
+    def __getstate__(self):
+        return self._attr_info, self._model, self.tagName
+
+    def __setstate__(self, state):
+        self._attr_info, self._model, self.tagName = state
+
+    def getAttributeType(self, aname):
+        for info in self._attr_info:
+            if info[1] == aname:
+                t = info[-2]
+                if t[0] == "(":
+                    return _typeinfo_map["ENUM"]
+                else:
+                    return _typeinfo_map[info[-2]]
+        return minidom._no_type
+
+    def getAttributeTypeNS(self, namespaceURI, localName):
+        return minidom._no_type
+
+    def isElementContent(self):
+        if self._model:
+            type = self._model[0]
+            return type not in (expat.model.XML_CTYPE_ANY,
+                                expat.model.XML_CTYPE_MIXED)
+        else:
+            return False
+
+    def isEmpty(self):
+        if self._model:
+            return self._model[0] == expat.model.XML_CTYPE_EMPTY
+        else:
+            return False
+
+    def isId(self, aname):
+        for info in self._attr_info:
+            if info[1] == aname:
+                return info[-2] == "ID"
+        return False
+
+    def isIdNS(self, euri, ename, auri, aname):
+        # not sure this is meaningful
+        return self.isId((auri, aname))
+
+def _intern(builder, s):
+    return builder._intern_setdefault(s, s)
+
+def _parse_ns_name(builder, name):
+    assert ' ' in name
+    parts = name.split(' ')
+    intern = builder._intern_setdefault
+    if len(parts) == 3:
+        uri, localname, prefix = parts
+        prefix = intern(prefix, prefix)
+        qname = "%s:%s" % (prefix, localname)
+        qname = intern(qname, qname)
+        localname = intern(localname, localname)
+    elif len(parts) == 2:
+        uri, localname = parts
+        prefix = EMPTY_PREFIX
+        qname = localname = intern(localname, localname)
+    else:
+        raise ValueError("Unsupported syntax: spaces in URIs not supported: %r" % name)
+    return intern(uri, uri), localname, prefix, qname
+
+
+class ExpatBuilder:
+    """Document builder that uses Expat to build a ParsedXML.DOM document
+    instance."""
+
+    def __init__(self, options=None):
+        if options is None:
+            options = xmlbuilder.Options()
+        self._options = options
+        if self._options.filter is not None:
+            self._filter = FilterVisibilityController(self._options.filter)
+        else:
+            self._filter = None
+            # This *really* doesn't do anything in this case, so
+            # override it with something fast & minimal.
+            self._finish_start_element = id
+        self._parser = None
+        self.reset()
+
+    def createParser(self):
+        """Create a new parser object."""
+        return expat.ParserCreate()
+
+    def getParser(self):
+        """Return the parser object, creating a new one if needed."""
+        if not self._parser:
+            self._parser = self.createParser()
+            self._intern_setdefault = self._parser.intern.setdefault
+            self._parser.buffer_text = True
+            self._parser.ordered_attributes = True
+            self._parser.specified_attributes = True
+            self.install(self._parser)
+        return self._parser
+
+    def reset(self):
+        """Free all data structures used during DOM construction."""
+        self.document = theDOMImplementation.createDocument(
+            EMPTY_NAMESPACE, None, None)
+        self.curNode = self.document
+        self._elem_info = self.document._elem_info
+        self._cdata = False
+
+    def install(self, parser):
+        """Install the callbacks needed to build the DOM into the parser."""
+        # This creates circular references!
+        parser.StartDoctypeDeclHandler = self.start_doctype_decl_handler
+        parser.StartElementHandler = self.first_element_handler
+        parser.EndElementHandler = self.end_element_handler
+        parser.ProcessingInstructionHandler = self.pi_handler
+        if self._options.entities:
+            parser.EntityDeclHandler = self.entity_decl_handler
+        parser.NotationDeclHandler = self.notation_decl_handler
+        if self._options.comments:
+            parser.CommentHandler = self.comment_handler
+        if self._options.cdata_sections:
+            parser.StartCdataSectionHandler = self.start_cdata_section_handler
+            parser.EndCdataSectionHandler = self.end_cdata_section_handler
+            parser.CharacterDataHandler = self.character_data_handler_cdata
+        else:
+            parser.CharacterDataHandler = self.character_data_handler
+        parser.ExternalEntityRefHandler = self.external_entity_ref_handler
+        parser.XmlDeclHandler = self.xml_decl_handler
+        parser.ElementDeclHandler = self.element_decl_handler
+        parser.AttlistDeclHandler = self.attlist_decl_handler
+
+    def parseFile(self, file):
+        """Parse a document from a file object, returning the document
+        node."""
+        parser = self.getParser()
+        first_buffer = True
+        try:
+            while buffer := file.read(16*1024):
+                parser.Parse(buffer, False)
+                if first_buffer and self.document.documentElement:
+                    self._setup_subset(buffer)
+                first_buffer = False
+            parser.Parse(b"", True)
+        except ParseEscape:
+            pass
+        doc = self.document
+        self.reset()
+        self._parser = None
+        return doc
+
+    def parseString(self, string):
+        """Parse a document from a string, returning the document node."""
+        parser = self.getParser()
+        try:
+            parser.Parse(string, True)
+            self._setup_subset(string)
+        except ParseEscape:
+            pass
+        doc = self.document
+        self.reset()
+        self._parser = None
+        return doc
+
+    def _setup_subset(self, buffer):
+        """Load the internal subset if there might be one."""
+        if self.document.doctype:
+            extractor = InternalSubsetExtractor()
+            extractor.parseString(buffer)
+            subset = extractor.getSubset()
+            self.document.doctype.internalSubset = subset
+
+    def start_doctype_decl_handler(self, doctypeName, systemId, publicId,
+                                   has_internal_subset):
+        doctype = self.document.implementation.createDocumentType(
+            doctypeName, publicId, systemId)
+        doctype.ownerDocument = self.document
+        _append_child(self.document, doctype)
+        self.document.doctype = doctype
+        if self._filter and self._filter.acceptNode(doctype) == FILTER_REJECT:
+            self.document.doctype = None
+            del self.document.childNodes[-1]
+            doctype = None
+            self._parser.EntityDeclHandler = None
+            self._parser.NotationDeclHandler = None
+        if has_internal_subset:
+            if doctype is not None:
+                doctype.entities._seq = []
+                doctype.notations._seq = []
+            self._parser.CommentHandler = None
+            self._parser.ProcessingInstructionHandler = None
+            self._parser.EndDoctypeDeclHandler = self.end_doctype_decl_handler
+
+    def end_doctype_decl_handler(self):
+        if self._options.comments:
+            self._parser.CommentHandler = self.comment_handler
+        self._parser.ProcessingInstructionHandler = self.pi_handler
+        if not (self._elem_info or self._filter):
+            self._finish_end_element = id
+
+    def pi_handler(self, target, data):
+        node = self.document.createProcessingInstruction(target, data)
+        _append_child(self.curNode, node)
+        if self._filter and self._filter.acceptNode(node) == FILTER_REJECT:
+            self.curNode.removeChild(node)
+
+    def character_data_handler_cdata(self, data):
+        childNodes = self.curNode.childNodes
+        if self._cdata:
+            if (  self._cdata_continue
+                  and childNodes[-1].nodeType == CDATA_SECTION_NODE):
+                childNodes[-1].appendData(data)
+                return
+            node = self.document.createCDATASection(data)
+            self._cdata_continue = True
+        elif childNodes and childNodes[-1].nodeType == TEXT_NODE:
+            node = childNodes[-1]
+            value = node.data + data
+            node.data = value
+            return
+        else:
+            node = minidom.Text()
+            node.data = data
+            node.ownerDocument = self.document
+        _append_child(self.curNode, node)
+
+    def character_data_handler(self, data):
+        childNodes = self.curNode.childNodes
+        if childNodes and childNodes[-1].nodeType == TEXT_NODE:
+            node = childNodes[-1]
+            node.data = node.data + data
+            return
+        node = minidom.Text()
+        node.data = node.data + data
+        node.ownerDocument = self.document
+        _append_child(self.curNode, node)
+
+    def entity_decl_handler(self, entityName, is_parameter_entity, value,
+                            base, systemId, publicId, notationName):
+        if is_parameter_entity:
+            # we don't care about parameter entities for the DOM
+            return
+        if not self._options.entities:
+            return
+        node = self.document._create_entity(entityName, publicId,
+                                            systemId, notationName)
+        if value is not None:
+            # internal entity
+            # node *should* be readonly, but we'll cheat
+            child = self.document.createTextNode(value)
+            node.childNodes.append(child)
+        self.document.doctype.entities._seq.append(node)
+        if self._filter and self._filter.acceptNode(node) == FILTER_REJECT:
+            del self.document.doctype.entities._seq[-1]
+
+    def notation_decl_handler(self, notationName, base, systemId, publicId):
+        node = self.document._create_notation(notationName, publicId, systemId)
+        self.document.doctype.notations._seq.append(node)
+        if self._filter and self._filter.acceptNode(node) == FILTER_ACCEPT:
+            del self.document.doctype.notations._seq[-1]
+
+    def comment_handler(self, data):
+        node = self.document.createComment(data)
+        _append_child(self.curNode, node)
+        if self._filter and self._filter.acceptNode(node) == FILTER_REJECT:
+            self.curNode.removeChild(node)
+
+    def start_cdata_section_handler(self):
+        self._cdata = True
+        self._cdata_continue = False
+
+    def end_cdata_section_handler(self):
+        self._cdata = False
+        self._cdata_continue = False
+
+    def external_entity_ref_handler(self, context, base, systemId, publicId):
+        return 1
+
+    def first_element_handler(self, name, attributes):
+        if self._filter is None and not self._elem_info:
+            self._finish_end_element = id
+        self.getParser().StartElementHandler = self.start_element_handler
+        self.start_element_handler(name, attributes)
+
+    def start_element_handler(self, name, attributes):
+        node = self.document.createElement(name)
+        _append_child(self.curNode, node)
+        self.curNode = node
+
+        if attributes:
+            for i in range(0, len(attributes), 2):
+                a = minidom.Attr(attributes[i], EMPTY_NAMESPACE,
+                                 None, EMPTY_PREFIX)
+                value = attributes[i+1]
+                a.value = value
+                a.ownerDocument = self.document
+                _set_attribute_node(node, a)
+
+        if node is not self.document.documentElement:
+            self._finish_start_element(node)
+
+    def _finish_start_element(self, node):
+        if self._filter:
+            # To be general, we'd have to call isSameNode(), but this
+            # is sufficient for minidom:
+            if node is self.document.documentElement:
+                return
+            filt = self._filter.startContainer(node)
+            if filt == FILTER_REJECT:
+                # ignore this node & all descendents
+                Rejecter(self)
+            elif filt == FILTER_SKIP:
+                # ignore this node, but make it's children become
+                # children of the parent node
+                Skipper(self)
+            else:
+                return
+            self.curNode = node.parentNode
+            node.parentNode.removeChild(node)
+            node.unlink()
+
+    # If this ever changes, Namespaces.end_element_handler() needs to
+    # be changed to match.
+    #
+    def end_element_handler(self, name):
+        curNode = self.curNode
+        self.curNode = curNode.parentNode
+        self._finish_end_element(curNode)
+
+    def _finish_end_element(self, curNode):
+        info = self._elem_info.get(curNode.tagName)
+        if info:
+            self._handle_white_text_nodes(curNode, info)
+        if self._filter:
+            if curNode is self.document.documentElement:
+                return
+            if self._filter.acceptNode(curNode) == FILTER_REJECT:
+                self.curNode.removeChild(curNode)
+                curNode.unlink()
+
+    def _handle_white_text_nodes(self, node, info):
+        if (self._options.whitespace_in_element_content
+            or not info.isElementContent()):
+            return
+
+        # We have element type information and should remove ignorable
+        # whitespace; identify for text nodes which contain only
+        # whitespace.
+        L = []
+        for child in node.childNodes:
+            if child.nodeType == TEXT_NODE and not child.data.strip():
+                L.append(child)
+
+        # Remove ignorable whitespace from the tree.
+        for child in L:
+            node.removeChild(child)
+
+    def element_decl_handler(self, name, model):
+        info = self._elem_info.get(name)
+        if info is None:
+            self._elem_info[name] = ElementInfo(name, model)
+        else:
+            assert info._model is None
+            info._model = model
+
+    def attlist_decl_handler(self, elem, name, type, default, required):
+        info = self._elem_info.get(elem)
+        if info is None:
+            info = ElementInfo(elem)
+            self._elem_info[elem] = info
+        info._attr_info.append(
+            [None, name, None, None, default, 0, type, required])
+
+    def xml_decl_handler(self, version, encoding, standalone):
+        self.document.version = version
+        self.document.encoding = encoding
+        # This is still a little ugly, thanks to the pyexpat API. ;-(
+        if standalone >= 0:
+            if standalone:
+                self.document.standalone = True
+            else:
+                self.document.standalone = False
+
+
+# Don't include FILTER_INTERRUPT, since that's checked separately
+# where allowed.
+_ALLOWED_FILTER_RETURNS = (FILTER_ACCEPT, FILTER_REJECT, FILTER_SKIP)
+
+class FilterVisibilityController(object):
+    """Wrapper around a DOMBuilderFilter which implements the checks
+    to make the whatToShow filter attribute work."""
+
+    __slots__ = 'filter',
+
+    def __init__(self, filter):
+        self.filter = filter
+
+    def startContainer(self, node):
+        mask = self._nodetype_mask[node.nodeType]
+        if self.filter.whatToShow & mask:
+            val = self.filter.startContainer(node)
+            if val == FILTER_INTERRUPT:
+                raise ParseEscape
+            if val not in _ALLOWED_FILTER_RETURNS:
+                raise ValueError(
+                      "startContainer() returned illegal value: " + repr(val))
+            return val
+        else:
+            return FILTER_ACCEPT
+
+    def acceptNode(self, node):
+        mask = self._nodetype_mask[node.nodeType]
+        if self.filter.whatToShow & mask:
+            val = self.filter.acceptNode(node)
+            if val == FILTER_INTERRUPT:
+                raise ParseEscape
+            if val == FILTER_SKIP:
+                # move all child nodes to the parent, and remove this node
+                parent = node.parentNode
+                for child in node.childNodes[:]:
+                    parent.appendChild(child)
+                # node is handled by the caller
+                return FILTER_REJECT
+            if val not in _ALLOWED_FILTER_RETURNS:
+                raise ValueError(
+                      "acceptNode() returned illegal value: " + repr(val))
+            return val
+        else:
+            return FILTER_ACCEPT
+
+    _nodetype_mask = {
+        Node.ELEMENT_NODE:                NodeFilter.SHOW_ELEMENT,
+        Node.ATTRIBUTE_NODE:              NodeFilter.SHOW_ATTRIBUTE,
+        Node.TEXT_NODE:                   NodeFilter.SHOW_TEXT,
+        Node.CDATA_SECTION_NODE:          NodeFilter.SHOW_CDATA_SECTION,
+        Node.ENTITY_REFERENCE_NODE:       NodeFilter.SHOW_ENTITY_REFERENCE,
+        Node.ENTITY_NODE:                 NodeFilter.SHOW_ENTITY,
+        Node.PROCESSING_INSTRUCTION_NODE: NodeFilter.SHOW_PROCESSING_INSTRUCTION,
+        Node.COMMENT_NODE:                NodeFilter.SHOW_COMMENT,
+        Node.DOCUMENT_NODE:               NodeFilter.SHOW_DOCUMENT,
+        Node.DOCUMENT_TYPE_NODE:          NodeFilter.SHOW_DOCUMENT_TYPE,
+        Node.DOCUMENT_FRAGMENT_NODE:      NodeFilter.SHOW_DOCUMENT_FRAGMENT,
+        Node.NOTATION_NODE:               NodeFilter.SHOW_NOTATION,
+        }
+
+
+class FilterCrutch(object):
+    __slots__ = '_builder', '_level', '_old_start', '_old_end'
+
+    def __init__(self, builder):
+        self._level = 0
+        self._builder = builder
+        parser = builder._parser
+        self._old_start = parser.StartElementHandler
+        self._old_end = parser.EndElementHandler
+        parser.StartElementHandler = self.start_element_handler
+        parser.EndElementHandler = self.end_element_handler
+
+class Rejecter(FilterCrutch):
+    __slots__ = ()
+
+    def __init__(self, builder):
+        FilterCrutch.__init__(self, builder)
+        parser = builder._parser
+        for name in ("ProcessingInstructionHandler",
+                     "CommentHandler",
+                     "CharacterDataHandler",
+                     "StartCdataSectionHandler",
+                     "EndCdataSectionHandler",
+                     "ExternalEntityRefHandler",
+                     ):
+            setattr(parser, name, None)
+
+    def start_element_handler(self, *args):
+        self._level = self._level + 1
+
+    def end_element_handler(self, *args):
+        if self._level == 0:
+            # restore the old handlers
+            parser = self._builder._parser
+            self._builder.install(parser)
+            parser.StartElementHandler = self._old_start
+            parser.EndElementHandler = self._old_end
+        else:
+            self._level = self._level - 1
+
+class Skipper(FilterCrutch):
+    __slots__ = ()
+
+    def start_element_handler(self, *args):
+        node = self._builder.curNode
+        self._old_start(*args)
+        if self._builder.curNode is not node:
+            self._level = self._level + 1
+
+    def end_element_handler(self, *args):
+        if self._level == 0:
+            # We're popping back out of the node we're skipping, so we
+            # shouldn't need to do anything but reset the handlers.
+            self._builder._parser.StartElementHandler = self._old_start
+            self._builder._parser.EndElementHandler = self._old_end
+            self._builder = None
+        else:
+            self._level = self._level - 1
+            self._old_end(*args)
+
+
+# framework document used by the fragment builder.
+# Takes a string for the doctype, subset string, and namespace attrs string.
+
+_FRAGMENT_BUILDER_INTERNAL_SYSTEM_ID = \
+    "http://xml.python.org/entities/fragment-builder/internal"
+
+_FRAGMENT_BUILDER_TEMPLATE = (
+    '''\
+<!DOCTYPE wrapper
+  %%s [
+  <!ENTITY fragment-builder-internal
+    SYSTEM "%s">
+%%s
+]>
+<wrapper %%s
+>&fragment-builder-internal;</wrapper>'''
+    % _FRAGMENT_BUILDER_INTERNAL_SYSTEM_ID)
+
+
+class FragmentBuilder(ExpatBuilder):
+    """Builder which constructs document fragments given XML source
+    text and a context node.
+
+    The context node is expected to provide information about the
+    namespace declarations which are in scope at the start of the
+    fragment.
+    """
+
+    def __init__(self, context, options=None):
+        if context.nodeType == DOCUMENT_NODE:
+            self.originalDocument = context
+            self.context = context
+        else:
+            self.originalDocument = context.ownerDocument
+            self.context = context
+        ExpatBuilder.__init__(self, options)
+
+    def reset(self):
+        ExpatBuilder.reset(self)
+        self.fragment = None
+
+    def parseFile(self, file):
+        """Parse a document fragment from a file object, returning the
+        fragment node."""
+        return self.parseString(file.read())
+
+    def parseString(self, string):
+        """Parse a document fragment from a string, returning the
+        fragment node."""
+        self._source = string
+        parser = self.getParser()
+        doctype = self.originalDocument.doctype
+        ident = ""
+        if doctype:
+            subset = doctype.internalSubset or self._getDeclarations()
+            if doctype.publicId:
+                ident = ('PUBLIC "%s" "%s"'
+                         % (doctype.publicId, doctype.systemId))
+            elif doctype.systemId:
+                ident = 'SYSTEM "%s"' % doctype.systemId
+        else:
+            subset = ""
+        nsattrs = self._getNSattrs() # get ns decls from node's ancestors
+        document = _FRAGMENT_BUILDER_TEMPLATE % (ident, subset, nsattrs)
+        try:
+            parser.Parse(document, True)
+        except:
+            self.reset()
+            raise
+        fragment = self.fragment
+        self.reset()
+##         self._parser = None
+        return fragment
+
+    def _getDeclarations(self):
+        """Re-create the internal subset from the DocumentType node.
+
+        This is only needed if we don't already have the
+        internalSubset as a string.
+        """
+        doctype = self.context.ownerDocument.doctype
+        s = ""
+        if doctype:
+            for i in range(doctype.notations.length):
+                notation = doctype.notations.item(i)
+                if s:
+                    s = s + "\n  "
+                s = "%s<!NOTATION %s" % (s, notation.nodeName)
+                if notation.publicId:
+                    s = '%s PUBLIC "%s"\n             "%s">' \
+                        % (s, notation.publicId, notation.systemId)
+                else:
+                    s = '%s SYSTEM "%s">' % (s, notation.systemId)
+            for i in range(doctype.entities.length):
+                entity = doctype.entities.item(i)
+                if s:
+                    s = s + "\n  "
+                s = "%s<!ENTITY %s" % (s, entity.nodeName)
+                if entity.publicId:
+                    s = '%s PUBLIC "%s"\n             "%s"' \
+                        % (s, entity.publicId, entity.systemId)
+                elif entity.systemId:
+                    s = '%s SYSTEM "%s"' % (s, entity.systemId)
+                else:
+                    s = '%s "%s"' % (s, entity.firstChild.data)
+                if entity.notationName:
+                    s = "%s NOTATION %s" % (s, entity.notationName)
+                s = s + ">"
+        return s
+
+    def _getNSattrs(self):
+        return ""
+
+    def external_entity_ref_handler(self, context, base, systemId, publicId):
+        if systemId == _FRAGMENT_BUILDER_INTERNAL_SYSTEM_ID:
+            # this entref is the one that we made to put the subtree
+            # in; all of our given input is parsed in here.
+            old_document = self.document
+            old_cur_node = self.curNode
+            parser = self._parser.ExternalEntityParserCreate(context)
+            # put the real document back, parse into the fragment to return
+            self.document = self.originalDocument
+            self.fragment = self.document.createDocumentFragment()
+            self.curNode = self.fragment
+            try:
+                parser.Parse(self._source, True)
+            finally:
+                self.curNode = old_cur_node
+                self.document = old_document
+                self._source = None
+            return -1
+        else:
+            return ExpatBuilder.external_entity_ref_handler(
+                self, context, base, systemId, publicId)
+
+
+class Namespaces:
+    """Mix-in class for builders; adds support for namespaces."""
+
+    def _initNamespaces(self):
+        # list of (prefix, uri) ns declarations.  Namespace attrs are
+        # constructed from this and added to the element's attrs.
+        self._ns_ordered_prefixes = []
+
+    def createParser(self):
+        """Create a new namespace-handling parser."""
+        parser = expat.ParserCreate(namespace_separator=" ")
+        parser.namespace_prefixes = True
+        return parser
+
+    def install(self, parser):
+        """Insert the namespace-handlers onto the parser."""
+        ExpatBuilder.install(self, parser)
+        if self._options.namespace_declarations:
+            parser.StartNamespaceDeclHandler = (
+                self.start_namespace_decl_handler)
+
+    def start_namespace_decl_handler(self, prefix, uri):
+        """Push this namespace declaration on our storage."""
+        self._ns_ordered_prefixes.append((prefix, uri))
+
+    def start_element_handler(self, name, attributes):
+        if ' ' in name:
+            uri, localname, prefix, qname = _parse_ns_name(self, name)
+        else:
+            uri = EMPTY_NAMESPACE
+            qname = name
+            localname = None
+            prefix = EMPTY_PREFIX
+        node = minidom.Element(qname, uri, prefix, localname)
+        node.ownerDocument = self.document
+        _append_child(self.curNode, node)
+        self.curNode = node
+
+        if self._ns_ordered_prefixes:
+            for prefix, uri in self._ns_ordered_prefixes:
+                if prefix:
+                    a = minidom.Attr(_intern(self, 'xmlns:' + prefix),
+                                     XMLNS_NAMESPACE, prefix, "xmlns")
+                else:
+                    a = minidom.Attr("xmlns", XMLNS_NAMESPACE,
+                                     "xmlns", EMPTY_PREFIX)
+                a.value = uri
+                a.ownerDocument = self.document
+                _set_attribute_node(node, a)
+            del self._ns_ordered_prefixes[:]
+
+        if attributes:
+            node._ensure_attributes()
+            _attrs = node._attrs
+            _attrsNS = node._attrsNS
+            for i in range(0, len(attributes), 2):
+                aname = attributes[i]
+                value = attributes[i+1]
+                if ' ' in aname:
+                    uri, localname, prefix, qname = _parse_ns_name(self, aname)
+                    a = minidom.Attr(qname, uri, localname, prefix)
+                    _attrs[qname] = a
+                    _attrsNS[(uri, localname)] = a
+                else:
+                    a = minidom.Attr(aname, EMPTY_NAMESPACE,
+                                     aname, EMPTY_PREFIX)
+                    _attrs[aname] = a
+                    _attrsNS[(EMPTY_NAMESPACE, aname)] = a
+                a.ownerDocument = self.document
+                a.value = value
+                a.ownerElement = node
+
+    if __debug__:
+        # This only adds some asserts to the original
+        # end_element_handler(), so we only define this when -O is not
+        # used.  If changing one, be sure to check the other to see if
+        # it needs to be changed as well.
+        #
+        def end_element_handler(self, name):
+            curNode = self.curNode
+            if ' ' in name:
+                uri, localname, prefix, qname = _parse_ns_name(self, name)
+                assert (curNode.namespaceURI == uri
+                        and curNode.localName == localname
+                        and curNode.prefix == prefix), \
+                        "element stack messed up! (namespace)"
+            else:
+                assert curNode.nodeName == name, \
+                       "element stack messed up - bad nodeName"
+                assert curNode.namespaceURI == EMPTY_NAMESPACE, \
+                       "element stack messed up - bad namespaceURI"
+            self.curNode = curNode.parentNode
+            self._finish_end_element(curNode)
+
+
+class ExpatBuilderNS(Namespaces, ExpatBuilder):
+    """Document builder that supports namespaces."""
+
+    def reset(self):
+        ExpatBuilder.reset(self)
+        self._initNamespaces()
+
+
+class FragmentBuilderNS(Namespaces, FragmentBuilder):
+    """Fragment builder that supports namespaces."""
+
+    def reset(self):
+        FragmentBuilder.reset(self)
+        self._initNamespaces()
+
+    def _getNSattrs(self):
+        """Return string of namespace attributes from this element and
+        ancestors."""
+        # XXX This needs to be re-written to walk the ancestors of the
+        # context to build up the namespace information from
+        # declarations, elements, and attributes found in context.
+        # Otherwise we have to store a bunch more data on the DOM
+        # (though that *might* be more reliable -- not clear).
+        attrs = ""
+        context = self.context
+        L = []
+        while context:
+            if hasattr(context, '_ns_prefix_uri'):
+                for prefix, uri in context._ns_prefix_uri.items():
+                    # add every new NS decl from context to L and attrs string
+                    if prefix in L:
+                        continue
+                    L.append(prefix)
+                    if prefix:
+                        declname = "xmlns:" + prefix
+                    else:
+                        declname = "xmlns"
+                    if attrs:
+                        attrs = "%s\n    %s='%s'" % (attrs, declname, uri)
+                    else:
+                        attrs = " %s='%s'" % (declname, uri)
+            context = context.parentNode
+        return attrs
+
+
+class ParseEscape(Exception):
+    """Exception raised to short-circuit parsing in InternalSubsetExtractor."""
+    pass
+
+class InternalSubsetExtractor(ExpatBuilder):
+    """XML processor which can rip out the internal document type subset."""
+
+    subset = None
+
+    def getSubset(self):
+        """Return the internal subset as a string."""
+        return self.subset
+
+    def parseFile(self, file):
+        try:
+            ExpatBuilder.parseFile(self, file)
+        except ParseEscape:
+            pass
+
+    def parseString(self, string):
+        try:
+            ExpatBuilder.parseString(self, string)
+        except ParseEscape:
+            pass
+
+    def install(self, parser):
+        parser.StartDoctypeDeclHandler = self.start_doctype_decl_handler
+        parser.StartElementHandler = self.start_element_handler
+
+    def start_doctype_decl_handler(self, name, publicId, systemId,
+                                   has_internal_subset):
+        if has_internal_subset:
+            parser = self.getParser()
+            self.subset = []
+            parser.DefaultHandler = self.subset.append
+            parser.EndDoctypeDeclHandler = self.end_doctype_decl_handler
+        else:
+            raise ParseEscape()
+
+    def end_doctype_decl_handler(self):
+        s = ''.join(self.subset).replace('\r\n', '\n').replace('\r', '\n')
+        self.subset = s
+        raise ParseEscape()
+
+    def start_element_handler(self, name, attrs):
+        raise ParseEscape()
+
+
+def parse(file, namespaces=True):
+    """Parse a document, returning the resulting Document node.
+
+    'file' may be either a file name or an open file object.
+    """
+    if namespaces:
+        builder = ExpatBuilderNS()
+    else:
+        builder = ExpatBuilder()
+
+    if isinstance(file, str):
+        with open(file, 'rb') as fp:
+            result = builder.parseFile(fp)
+    else:
+        result = builder.parseFile(file)
+    return result
+
+
+def parseString(string, namespaces=True):
+    """Parse a document from a string, returning the resulting
+    Document node.
+    """
+    if namespaces:
+        builder = ExpatBuilderNS()
+    else:
+        builder = ExpatBuilder()
+    return builder.parseString(string)
+
+
+def parseFragment(file, context, namespaces=True):
+    """Parse a fragment of a document, given the context from which it
+    was originally extracted.  context should be the parent of the
+    node(s) which are in the fragment.
+
+    'file' may be either a file name or an open file object.
+    """
+    if namespaces:
+        builder = FragmentBuilderNS(context)
+    else:
+        builder = FragmentBuilder(context)
+
+    if isinstance(file, str):
+        with open(file, 'rb') as fp:
+            result = builder.parseFile(fp)
+    else:
+        result = builder.parseFile(file)
+    return result
+
+
+def parseFragmentString(string, context, namespaces=True):
+    """Parse a fragment of a document from a string, given the context
+    from which it was originally extracted.  context should be the
+    parent of the node(s) which are in the fragment.
+    """
+    if namespaces:
+        builder = FragmentBuilderNS(context)
+    else:
+        builder = FragmentBuilder(context)
+    return builder.parseString(string)
+
+
+def makeBuilder(options):
+    """Create a builder based on an Options object."""
+    if options.namespaces:
+        return ExpatBuilderNS(options)
+    else:
+        return ExpatBuilder(options)