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"""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 later 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
from xml.dom.minicompat import *
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(NewStyle):
__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)
else:
uri, localname = parts
prefix = EMPTY_PREFIX
qname = localname = intern(localname, localname)
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 1:
buffer = file.read(16*1024)
if not buffer:
break
parser.Parse(buffer, 0)
if first_buffer and self.document.documentElement:
self._setup_subset(buffer)
first_buffer = False
parser.Parse("", 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
self.document.childNodes.append(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
d = node.__dict__
d['data'] = d['nodeValue'] = value
return
else:
node = minidom.Text()
d = node.__dict__
d['data'] = d['nodeValue'] = data
d['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]
d = node.__dict__
d['data'] = d['nodeValue'] = node.data + data
return
node = minidom.Text()
d = node.__dict__
d['data'] = d['nodeValue'] = node.data + data
d['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]
d = a.childNodes[0].__dict__
d['data'] = d['nodeValue'] = value
d = a.__dict__
d['value'] = d['nodeValue'] = value
d['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(NewStyle):
"""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(NewStyle):
__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, 1)
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, 1)
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)
# we're only interested in the URI as text at this point
uri = uri or ""
d = a.childNodes[0].__dict__
d['data'] = d['nodeValue'] = uri
d = a.__dict__
d['value'] = d['nodeValue'] = uri
d['ownerDocument'] = self.document
_set_attribute_node(node, a)
del self._ns_ordered_prefixes[:]
if 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
d = a.childNodes[0].__dict__
d['data'] = d['nodeValue'] = value
d = a.__dict__
d['ownerDocument'] = self.document
d['value'] = d['nodeValue'] = value
d['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=1):
"""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, StringTypes):
fp = open(file, 'rb')
try:
result = builder.parseFile(fp)
finally:
fp.close()
else:
result = builder.parseFile(file)
return result
def parseString(string, namespaces=1):
"""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=1):
"""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, StringTypes):
fp = open(file, 'rb')
try:
result = builder.parseFile(fp)
finally:
fp.close()
else:
result = builder.parseFile(file)
return result
def parseFragmentString(string, context, namespaces=1):
"""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)
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