cpython/Lib/xml/dom/pulldom.py
Martin v. Löwis b417be2ad9 Do not allow empty qualifiedName in createDocument.
Rearrange pulldom to create documents with root element.
Provide clear methods so that the ContentHandler releases its hold on the
document.
2001-02-06 01:16:06 +00:00

279 lines
8.9 KiB
Python

import xml.sax
import xml.sax.handler
import types
try:
_StringTypes = [types.StringType, types.UnicodeType]
except AttributeError:
_StringTypes = [types.StringType]
START_ELEMENT = "START_ELEMENT"
END_ELEMENT = "END_ELEMENT"
COMMENT = "COMMENT"
START_DOCUMENT = "START_DOCUMENT"
END_DOCUMENT = "END_DOCUMENT"
PROCESSING_INSTRUCTION = "PROCESSING_INSTRUCTION"
IGNORABLE_WHITESPACE = "IGNORABLE_WHITESPACE"
CHARACTERS = "CHARACTERS"
class PullDOM(xml.sax.ContentHandler):
_locator = None
document = None
def __init__(self, documentFactory=None):
self.documentFactory = documentFactory
self.firstEvent = [None, None]
self.lastEvent = self.firstEvent
self.elementStack = []
self.push = self.elementStack.append
try:
self.pop = self.elementStack.pop
except AttributeError:
# use class' pop instead
pass
self._ns_contexts = [{}] # contains uri -> prefix dicts
self._current_context = self._ns_contexts[-1]
def pop(self):
result = self.elementStack[-1]
del self.elementStack[-1]
return result
def setDocumentLocator(self, locator):
self._locator = locator
def startPrefixMapping(self, prefix, uri):
self._ns_contexts.append(self._current_context.copy())
self._current_context[uri] = prefix or ''
def endPrefixMapping(self, prefix):
self._current_context = self._ns_contexts.pop()
def startElementNS(self, name, tagName , attrs):
uri, localname = name
if uri:
# When using namespaces, the reader may or may not
# provide us with the original name. If not, create
# *a* valid tagName from the current context.
if tagName is None:
prefix = self._current_context[uri]
if prefix:
tagName = prefix + ":" + localname
else:
tagName = localname
if self.document:
node = self.document.createElementNS(uri, tagName)
else:
node = self.buildDocument(uri, tagName)
else:
# When the tagname is not prefixed, it just appears as
# localname
if self.document:
node = self.document.createElement(localname)
else:
node = self.buildDocument(None, localname)
for aname,value in attrs.items():
a_uri, a_localname = aname
if a_uri:
prefix = self._current_context[a_uri]
if prefix:
qname = prefix + ":" + a_localname
else:
qname = a_localname
attr = self.document.createAttributeNS(a_uri, qname)
else:
attr = self.document.createAttribute(a_localname)
attr.value = value
node.setAttributeNode(attr)
self.lastEvent[1] = [(START_ELEMENT, node), None]
self.lastEvent = self.lastEvent[1]
self.push(node)
def endElementNS(self, name, tagName):
self.lastEvent[1] = [(END_ELEMENT, self.pop()), None]
self.lastEvent = self.lastEvent[1]
def startElement(self, name, attrs):
if self.document:
node = self.document.createElement(name)
else:
node = self.buildDocument(None, name)
for aname,value in attrs.items():
attr = self.document.createAttribute(aname)
attr.value = value
node.setAttributeNode(attr)
self.lastEvent[1] = [(START_ELEMENT, node), None]
self.lastEvent = self.lastEvent[1]
self.push(node)
def endElement(self, name):
self.lastEvent[1] = [(END_ELEMENT, self.pop()), None]
self.lastEvent = self.lastEvent[1]
def comment(self, s):
node = self.document.createComment(s)
self.lastEvent[1] = [(COMMENT, node), None]
self.lastEvent = self.lastEvent[1]
def processingInstruction(self, target, data):
node = self.document.createProcessingInstruction(target, data)
self.lastEvent[1] = [(PROCESSING_INSTRUCTION, node), None]
self.lastEvent = self.lastEvent[1]
def ignorableWhitespace(self, chars):
node = self.document.createTextNode(chars)
self.lastEvent[1] = [(IGNORABLE_WHITESPACE, node), None]
self.lastEvent = self.lastEvent[1]
def characters(self, chars):
node = self.document.createTextNode(chars)
self.lastEvent[1] = [(CHARACTERS, node), None]
self.lastEvent = self.lastEvent[1]
def startDocument(self):
if self.documentFactory is None:
import xml.dom.minidom
self.documentFactory = xml.dom.minidom.Document.implementation
def buildDocument(self, uri, tagname):
# Can't do that in startDocument, since we need the tagname
# XXX: obtain DocumentType
node = self.documentFactory.createDocument(uri, tagname, None)
self.document = node
self.lastEvent[1] = [(START_DOCUMENT, node), None]
self.lastEvent = self.lastEvent[1]
self.push(node)
return node.firstChild
def endDocument(self):
self.lastEvent[1] = [(END_DOCUMENT, self.document), None]
self.pop()
def clear(self):
"clear(): Explicitly release parsing structures"
self.document = None
class ErrorHandler:
def warning(self, exception):
print exception
def error(self, exception):
raise exception
def fatalError(self, exception):
raise exception
class DOMEventStream:
def __init__(self, stream, parser, bufsize):
self.stream = stream
self.parser = parser
self.bufsize = bufsize
self.reset()
def reset(self):
self.pulldom = PullDOM()
# This content handler relies on namespace support
self.parser.setFeature(xml.sax.handler.feature_namespaces, 1)
self.parser.setContentHandler(self.pulldom)
def __getitem__(self, pos):
rc = self.getEvent()
if rc:
return rc
raise IndexError
def expandNode(self, node):
event = self.getEvent()
parents = [node]
while event:
token, cur_node = event
if cur_node is node:
return
if token != END_ELEMENT:
parents[-1].appendChild(cur_node)
if token == START_ELEMENT:
parents.append(cur_node)
elif token == END_ELEMENT:
del parents[-1]
event = self.getEvent()
def getEvent(self):
if not self.pulldom.firstEvent[1]:
self.pulldom.lastEvent = self.pulldom.firstEvent
while not self.pulldom.firstEvent[1]:
buf = self.stream.read(self.bufsize)
if not buf:
self.parser.close()
return None
self.parser.feed(buf)
rc = self.pulldom.firstEvent[1][0]
self.pulldom.firstEvent[1] = self.pulldom.firstEvent[1][1]
return rc
def clear(self):
"clear(): Explicitly release parsing objects"
self.pulldom.clear()
del self.pulldom
self.parser = None
self.stream = None
class SAX2DOM(PullDOM):
def startElementNS(self, name, tagName , attrs):
PullDOM.startElementNS(self, name, tagName, attrs)
curNode = self.elementStack[-1]
parentNode = self.elementStack[-2]
parentNode.appendChild(curNode)
def startElement(self, name, attrs):
PullDOM.startElement(self, name, attrs)
curNode = self.elementStack[-1]
parentNode = self.elementStack[-2]
parentNode.appendChild(curNode)
def processingInstruction(self, target, data):
PullDOM.processingInstruction(self, target, data)
node = self.lastEvent[0][1]
parentNode = self.elementStack[-1]
parentNode.appendChild(node)
def ignorableWhitespace(self, chars):
PullDOM.ignorableWhitespace(self, chars)
node = self.lastEvent[0][1]
parentNode = self.elementStack[-1]
parentNode.appendChild(node)
def characters(self, chars):
PullDOM.characters(self, chars)
node = self.lastEvent[0][1]
parentNode = self.elementStack[-1]
parentNode.appendChild(node)
default_bufsize = (2 ** 14) - 20
def parse(stream_or_string, parser=None, bufsize=None):
if bufsize is None:
bufsize = default_bufsize
if type(stream_or_string) in _StringTypes:
stream = open(stream_or_string)
else:
stream = stream_or_string
if not parser:
parser = xml.sax.make_parser()
return DOMEventStream(stream, parser, bufsize)
def parseString(string, parser=None):
try:
from cStringIO import StringIO
except ImportError:
from StringIO import StringIO
bufsize = len(string)
buf = StringIO(string)
if not parser:
parser = xml.sax.make_parser()
return DOMEventStream(buf, parser, bufsize)