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Diffstat (limited to 'Lib/xml/sax/expatreader.py')
| -rw-r--r-- | Lib/xml/sax/expatreader.py | 414 |
1 files changed, 414 insertions, 0 deletions
diff --git a/Lib/xml/sax/expatreader.py b/Lib/xml/sax/expatreader.py new file mode 100644 index 0000000..bb9c294 --- /dev/null +++ b/Lib/xml/sax/expatreader.py @@ -0,0 +1,414 @@ +""" +SAX driver for the pyexpat C module. This driver works with +pyexpat.__version__ == '2.22'. +""" + +version = "0.20" + +from xml.sax._exceptions import * +from xml.sax.handler import feature_validation, feature_namespaces +from xml.sax.handler import feature_namespace_prefixes +from xml.sax.handler import feature_external_ges, feature_external_pes +from xml.sax.handler import feature_string_interning +from xml.sax.handler import property_xml_string, property_interning_dict + +# xml.parsers.expat does not raise ImportError in Jython +import sys +if sys.platform[:4] == "java": + raise SAXReaderNotAvailable("expat not available in Java", None) +del sys + +try: + from xml.parsers import expat +except ImportError: + raise SAXReaderNotAvailable("expat not supported", None) +else: + if not hasattr(expat, "ParserCreate"): + raise SAXReaderNotAvailable("expat not supported", None) +from xml.sax import xmlreader, saxutils, handler + +AttributesImpl = xmlreader.AttributesImpl +AttributesNSImpl = xmlreader.AttributesNSImpl + +# If we're using a sufficiently recent version of Python, we can use +# weak references to avoid cycles between the parser and content +# handler, otherwise we'll just have to pretend. +try: + import _weakref +except ImportError: + def _mkproxy(o): + return o +else: + import weakref + _mkproxy = weakref.proxy + del weakref, _weakref + +# --- ExpatLocator + +class ExpatLocator(xmlreader.Locator): + """Locator for use with the ExpatParser class. + + This uses a weak reference to the parser object to avoid creating + a circular reference between the parser and the content handler. + """ + def __init__(self, parser): + self._ref = _mkproxy(parser) + + def getColumnNumber(self): + parser = self._ref + if parser._parser is None: + return None + return parser._parser.ErrorColumnNumber + + def getLineNumber(self): + parser = self._ref + if parser._parser is None: + return 1 + return parser._parser.ErrorLineNumber + + def getPublicId(self): + parser = self._ref + if parser is None: + return None + return parser._source.getPublicId() + + def getSystemId(self): + parser = self._ref + if parser is None: + return None + return parser._source.getSystemId() + + +# --- ExpatParser + +class ExpatParser(xmlreader.IncrementalParser, xmlreader.Locator): + """SAX driver for the pyexpat C module.""" + + def __init__(self, namespaceHandling=0, bufsize=2**16-20): + xmlreader.IncrementalParser.__init__(self, bufsize) + self._source = xmlreader.InputSource() + self._parser = None + self._namespaces = namespaceHandling + self._lex_handler_prop = None + self._parsing = 0 + self._entity_stack = [] + self._external_ges = 1 + self._interning = None + + # XMLReader methods + + def parse(self, source): + "Parse an XML document from a URL or an InputSource." + source = saxutils.prepare_input_source(source) + + self._source = source + self.reset() + self._cont_handler.setDocumentLocator(ExpatLocator(self)) + xmlreader.IncrementalParser.parse(self, source) + + def prepareParser(self, source): + if source.getSystemId() != None: + self._parser.SetBase(source.getSystemId()) + + # Redefined setContentHandler to allow changing handlers during parsing + + def setContentHandler(self, handler): + xmlreader.IncrementalParser.setContentHandler(self, handler) + if self._parsing: + self._reset_cont_handler() + + def getFeature(self, name): + if name == feature_namespaces: + return self._namespaces + elif name == feature_string_interning: + return self._interning is not None + elif name in (feature_validation, feature_external_pes, + feature_namespace_prefixes): + return 0 + elif name == feature_external_ges: + return self._external_ges + raise SAXNotRecognizedException("Feature '%s' not recognized" % name) + + def setFeature(self, name, state): + if self._parsing: + raise SAXNotSupportedException("Cannot set features while parsing") + + if name == feature_namespaces: + self._namespaces = state + elif name == feature_external_ges: + self._external_ges = state + elif name == feature_string_interning: + if state: + if self._interning is None: + self._interning = {} + else: + self._interning = None + elif name == feature_validation: + if state: + raise SAXNotSupportedException( + "expat does not support validation") + elif name == feature_external_pes: + if state: + raise SAXNotSupportedException( + "expat does not read external parameter entities") + elif name == feature_namespace_prefixes: + if state: + raise SAXNotSupportedException( + "expat does not report namespace prefixes") + else: + raise SAXNotRecognizedException( + "Feature '%s' not recognized" % name) + + def getProperty(self, name): + if name == handler.property_lexical_handler: + return self._lex_handler_prop + elif name == property_interning_dict: + return self._interning + elif name == property_xml_string: + if self._parser: + if hasattr(self._parser, "GetInputContext"): + return self._parser.GetInputContext() + else: + raise SAXNotRecognizedException( + "This version of expat does not support getting" + " the XML string") + else: + raise SAXNotSupportedException( + "XML string cannot be returned when not parsing") + raise SAXNotRecognizedException("Property '%s' not recognized" % name) + + def setProperty(self, name, value): + if name == handler.property_lexical_handler: + self._lex_handler_prop = value + if self._parsing: + self._reset_lex_handler_prop() + elif name == property_interning_dict: + self._interning = value + elif name == property_xml_string: + raise SAXNotSupportedException("Property '%s' cannot be set" % + name) + else: + raise SAXNotRecognizedException("Property '%s' not recognized" % + name) + + # IncrementalParser methods + + def feed(self, data, isFinal = 0): + if not self._parsing: + self.reset() + self._parsing = 1 + self._cont_handler.startDocument() + + try: + # The isFinal parameter is internal to the expat reader. + # If it is set to true, expat will check validity of the entire + # document. When feeding chunks, they are not normally final - + # except when invoked from close. + self._parser.Parse(data, isFinal) + except expat.error, e: + exc = SAXParseException(expat.ErrorString(e.code), e, self) + # FIXME: when to invoke error()? + self._err_handler.fatalError(exc) + + def close(self): + if self._entity_stack: + # If we are completing an external entity, do nothing here + return + self.feed("", isFinal = 1) + self._cont_handler.endDocument() + self._parsing = 0 + # break cycle created by expat handlers pointing to our methods + self._parser = None + + def _reset_cont_handler(self): + self._parser.ProcessingInstructionHandler = \ + self._cont_handler.processingInstruction + self._parser.CharacterDataHandler = self._cont_handler.characters + + def _reset_lex_handler_prop(self): + lex = self._lex_handler_prop + parser = self._parser + if lex is None: + parser.CommentHandler = None + parser.StartCdataSectionHandler = None + parser.EndCdataSectionHandler = None + parser.StartDoctypeDeclHandler = None + parser.EndDoctypeDeclHandler = None + else: + parser.CommentHandler = lex.comment + parser.StartCdataSectionHandler = lex.startCDATA + parser.EndCdataSectionHandler = lex.endCDATA + parser.StartDoctypeDeclHandler = self.start_doctype_decl + parser.EndDoctypeDeclHandler = lex.endDTD + + def reset(self): + if self._namespaces: + self._parser = expat.ParserCreate(self._source.getEncoding(), " ", + intern=self._interning) + self._parser.namespace_prefixes = 1 + self._parser.StartElementHandler = self.start_element_ns + self._parser.EndElementHandler = self.end_element_ns + else: + self._parser = expat.ParserCreate(self._source.getEncoding(), + intern = self._interning) + self._parser.StartElementHandler = self.start_element + self._parser.EndElementHandler = self.end_element + + self._reset_cont_handler() + self._parser.UnparsedEntityDeclHandler = self.unparsed_entity_decl + self._parser.NotationDeclHandler = self.notation_decl + self._parser.StartNamespaceDeclHandler = self.start_namespace_decl + self._parser.EndNamespaceDeclHandler = self.end_namespace_decl + + self._decl_handler_prop = None + if self._lex_handler_prop: + self._reset_lex_handler_prop() +# self._parser.DefaultHandler = +# self._parser.DefaultHandlerExpand = +# self._parser.NotStandaloneHandler = + self._parser.ExternalEntityRefHandler = self.external_entity_ref + try: + self._parser.SkippedEntityHandler = self.skipped_entity_handler + except AttributeError: + # This pyexpat does not support SkippedEntity + pass + self._parser.SetParamEntityParsing( + expat.XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE) + + self._parsing = 0 + self._entity_stack = [] + + # Locator methods + + def getColumnNumber(self): + if self._parser is None: + return None + return self._parser.ErrorColumnNumber + + def getLineNumber(self): + if self._parser is None: + return 1 + return self._parser.ErrorLineNumber + + def getPublicId(self): + return self._source.getPublicId() + + def getSystemId(self): + return self._source.getSystemId() + + # event handlers + def start_element(self, name, attrs): + self._cont_handler.startElement(name, AttributesImpl(attrs)) + + def end_element(self, name): + self._cont_handler.endElement(name) + + def start_element_ns(self, name, attrs): + pair = name.split() + if len(pair) == 1: + # no namespace + pair = (None, name) + elif len(pair) == 3: + pair = pair[0], pair[1] + else: + # default namespace + pair = tuple(pair) + + newattrs = {} + qnames = {} + for (aname, value) in attrs.items(): + parts = aname.split() + length = len(parts) + if length == 1: + # no namespace + qname = aname + apair = (None, aname) + elif length == 3: + qname = "%s:%s" % (parts[2], parts[1]) + apair = parts[0], parts[1] + else: + # default namespace + qname = parts[1] + apair = tuple(parts) + + newattrs[apair] = value + qnames[apair] = qname + + self._cont_handler.startElementNS(pair, None, + AttributesNSImpl(newattrs, qnames)) + + def end_element_ns(self, name): + pair = name.split() + if len(pair) == 1: + pair = (None, name) + elif len(pair) == 3: + pair = pair[0], pair[1] + else: + pair = tuple(pair) + + self._cont_handler.endElementNS(pair, None) + + # this is not used (call directly to ContentHandler) + def processing_instruction(self, target, data): + self._cont_handler.processingInstruction(target, data) + + # this is not used (call directly to ContentHandler) + def character_data(self, data): + self._cont_handler.characters(data) + + def start_namespace_decl(self, prefix, uri): + self._cont_handler.startPrefixMapping(prefix, uri) + + def end_namespace_decl(self, prefix): + self._cont_handler.endPrefixMapping(prefix) + + def start_doctype_decl(self, name, sysid, pubid, has_internal_subset): + self._lex_handler_prop.startDTD(name, pubid, sysid) + + def unparsed_entity_decl(self, name, base, sysid, pubid, notation_name): + self._dtd_handler.unparsedEntityDecl(name, pubid, sysid, notation_name) + + def notation_decl(self, name, base, sysid, pubid): + self._dtd_handler.notationDecl(name, pubid, sysid) + + def external_entity_ref(self, context, base, sysid, pubid): + if not self._external_ges: + return 1 + + source = self._ent_handler.resolveEntity(pubid, sysid) + source = saxutils.prepare_input_source(source, + self._source.getSystemId() or + "") + + self._entity_stack.append((self._parser, self._source)) + self._parser = self._parser.ExternalEntityParserCreate(context) + self._source = source + + try: + xmlreader.IncrementalParser.parse(self, source) + except: + return 0 # FIXME: save error info here? + + (self._parser, self._source) = self._entity_stack[-1] + del self._entity_stack[-1] + return 1 + + def skipped_entity_handler(self, name, is_pe): + if is_pe: + # The SAX spec requires to report skipped PEs with a '%' + name = '%'+name + self._cont_handler.skippedEntity(name) + +# --- + +def create_parser(*args, **kwargs): + return ExpatParser(*args, **kwargs) + +# --- + +if __name__ == "__main__": + import xml.sax + p = create_parser() + p.setContentHandler(xml.sax.XMLGenerator()) + p.setErrorHandler(xml.sax.ErrorHandler()) + p.parse("../../../hamlet.xml") |