1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
|
"""
SAX driver for the Pyexpat C module. This driver works with
pyexpat.__version__ == '2.22'.
"""
version = "0.20"
from xml.sax._exceptions import *
try:
from xml.parsers import expat
except ImportError:
raise SAXReaderNotAvailable("expat not supported",None)
from xml.sax import xmlreader, saxutils, handler
AttributesImpl = xmlreader.AttributesImpl
AttributesNSImpl = xmlreader.AttributesNSImpl
import string
import 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 = weakref.ref(parser)
def getColumnNumber(self):
parser = self._ref()
if parser is None or parser._parser is None:
return None
return parser._parser.ErrorColumnNumber
def getLineNumber(self):
parser = self._ref()
if parser is None or 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 = []
# 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())
def getFeature(self, name):
if name == handler.feature_namespaces:
return self._namespaces
raise SAXNotRecognizedException("Feature '%s' not recognized" % name)
def setFeature(self, name, state):
if self._parsing:
raise SAXNotSupportedException("Cannot set features while parsing")
if name == handler.feature_namespaces:
self._namespaces = state
else:
raise SAXNotRecognizedException("Feature '%s' not recognized" %
name)
def getProperty(self, name):
if name == handler.property_lexical_handler:
return self._lex_handler_prop
raise SAXNotRecognizedException("Property '%s' not recognized" % name)
def setProperty(self, name, value):
if name == handler.property_lexical_handler:
self._lex_handler_prop = value
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:
error_code = self._parser.ErrorCode
exc = SAXParseException(expat.ErrorString(error_code), None, 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(self):
if self._namespaces:
self._parser = expat.ParserCreate(None, " ")
self._parser.StartElementHandler = self.start_element_ns
self._parser.EndElementHandler = self.end_element_ns
else:
self._parser = expat.ParserCreate()
self._parser.StartElementHandler = self.start_element
self._parser.EndElementHandler = self.end_element
self._parser.ProcessingInstructionHandler = \
self._cont_handler.processingInstruction
self._parser.CharacterDataHandler = self._cont_handler.characters
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._parser.CommentHandler = self._lex_handler_prop.comment
self._parser.StartCdataSectionHandler = self._lex_handler_prop.startCDATA
self._parser.EndCdataSectionHandler = self._lex_handler_prop.endCDATA
# self._parser.DefaultHandler =
# self._parser.DefaultHandlerExpand =
# self._parser.NotStandaloneHandler =
self._parser.ExternalEntityRefHandler = self.external_entity_ref
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 = string.split(name)
if len(pair) == 1:
pair = (None, name)
else:
pair = tuple(pair)
newattrs = {}
for (aname, value) in attrs.items():
apair = string.split(aname)
if len(apair) == 1:
apair = (None, aname)
else:
apair = tuple(apair)
newattrs[apair] = value
self._cont_handler.startElementNS(pair, None,
AttributesNSImpl(newattrs, {}))
def end_element_ns(self, name):
pair = string.split(name)
if len(pair) == 1:
pair = (None, name)
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 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):
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 create_parser(*args, **kwargs):
return apply(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")
|
