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- Committer: Martin Pool
- Date: 2005-04-15 02:50:53 UTC
- Revision ID: mbp@sourcefrog.net-20050415025053-645d8aae1d4debed
- gen_file_id: break the file on either / or \ when looking
for a safe prefix of the name
for a safe prefix of the name
- files added:
- .bzrignore
- bzrlib
- doc
- elementtree
- notes
- urlgrabber
- files removed:
- .bzrignore
- foreign
- notes
- tests
added
removed
elementtree/ElementTree.py
1
#
2
# ElementTree
3
# $Id: ElementTree.py 1862 2004-06-18 07:31:02Z Fredrik $
4
#
5
# light-weight XML support for Python 1.5.2 and later.
6
#
7
# this is a stripped-down version of Secret Labs' effDOM library (part
8
# of xmlToolkit). compared to effDOM, this implementation has:
9
#
10
# - no support for observers
11
# - no html-specific extensions (e.g. entity preload)
12
# - no custom entities, doctypes, etc
13
# - no accelerator module
14
#
15
# history:
16
# 2001-10-20 fl created (from various sources)
17
# 2001-11-01 fl return root from parse method
18
# 2002-02-16 fl sort attributes in lexical order
19
# 2002-04-06 fl TreeBuilder refactoring, added PythonDoc markup
20
# 2002-05-01 fl finished TreeBuilder refactoring
21
# 2002-07-14 fl added basic namespace support to ElementTree.write
22
# 2002-07-25 fl added QName attribute support
23
# 2002-10-20 fl fixed encoding in write
24
# 2002-11-24 fl changed default encoding to ascii; fixed attribute encoding
25
# 2002-11-27 fl accept file objects or file names for parse/write
26
# 2002-12-04 fl moved XMLTreeBuilder back to this module
27
# 2003-01-11 fl fixed entity encoding glitch for us-ascii
28
# 2003-02-13 fl added XML literal factory
29
# 2003-02-21 fl added ProcessingInstruction/PI factory
30
# 2003-05-11 fl added tostring/fromstring helpers
31
# 2003-05-26 fl added ElementPath support
32
# 2003-07-05 fl added makeelement factory method
33
# 2003-07-28 fl added more well-known namespace prefixes
34
# 2003-08-15 fl fixed typo in ElementTree.findtext (Thomas Dartsch)
35
# 2003-09-04 fl fall back on emulator if ElementPath is not installed
36
# 2003-10-31 fl markup updates
37
# 2003-11-15 fl fixed nested namespace bug
38
# 2004-03-28 fl added XMLID helper
39
# 2004-06-02 fl added default support to findtext
40
# 2004-06-08 fl fixed encoding of non-ascii element/attribute names
41
#
42
# Copyright (c) 1999-2004 by Fredrik Lundh. All rights reserved.
43
#
44
# fredrik@pythonware.com
45
# http://www.pythonware.com
46
#
47
# --------------------------------------------------------------------
48
# The ElementTree toolkit is
49
#
50
# Copyright (c) 1999-2004 by Fredrik Lundh
51
#
52
# By obtaining, using, and/or copying this software and/or its
53
# associated documentation, you agree that you have read, understood,
54
# and will comply with the following terms and conditions:
55
#
56
# Permission to use, copy, modify, and distribute this software and
57
# its associated documentation for any purpose and without fee is
58
# hereby granted, provided that the above copyright notice appears in
59
# all copies, and that both that copyright notice and this permission
60
# notice appear in supporting documentation, and that the name of
61
# Secret Labs AB or the author not be used in advertising or publicity
62
# pertaining to distribution of the software without specific, written
63
# prior permission.
64
#
65
# SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
66
# TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANT-
67
# ABILITY AND FITNESS. IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR
68
# BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
69
# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
70
# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
71
# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
72
# OF THIS SOFTWARE.
73
# --------------------------------------------------------------------
74
75
__all__ = [
76
# public symbols
77
"Comment",
78
"dump",
79
"Element", "ElementTree",
80
"fromstring",
81
"iselement",
82
"parse",
83
"PI", "ProcessingInstruction",
84
"QName",
85
"SubElement",
86
"tostring",
87
"TreeBuilder",
88
"VERSION", "XML",
89
"XMLTreeBuilder",
90
]
91
92
##
93
# The <b>Element</b> type is a flexible container object, designed to
94
# store hierarchical data structures in memory. The type can be
95
# described as a cross between a list and a dictionary.
96
# <p>
97
# Each element has a number of properties associated with it:
98
# <ul>
99
# <li>a <i>tag</i>. This is a string identifying what kind of data
100
# this element represents (the element type, in other words).</li>
101
# <li>a number of <i>attributes</i>, stored in a Python dictionary.</li>
102
# <li>a <i>text</i> string.</li>
103
# <li>an optional <i>tail</i> string.</li>
104
# <li>a number of <i>child elements</i>, stored in a Python sequence</li>
105
# </ul>
106
#
107
# To create an element instance, use the {@link #Element} or {@link
108
# #SubElement} factory functions.
109
# <p>
110
# The {@link #ElementTree} class can be used to wrap an element
111
# structure, and convert it from and to XML.
112
##
113
114
import string, sys, re
115
116
class _SimpleElementPath:
117
# emulate pre-1.2 find/findtext/findall behaviour
118
def find(self, element, tag):
119
for elem in element:
120
if elem.tag == tag:
121
return elem
122
return None
123
def findtext(self, element, tag, default=None):
124
for elem in element:
125
if elem.tag == tag:
126
return elem.text or ""
127
return default
128
def findall(self, element, tag):
129
if tag[:3] == ".//":
130
return element.getiterator(tag[3:])
131
result = []
132
for elem in element:
133
if elem.tag == tag:
134
result.append(elem)
135
return result
136
137
try:
138
import ElementPath
139
except ImportError:
140
# FIXME: issue warning in this case?
141
ElementPath = _SimpleElementPath()
142
143
# TODO: add support for custom namespace resolvers/default namespaces
144
# TODO: add improved support for incremental parsing
145
146
VERSION = "1.2"
147
148
##
149
# Internal element class. This class defines the Element interface,
150
# and provides a reference implementation of this interface.
151
# <p>
152
# You should not create instances of this class directly. Use the
153
# appropriate factory functions instead, such as {@link #Element}
154
# and {@link #SubElement}.
155
#
156
# @see Element
157
# @see SubElement
158
# @see Comment
159
# @see ProcessingInstruction
160
161
class _ElementInterface:
162
# <tag attrib>text<child/>...</tag>tail
163
164
##
165
# (Attribute) Element tag.
166
167
tag = None
168
169
##
170
# (Attribute) Element attribute dictionary. Where possible, use
171
# {@link #_ElementInterface.get},
172
# {@link #_ElementInterface.set},
173
# {@link #_ElementInterface.keys}, and
174
# {@link #_ElementInterface.items} to access
175
# element attributes.
176
177
attrib = None
178
179
##
180
# (Attribute) Text before first subelement. This is either a
181
# string or the value None, if there was no text.
182
183
text = None
184
185
##
186
# (Attribute) Text after this element's end tag, but before the
187
# next sibling element's start tag. This is either a string or
188
# the value None, if there was no text.
189
190
tail = None # text after end tag, if any
191
192
def __init__(self, tag, attrib):
193
self.tag = tag
194
self.attrib = attrib
195
self._children = []
196
197
def __repr__(self):
198
return "<Element %s at %x>" % (self.tag, id(self))
199
200
##
201
# Creates a new element object of the same type as this element.
202
#
203
# @param tag Element tag.
204
# @param attrib Element attributes, given as a dictionary.
205
# @return A new element instance.
206
207
def makeelement(self, tag, attrib):
208
return Element(tag, attrib)
209
210
##
211
# Returns the number of subelements.
212
#
213
# @return The number of subelements.
214
215
def __len__(self):
216
return len(self._children)
217
218
##
219
# Returns the given subelement.
220
#
221
# @param index What subelement to return.
222
# @return The given subelement.
223
# @exception IndexError If the given element does not exist.
224
225
def __getitem__(self, index):
226
return self._children[index]
227
228
##
229
# Replaces the given subelement.
230
#
231
# @param index What subelement to replace.
232
# @param element The new element value.
233
# @exception IndexError If the given element does not exist.
234
# @exception AssertionError If element is not a valid object.
235
236
def __setitem__(self, index, element):
237
assert iselement(element)
238
self._children[index] = element
239
240
##
241
# Deletes the given subelement.
242
#
243
# @param index What subelement to delete.
244
# @exception IndexError If the given element does not exist.
245
246
def __delitem__(self, index):
247
del self._children[index]
248
249
##
250
# Returns a list containing subelements in the given range.
251
#
252
# @param start The first subelement to return.
253
# @param stop The first subelement that shouldn't be returned.
254
# @return A sequence object containing subelements.
255
256
def __getslice__(self, start, stop):
257
return self._children[start:stop]
258
259
##
260
# Replaces a number of subelements with elements from a sequence.
261
#
262
# @param start The first subelement to replace.
263
# @param stop The first subelement that shouldn't be replaced.
264
# @param elements A sequence object with zero or more elements.
265
# @exception AssertionError If a sequence member is not a valid object.
266
267
def __setslice__(self, start, stop, elements):
268
for element in elements:
269
assert iselement(element)
270
self._children[start:stop] = list(elements)
271
272
##
273
# Deletes a number of subelements.
274
#
275
# @param start The first subelement to delete.
276
# @param stop The first subelement to leave in there.
277
278
def __delslice__(self, start, stop):
279
del self._children[start:stop]
280
281
##
282
# Adds a subelement to the end of this element.
283
#
284
# @param element The element to add.
285
# @exception AssertionError If a sequence member is not a valid object.
286
287
def append(self, element):
288
assert iselement(element)
289
self._children.append(element)
290
291
##
292
# Inserts a subelement at the given position in this element.
293
#
294
# @param index Where to insert the new subelement.
295
# @exception AssertionError If the element is not a valid object.
296
297
def insert(self, index, element):
298
assert iselement(element)
299
self._children.insert(index, element)
300
301
##
302
# Removes a matching subelement. Unlike the <b>find</b> methods,
303
# this method compares elements based on identity, not on tag
304
# value or contents.
305
#
306
# @param element What element to remove.
307
# @exception ValueError If a matching element could not be found.
308
# @exception AssertionError If the element is not a valid object.
309
310
def remove(self, element):
311
assert iselement(element)
312
self._children.remove(element)
313
314
##
315
# Returns all subelements. The elements are returned in document
316
# order.
317
#
318
# @return A list of subelements.
319
# @defreturn list of Element instances
320
321
def getchildren(self):
322
return self._children
323
324
##
325
# Finds the first matching subelement, by tag name or path.
326
#
327
# @param path What element to look for.
328
# @return The first matching element, or None if no element was found.
329
# @defreturn Element or None
330
331
def find(self, path):
332
return ElementPath.find(self, path)
333
334
##
335
# Finds text for the first matching subelement, by tag name or path.
336
#
337
# @param path What element to look for.
338
# @param default What to return if the element was not found.
339
# @return The text content of the first matching element, or the
340
# default value no element was found. Note that if the element
341
# has is found, but has no text content, this method returns an
342
# empty string.
343
# @defreturn string
344
345
def findtext(self, path, default=None):
346
return ElementPath.findtext(self, path, default)
347
348
##
349
# Finds all matching subelements, by tag name or path.
350
#
351
# @param path What element to look for.
352
# @return A list or iterator containing all matching elements,
353
# in document order.
354
# @defreturn list of Element instances
355
356
def findall(self, path):
357
return ElementPath.findall(self, path)
358
359
##
360
# Resets an element. This function removes all subelements, clears
361
# all attributes, and sets the text and tail attributes to None.
362
363
def clear(self):
364
self.attrib.clear()
365
self._children = []
366
self.text = self.tail = None
367
368
##
369
# Gets an element attribute.
370
#
371
# @param key What attribute to look for.
372
# @param default What to return if the attribute was not found.
373
# @return The attribute value, or the default value, if the
374
# attribute was not found.
375
# @defreturn string or None
376
377
def get(self, key, default=None):
378
return self.attrib.get(key, default)
379
380
##
381
# Sets an element attribute.
382
#
383
# @param key What attribute to set.
384
# @param value The attribute value.
385
386
def set(self, key, value):
387
self.attrib[key] = value
388
389
##
390
# Gets a list of attribute names. The names are returned in an
391
# arbitrary order (just like for an ordinary Python dictionary).
392
#
393
# @return A list of element attribute names.
394
# @defreturn list of strings
395
396
def keys(self):
397
return self.attrib.keys()
398
399
##
400
# Gets element attributes, as a sequence. The attributes are
401
# returned in an arbitrary order.
402
#
403
# @return A list of (name, value) tuples for all attributes.
404
# @defreturn list of (string, string) tuples
405
406
def items(self):
407
return self.attrib.items()
408
409
##
410
# Creates a tree iterator. The iterator loops over this element
411
# and all subelements, in document order, and returns all elements
412
# with a matching tag.
413
# <p>
414
# If the tree structure is modified during iteration, the result
415
# is undefined.
416
#
417
# @param tag What tags to look for (default is to return all elements).
418
# @return A list or iterator containing all the matching elements.
419
# @defreturn list or iterator
420
421
def getiterator(self, tag=None):
422
nodes = []
423
if tag == "*":
424
tag = None
425
if tag is None or self.tag == tag:
426
nodes.append(self)
427
for node in self._children:
428
nodes.extend(node.getiterator(tag))
429
return nodes
430
431
# compatibility
432
_Element = _ElementInterface
433
434
##
435
# Element factory. This function returns an object implementing the
436
# standard Element interface. The exact class or type of that object
437
# is implementation dependent, but it will always be compatible with
438
# the {@link #_ElementInterface} class in this module.
439
# <p>
440
# The element name, attribute names, and attribute values can be
441
# either 8-bit ASCII strings or Unicode strings.
442
#
443
# @param tag The element name.
444
# @param attrib An optional dictionary, containing element attributes.
445
# @param **extra Additional attributes, given as keyword arguments.
446
# @return An element instance.
447
# @defreturn Element
448
449
def Element(tag, attrib={}, **extra):
450
attrib = attrib.copy()
451
attrib.update(extra)
452
return _ElementInterface(tag, attrib)
453
454
##
455
# Subelement factory. This function creates an element instance, and
456
# appends it to an existing element.
457
# <p>
458
# The element name, attribute names, and attribute values can be
459
# either 8-bit ASCII strings or Unicode strings.
460
#
461
# @param parent The parent element.
462
# @param tag The subelement name.
463
# @param attrib An optional dictionary, containing element attributes.
464
# @param **extra Additional attributes, given as keyword arguments.
465
# @return An element instance.
466
# @defreturn Element
467
468
def SubElement(parent, tag, attrib={}, **extra):
469
attrib = attrib.copy()
470
attrib.update(extra)
471
element = parent.makeelement(tag, attrib)
472
parent.append(element)
473
return element
474
475
##
476
# Comment element factory. This factory function creates a special
477
# element that will be serialized as an XML comment.
478
# <p>
479
# The comment string can be either an 8-bit ASCII string or a Unicode
480
# string.
481
#
482
# @param text A string containing the comment string.
483
# @return An element instance, representing a comment.
484
# @defreturn Element
485
486
def Comment(text=None):
487
element = Element(Comment)
488
element.text = text
489
return element
490
491
##
492
# PI element factory. This factory function creates a special element
493
# that will be serialized as an XML processing instruction.
494
#
495
# @param target A string containing the PI target.
496
# @param text A string containing the PI contents, if any.
497
# @return An element instance, representing a PI.
498
# @defreturn Element
499
500
def ProcessingInstruction(target, text=None):
501
element = Element(ProcessingInstruction)
502
element.text = target
503
if text:
504
element.text = element.text + " " + text
505
return element
506
507
PI = ProcessingInstruction
508
509
##
510
# QName wrapper. This can be used to wrap a QName attribute value, in
511
# order to get proper namespace handling on output.
512
#
513
# @param text A string containing the QName value, in the form {uri}local,
514
# or, if the tag argument is given, the URI part of a QName.
515
# @param tag Optional tag. If given, the first argument is interpreted as
516
# an URI, and this argument is interpreted as a local name.
517
# @return An opaque object, representing the QName.
518
519
class QName:
520
def __init__(self, text_or_uri, tag=None):
521
if tag:
522
text_or_uri = "{%s}%s" % (text_or_uri, tag)
523
self.text = text_or_uri
524
def __str__(self):
525
return self.text
526
def __hash__(self):
527
return hash(self.text)
528
def __cmp__(self, other):
529
if isinstance(other, QName):
530
return cmp(self.text, other.text)
531
return cmp(self.text, other)
532
533
##
534
# ElementTree wrapper class. This class represents an entire element
535
# hierarchy, and adds some extra support for serialization to and from
536
# standard XML.
537
#
538
# @param element Optional root element.
539
# @keyparam file Optional file handle or name. If given, the
540
# tree is initialized with the contents of this XML file.
541
542
class ElementTree:
543
544
def __init__(self, element=None, file=None):
545
assert element is None or iselement(element)
546
self._root = element # first node
547
if file:
548
self.parse(file)
549
550
##
551
# Gets the root element for this tree.
552
#
553
# @return An element instance.
554
# @defreturn Element
555
556
def getroot(self):
557
return self._root
558
559
##
560
# Replaces the root element for this tree. This discards the
561
# current contents of the tree, and replaces it with the given
562
# element. Use with care.
563
#
564
# @param element An element instance.
565
566
def _setroot(self, element):
567
assert iselement(element)
568
self._root = element
569
570
##
571
# Loads an external XML document into this element tree.
572
#
573
# @param source A file name or file object.
574
# @param parser An optional parser instance. If not given, the
575
# standard {@link XMLTreeBuilder} parser is used.
576
# @return The document root element.
577
# @defreturn Element
578
579
def parse(self, source, parser=None):
580
if not hasattr(source, "read"):
581
source = open(source, "rb")
582
if not parser:
583
parser = XMLTreeBuilder()
584
while 1:
585
data = source.read(32768)
586
if not data:
587
break
588
parser.feed(data)
589
self._root = parser.close()
590
return self._root
591
592
##
593
# Creates a tree iterator for the root element. The iterator loops
594
# over all elements in this tree, in document order.
595
#
596
# @param tag What tags to look for (default is to return all elements)
597
# @return An iterator.
598
# @defreturn iterator
599
600
def getiterator(self, tag=None):
601
assert self._root is not None
602
return self._root.getiterator(tag)
603
604
##
605
# Finds the first toplevel element with given tag.
606
# Same as getroot().find(path).
607
#
608
# @param path What element to look for.
609
# @return The first matching element, or None if no element was found.
610
# @defreturn Element or None
611
612
def find(self, path):
613
assert self._root is not None
614
if path[:1] == "/":
615
path = "." + path
616
return self._root.find(path)
617
618
##
619
# Finds the element text for the first toplevel element with given
620
# tag. Same as getroot().findtext(path).
621
#
622
# @param path What toplevel element to look for.
623
# @param default What to return if the element was not found.
624
# @return The text content of the first matching element, or the
625
# default value no element was found. Note that if the element
626
# has is found, but has no text content, this method returns an
627
# empty string.
628
# @defreturn string
629
630
def findtext(self, path, default=None):
631
assert self._root is not None
632
if path[:1] == "/":
633
path = "." + path
634
return self._root.findtext(path, default)
635
636
##
637
# Finds all toplevel elements with the given tag.
638
# Same as getroot().findall(path).
639
#
640
# @param path What element to look for.
641
# @return A list or iterator containing all matching elements,
642
# in document order.
643
# @defreturn list of Element instances
644
645
def findall(self, path):
646
assert self._root is not None
647
if path[:1] == "/":
648
path = "." + path
649
return self._root.findall(path)
650
651
##
652
# Writes the element tree to a file, as XML.
653
#
654
# @param file A file name, or a file object opened for writing.
655
# @param encoding Optional output encoding (default is US-ASCII).
656
657
def write(self, file, encoding="us-ascii"):
658
assert self._root is not None
659
if not hasattr(file, "write"):
660
file = open(file, "wb")
661
if not encoding:
662
encoding = "us-ascii"
663
elif encoding != "utf-8" and encoding != "us-ascii":
664
file.write("<?xml version='1.0' encoding='%s'?>\n" % encoding)
665
self._write(file, self._root, encoding, {})
666
667
def _write(self, file, node, encoding, namespaces):
668
# write XML to file
669
tag = node.tag
670
if tag is Comment:
671
file.write("<!-- %s -->" % _escape_cdata(node.text, encoding))
672
elif tag is ProcessingInstruction:
673
file.write("<?%s?>" % _escape_cdata(node.text, encoding))
674
else:
675
items = node.items()
676
xmlns_items = [] # new namespaces in this scope
677
try:
678
if isinstance(tag, QName) or tag[:1] == "{":
679
tag, xmlns = fixtag(tag, namespaces)
680
if xmlns: xmlns_items.append(xmlns)
681
except TypeError:
682
_raise_serialization_error(tag)
683
file.write("<" + _encode(tag, encoding))
684
if items or xmlns_items:
685
items.sort() # lexical order
686
for k, v in items:
687
try:
688
if isinstance(k, QName) or k[:1] == "{":
689
k, xmlns = fixtag(k, namespaces)
690
if xmlns: xmlns_items.append(xmlns)
691
except TypeError:
692
_raise_serialization_error(k)
693
try:
694
if isinstance(v, QName):
695
v, xmlns = fixtag(v, namespaces)
696
if xmlns: xmlns_items.append(xmlns)
697
except TypeError:
698
_raise_serialization_error(v)
699
file.write(" %s=\"%s\"" % (_encode(k, encoding),
700
_escape_attrib(v, encoding)))
701
for k, v in xmlns_items:
702
file.write(" %s=\"%s\"" % (_encode(k, encoding),
703
_escape_attrib(v, encoding)))
704
if node.text or node:
705
file.write(">")
706
if node.text:
707
file.write(_escape_cdata(node.text, encoding))
708
for n in node:
709
self._write(file, n, encoding, namespaces)
710
file.write("</" + _encode(tag, encoding) + ">")
711
else:
712
file.write(" />")
713
for k, v in xmlns_items:
714
del namespaces[v]
715
if node.tail:
716
file.write(_escape_cdata(node.tail, encoding))
717
718
# --------------------------------------------------------------------
719
# helpers
720
721
##
722
# Checks if an object appears to be a valid element object.
723
#
724
# @param An element instance.
725
# @return A true value if this is an element object.
726
# @defreturn flag
727
728
def iselement(element):
729
# FIXME: not sure about this; might be a better idea to look
730
# for tag/attrib/text attributes
731
return isinstance(element, _ElementInterface) or hasattr(element, "tag")
732
733
##
734
# Writes an element tree or element structure to sys.stdout. This
735
# function should be used for debugging only.
736
# <p>
737
# The exact output format is implementation dependent. In this
738
# version, it's written as an ordinary XML file.
739
#
740
# @param elem An element tree or an individual element.
741
742
def dump(elem):
743
# debugging
744
if not isinstance(elem, ElementTree):
745
elem = ElementTree(elem)
746
elem.write(sys.stdout)
747
tail = elem.getroot().tail
748
if not tail or tail[-1] != "\n":
749
sys.stdout.write("\n")
750
751
def _encode(s, encoding):
752
try:
753
return s.encode(encoding)
754
except AttributeError:
755
return s # 1.5.2: assume the string uses the right encoding
756
757
if sys.version[:3] == "1.5":
758
_escape = re.compile(r"[&<>\"\x80-\xff]+") # 1.5.2
759
else:
760
_escape = re.compile(eval(r'u"[&<>\"\u0080-\uffff]+"'))
761
762
_escape_map = {
763
"&": "&",
764
"<": "<",
765
">": ">",
766
'"': """,
767
}
768
769
_namespace_map = {
770
# "well-known" namespace prefixes
771
"http://www.w3.org/XML/1998/namespace": "xml",
772
"http://www.w3.org/1999/xhtml": "html",
773
"http://www.w3.org/1999/02/22-rdf-syntax-ns#": "rdf",
774
"http://schemas.xmlsoap.org/wsdl/": "wsdl",
775
}
776
777
def _raise_serialization_error(text):
778
raise TypeError(
779
"cannot serialize %r (type %s)" % (text, type(text).__name__)
780
)
781
782
def _encode_entity(text, pattern=_escape):
783
# map reserved and non-ascii characters to numerical entities
784
def escape_entities(m, map=_escape_map):
785
out = []
786
append = out.append
787
for char in m.group():
788
text = map.get(char)
789
if text is None:
790
text = "&#%d;" % ord(char)
791
append(text)
792
return string.join(out, "")
793
try:
794
return _encode(pattern.sub(escape_entities, text), "ascii")
795
except TypeError:
796
_raise_serialization_error(text)
797
798
#
799
# the following functions assume an ascii-compatible encoding
800
# (or "utf-16")
801
802
def _escape_cdata(text, encoding=None, replace=string.replace):
803
# escape character data
804
try:
805
if encoding:
806
try:
807
text = _encode(text, encoding)
808
except UnicodeError:
809
return _encode_entity(text)
810
text = replace(text, "&", "&")
811
text = replace(text, "<", "<")
812
text = replace(text, ">", ">")
813
return text
814
except (TypeError, AttributeError):
815
_raise_serialization_error(text)
816
817
def _escape_attrib(text, encoding=None, replace=string.replace):
818
# escape attribute value
819
try:
820
if encoding:
821
try:
822
text = _encode(text, encoding)
823
except UnicodeError:
824
return _encode_entity(text)
825
text = replace(text, "&", "&")
826
text = replace(text, "'", "'") # FIXME: overkill
827
text = replace(text, "\"", """)
828
text = replace(text, "<", "<")
829
text = replace(text, ">", ">")
830
return text
831
except (TypeError, AttributeError):
832
_raise_serialization_error(text)
833
834
def fixtag(tag, namespaces):
835
# given a decorated tag (of the form {uri}tag), return prefixed
836
# tag and namespace declaration, if any
837
if isinstance(tag, QName):
838
tag = tag.text
839
namespace_uri, tag = string.split(tag[1:], "}", 1)
840
prefix = namespaces.get(namespace_uri)
841
if prefix is None:
842
prefix = _namespace_map.get(namespace_uri)
843
if prefix is None:
844
prefix = "ns%d" % len(namespaces)
845
namespaces[namespace_uri] = prefix
846
if prefix == "xml":
847
xmlns = None
848
else:
849
xmlns = ("xmlns:%s" % prefix, namespace_uri)
850
else:
851
xmlns = None
852
return "%s:%s" % (prefix, tag), xmlns
853
854
##
855
# Parses an XML document into an element tree.
856
#
857
# @param source A filename or file object containing XML data.
858
# @param parser An optional parser instance. If not given, the
859
# standard {@link XMLTreeBuilder} parser is used.
860
# @return An ElementTree instance
861
862
def parse(source, parser=None):
863
tree = ElementTree()
864
tree.parse(source, parser)
865
return tree
866
867
##
868
# Parses an XML document from a string constant. This function can
869
# be used to embed "XML literals" in Python code.
870
#
871
# @param source A string containing XML data.
872
# @return An Element instance.
873
# @defreturn Element
874
875
def XML(text):
876
parser = XMLTreeBuilder()
877
parser.feed(text)
878
return parser.close()
879
880
##
881
# Parses an XML document from a string constant, and also returns
882
# a dictionary which maps from element id:s to elements.
883
#
884
# @param source A string containing XML data.
885
# @return A tuple containing an Element instance and a dictionary.
886
# @defreturn (Element, dictionary)
887
888
def XMLID(text):
889
parser = XMLTreeBuilder()
890
parser.feed(text)
891
tree = parser.close()
892
ids = {}
893
for elem in tree.getiterator():
894
id = elem.get("id")
895
if id:
896
ids[id] = elem
897
return tree, ids
898
899
##
900
# Parses an XML document from a string constant. Same as {@link #XML}.
901
#
902
# @def fromstring(text)
903
# @param source A string containing XML data.
904
# @return An Element instance.
905
# @defreturn Element
906
907
fromstring = XML
908
909
##
910
# Generates a string representation of an XML element, including all
911
# subelements.
912
#
913
# @param element An Element instance.
914
# @return An encoded string containing the XML data.
915
# @defreturn string
916
917
def tostring(element, encoding=None):
918
class dummy:
919
pass
920
data = []
921
file = dummy()
922
file.write = data.append
923
ElementTree(element).write(file, encoding)
924
return string.join(data, "")
925
926
##
927
# Generic element structure builder. This builder converts a sequence
928
# of {@link #TreeBuilder.start}, {@link #TreeBuilder.data}, and {@link
929
# #TreeBuilder.end} method calls to a well-formed element structure.
930
# <p>
931
# You can use this class to build an element structure using a custom XML
932
# parser, or a parser for some other XML-like format.
933
#
934
# @param element_factory Optional element factory. This factory
935
# is called to create new Element instances, as necessary.
936
937
class TreeBuilder:
938
939
def __init__(self, element_factory=None):
940
self._data = [] # data collector
941
self._elem = [] # element stack
942
self._last = None # last element
943
self._tail = None # true if we're after an end tag
944
if element_factory is None:
945
element_factory = _ElementInterface
946
self._factory = element_factory
947
948
##
949
# Flushes the parser buffers, and returns the toplevel documen
950
# element.
951
#
952
# @return An Element instance.
953
# @defreturn Element
954
955
def close(self):
956
assert len(self._elem) == 0, "missing end tags"
957
assert self._last != None, "missing toplevel element"
958
return self._last
959
960
def _flush(self):
961
if self._data:
962
if self._last is not None:
963
text = string.join(self._data, "")
964
if self._tail:
965
assert self._last.tail is None, "internal error (tail)"
966
self._last.tail = text
967
else:
968
assert self._last.text is None, "internal error (text)"
969
self._last.text = text
970
self._data = []
971
972
##
973
# Adds text to the current element.
974
#
975
# @param data A string. This should be either an 8-bit string
976
# containing ASCII text, or a Unicode string.
977
978
def data(self, data):
979
self._data.append(data)
980
981
##
982
# Opens a new element.
983
#
984
# @param tag The element name.
985
# @param attrib A dictionary containing element attributes.
986
# @return The opened element.
987
# @defreturn Element
988
989
def start(self, tag, attrs):
990
self._flush()
991
self._last = elem = self._factory(tag, attrs)
992
if self._elem:
993
self._elem[-1].append(elem)
994
self._elem.append(elem)
995
self._tail = 0
996
return elem
997
998
##
999
# Closes the current element.
1000
#
1001
# @param tag The element name.
1002
# @return The closed element.
1003
# @defreturn Element
1004
1005
def end(self, tag):
1006
self._flush()
1007
self._last = self._elem.pop()
1008
assert self._last.tag == tag,\
1009
"end tag mismatch (expected %s, got %s)" % (
1010
self._last.tag, tag)
1011
self._tail = 1
1012
return self._last
1013
1014
##
1015
# Element structure builder for XML source data, based on the
1016
# <b>expat</b> parser.
1017
#
1018
# @keyparam target Target object. If omitted, the builder uses an
1019
# instance of the standard {@link #TreeBuilder} class.
1020
# @keyparam html Predefine HTML entities. This flag is not supported
1021
# by the current implementation.
1022
# @see #ElementTree
1023
# @see #TreeBuilder
1024
1025
class XMLTreeBuilder:
1026
1027
def __init__(self, html=0, target=None):
1028
from xml.parsers import expat
1029
self._parser = parser = expat.ParserCreate(None, "}")
1030
if target is None:
1031
target = TreeBuilder()
1032
self._target = target
1033
self._names = {} # name memo cache
1034
parser.DefaultHandler = self._default
1035
parser.StartElementHandler = self._start
1036
parser.EndElementHandler = self._end
1037
parser.CharacterDataHandler = self._data
1038
encoding = None
1039
if not parser.returns_unicode:
1040
encoding = "utf-8"
1041
# target.xml(encoding, None)
1042
self._doctype = None
1043
self.entity = {}
1044
1045
def _fixtext(self, text):
1046
# convert text string to ascii, if possible
1047
try:
1048
return str(text) # what if the default encoding is changed?
1049
except UnicodeError:
1050
return text
1051
1052
def _fixname(self, key):
1053
# expand qname, and convert name string to ascii, if possible
1054
try:
1055
name = self._names[key]
1056
except KeyError:
1057
name = key
1058
if "}" in name:
1059
name = "{" + name
1060
self._names[key] = name = self._fixtext(name)
1061
return name
1062
1063
def _start(self, tag, attrib_in):
1064
fixname = self._fixname
1065
tag = fixname(tag)
1066
attrib = {}
1067
for key, value in attrib_in.items():
1068
attrib[fixname(key)] = self._fixtext(value)
1069
return self._target.start(tag, attrib)
1070
1071
def _data(self, text):
1072
return self._target.data(self._fixtext(text))
1073
1074
def _end(self, tag):
1075
return self._target.end(self._fixname(tag))
1076
1077
def _default(self, text):
1078
prefix = text[:1]
1079
if prefix == "&":
1080
# deal with undefined entities
1081
try:
1082
self._target.data(self.entity[text[1:-1]])
1083
except KeyError:
1084
from xml.parsers import expat
1085
raise expat.error(
1086
"undefined entity %s: line %d, column %d" %
1087
(text, self._parser.ErrorLineNumber,
1088
self._parser.ErrorColumnNumber)
1089
)
1090
elif prefix == "<" and text[:9] == "<!DOCTYPE":
1091
self._doctype = [] # inside a doctype declaration
1092
elif self._doctype is not None:
1093
# parse doctype contents
1094
if prefix == ">":
1095
self._doctype = None
1096
return
1097
text = string.strip(text)
1098
if not text:
1099
return
1100
self._doctype.append(text)
1101
n = len(self._doctype)
1102
if n > 2:
1103
type = self._doctype[1]
1104
if type == "PUBLIC" and n == 4:
1105
name, type, pubid, system = self._doctype
1106
elif type == "SYSTEM" and n == 3:
1107
name, type, system = self._doctype
1108
pubid = None
1109
else:
1110
return
1111
if pubid:
1112
pubid = pubid[1:-1]
1113
self.doctype(name, pubid, system[1:-1])
1114
self._doctype = None
1115
1116
##
1117
# Handles a doctype declaration.
1118
#
1119
# @param name Doctype name.
1120
# @param pubid Public identifier.
1121
# @param system System identifier.
1122
1123
def doctype(self, name, pubid, system):
1124
pass
1125
1126
##
1127
# Feeds data to the parser.
1128
#
1129
# @param data Encoded data.
1130
1131
def feed(self, data):
1132
self._parser.Parse(data, 0)
1133
1134
##
1135
# Finishes feeding data to the parser.
1136
#
1137
# @return An element structure.
1138
# @defreturn Element
1139
1140
def close(self):
1141
self._parser.Parse("", 1) # end of data
1142
tree = self._target.close()
1143
del self._target, self._parser # get rid of circular references
1144
return tree
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0