comparison elementtree/ElementInclude.py @ 0:5169fce2d144 upstream

Import ElementTree (1.3a3-20070912-preview).
author Bastian Blank <bblank@thinkmo.de>
date Fri, 30 May 2008 18:02:30 +0200
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-1:000000000000 0:5169fce2d144
1 #
2 # ElementTree
3 # $Id: ElementInclude.py 3265 2007-09-06 20:42:00Z fredrik $
4 #
5 # limited xinclude support for element trees
6 #
7 # history:
8 # 2003-08-15 fl created
9 # 2003-11-14 fl fixed default loader
10 #
11 # Copyright (c) 2003-2004 by Fredrik Lundh. All rights reserved.
12 #
13 # fredrik@pythonware.com
14 # http://www.pythonware.com
15 #
16 # --------------------------------------------------------------------
17 # The ElementTree toolkit is
18 #
19 # Copyright (c) 1999-2007 by Fredrik Lundh
20 #
21 # By obtaining, using, and/or copying this software and/or its
22 # associated documentation, you agree that you have read, understood,
23 # and will comply with the following terms and conditions:
24 #
25 # Permission to use, copy, modify, and distribute this software and
26 # its associated documentation for any purpose and without fee is
27 # hereby granted, provided that the above copyright notice appears in
28 # all copies, and that both that copyright notice and this permission
29 # notice appear in supporting documentation, and that the name of
30 # Secret Labs AB or the author not be used in advertising or publicity
31 # pertaining to distribution of the software without specific, written
32 # prior permission.
33 #
34 # SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
35 # TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANT-
36 # ABILITY AND FITNESS. IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR
37 # BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
38 # DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
39 # WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
40 # ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
41 # OF THIS SOFTWARE.
42 # --------------------------------------------------------------------
43
44 ##
45 # Limited XInclude support for the ElementTree package.
46 ##
47
48 import copy
49 import ElementTree
50
51 XINCLUDE = "{http://www.w3.org/2001/XInclude}"
52
53 XINCLUDE_INCLUDE = XINCLUDE + "include"
54 XINCLUDE_FALLBACK = XINCLUDE + "fallback"
55
56 ##
57 # Fatal include error.
58
59 class FatalIncludeError(SyntaxError):
60 pass
61
62 ##
63 # Default loader. This loader reads an included resource from disk.
64 #
65 # @param href Resource reference.
66 # @param parse Parse mode. Either "xml" or "text".
67 # @param encoding Optional text encoding.
68 # @return The expanded resource. If the parse mode is "xml", this
69 # is an ElementTree instance. If the parse mode is "text", this
70 # is a Unicode string. If the loader fails, it can return None
71 # or raise an IOError exception.
72 # @throws IOError If the loader fails to load the resource.
73
74 def default_loader(href, parse, encoding=None):
75 file = open(href)
76 if parse == "xml":
77 data = ElementTree.parse(file).getroot()
78 else:
79 data = file.read()
80 if encoding:
81 data = data.decode(encoding)
82 file.close()
83 return data
84
85 ##
86 # Expand XInclude directives.
87 #
88 # @param elem Root element.
89 # @param loader Optional resource loader. If omitted, it defaults
90 # to {@link default_loader}. If given, it should be a callable
91 # that implements the same interface as <b>default_loader</b>.
92 # @throws FatalIncludeError If the function fails to include a given
93 # resource, or if the tree contains malformed XInclude elements.
94 # @throws IOError If the function fails to load a given resource.
95
96 def include(elem, loader=None):
97 if loader is None:
98 loader = default_loader
99 # look for xinclude elements
100 i = 0
101 while i < len(elem):
102 e = elem[i]
103 if e.tag == XINCLUDE_INCLUDE:
104 # process xinclude directive
105 href = e.get("href")
106 parse = e.get("parse", "xml")
107 if parse == "xml":
108 node = loader(href, parse)
109 if node is None:
110 raise FatalIncludeError(
111 "cannot load %r as %r" % (href, parse)
112 )
113 node = copy.copy(node)
114 if e.tail:
115 node.tail = (node.tail or "") + e.tail
116 elem[i] = node
117 elif parse == "text":
118 text = loader(href, parse, e.get("encoding"))
119 if text is None:
120 raise FatalIncludeError(
121 "cannot load %r as %r" % (href, parse)
122 )
123 if i:
124 node = elem[i-1]
125 node.tail = (node.tail or "") + text
126 else:
127 elem.text = (elem.text or "") + text + (e.tail or "")
128 del elem[i]
129 continue
130 else:
131 raise FatalIncludeError(
132 "unknown parse type in xi:include tag (%r)" % parse
133 )
134 elif e.tag == XINCLUDE_FALLBACK:
135 raise FatalIncludeError(
136 "xi:fallback tag must be child of xi:include (%r)" % e.tag
137 )
138 else:
139 include(e, loader)
140 i = i + 1