source: exist/trunk/python/elementtree-1.3a6-20070220-badc/elementtree/ElementInclude.py @ 3578

Subversion URL: http://proj.badc.rl.ac.uk/svn/ndg/exist/trunk/python/elementtree-1.3a6-20070220-badc/elementtree/ElementInclude.py@3578
Revision 3578, 4.9 KB checked in by pjkersha, 11 years ago (diff)

Latest releases from Fredrik Lundh. 10 March release has exclusive C14N support with namespace prefixes.

Line 
1#
2# ElementTree
3# $Id: ElementInclude.py 3375 2008-02-13 08:05:08Z 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) 1999-2008 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
48import copy
49import ElementTree
50
51XINCLUDE = "{http://www.w3.org/2001/XInclude}"
52
53XINCLUDE_INCLUDE = XINCLUDE + "include"
54XINCLUDE_FALLBACK = XINCLUDE + "fallback"
55
56##
57# Fatal include error.
58
59class 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
74def 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
96def 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
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