AppPkg/Applications/Python/Python-2.7.10/Lib/xml/etree/ElementInclude.py

   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 # Licensed to PSF under a Contributor Agreement.
  45 # See http://www.python.org/psf/license for licensing details.
  46
  47 ##
  48 # Limited XInclude support for the ElementTree package.
  49 ##
  50
  51 import copy
  52 from . import ElementTree
  53
  54 XINCLUDE = "{http://www.w3.org/2001/XInclude}"
  55
  56 XINCLUDE_INCLUDE = XINCLUDE + "include"
  57 XINCLUDE_FALLBACK = XINCLUDE + "fallback"
  58
  59 ##
  60 # Fatal include error.
  61
  62 class FatalIncludeError(SyntaxError):
  63     pass
  64
  65 ##
  66 # Default loader.  This loader reads an included resource from disk.
  67 #
  68 # @param href Resource reference.
  69 # @param parse Parse mode.  Either "xml" or "text".
  70 # @param encoding Optional text encoding.
  71 # @return The expanded resource.  If the parse mode is "xml", this
  72 #    is an ElementTree instance.  If the parse mode is "text", this
  73 #    is a Unicode string.  If the loader fails, it can return None
  74 #    or raise an IOError exception.
  75 # @throws IOError If the loader fails to load the resource.
  76
  77 def default_loader(href, parse, encoding=None):
  78     with open(href) as file:
  79         if parse == "xml":
  80             data = ElementTree.parse(file).getroot()
  81         else:
  82             data = file.read()
  83             if encoding:
  84                 data = data.decode(encoding)
  85     return data
  86
  87 ##
  88 # Expand XInclude directives.
  89 #
  90 # @param elem Root element.
  91 # @param loader Optional resource loader.  If omitted, it defaults
  92 #     to {@link default_loader}.  If given, it should be a callable
  93 #     that implements the same interface as <b>default_loader</b>.
  94 # @throws FatalIncludeError If the function fails to include a given
  95 #     resource, or if the tree contains malformed XInclude elements.
  96 # @throws IOError If the function fails to load a given resource.
  97
  98 def include(elem, loader=None):
  99     if loader is None:
 100         loader = default_loader
 101     # look for xinclude elements
 102     i = 0
 103     while i < len(elem):
 104         e = elem[i]
 105         if e.tag == XINCLUDE_INCLUDE:
 106             # process xinclude directive
 107             href = e.get("href")
 108             parse = e.get("parse", "xml")
 109             if parse == "xml":
 110                 node = loader(href, parse)
 111                 if node is None:
 112                     raise FatalIncludeError(
 113                         "cannot load %r as %r" % (href, parse)
 114                         )
 115                 node = copy.copy(node)
 116                 if e.tail:
 117                     node.tail = (node.tail or "") + e.tail
 118                 elem[i] = node
 119             elif parse == "text":
 120                 text = loader(href, parse, e.get("encoding"))
 121                 if text is None:
 122                     raise FatalIncludeError(
 123                         "cannot load %r as %r" % (href, parse)
 124                         )
 125                 if i:
 126                     node = elem[i-1]
 127                     node.tail = (node.tail or "") + text + (e.tail or "")
 128                 else:
 129                     elem.text = (elem.text or "") + text + (e.tail or "")
 130                 del elem[i]
 131                 continue
 132             else:
 133                 raise FatalIncludeError(
 134                     "unknown parse type in xi:include tag (%r)" % parse
 135                 )
 136         elif e.tag == XINCLUDE_FALLBACK:
 137             raise FatalIncludeError(
 138                 "xi:fallback tag must be child of xi:include (%r)" % e.tag
 139                 )
 140         else:
 141             include(e, loader)
 142         i = i + 1