libs/elementtree/XMLTreeBuilder.py

   1 #
   2 # ElementTree
   3 # $Id: XMLTreeBuilder.py 2305 2005-03-01 17:43:09Z fredrik $
   4 #
   5 # an XML tree builder
   6 #
   7 # history:
   8 # 2001-10-20 fl   created
   9 # 2002-05-01 fl   added namespace support for xmllib
  10 # 2002-07-27 fl   require expat (1.5.2 code can use SimpleXMLTreeBuilder)
  11 # 2002-08-17 fl   use tag/attribute name memo cache
  12 # 2002-12-04 fl   moved XMLTreeBuilder to the ElementTree module
  13 #
  14 # Copyright (c) 1999-2004 by Fredrik Lundh.  All rights reserved.
  15 #
  16 # fredrik@pythonware.com
  17 # http://www.pythonware.com
  18 #
  19 # --------------------------------------------------------------------
  20 # The ElementTree toolkit is
  21 #
  22 # Copyright (c) 1999-2004 by Fredrik Lundh
  23 #
  24 # By obtaining, using, and/or copying this software and/or its
  25 # associated documentation, you agree that you have read, understood,
  26 # and will comply with the following terms and conditions:
  27 #
  28 # Permission to use, copy, modify, and distribute this software and
  29 # its associated documentation for any purpose and without fee is
  30 # hereby granted, provided that the above copyright notice appears in
  31 # all copies, and that both that copyright notice and this permission
  32 # notice appear in supporting documentation, and that the name of
  33 # Secret Labs AB or the author not be used in advertising or publicity
  34 # pertaining to distribution of the software without specific, written
  35 # prior permission.
  36 #
  37 # SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
  38 # TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANT-
  39 # ABILITY AND FITNESS.  IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR
  40 # BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
  41 # DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  42 # WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  43 # ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  44 # OF THIS SOFTWARE.
  45 # --------------------------------------------------------------------
  46
  47 ##
  48 # Tools to build element trees from XML files.
  49 ##
  50
  51 import ElementTree
  52
  53 ##
  54 # (obsolete) ElementTree builder for XML source data, based on the
  55 # <b>expat</b> parser.
  56 # <p>
  57 # This class is an alias for ElementTree.XMLTreeBuilder.  New code
  58 # should use that version instead.
  59 #
  60 # @see elementtree.ElementTree
  61
  62 class TreeBuilder(ElementTree.XMLTreeBuilder):
  63     pass
  64
  65 ##
  66 # (experimental) An alternate builder that supports manipulation of
  67 # new elements.
  68
  69 class FancyTreeBuilder(TreeBuilder):
  70
  71     def __init__(self, html=0):
  72         TreeBuilder.__init__(self, html)
  73         self._parser.StartNamespaceDeclHandler = self._start_ns
  74         self._parser.EndNamespaceDeclHandler = self._end_ns
  75         self.namespaces = []
  76
  77     def _start(self, tag, attrib_in):
  78         elem = TreeBuilder._start(self, tag, attrib_in)
  79         self.start(elem)
  80
  81     def _start_list(self, tag, attrib_in):
  82         elem = TreeBuilder._start_list(self, tag, attrib_in)
  83         self.start(elem)
  84
  85     def _end(self, tag):
  86         elem = TreeBuilder._end(self, tag)
  87         self.end(elem)
  88
  89     def _start_ns(self, prefix, value):
  90         self.namespaces.insert(0, (prefix, value))
  91
  92     def _end_ns(self, prefix):
  93         assert self.namespaces.pop(0)[0] == prefix, "implementation confused"
  94
  95     ##
  96     # Hook method that's called when a new element has been opened.
  97     # May access the <b>namespaces</b> attribute.
  98     #
  99     # @param element The new element.  The tag name and attributes are,
 100     #     set, but it has no children, and the text and tail attributes
 101     #     are still empty.
 102
 103     def start(self, element):
 104         pass
 105
 106     ##
 107     # Hook method that's called when a new element has been closed.
 108     # May access the <b>namespaces</b> attribute.
 109     #
 110     # @param element The new element.
 111
 112     def end(self, element):
 113         pass