Package translate :: Package storage :: Package xml_extract :: Module unit_tree |
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# Source Code for Module translate.storage.xml_extract.unit_tree

      1  #!/usr/bin/env python
      2  # -*- coding: utf-8 -*-
      3  #
      4  # Copyright 2002-2006 Zuza Software Foundation
      5  #
      6  # This file is part of translate.
      7  #
      8  # translate is free software; you can redistribute it and/or modify
      9  # it under the terms of the GNU General Public License as published by
     10  # the Free Software Foundation; either version 2 of the License, or
     11  # (at your option) any later version.
     12  #
     13  # translate is distributed in the hope that it will be useful,
     14  # but WITHOUT ANY WARRANTY; without even the implied warranty of
     15  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     16  # GNU General Public License for more details.
     17  #
     18  # You should have received a copy of the GNU General Public License
     19  # along with translate; if not, write to the Free Software
     20  # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
     21  #
     22
     23  from lxml import etree
     24
     25  from translate.storage import base
     26  from translate.misc.typecheck import accepts, Self, IsCallable, IsOneOf, Any
     27  from translate.misc.typecheck.typeclasses import Number
     28
     29 -class XPathTree(object):
     30      @accepts(Self(), base.TranslationUnit)
     31 -    def __init__(self, unit = None):
     32          self.unit = unit
     33          self.children = {}
     34
     35 -    def __eq__(self, other):
     36          return isinstance(other, XPathTree) and \
     37              self.unit == other.unit and \
     38              self.children == other.children
     39
     40  @accepts(unicode)
     41 -def _split_xpath_component(xpath_component):
     42      """Split an xpath component into a tag-index tuple.
     43
     44      >>> split_xpath_component('{urn:oasis:names:tc:opendocument:xmlns:office:1.0}document-content[0]')
     45      ('{urn:oasis:names:tc:opendocument:xmlns:office:1.0}document-content', 0).
     46      """
     47      lbrac = xpath_component.rfind(u'[')
     48      rbrac = xpath_component.rfind(u']')
     49      tag   = xpath_component[:lbrac]
     50      index = int(xpath_component[lbrac+1:rbrac])
     51      return tag, index
     52
     53  @accepts(unicode)
     54 -def _split_xpath(xpath):
     55      """Split an 'xpath' string separated by / into a reversed list of its components. Thus:
     56
     57      >>> split_xpath('document-content[1]/body[2]/text[3]/p[4]')
     58      [('p', 4), ('text', 3), ('body', 2), ('document-content', 1)]
     59
     60      The list is reversed so that it can be used as a stack, where the top of the stack is
     61      the first component.
     62      """
     63      components = xpath.split(u'/')
     64      components = [_split_xpath_component(component) for component in components]
     65      return list(reversed(components))
     66
     67  @accepts(etree._Element, [(unicode, Number)], base.TranslationUnit)
     68 -def _add_unit_to_tree(node, xpath_components, unit):
     69      """Walk down the tree rooted a node, and follow nodes which correspond to the
     70      components of xpath_components. When reaching the end of xpath_components,
     71      set the reference of the node to unit.
     72
     73      With reference to the tree diagram in build_unit_tree::
     74
     75        add_unit_to_tree(node, [('p', 2), ('text', 3), ('body', 2), ('document-content', 1)], unit)
     76
     77      would begin by popping ('document-content', 1) from the path and following the node marked
     78      ('document-content', 1) in the tree. Likewise, will descend down the nodes marked ('body', 2)
     79      and ('text', 3).
     80
     81      Since the node marked ('text', 3) has no child node marked ('p', 2), this node is created. Then
     82      the add_unit_to_tree descends down this node. When this happens, there are no xpath components
     83      left to pop. Thus, node.unit = unit is executed.
     84      """
     85      if len(xpath_components) > 0:
     86          component = xpath_components.pop() # pop the stack; is a component such as ('p', 4)
     87          # if the current node does not have any children indexed by
     88          # the current component, add such a child
     89          if component not in node.children:
     90              node.children[component] = XPathTree()
     91          _add_unit_to_tree(node.children[component], xpath_components, unit)
     92      else:
     93          node.unit = unit
     94
     95  @accepts(base.TranslationStore)
     96 -def build_unit_tree(store):
     97      """Enumerate a translation store and build a tree with XPath components as nodes
     98      and where a node contains a unit if a path from the root of the tree to the node
     99      containing the unit, is equal to the XPath of the unit.
    100
    101      The tree looks something like this::
    102          root
    103             `- ('document-content', 1)
    104                `- ('body', 2)
    105                   |- ('text', 1)
    106                   |  `- ('p', 1)
    107                   |     `- <reference to a unit>
    108                   |- ('text', 2)
    109                   |  `- ('p', 1)
    110                   |     `- <reference to a unit>
    111                   `- ('text', 3)
    112                      `- ('p', 1)
    113                         `- <reference to a unit>
    114      """
    115      tree = XPathTree()
    116      for unit in store.units:
    117          location = _split_xpath(unit.getlocations()[0])
    118          _add_unit_to_tree(tree, location, unit)
    119      return tree
    120