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# Source Code for Package cssutils

      1  #!/usr/bin/env python
      2  """cssutils - CSS Cascading Style Sheets library for Python
      3
      4      Copyright (C) 2004-2008 Christof Hoeke
      5
      6      This library is free software; you can redistribute it and/or
      7      modify it under the terms of the GNU Lesser General Public
      8      License as published by the Free Software Foundation; either
      9      version 2.1 of the License, or (at your option) any later version.
     10
     11      This library is distributed in the hope that it will be useful,
     12      but WITHOUT ANY WARRANTY; without even the implied warranty of
     13      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     14      Lesser General Public License for more details.
     15
     16      You should have received a copy of the GNU Lesser General Public
     17      License along with this library; if not, write to the Free Software
     18      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
     19
     20  A Python package to parse and build CSS Cascading Style Sheets. DOM only, not any rendering facilities!
     21
     22  Based upon and partly implementing the following specifications :
     23
     24  `CSS 2.1 <http://www.w3.org/TR/CSS21/>`__
     25      General CSS rules and properties are defined here
     26  `CSS 2.1 Errata  <http://www.w3.org/Style/css2-updates/CR-CSS21-20070719-errata.html>`__
     27      A few errata, mainly the definition of CHARSET_SYM tokens
     28  `CSS3 Module: Syntax <http://www.w3.org/TR/css3-syntax/>`__
     29      Used in parts since cssutils 0.9.4. cssutils tries to use the features from CSS 2.1 and CSS 3 with preference to CSS3 but as this is not final yet some parts are from CSS 2.1
     30  `MediaQueries <http://www.w3.org/TR/css3-mediaqueries/>`__
     31      MediaQueries are part of ``stylesheets.MediaList`` since v0.9.4, used in @import and @media rules.
     32  `Namespaces <http://dev.w3.org/csswg/css3-namespace/>`__
     33      Added in v0.9.1, updated to definition in CSSOM in v0.9.4, updated in 0.9.5 for dev version
     34  `Selectors <http://www.w3.org/TR/css3-selectors/>`__
     35      The selector syntax defined here (and not in CSS 2.1) should be parsable with cssutils (*should* mind though ;) )
     36
     37  `DOM Level 2 Style CSS <http://www.w3.org/TR/DOM-Level-2-Style/css.html>`__
     38      DOM for package css
     39  `DOM Level 2 Style Stylesheets <http://www.w3.org/TR/DOM-Level-2-Style/stylesheets.html>`__
     40      DOM for package stylesheets
     41  `CSSOM <http://dev.w3.org/csswg/cssom/>`__
     42      A few details (mainly the NamespaceRule DOM) is taken from here. Plan is to move implementation to the stuff defined here which is newer but still no REC so might change anytime...
     43
     44
     45  The cssutils tokenizer is a customized implementation of `CSS3 Module: Syntax (W3C Working Draft 13 August 2003) <http://www.w3.org/TR/css3-syntax/>`_ which itself is based on the CSS 2.1 tokenizer. It tries to be as compliant as possible but uses some (helpful) parts of the CSS 2.1 tokenizer.
     46
     47  I guess cssutils is neither CSS 2.1 nor CSS 3 compliant but tries to at least be able to parse both grammars including some more real world cases (some CSS hacks are actually parsed and serialized). Both official grammars are not final nor bugfree but still feasible. cssutils aim is not to be fully compliant to any CSS specification (the specifications seem to be in a constant flow anyway) but cssutils *should* be able to read and write as many as possible CSS stylesheets "in the wild" while at the same time implement the official APIs which are well documented. Some minor extensions are provided as well.
     48
     49  Please visit http://cthedot.de/cssutils/ for more details.
     50
     51
     52  Tested with Python 2.5 on Windows XP.
     53
     54
     55  This library may be used ``from cssutils import *`` which
     56  import subpackages ``css`` and ``stylesheets``, CSSParser and
     57  CSSSerializer classes only.
     58
     59  Usage may be::
     60
     61      >>> from cssutils import *
     62      >>> parser = CSSParser()
     63      >>> sheet = parser.parseString(u'a { color: red}')
     64      >>> print sheet.cssText
     65
     66  """
     67  __all__ = ['css', 'stylesheets', 'CSSParser', 'CSSSerializer']
     68  __docformat__ = 'restructuredtext'
     69  __author__ = 'Christof Hoeke with contributions by Walter Doerwald'
     70  __date__ = '$LastChangedDate:: 2008-03-21 23:33:10 +0100 #$:'
     71  __version__ = '0.9.5b2 $Id: __init__.py 1189 2008-03-21 22:33:10Z cthedot $'
     72
     73  import codec
     74
     75  # order of imports is important (maybe as it is partly circular)
     76  import xml.dom
     77
     78  import errorhandler
     79  log = errorhandler.ErrorHandler()
     80
     81  import util
     82  import css
     83  import stylesheets
     84  from parse import CSSParser
     85
     86  from serialize import CSSSerializer
     87  ser = CSSSerializer()
     88
     89  # used by Selector defining namespace prefix '*'
     90  _ANYNS = -1
     91
     92 -class DOMImplementationCSS(object):
     93      """
     94      This interface allows the DOM user to create a CSSStyleSheet
     95      outside the context of a document. There is no way to associate
     96      the new CSSStyleSheet with a document in DOM Level 2.
     97
     98      This class is its *own factory*, as it is given to
     99      xml.dom.registerDOMImplementation which simply calls it and receives
    100      an instance of this class then.
    101      """
    102      _features = [
    103          ('css', '1.0'),
    104          ('css', '2.0'),
    105          ('stylesheets', '1.0'),
    106          ('stylesheets', '2.0')
    107      ]
    108
    109 -    def createCSSStyleSheet(self, title, media):
    110          """
    111          Creates a new CSSStyleSheet.
    112
    113          title of type DOMString
    114              The advisory title. See also the Style Sheet Interfaces
    115              section.
    116          media of type DOMString
    117              The comma-separated list of media associated with the new style
    118              sheet. See also the Style Sheet Interfaces section.
    119
    120          returns
    121              CSSStyleSheet: A new CSS style sheet.
    122
    123          TODO: DOMException
    124              SYNTAX_ERR: Raised if the specified media string value has a
    125              syntax error and is unparsable.
    126          """
    127          return css.CSSStyleSheet(title=title, media=media)
    128
    129 -    def createDocument(self, *args):
    130          # not needed to HTML, also not for CSS?
    131          raise NotImplementedError
    132
    133 -    def createDocumentType(self, *args):
    134          # not needed to HTML, also not for CSS?
    135          raise NotImplementedError
    136
    137 -    def hasFeature(self, feature, version):
    138          return (feature.lower(), unicode(version)) in self._features
    139
    140  xml.dom.registerDOMImplementation('cssutils', DOMImplementationCSS)
    141
    142
    143 -def parseString(*a, **k):
    144      return CSSParser().parseString(*a, **k)
    145  parseString.__doc__ = CSSParser.parseString.__doc__
    146
    147 -def parse(*a, **k):
    148      return CSSParser().parse(*a, **k)
    149  parse.__doc__ = CSSParser.parse.__doc__
    150
    151 -def parseUrl(*a, **k):
    152      return CSSParser().parseUrl(*a, **k)
    153  parseUrl.__doc__ = CSSParser.parseUrl.__doc__
    154
    155
    156  # set "ser", default serializer
    157 -def setSerializer(serializer):
    158      """
    159      sets the global serializer used by all class in cssutils
    160      """
    161      global ser
    162      ser = serializer
    163
    164
    165 -def getUrls(sheet):
    166      """
    167      Utility function to get all ``url(urlstring)`` values in
    168      ``CSSImportRules`` and ``CSSStyleDeclaration`` objects (properties)
    169      of given CSSStyleSheet ``sheet``.
    170
    171      This function is a generator. The url values exclude ``url(`` and ``)``
    172      and surrounding single or double quotes.
    173      """
    174      for importrule in (r for r in sheet if r.type == r.IMPORT_RULE):
    175          yield importrule.href
    176
    177      def getUrl(v):
    178          if v.CSS_PRIMITIVE_VALUE == v.cssValueType and\
    179             v.CSS_URI == v.primitiveType:
    180                  return v.getStringValue()
    181
    182      def styleDeclarations(base):
    183          "recursive generator to find all CSSStyleDeclarations"
    184          if hasattr(base, 'cssRules'):
    185              for rule in base.cssRules:
    186                  for s in styleDeclarations(rule):
    187                      yield s
    188          elif hasattr(base, 'style'):
    189              yield base.style
    190
    191      for style in styleDeclarations(sheet):
    192          for p in style.getProperties(all=True):
    193              v = p.cssValue
    194              if v.CSS_VALUE_LIST == v.cssValueType:
    195                  for item in v:
    196                      u = getUrl(item)
    197                      if u is not None:
    198                          yield u
    199              elif v.CSS_PRIMITIVE_VALUE == v.cssValueType:
    200                  u = getUrl(v)
    201                  if u is not None:
    202                      yield u
    203
    204 -def replaceUrls(sheet, replacer):
    205      """
    206      Utility function to replace all ``url(urlstring)`` values in
    207      ``CSSImportRules`` and ``CSSStyleDeclaration`` objects (properties)
    208      of given CSSStyleSheet ``sheet``.
    209
    210      ``replacer`` must be a function which is called with a single
    211      argument ``urlstring`` which is the current value of url()
    212      excluding ``url(`` and ``)`` and surrounding single or double quotes.
    213      """
    214      for importrule in (r for r in sheet if r.type == r.IMPORT_RULE):
    215          importrule.href = replacer(importrule.href)
    216
    217      def setProperty(v):
    218          if v.CSS_PRIMITIVE_VALUE == v.cssValueType and\
    219             v.CSS_URI == v.primitiveType:
    220                  v.setStringValue(v.CSS_URI,
    221                                   replacer(v.getStringValue()))
    222
    223      def styleDeclarations(base):
    224          "recursive generator to find all CSSStyleDeclarations"
    225          if hasattr(base, 'cssRules'):
    226              for rule in base.cssRules:
    227                  for s in styleDeclarations(rule):
    228                      yield s
    229          elif hasattr(base, 'style'):
    230              yield base.style
    231
    232      for style in styleDeclarations(sheet):
    233          for p in style.getProperties(all=True):
    234              v = p.cssValue
    235              if v.CSS_VALUE_LIST == v.cssValueType:
    236                  for item in v:
    237                      setProperty(item)
    238              elif v.CSS_PRIMITIVE_VALUE == v.cssValueType:
    239                  setProperty(v)
    240
    241
    242  if __name__ == '__main__':
    243      print __doc__
    244