Package cssutils
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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      cssutils is free software: you can redistribute it and/or modify 
  7      it under the terms of the GNU Lesser General Public License as published by 
  8      the Free Software Foundation, either version 3 of the License, or 
  9      (at your option) any later version. 
 10   
 11      This program 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 
 14      GNU Lesser General Public License for more details. 
 15   
 16      You should have received a copy of the GNU Lesser General Public License 
 17      along with this program.  If not, see <http://www.gnu.org/licenses/>. 
 18   
 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 Vista mainly. 
 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      a { 
 66      color: red 
 67      } 
 68   
 69  """ 
 70  __all__ = ['css', 'stylesheets', 'CSSParser', 'CSSSerializer'] 
 71  __docformat__ = 'restructuredtext' 
 72  __author__ = 'Christof Hoeke with contributions by Walter Doerwald' 
 73  __date__ = '$LastChangedDate:: 2008-07-30 00:42:29 +0200 #$:' 
 74  __version__ = '0.9.5 $Id: __init__.py 1406 2008-07-29 22:42:29Z cthedot $' 
 75   
 76  import codec 
 77  import xml.dom 
 78   
 79  # order of imports is important (maybe as it is partly circular) 
 80  from helper import Deprecated 
 81  import errorhandler 
 82  log = errorhandler.ErrorHandler() 
 83   
 84  import util 
 85  import css 
 86  import stylesheets 
 87  from parse import CSSParser 
 88   
 89  from serialize import CSSSerializer 
 90  ser = CSSSerializer() 
91 92 # used by Selector defining namespace prefix '*' 93 _ANYNS = -1 94 95 -class DOMImplementationCSS(object):
96 """ 97 This interface allows the DOM user to create a CSSStyleSheet 98 outside the context of a document. There is no way to associate 99 the new CSSStyleSheet with a document in DOM Level 2. 100 101 This class is its *own factory*, as it is given to 102 xml.dom.registerDOMImplementation which simply calls it and receives 103 an instance of this class then. 104 """ 105 _features = [ 106 ('css', '1.0'), 107 ('css', '2.0'), 108 ('stylesheets', '1.0'), 109 ('stylesheets', '2.0') 110 ] 111
112 - def createCSSStyleSheet(self, title, media):
113 """ 114 Creates a new CSSStyleSheet. 115 116 title of type DOMString 117 The advisory title. See also the Style Sheet Interfaces 118 section. 119 media of type DOMString 120 The comma-separated list of media associated with the new style 121 sheet. See also the Style Sheet Interfaces section. 122 123 returns 124 CSSStyleSheet: A new CSS style sheet. 125 126 TODO: DOMException 127 SYNTAX_ERR: Raised if the specified media string value has a 128 syntax error and is unparsable. 129 """ 130 return css.CSSStyleSheet(title=title, media=media)
131
132 - def createDocument(self, *args):
133 # not needed to HTML, also not for CSS? 134 raise NotImplementedError
135
136 - def createDocumentType(self, *args):
137 # not needed to HTML, also not for CSS? 138 raise NotImplementedError
139
140 - def hasFeature(self, feature, version):
141 return (feature.lower(), unicode(version)) in self._features
142 143 xml.dom.registerDOMImplementation('cssutils', DOMImplementationCSS)
144 145 146 -def parseString(*a, **k):
147 return CSSParser().parseString(*a, **k)
148 parseString.__doc__ = CSSParser.parseString.__doc__
149 150 -def parseFile(*a, **k):
151 return CSSParser().parseFile(*a, **k)
152 parseFile.__doc__ = CSSParser.parseFile.__doc__
153 154 -def parseUrl(*a, **k):
155 return CSSParser().parseUrl(*a, **k)
156 parseUrl.__doc__ = CSSParser.parseUrl.__doc__
157 158 @Deprecated('Use cssutils.parseFile() instead.') 159 -def parse(*a, **k):
160 return parseFile(*a, **k)
161 parse.__doc__ = CSSParser.parse.__doc__
162 163 164 # set "ser", default serializer 165 -def setSerializer(serializer):
166 """ 167 sets the global serializer used by all class in cssutils 168 """ 169 global ser 170 ser = serializer
171
172 173 -def getUrls(sheet):
174 """ 175 Utility function to get all ``url(urlstring)`` values in 176 ``CSSImportRules`` and ``CSSStyleDeclaration`` objects (properties) 177 of given CSSStyleSheet ``sheet``. 178 179 This function is a generator. The url values exclude ``url(`` and ``)`` 180 and surrounding single or double quotes. 181 """ 182 for importrule in (r for r in sheet if r.type == r.IMPORT_RULE): 183 yield importrule.href 184 185 def getUrl(v): 186 if v.CSS_PRIMITIVE_VALUE == v.cssValueType and\ 187 v.CSS_URI == v.primitiveType: 188 return v.getStringValue()
189 190 def styleDeclarations(base): 191 "recursive generator to find all CSSStyleDeclarations" 192 if hasattr(base, 'cssRules'): 193 for rule in base.cssRules: 194 for s in styleDeclarations(rule): 195 yield s 196 elif hasattr(base, 'style'): 197 yield base.style 198 199 for style in styleDeclarations(sheet): 200 for p in style.getProperties(all=True): 201 v = p.cssValue 202 if v.CSS_VALUE_LIST == v.cssValueType: 203 for item in v: 204 u = getUrl(item) 205 if u is not None: 206 yield u 207 elif v.CSS_PRIMITIVE_VALUE == v.cssValueType: 208 u = getUrl(v) 209 if u is not None: 210 yield u 211
212 -def replaceUrls(sheet, replacer):
213 """ 214 Utility function to replace all ``url(urlstring)`` values in 215 ``CSSImportRules`` and ``CSSStyleDeclaration`` objects (properties) 216 of given CSSStyleSheet ``sheet``. 217 218 ``replacer`` must be a function which is called with a single 219 argument ``urlstring`` which is the current value of url() 220 excluding ``url(`` and ``)`` and surrounding single or double quotes. 221 """ 222 for importrule in (r for r in sheet if r.type == r.IMPORT_RULE): 223 importrule.href = replacer(importrule.href) 224 225 def setProperty(v): 226 if v.CSS_PRIMITIVE_VALUE == v.cssValueType and\ 227 v.CSS_URI == v.primitiveType: 228 v.setStringValue(v.CSS_URI, 229 replacer(v.getStringValue()))
230 231 def styleDeclarations(base): 232 "recursive generator to find all CSSStyleDeclarations" 233 if hasattr(base, 'cssRules'): 234 for rule in base.cssRules: 235 for s in styleDeclarations(rule): 236 yield s 237 elif hasattr(base, 'style'): 238 yield base.style 239 240 for style in styleDeclarations(sheet): 241 for p in style.getProperties(all=True): 242 v = p.cssValue 243 if v.CSS_VALUE_LIST == v.cssValueType: 244 for item in v: 245 setProperty(item) 246 elif v.CSS_PRIMITIVE_VALUE == v.cssValueType: 247 setProperty(v) 248 249 250 if __name__ == '__main__': 251 print __doc__ 252