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#!/usr/bin/env python
"""cssutils - CSS Cascading Style Sheets library for Python
Copyright (C) 2004-2013 Christof Hoeke
cssutils is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
A Python package to parse and build CSS Cascading Style Sheets. DOM only, not
any rendering facilities!
Based upon and partly implementing the following specifications :
`CSS 2.1 <http://www.w3.org/TR/CSS2/>`__
General CSS rules and properties are defined here
`CSS 2.1 Errata <http://www.w3.org/Style/css2-updates/CR-CSS21-20070719-errata.html>`__
A few errata, mainly the definition of CHARSET_SYM tokens
`CSS3 Module: Syntax <http://www.w3.org/TR/css3-syntax/>`__
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
`MediaQueries <http://www.w3.org/TR/css3-mediaqueries/>`__
MediaQueries are part of ``stylesheets.MediaList`` since v0.9.4, used in
@import and @media rules.
`Namespaces <http://dev.w3.org/csswg/css3-namespace/>`__
Added in v0.9.1, updated to definition in CSSOM in v0.9.4, updated in 0.9.5
for dev version
`CSS3 Module: Pages Media <http://www.w3.org/TR/css3-page/>`__
Most properties of this spec are implemented including MarginRules
`Selectors <http://www.w3.org/TR/css3-selectors/>`__
The selector syntax defined here (and not in CSS 2.1) should be parsable
with cssutils (*should* mind though ;) )
`DOM Level 2 Style CSS <http://www.w3.org/TR/DOM-Level-2-Style/css.html>`__
DOM for package css. 0.9.8 removes support for CSSValue and related API,
see PropertyValue and Value API for now
`DOM Level 2 Style Stylesheets <http://www.w3.org/TR/DOM-Level-2-Style/stylesheets.html>`__
DOM for package stylesheets
`CSSOM <http://dev.w3.org/csswg/cssom/>`__
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...
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.
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.
Please visit http://cthedot.de/cssutils/ for more details.
Tested with Python 2.7.3 and 3.3 on Windows 8 64bit.
This library may be used ``from cssutils import *`` which
import subpackages ``css`` and ``stylesheets``, CSSParser and
CSSSerializer classes only.
Usage may be::
>>> from cssutils import *
>>> parser = CSSParser()
>>> sheet = parser.parseString(u'a { color: red}')
>>> print sheet.cssText
a {
color: red
}
"""
__all__ = ['css', 'stylesheets', 'CSSParser', 'CSSSerializer']
__docformat__ = 'restructuredtext'
__author__ = 'Christof Hoeke with contributions by Walter Doerwald'
__date__ = '$LastChangedDate:: $:'
VERSION = '0.9.10'
__version__ = '%s $Id$' % VERSION
import sys
if sys.version_info < (2,6):
bytes = str
import codec
import os.path
import urllib
import urlparse
import xml.dom
# order of imports is important (partly circular)
from . import util
import errorhandler
log = errorhandler.ErrorHandler()
import css
import stylesheets
from parse import CSSParser
from serialize import CSSSerializer
ser = CSSSerializer()
from profiles import Profiles
profile = Profiles(log=log)
# used by Selector defining namespace prefix '*'
_ANYNS = -1
class DOMImplementationCSS(object):
"""This interface allows the DOM user to create a CSSStyleSheet
outside the context of a document. There is no way to associate
the new CSSStyleSheet with a document in DOM Level 2.
This class is its *own factory*, as it is given to
xml.dom.registerDOMImplementation which simply calls it and receives
an instance of this class then.
"""
_features = [
('css', '1.0'),
('css', '2.0'),
('stylesheets', '1.0'),
('stylesheets', '2.0')
]
def createCSSStyleSheet(self, title, media):
"""
Creates a new CSSStyleSheet.
title of type DOMString
The advisory title. See also the Style Sheet Interfaces
section.
media of type DOMString
The comma-separated list of media associated with the new style
sheet. See also the Style Sheet Interfaces section.
returns
CSSStyleSheet: A new CSS style sheet.
TODO: DOMException
SYNTAX_ERR: Raised if the specified media string value has a
syntax error and is unparsable.
"""
return css.CSSStyleSheet(title=title, media=media)
def createDocument(self, *args):
# not needed to HTML, also not for CSS?
raise NotImplementedError
def createDocumentType(self, *args):
# not needed to HTML, also not for CSS?
raise NotImplementedError
def hasFeature(self, feature, version):
return (feature.lower(), unicode(version)) in self._features
xml.dom.registerDOMImplementation('cssutils', DOMImplementationCSS)
def parseString(*a, **k):
return CSSParser().parseString(*a, **k)
parseString.__doc__ = CSSParser.parseString.__doc__
def parseFile(*a, **k):
return CSSParser().parseFile(*a, **k)
parseFile.__doc__ = CSSParser.parseFile.__doc__
def parseUrl(*a, **k):
return CSSParser().parseUrl(*a, **k)
parseUrl.__doc__ = CSSParser.parseUrl.__doc__
def parseStyle(*a, **k):
return CSSParser().parseStyle(*a, **k)
parseStyle.__doc__ = CSSParser.parseStyle.__doc__
# set "ser", default serializer
def setSerializer(serializer):
"""Set the global serializer used by all class in cssutils."""
global ser
ser = serializer
def getUrls(sheet):
"""Retrieve all ``url(urlstring)`` values (in e.g.
:class:`cssutils.css.CSSImportRule` or :class:`cssutils.css.CSSValue`
objects of given `sheet`.
:param sheet:
:class:`cssutils.css.CSSStyleSheet` object whose URLs are yielded
This function is a generator. The generated URL values exclude ``url(`` and
``)`` and surrounding single or double quotes.
"""
for importrule in (r for r in sheet if r.type == r.IMPORT_RULE):
yield importrule.href
def styleDeclarations(base):
"recursive generator to find all CSSStyleDeclarations"
if hasattr(base, 'cssRules'):
for rule in base.cssRules:
for s in styleDeclarations(rule):
yield s
elif hasattr(base, 'style'):
yield base.style
for style in styleDeclarations(sheet):
for p in style.getProperties(all=True):
for v in p.propertyValue:
if v.type == 'URI':
yield v.uri
def replaceUrls(sheetOrStyle, replacer, ignoreImportRules=False):
"""Replace all URLs in :class:`cssutils.css.CSSImportRule` or
:class:`cssutils.css.CSSValue` objects of given `sheetOrStyle`.
:param sheetOrStyle:
a :class:`cssutils.css.CSSStyleSheet` or a
:class:`cssutils.css.CSSStyleDeclaration` which is changed in place
:param replacer:
a function which is called with a single argument `url` which
is the current value of each url() excluding ``url(``, ``)`` and
surrounding (single or double) quotes.
:param ignoreImportRules:
if ``True`` does not call `replacer` with URLs from @import rules.
"""
if not ignoreImportRules and not isinstance(sheetOrStyle,
css.CSSStyleDeclaration):
for importrule in (r for r in sheetOrStyle if r.type == r.IMPORT_RULE):
importrule.href = replacer(importrule.href)
def styleDeclarations(base):
"recursive generator to find all CSSStyleDeclarations"
if hasattr(base, 'cssRules'):
for rule in base.cssRules:
for s in styleDeclarations(rule):
yield s
elif hasattr(base, 'style'):
yield base.style
elif isinstance(sheetOrStyle, css.CSSStyleDeclaration):
# base is a style already
yield base
for style in styleDeclarations(sheetOrStyle):
for p in style.getProperties(all=True):
for v in p.propertyValue:
if v.type == v.URI:
v.uri = replacer(v.uri)
def resolveImports(sheet, target=None):
"""Recurcively combine all rules in given `sheet` into a `target` sheet.
@import rules which use media information are tried to be wrapped into
@media rules so keeping the media information. This may not work in
all instances (if e.g. an @import rule itself contains an @import rule
with different media infos or if it contains rules which may not be
used inside an @media block like @namespace rules.). In these cases
the @import rule is kept as in the original sheet and a WARNING is issued.
:param sheet:
in this given :class:`cssutils.css.CSSStyleSheet` all import rules are
resolved and added to a resulting *flat* sheet.
:param target:
A :class:`cssutils.css.CSSStyleSheet` object which will be the
resulting *flat* sheet if given
:returns: given `target` or a new :class:`cssutils.css.CSSStyleSheet`
object
"""
if not target:
target = css.CSSStyleSheet(href=sheet.href,
media=sheet.media,
title=sheet.title)
def getReplacer(targetbase):
"Return a replacer which uses base to return adjusted URLs"
basesch, baseloc, basepath, basequery, basefrag = urlparse.urlsplit(targetbase)
basepath, basepathfilename = os.path.split(basepath)
def replacer(uri):
scheme, location, path, query, fragment = urlparse.urlsplit(uri)
if not scheme and not location and not path.startswith(u'/'):
# relative
path, filename = os.path.split(path)
combined = os.path.normpath(os.path.join(basepath, path, filename))
return urllib.pathname2url(combined)
else:
# keep anything absolute
return uri
return replacer
for rule in sheet.cssRules:
if rule.type == rule.CHARSET_RULE:
pass
elif rule.type == rule.IMPORT_RULE:
log.info(u'Processing @import %r' % rule.href, neverraise=True)
if rule.hrefFound:
# add all rules of @import to current sheet
target.add(css.CSSComment(cssText=u'/* START @import "%s" */'
% rule.href))
try:
# nested imports
importedSheet = resolveImports(rule.styleSheet)
except xml.dom.HierarchyRequestErr, e:
log.warn(u'@import: Cannot resolve target, keeping rule: %s'
% e, neverraise=True)
target.add(rule)
else:
# adjust relative URI references
log.info(u'@import: Adjusting paths for %r' % rule.href,
neverraise=True)
replaceUrls(importedSheet,
getReplacer(rule.href),
ignoreImportRules=True)
# might have to wrap rules in @media if media given
if rule.media.mediaText == u'all':
mediaproxy = None
else:
keepimport = False
for r in importedSheet:
# check if rules present which may not be
# combined with media
if r.type not in (r.COMMENT,
r.STYLE_RULE,
r.IMPORT_RULE):
keepimport = True
break
if keepimport:
log.warn(u'Cannot combine imported sheet with'
u' given media as other rules then'
u' comments or stylerules found %r,'
u' keeping %r' % (r,
rule.cssText),
neverraise=True)
target.add(rule)
continue
# wrap in @media if media is not `all`
log.info(u'@import: Wrapping some rules in @media '
u' to keep media: %s'
% rule.media.mediaText, neverraise=True)
mediaproxy = css.CSSMediaRule(rule.media.mediaText)
for r in importedSheet:
if mediaproxy:
mediaproxy.add(r)
else:
# add to top sheet directly but are difficult anyway
target.add(r)
if mediaproxy:
target.add(mediaproxy)
else:
# keep @import as it is
log.error(u'Cannot get referenced stylesheet %r, keeping rule'
% rule.href, neverraise=True)
target.add(rule)
else:
target.add(rule)
return target
if __name__ == '__main__':
print __doc__