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Edit File: yocto_css.py
#!/usr/bin/env python # -*- coding: utf-8 -*- # yocto-css, an extremely bare minimum CSS parser # # Copyright 2009 Jeff Schiller # # This file is part of Scour, http://www.codedread.com/scour/ # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # In order to resolve Bug 368716 (https://bugs.launchpad.net/scour/+bug/368716) # scour needed a bare-minimum CSS parser in order to determine if some elements # were still referenced by CSS properties. # I looked at css-py (a CSS parser built in Python), but that library # is about 35k of Python and requires ply to be installed. I just need # something very basic to suit scour's needs. # yocto-css takes a string of CSS and tries to spit out a list of rules # A rule is an associative array (dictionary) with the following keys: # - selector: contains the string of the selector (see CSS grammar) # - properties: contains an associative array of CSS properties for this rule # TODO: need to build up some unit tests for yocto_css # stylesheet : [ CDO | CDC | S | statement ]*; # statement : ruleset | at-rule; # at-rule : ATKEYWORD S* any* [ block | ';' S* ]; # block : '{' S* [ any | block | ATKEYWORD S* | ';' S* ]* '}' S*; # ruleset : selector? '{' S* declaration? [ ';' S* declaration? ]* '}' S*; # selector : any+; # declaration : property S* ':' S* value; # property : IDENT; # value : [ any | block | ATKEYWORD S* ]+; # any : [ IDENT | NUMBER | PERCENTAGE | DIMENSION | STRING # | DELIM | URI | HASH | UNICODE-RANGE | INCLUDES # | DASHMATCH | FUNCTION S* any* ')' # | '(' S* any* ')' | '[' S* any* ']' ] S*; def parseCssString(str): rules = [] # first, split on } to get the rule chunks chunks = str.split('}') for chunk in chunks: # second, split on { to get the selector and the list of properties bits = chunk.split('{') if len(bits) != 2: continue rule = {} rule['selector'] = bits[0].strip() # third, split on ; to get the property declarations bites = bits[1].strip().split(';') if len(bites) < 1: continue props = {} for bite in bites: # fourth, split on : to get the property name and value nibbles = bite.strip().split(':') if len(nibbles) != 2: continue props[nibbles[0].strip()] = nibbles[1].strip() rule['properties'] = props rules.append(rule) return rules