Module rcssmin

Source Code for Module rcssmin

  1  #!/usr/bin/env python 
  2  # -*- coding: ascii -*- 
  3  # 
  4  # Copyright 2011, 2012 
  5  # Andr\xe9 Malo or his licensors, as applicable 
  6  # 
  7  # Licensed under the Apache License, Version 2.0 (the "License"); 
  8  # you may not use this file except in compliance with the License. 
  9  # You may obtain a copy of the License at 
 10  # 
 11  #     http://www.apache.org/licenses/LICENSE-2.0 
 12  # 
 13  # Unless required by applicable law or agreed to in writing, software 
 14  # distributed under the License is distributed on an "AS IS" BASIS, 
 15  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
 16  # See the License for the specific language governing permissions and 
 17  # limitations under the License. 
 18  r""" 
 19  ============== 
 20   CSS Minifier 
 21  ============== 
 22   
 23  CSS Minifier. 
 24   
 25  The minifier is based on the semantics of the `YUI compressor`_\, which itself 
 26  is based on `the rule list by Isaac Schlueter`_\. 
 27   
 28  This module is a re-implementation aiming for speed instead of maximum 
 29  compression, so it can be used at runtime (rather than during a preprocessing 
 30  step). RCSSmin does syntactical compression only (removing spaces, comments 
 31  and possibly semicolons). It does not provide semantic compression (like 
 32  removing empty blocks, collapsing redundant properties etc). It does, however, 
 33  support various CSS hacks (by keeping them working as intended). 
 34   
 35  Here's a feature list: 
 36   
 37  - Strings are kept, except that escaped newlines are stripped 
 38  - Space/Comments before the very end or before various characters are 
 39    stripped: ``:{});=>+],!`` (The colon (``:``) is a special case, a single 
 40    space is kept if it's outside a ruleset.) 
 41  - Space/Comments at the very beginning or after various characters are 
 42    stripped: ``{}(=:>+[,!`` 
 43  - Optional space after unicode escapes is kept, resp. replaced by a simple 
 44    space 
 45  - whitespaces inside ``url()`` definitions are stripped 
 46  - Comments starting with an exclamation mark (``!``) can be kept optionally. 
 47  - All other comments and/or whitespace characters are replaced by a single 
 48    space. 
 49  - Multiple consecutive semicolons are reduced to one 
 50  - The last semicolon within a ruleset is stripped 
 51  - CSS Hacks supported: 
 52   
 53    - IE7 hack (``>/**/``) 
 54    - Mac-IE5 hack (``/*\*/.../**/``) 
 55    - The boxmodelhack is supported naturally because it relies on valid CSS2 
 56      strings 
 57    - Between ``:first-line`` and the following comma or curly brace a space is 
 58      inserted. (apparently it's needed for IE6) 
 59    - Same for ``:first-letter`` 
 60   
 61  rcssmin.c is a reimplementation of rcssmin.py in C and improves runtime up to 
 62  factor 50 or so (depending on the input). 
 63   
 64  Both python 2 (>= 2.4) and python 3 are supported. 
 65   
 66  .. _YUI compressor: https://github.com/yui/yuicompressor/ 
 67   
 68  .. _the rule list by Isaac Schlueter: https://github.com/isaacs/cssmin/tree/ 
 69  """ 
 70  __author__ = "Andr\xe9 Malo" 
 71  __author__ = getattr(__author__, 'decode', lambda x: __author__)('latin-1') 
 72  __docformat__ = "restructuredtext en" 
 73  __license__ = "Apache License, Version 2.0" 
 74  __version__ = '1.0.2' 
 75  __all__ = ['cssmin'] 
 76   
 77  import re as _re 
 78   
 79   
80 -def _make_cssmin(python_only=False):
81 """ 82 Generate CSS minifier. 83 84 :Parameters: 85 `python_only` : ``bool`` 86 Use only the python variant. If true, the c extension is not even 87 tried to be loaded. 88 89 :Return: Minifier 90 :Rtype: ``callable`` 91 """ 92 # pylint: disable = W0612 93 # ("unused" variables) 94 95 # pylint: disable = R0911, R0912, R0914, R0915 96 # (too many anything) 97 98 if not python_only: 99 try: 100 import _rcssmin 101 except ImportError: 102 pass 103 else: 104 return _rcssmin.cssmin 105 106 nl = r'(?:[\n\f]|\r\n?)' # pylint: disable = C0103 107 spacechar = r'[\r\n\f\040\t]' 108 109 unicoded = r'[0-9a-fA-F]{1,6}(?:[\040\n\t\f]|\r\n?)?' 110 escaped = r'[^\n\r\f0-9a-fA-F]' 111 escape = r'(?:\\(?:%(unicoded)s|%(escaped)s))' % locals() 112 113 nmchar = r'[^\000-\054\056\057\072-\100\133-\136\140\173-\177]' 114 #nmstart = r'[^\000-\100\133-\136\140\173-\177]' 115 #ident = (r'(?:' 116 # r'-?(?:%(nmstart)s|%(escape)s)%(nmchar)s*(?:%(escape)s%(nmchar)s*)*' 117 #r')') % locals() 118 119 comment = r'(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)*/)' 120 121 # only for specific purposes. The bang is grouped: 122 _bang_comment = r'(?:/\*(!?)[^*]*\*+(?:[^/*][^*]*\*+)*/)' 123 124 string1 = \ 125 r'(?:\047[^\047\\\r\n\f]*(?:\\[^\r\n\f][^\047\\\r\n\f]*)*\047)' 126 string2 = r'(?:"[^"\\\r\n\f]*(?:\\[^\r\n\f][^"\\\r\n\f]*)*")' 127 strings = r'(?:%s|%s)' % (string1, string2) 128 129 nl_string1 = \ 130 r'(?:\047[^\047\\\r\n\f]*(?:\\(?:[^\r]|\r\n?)[^\047\\\r\n\f]*)*\047)' 131 nl_string2 = r'(?:"[^"\\\r\n\f]*(?:\\(?:[^\r]|\r\n?)[^"\\\r\n\f]*)*")' 132 nl_strings = r'(?:%s|%s)' % (nl_string1, nl_string2) 133 134 uri_nl_string1 = r'(?:\047[^\047\\]*(?:\\(?:[^\r]|\r\n?)[^\047\\]*)*\047)' 135 uri_nl_string2 = r'(?:"[^"\\]*(?:\\(?:[^\r]|\r\n?)[^"\\]*)*")' 136 uri_nl_strings = r'(?:%s|%s)' % (uri_nl_string1, uri_nl_string2) 137 138 nl_escaped = r'(?:\\%(nl)s)' % locals() 139 140 space = r'(?:%(spacechar)s|%(comment)s)' % locals() 141 142 ie7hack = r'(?:>/\*\*/)' 143 144 uri = (r'(?:' 145 r'(?:[^\000-\040"\047()\\\177]*' 146 r'(?:%(escape)s[^\000-\040"\047()\\\177]*)*)' 147 r'(?:' 148 r'(?:%(spacechar)s+|%(nl_escaped)s+)' 149 r'(?:' 150 r'(?:[^\000-\040"\047()\\\177]|%(escape)s|%(nl_escaped)s)' 151 r'[^\000-\040"\047()\\\177]*' 152 r'(?:%(escape)s[^\000-\040"\047()\\\177]*)*' 153 r')+' 154 r')*' 155 r')') % locals() 156 157 nl_unesc_sub = _re.compile(nl_escaped).sub 158 159 uri_space_sub = _re.compile(( 160 r'(%(escape)s+)|%(spacechar)s+|%(nl_escaped)s+' 161 ) % locals()).sub 162 uri_space_subber = lambda m: m.groups()[0] or '' 163 164 space_sub_simple = _re.compile(( 165 r'[\r\n\f\040\t;]+|(%(comment)s+)' 166 ) % locals()).sub 167 space_sub_banged = _re.compile(( 168 r'[\r\n\f\040\t;]+|(%(_bang_comment)s+)' 169 ) % locals()).sub 170 171 post_esc_sub = _re.compile(r'[\r\n\f\t]+').sub 172 173 main_sub = _re.compile(( 174 r'([^\\"\047u>@\r\n\f\040\t/;:{}]+)' 175 r'|(?<=[{}(=:>+[,!])(%(space)s+)' 176 r'|^(%(space)s+)' 177 r'|(%(space)s+)(?=(([:{});=>+\],!])|$)?)' 178 r'|;(%(space)s*(?:;%(space)s*)*)(?=(\})?)' 179 r'|(\{)' 180 r'|(\})' 181 r'|(%(strings)s)' 182 r'|(?<!%(nmchar)s)url\(%(spacechar)s*(' 183 r'%(uri_nl_strings)s' 184 r'|%(uri)s' 185 r')%(spacechar)s*\)' 186 r'|(@[mM][eE][dD][iI][aA])(?!%(nmchar)s)' 187 r'|(%(ie7hack)s)(%(space)s*)' 188 r'|(:[fF][iI][rR][sS][tT]-[lL]' 189 r'(?:[iI][nN][eE]|[eE][tT][tT][eE][rR]))' 190 r'(%(space)s*)(?=[{,])' 191 r'|(%(nl_strings)s)' 192 r'|(%(escape)s[^\\"\047u>@\r\n\f\040\t/;:{}]*)' 193 ) % locals()).sub 194 195 #print main_sub.__self__.pattern 196 197 def main_subber(keep_bang_comments): 198 """ Make main subber """ 199 in_macie5, in_rule, at_media = [0], [0], [0] 200 201 if keep_bang_comments: 202 space_sub = space_sub_banged 203 def space_subber(match): 204 """ Space|Comment subber """ 205 if match.lastindex: 206 group1, group2 = match.group(1, 2) 207 if group2: 208 if group1.endswith(r'\*/'): 209 in_macie5[0] = 1 210 else: 211 in_macie5[0] = 0 212 return group1 213 elif group1: 214 if group1.endswith(r'\*/'): 215 if in_macie5[0]: 216 return '' 217 in_macie5[0] = 1 218 return r'/*\*/' 219 elif in_macie5[0]: 220 in_macie5[0] = 0 221 return '/**/' 222 return ''
223 else: 224 space_sub = space_sub_simple 225 def space_subber(match): 226 """ Space|Comment subber """ 227 if match.lastindex: 228 if match.group(1).endswith(r'\*/'): 229 if in_macie5[0]: 230 return '' 231 in_macie5[0] = 1 232 return r'/*\*/' 233 elif in_macie5[0]: 234 in_macie5[0] = 0 235 return '/**/' 236 return '' 237 238 def fn_space_post(group): 239 """ space with token after """ 240 if group(5) is None or ( 241 group(6) == ':' and not in_rule[0] and not at_media[0]): 242 return ' ' + space_sub(space_subber, group(4)) 243 return space_sub(space_subber, group(4)) 244 245 def fn_semicolon(group): 246 """ ; handler """ 247 return ';' + space_sub(space_subber, group(7)) 248 249 def fn_semicolon2(group): 250 """ ; handler """ 251 if in_rule[0]: 252 return space_sub(space_subber, group(7)) 253 return ';' + space_sub(space_subber, group(7)) 254 255 def fn_open(group): 256 """ { handler """ 257 # pylint: disable = W0613 258 if at_media[0]: 259 at_media[0] -= 1 260 else: 261 in_rule[0] = 1 262 return '{' 263 264 def fn_close(group): 265 """ } handler """ 266 # pylint: disable = W0613 267 in_rule[0] = 0 268 return '}' 269 270 def fn_media(group): 271 """ @media handler """ 272 at_media[0] += 1 273 return group(13) 274 275 def fn_ie7hack(group): 276 """ IE7 Hack handler """ 277 if not in_rule[0] and not at_media[0]: 278 in_macie5[0] = 0 279 return group(14) + space_sub(space_subber, group(15)) 280 return '>' + space_sub(space_subber, group(15)) 281 282 table = ( 283 None, 284 None, 285 None, 286 None, 287 fn_space_post, # space with token after 288 fn_space_post, # space with token after 289 fn_space_post, # space with token after 290 fn_semicolon, # semicolon 291 fn_semicolon2, # semicolon 292 fn_open, # { 293 fn_close, # } 294 lambda g: g(11), # string 295 lambda g: 'url(%s)' % uri_space_sub(uri_space_subber, g(12)), 296 # url(...) 297 fn_media, # @media 298 None, 299 fn_ie7hack, # ie7hack 300 None, 301 lambda g: g(16) + ' ' + space_sub(space_subber, g(17)), 302 # :first-line|letter followed 303 # by [{,] (apparently space 304 # needed for IE6) 305 lambda g: nl_unesc_sub('', g(18)), # nl_string 306 lambda g: post_esc_sub(' ', g(19)), # escape 307 ) 308 309 def func(match): 310 """ Main subber """ 311 idx, group = match.lastindex, match.group 312 if idx > 3: 313 return table[idx](group) 314 315 # shortcuts for frequent operations below: 316 elif idx == 1: # not interesting 317 return group(1) 318 #else: # space with token before or at the beginning 319 return space_sub(space_subber, group(idx)) 320 321 return func 322 323 def cssmin(style, keep_bang_comments=False): # pylint: disable = W0621 324 """ 325 Minify CSS. 326 327 :Parameters: 328 `style` : ``str`` 329 CSS to minify 330 331 `keep_bang_comments` : ``bool`` 332 Keep comments starting with an exclamation mark? (``/*!...*/``) 333 334 :Return: Minified style 335 :Rtype: ``str`` 336 """ 337 return main_sub(main_subber(keep_bang_comments), style) 338 339 return cssmin 340 341 cssmin = _make_cssmin() 342 343 344 if __name__ == '__main__':
345 - def main():
346 """ Main """ 347 import sys as _sys 348 keep_bang_comments = ( 349 '-b' in _sys.argv[1:] 350 or '-bp' in _sys.argv[1:] 351 or '-pb' in _sys.argv[1:] 352 ) 353 if '-p' in _sys.argv[1:] or '-bp' in _sys.argv[1:] \ 354 or '-pb' in _sys.argv[1:]: 355 global cssmin # pylint: disable = W0603 356 cssmin = _make_cssmin(python_only=True) 357 _sys.stdout.write(cssmin( 358 _sys.stdin.read(), keep_bang_comments=keep_bang_comments 359 ))
360 main() 361