rcssmin

Source Code for Module rcssmin

1 #!/usr/bin/env python 2 # -*- coding: ascii -*- 3 r""" 4 ============== 5 CSS Minifier 6 ============== 7 8 CSS Minifier. 9 10 The minifier is based on the semantics of the `YUI compressor`_\\, which 11 itself is based on `the rule list by Isaac Schlueter`_\\. 12 13 :Copyright: 14 15 Copyright 2011 - 2015 16 Andr\xe9 Malo or his licensors, as applicable 17 18 :License: 19 20 Licensed under the Apache License, Version 2.0 (the "License"); 21 you may not use this file except in compliance with the License. 22 You may obtain a copy of the License at 23 24 http://www.apache.org/licenses/LICENSE-2.0 25 26 Unless required by applicable law or agreed to in writing, software 27 distributed under the License is distributed on an "AS IS" BASIS, 28 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 29 See the License for the specific language governing permissions and 30 limitations under the License. 31 32 This module is a re-implementation aiming for speed instead of maximum 33 compression, so it can be used at runtime (rather than during a preprocessing 34 step). RCSSmin does syntactical compression only (removing spaces, comments 35 and possibly semicolons). It does not provide semantic compression (like 36 removing empty blocks, collapsing redundant properties etc). It does, however, 37 support various CSS hacks (by keeping them working as intended). 38 39 Here's a feature list: 40 41 - Strings are kept, except that escaped newlines are stripped 42 - Space/Comments before the very end or before various characters are 43 stripped: ``:{});=>],!`` (The colon (``:``) is a special case, a single 44 space is kept if it's outside a ruleset.) 45 - Space/Comments at the very beginning or after various characters are 46 stripped: ``{}(=:>[,!`` 47 - Optional space after unicode escapes is kept, resp. replaced by a simple 48 space 49 - whitespaces inside ``url()`` definitions are stripped 50 - Comments starting with an exclamation mark (``!``) can be kept optionally. 51 - All other comments and/or whitespace characters are replaced by a single 52 space. 53 - Multiple consecutive semicolons are reduced to one 54 - The last semicolon within a ruleset is stripped 55 - CSS Hacks supported: 56 57 - IE7 hack (``>/**/``) 58 - Mac-IE5 hack (``/*\\*/.../**/``) 59 - The boxmodelhack is supported naturally because it relies on valid CSS2 60 strings 61 - Between ``:first-line`` and the following comma or curly brace a space is 62 inserted. (apparently it's needed for IE6) 63 - Same for ``:first-letter`` 64 65 rcssmin.c is a reimplementation of rcssmin.py in C and improves runtime up to 66 factor 100 or so (depending on the input). docs/BENCHMARKS in the source 67 distribution contains the details. 68 69 Both python 2 (>= 2.4) and python 3 are supported. 70 71 .. _YUI compressor: https://github.com/yui/yuicompressor/ 72 73 .. _the rule list by Isaac Schlueter: https://github.com/isaacs/cssmin/ 74 """ 75 if __doc__: 76 # pylint: disable = W0622 77 __doc__ = __doc__.encode('ascii').decode('unicode_escape') 78 __author__ = r"Andr\xe9 Malo".encode('ascii').decode('unicode_escape') 79 __docformat__ = "restructuredtext en" 80 __license__ = "Apache License, Version 2.0" 81 __version__ = '1.0.6' 82 __all__ = ['cssmin'] 83 84 import re as _re 85 86

87 -def _make_cssmin(python_only=False):

88 """ 89 Generate CSS minifier. 90 91 :Parameters: 92 `python_only` : ``bool`` 93 Use only the python variant. If true, the c extension is not even 94 tried to be loaded. 95 96 :Return: Minifier 97 :Rtype: ``callable`` 98 """ 99 # pylint: disable = R0912, R0914, W0612 100 101 if not python_only: 102 try: 103 import _rcssmin 104 except ImportError: 105 pass 106 else: 107 return _rcssmin.cssmin 108 109 nl = r'(?:[\n\f]|\r\n?)' # pylint: disable = C0103 110 spacechar = r'[\r\n\f\040\t]' 111 112 unicoded = r'[0-9a-fA-F]{1,6}(?:[\040\n\t\f]|\r\n?)?' 113 escaped = r'[^\n\r\f0-9a-fA-F]' 114 escape = r'(?:\\(?:%(unicoded)s|%(escaped)s))' % locals() 115 116 nmchar = r'[^\000-\054\056\057\072-\100\133-\136\140\173-\177]' 117 # nmstart = r'[^\000-\100\133-\136\140\173-\177]' 118 # ident = (r'(?:' 119 # r'-?(?:%(nmstart)s|%(escape)s)%(nmchar)s*(?:%(escape)s%(nmchar)s*)*' 120 # r')') % locals() 121 122 comment = r'(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)*/)' 123 124 # only for specific purposes. The bang is grouped: 125 _bang_comment = r'(?:/\*(!?)[^*]*\*+(?:[^/*][^*]*\*+)*/)' 126 127 string1 = \ 128 r'(?:\047[^\047\\\r\n\f]*(?:\\[^\r\n\f][^\047\\\r\n\f]*)*\047)' 129 string2 = r'(?:"[^"\\\r\n\f]*(?:\\[^\r\n\f][^"\\\r\n\f]*)*")' 130 strings = r'(?:%s|%s)' % (string1, string2) 131 132 nl_string1 = \ 133 r'(?:\047[^\047\\\r\n\f]*(?:\\(?:[^\r]|\r\n?)[^\047\\\r\n\f]*)*\047)' 134 nl_string2 = r'(?:"[^"\\\r\n\f]*(?:\\(?:[^\r]|\r\n?)[^"\\\r\n\f]*)*")' 135 nl_strings = r'(?:%s|%s)' % (nl_string1, nl_string2) 136 137 uri_nl_string1 = r'(?:\047[^\047\\]*(?:\\(?:[^\r]|\r\n?)[^\047\\]*)*\047)' 138 uri_nl_string2 = r'(?:"[^"\\]*(?:\\(?:[^\r]|\r\n?)[^"\\]*)*")' 139 uri_nl_strings = r'(?:%s|%s)' % (uri_nl_string1, uri_nl_string2) 140 141 nl_escaped = r'(?:\\%(nl)s)' % locals() 142 143 space = r'(?:%(spacechar)s|%(comment)s)' % locals() 144 145 ie7hack = r'(?:>/\*\*/)' 146 147 uri = (r'(?:' 148 # noqa pylint: disable = C0330 149 r'(?:[^\000-\040"\047()\\\177]*' 150 r'(?:%(escape)s[^\000-\040"\047()\\\177]*)*)' 151 r'(?:' 152 r'(?:%(spacechar)s+|%(nl_escaped)s+)' 153 r'(?:' 154 r'(?:[^\000-\040"\047()\\\177]|%(escape)s|%(nl_escaped)s)' 155 r'[^\000-\040"\047()\\\177]*' 156 r'(?:%(escape)s[^\000-\040"\047()\\\177]*)*' 157 r')+' 158 r')*' 159 r')') % locals() 160 161 nl_unesc_sub = _re.compile(nl_escaped).sub 162 163 uri_space_sub = _re.compile(( 164 r'(%(escape)s+)|%(spacechar)s+|%(nl_escaped)s+' 165 ) % locals()).sub 166 uri_space_subber = lambda m: m.groups()[0] or '' 167 168 space_sub_simple = _re.compile(( 169 r'[\r\n\f\040\t;]+|(%(comment)s+)' 170 ) % locals()).sub 171 space_sub_banged = _re.compile(( 172 r'[\r\n\f\040\t;]+|(%(_bang_comment)s+)' 173 ) % locals()).sub 174 175 post_esc_sub = _re.compile(r'[\r\n\f\t]+').sub 176 177 main_sub = _re.compile(( 178 # noqa pylint: disable = C0330 179 r'([^\\"\047u>@\r\n\f\040\t/;:{}+]+)' # 1 180 r'|(?<=[{}(=:>[,!])(%(space)s+)' # 2 181 r'|^(%(space)s+)' # 3 182 r'|(%(space)s+)(?=(([:{});=>\],!])|$)?)' # 4, 5, 6 183 r'|;(%(space)s*(?:;%(space)s*)*)(?=(\})?)' # 7, 8 184 r'|(\{)' # 9 185 r'|(\})' # 10 186 r'|(%(strings)s)' # 11 187 r'|(?<!%(nmchar)s)url$%(spacechar)s*(' # 12 188 r'%(uri_nl_strings)s' 189 r'|%(uri)s' 190 r')%(spacechar)s*$' 191 r'|(@(?:' # 13 192 r'[mM][eE][dD][iI][aA]' 193 r'|[sS][uU][pP][pP][oO][rR][tT][sS]' 194 r'|[dD][oO][cC][uU][mM][eE][nN][tT]' 195 r'|(?:-(?:' 196 r'[wW][eE][bB][kK][iI][tT]|[mM][oO][zZ]|[oO]|[mM][sS]' 197 r')-)?' 198 r'[kK][eE][yY][fF][rR][aA][mM][eE][sS]' 199 r'))(?!%(nmchar)s)' 200 r'|(%(ie7hack)s)(%(space)s*)' # 14, 15 201 r'|(:[fF][iI][rR][sS][tT]-[lL]' # 16 202 r'(?:[iI][nN][eE]|[eE][tT][tT][eE][rR]))' 203 r'(%(space)s*)(?=[{,])' # 17 204 r'|(%(nl_strings)s)' # 18 205 r'|(%(escape)s[^\\"\047u>@\r\n\f\040\t/;:{}+]*)' # 19 206 ) % locals()).sub 207 208 # print main_sub.__self__.pattern 209 210 def main_subber(keep_bang_comments): 211 """ Make main subber """ 212 in_macie5, in_rule, at_group = [0], [0], [0] 213 214 if keep_bang_comments: 215 space_sub = space_sub_banged 216 217 def space_subber(match): 218 """ Space|Comment subber """ 219 if match.lastindex: 220 group1, group2 = match.group(1, 2) 221 if group2: 222 if group1.endswith(r'\*/'): 223 in_macie5[0] = 1 224 else: 225 in_macie5[0] = 0 226 return group1 227 elif group1: 228 if group1.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 else: 238 space_sub = space_sub_simple 239 240 def space_subber(match): 241 """ Space|Comment subber """ 242 if match.lastindex: 243 if match.group(1).endswith(r'\*/'): 244 if in_macie5[0]: 245 return '' 246 in_macie5[0] = 1 247 return r'/*\*/' 248 elif in_macie5[0]: 249 in_macie5[0] = 0 250 return '/**/' 251 return '' 252 253 def fn_space_post(group): 254 """ space with token after """ 255 if group(5) is None or ( 256 group(6) == ':' and not in_rule[0] and not at_group[0]): 257 return ' ' + space_sub(space_subber, group(4)) 258 return space_sub(space_subber, group(4)) 259 260 def fn_semicolon(group): 261 """ ; handler """ 262 return ';' + space_sub(space_subber, group(7)) 263 264 def fn_semicolon2(group): 265 """ ; handler """ 266 if in_rule[0]: 267 return space_sub(space_subber, group(7)) 268 return ';' + space_sub(space_subber, group(7)) 269 270 def fn_open(_): 271 """ { handler """ 272 if at_group[0]: 273 at_group[0] -= 1 274 else: 275 in_rule[0] = 1 276 return '{' 277 278 def fn_close(_): 279 """ } handler """ 280 in_rule[0] = 0 281 return '}' 282 283 def fn_at_group(group): 284 """ @xxx group handler """ 285 at_group[0] += 1 286 return group(13) 287 288 def fn_ie7hack(group): 289 """ IE7 Hack handler """ 290 if not in_rule[0] and not at_group[0]: 291 in_macie5[0] = 0 292 return group(14) + space_sub(space_subber, group(15)) 293 return '>' + space_sub(space_subber, group(15)) 294 295 table = ( 296 # noqa pylint: disable = C0330 297 None, 298 None, 299 None, 300 None, 301 fn_space_post, # space with token after 302 fn_space_post, # space with token after 303 fn_space_post, # space with token after 304 fn_semicolon, # semicolon 305 fn_semicolon2, # semicolon 306 fn_open, # { 307 fn_close, # } 308 lambda g: g(11), # string 309 lambda g: 'url(%s)' % uri_space_sub(uri_space_subber, g(12)), 310 # url(...) 311 fn_at_group, # @xxx expecting {...} 312 None, 313 fn_ie7hack, # ie7hack 314 None, 315 lambda g: g(16) + ' ' + space_sub(space_subber, g(17)), 316 # :first-line|letter followed 317 # by [{,] (apparently space 318 # needed for IE6) 319 lambda g: nl_unesc_sub('', g(18)), # nl_string 320 lambda g: post_esc_sub(' ', g(19)), # escape 321 ) 322 323 def func(match): 324 """ Main subber """ 325 idx, group = match.lastindex, match.group 326 if idx > 3: 327 return table[idx](group) 328 329 # shortcuts for frequent operations below: 330 elif idx == 1: # not interesting 331 return group(1) 332 # else: # space with token before or at the beginning 333 return space_sub(space_subber, group(idx)) 334 335 return func 336 337 def cssmin(style, keep_bang_comments=False): # pylint: disable = W0621 338 """ 339 Minify CSS. 340 341 :Parameters: 342 `style` : ``str`` 343 CSS to minify 344 345 `keep_bang_comments` : ``bool`` 346 Keep comments starting with an exclamation mark? (``/*!...*/``) 347 348 :Return: Minified style 349 :Rtype: ``str`` 350 """ 351 return main_sub(main_subber(keep_bang_comments), style) 352 353 return cssmin 354 355 cssmin = _make_cssmin() 356 357 358 if __name__ == '__main__':

359 - def main():

360 """ Main """ 361 import sys as _sys 362 keep_bang_comments = ( 363 '-b' in _sys.argv[1:] 364 or '-bp' in _sys.argv[1:] 365 or '-pb' in _sys.argv[1:] 366 ) 367 if '-p' in _sys.argv[1:] or '-bp' in _sys.argv[1:] \ 368 or '-pb' in _sys.argv[1:]: 369 global cssmin # pylint: disable = W0603 370 cssmin = _make_cssmin(python_only=True) 371 _sys.stdout.write(cssmin( 372 _sys.stdin.read(), keep_bang_comments=keep_bang_comments 373 ))

374 main() 375