wp-super-minify / includes / min / lib / Minify / CSS / Compressor.php

Compressor.php in WP Super Minify • Minify, Compress and Cache HTML, CSS & JavaScript trunk, at includes/min/lib/Minify/CSS/Compressor.php

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1	<?php
2	/**
3	* Class Minify_CSS_Compressor
4	* @package Minify
5	*/
6
7	/**
8	* Compress CSS
9	*
10	* This is a heavy regex-based removal of whitespace, unnecessary
11	* comments and tokens, and some CSS value minimization, where practical.
12	* Many steps have been taken to avoid breaking comment-based hacks,
13	* including the ie5/mac filter (and its inversion), but expect tricky
14	* hacks involving comment tokens in 'content' value strings to break
15	* minimization badly. A test suite is available.
16	*
17	* Note: This replaces a lot of spaces with line breaks. It's rumored
18	* (https://github.com/yui/yuicompressor/blob/master/README.md#global-options)
19	* that some source control tools and old browsers don't like very long lines.
20	* Compressed files with shorter lines are also easier to diff. If this is
21	* unacceptable please use CSSmin instead.
22	*
23	* @package Minify
24	* @author Stephen Clay <steve@mrclay.org>
25	* @author http://code.google.com/u/1stvamp/ (Issue 64 patch)
26	*
27	* @deprecated Use CSSmin (tubalmartin/cssmin)
28	*/
29	class Minify_CSS_Compressor
30	{
31
32	/**
33	* Minify a CSS string
34	*
35	* @param string $css
36	*
37	* @param array $options (currently ignored)
38	*
39	* @return string
40	*/
41	public static function process($css, $options = array())
42	{
43	$obj = new Minify_CSS_Compressor($options);
44
45	return $obj->_process($css);
46	}
47
48	/**
49	* @var array
50	*/
51	protected $_options = null;
52
53	/**
54	* Are we "in" a hack? I.e. are some browsers targetted until the next comment?
55	*
56	* @var bool
57	*/
58	protected $_inHack = false;
59
60	/**
61	* Constructor
62	*
63	* @param array $options (currently ignored)
64	*/
65	private function __construct($options)
66	{
67	$this->_options = $options;
68	}
69
70	/**
71	* Minify a CSS string
72	*
73	* @param string $css
74	*
75	* @return string
76	*/
77	protected function _process($css)
78	{
79	$css = str_replace("\r\n", "\n", $css);
80
81	// preserve empty comment after '>'
82	// http://www.webdevout.net/css-hacks#in_css-selectors
83	$css = preg_replace('@>/\\\\s\\/@', '>/keep*/', $css);
84
85	// preserve empty comment between property and value
86	// http://css-discuss.incutio.com/?page=BoxModelHack
87	$css = preg_replace('@/\\\\s\\/\\s:@', '/keep/:', $css);
88	$css = preg_replace('@:\\s/\\\\s\\/@', ':/keep/', $css);
89
90	// apply callback to all valid comments (and strip out surrounding ws
91	$pattern = '@\\s/\\([\\s\\S]?)\\/\\s*@';
92	$css = preg_replace_callback($pattern, array($this, '_commentCB'), $css);
93
94	// remove ws around { } and last semicolon in declaration block
95	$css = preg_replace('/\\s{\\s/', '{', $css);
96	$css = preg_replace('/;?\\s}\\s/', '}', $css);
97
98	// remove ws surrounding semicolons
99	$css = preg_replace('/\\s;\\s/', ';', $css);
100
101	// remove ws around urls
102	$pattern = '/
103	url\\( # url(
104	\\s*
105	([^\\)]+?) # 1 = the URL (really just a bunch of non right parenthesis)
106	\\s*
107	\\) # )
108	/x';
109	$css = preg_replace($pattern, 'url($1)', $css);
110
111	// remove ws between rules and colons
112	$pattern = '/
113	\\s*
114	([{;]) # 1 = beginning of block or rule separator
115	\\s*
116	([\\*_]?[\\w\\-]+) # 2 = property (and maybe IE filter)
117	\\s*
118	:
119	\\s*
120	(\\b\|[#\'"-]) # 3 = first character of a value
121	/x';
122	$css = preg_replace($pattern, '$1$2:$3', $css);
123
124	// remove ws in selectors
125	$pattern = '/
126	(?: # non-capture
127	\\s*
128	[^~>+,\\s]+ # selector part
129	\\s*
130	[,>+~] # combinators
131	)+
132	\\s*
133	[^~>+,\\s]+ # selector part
134	{ # open declaration block
135	/x';
136	$css = preg_replace_callback($pattern, array($this, '_selectorsCB'), $css);
137
138	// minimize hex colors
139	$pattern = '/([^=])#([a-f\\d])\\2([a-f\\d])\\3([a-f\\d])\\4([\\s;\\}])/i';
140	$css = preg_replace($pattern, '$1#$2$3$4$5', $css);
141
142	// remove spaces between font families
143	$pattern = '/font-family:([^;}]+)([;}])/';
144	$css = preg_replace_callback($pattern, array($this, '_fontFamilyCB'), $css);
145
146	$css = preg_replace('/@import\\s+url/', '@import url', $css);
147
148	// replace any ws involving newlines with a single newline
149	$css = preg_replace('/[ \\t]\\n+\\s/', "\n", $css);
150
151	// separate common descendent selectors w/ newlines (to limit line lengths)
152	$pattern = '/([\\w#\\.\\]+)\\s+([\\w#\\.\\]+){/';
153	$css = preg_replace($pattern, "$1\n$2{", $css);
154
155	// Use newline after 1st numeric value (to limit line lengths).
156	$pattern = '/
157	((?:padding\|margin\|border\|outline):\\d+(?:px\|em)?) # 1 = prop : 1st numeric value
158	\\s+
159	/x';
160	$css = preg_replace($pattern, "$1\n", $css);
161
162	// prevent triggering IE6 bug: http://www.crankygeek.com/ie6pebug/
163	$css = preg_replace('/:first-l(etter\|ine)\\{/', ':first-l$1 {', $css);
164
165	return trim($css);
166	}
167
168	/**
169	* Replace what looks like a set of selectors
170	*
171	* @param array $m regex matches
172	*
173	* @return string
174	*/
175	protected function _selectorsCB($m)
176	{
177	// remove ws around the combinators
178	return preg_replace('/\\s([,>+~])\\s/', '$1', $m[0]);
179	}
180
181	/**
182	* Process a comment and return a replacement
183	*
184	* @param array $m regex matches
185	*
186	* @return string
187	*/
188	protected function _commentCB($m)
189	{
190	$hasSurroundingWs = (trim($m[0]) !== $m[1]);
191	$m = $m[1];
192	// $m is the comment content w/o the surrounding tokens,
193	// but the return value will replace the entire comment.
194	if ($m === 'keep') {
195	return '/**/';
196	}
197
198	if ($m === '" "') {
199	// component of http://tantek.com/CSS/Examples/midpass.html
200	return '/" "/';
201	}
202
203	if (preg_match('@";\\}\\s\\}/\\\\s+@', $m)) {
204	// component of http://tantek.com/CSS/Examples/midpass.html
205	return '/";}}/ */';
206	}
207
208	if ($this->_inHack) {
209	// inversion: feeding only to one browser
210	$pattern = '@
211	^/ # comment started like /*/
212	\\s*
213	(\\S[\\s\\S]+?) # has at least some non-ws content
214	\\s*
215	/\\* # ends like // or /*/
216	@x';
217	if (preg_match($pattern, $m, $n)) {
218	// end hack mode after this comment, but preserve the hack and comment content
219	$this->_inHack = false;
220
221	return "//{$n[1]}/*/";
222	}
223	}
224
225	if (substr($m, -1) === '\\') { // comment ends like \*/
226	// begin hack mode and preserve hack
227	$this->_inHack = true;
228
229	return '/\\/';
230	}
231
232	if ($m !== '' && $m[0] === '/') { // comment looks like // foo /
233	// begin hack mode and preserve hack
234	$this->_inHack = true;
235
236	return '///';
237	}
238
239	if ($this->_inHack) {
240	// a regular comment ends hack mode but should be preserved
241	$this->_inHack = false;
242
243	return '/**/';
244	}
245
246	// Issue 107: if there's any surrounding whitespace, it may be important, so
247	// replace the comment with a single space
248	return $hasSurroundingWs ? ' ' : ''; // remove all other comments
249	}
250
251	/**
252	* Process a font-family listing and return a replacement
253	*
254	* @param array $m regex matches
255	*
256	* @return string
257	*/
258	protected function _fontFamilyCB($m)
259	{
260	// Issue 210: must not eliminate WS between words in unquoted families
261	$flags = PREG_SPLIT_DELIM_CAPTURE \| PREG_SPLIT_NO_EMPTY;
262	$pieces = preg_split('/(\'[^\']+\'\|"[^"]+")/', $m[1], -1, $flags);
263	$out = 'font-family:';
264
265	while (null !== ($piece = array_shift($pieces))) {
266	if ($piece[0] !== '"' && $piece[0] !== "'") {
267	$piece = preg_replace('/\\s+/', ' ', $piece);
268	$piece = preg_replace('/\\s?,\\s?/', ',', $piece);
269	}
270	$out .= $piece;
271	}
272
273	return $out . $m[2];
274	}
275	}
276