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Diffstat (limited to 'min/lib/Minify/CSS/Compressor.php')
| -rw-r--r-- | min/lib/Minify/CSS/Compressor.php | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/min/lib/Minify/CSS/Compressor.php b/min/lib/Minify/CSS/Compressor.php new file mode 100644 index 0000000..d483b2f --- /dev/null +++ b/min/lib/Minify/CSS/Compressor.php @@ -0,0 +1,250 @@ +<?php +/** + * Class Minify_CSS_Compressor + * @package Minify + */ + +/** + * Compress CSS + * + * This is a heavy regex-based removal of whitespace, unnecessary + * comments and tokens, and some CSS value minimization, where practical. + * Many steps have been taken to avoid breaking comment-based hacks, + * including the ie5/mac filter (and its inversion), but expect tricky + * hacks involving comment tokens in 'content' value strings to break + * minimization badly. A test suite is available. + * + * @package Minify + * @author Stephen Clay <steve@mrclay.org> + * @author http://code.google.com/u/1stvamp/ (Issue 64 patch) + */ +class Minify_CSS_Compressor { + + /** + * Minify a CSS string + * + * @param string $css + * + * @param array $options (currently ignored) + * + * @return string + */ + public static function process($css, $options = array()) + { + $obj = new Minify_CSS_Compressor($options); + return $obj->_process($css); + } + + /** + * @var array options + */ + protected $_options = null; + + /** + * @var bool Are we "in" a hack? + * + * I.e. are some browsers targetted until the next comment? + */ + protected $_inHack = false; + + + /** + * Constructor + * + * @param array $options (currently ignored) + * + * @return null + */ + private function __construct($options) { + $this->_options = $options; + } + + /** + * Minify a CSS string + * + * @param string $css + * + * @return string + */ + protected function _process($css) + { + $css = str_replace("\r\n", "\n", $css); + + // preserve empty comment after '>' + // http://www.webdevout.net/css-hacks#in_css-selectors + $css = preg_replace('@>/\\*\\s*\\*/@', '>/*keep*/', $css); + + // preserve empty comment between property and value + // http://css-discuss.incutio.com/?page=BoxModelHack + $css = preg_replace('@/\\*\\s*\\*/\\s*:@', '/*keep*/:', $css); + $css = preg_replace('@:\\s*/\\*\\s*\\*/@', ':/*keep*/', $css); + + // apply callback to all valid comments (and strip out surrounding ws + $css = preg_replace_callback('@\\s*/\\*([\\s\\S]*?)\\*/\\s*@' + ,array($this, '_commentCB'), $css); + + // remove ws around { } and last semicolon in declaration block + $css = preg_replace('/\\s*{\\s*/', '{', $css); + $css = preg_replace('/;?\\s*}\\s*/', '}', $css); + + // remove ws surrounding semicolons + $css = preg_replace('/\\s*;\\s*/', ';', $css); + + // remove ws around urls + $css = preg_replace('/ + url\\( # url( + \\s* + ([^\\)]+?) # 1 = the URL (really just a bunch of non right parenthesis) + \\s* + \\) # ) + /x', 'url($1)', $css); + + // remove ws between rules and colons + $css = preg_replace('/ + \\s* + ([{;]) # 1 = beginning of block or rule separator + \\s* + ([\\*_]?[\\w\\-]+) # 2 = property (and maybe IE filter) + \\s* + : + \\s* + (\\b|[#\'"]) # 3 = first character of a value + /x', '$1$2:$3', $css); + + // remove ws in selectors + $css = preg_replace_callback('/ + (?: # non-capture + \\s* + [^~>+,\\s]+ # selector part + \\s* + [,>+~] # combinators + )+ + \\s* + [^~>+,\\s]+ # selector part + { # open declaration block + /x' + ,array($this, '_selectorsCB'), $css); + + // minimize hex colors + $css = preg_replace('/([^=])#([a-f\\d])\\2([a-f\\d])\\3([a-f\\d])\\4([\\s;\\}])/i' + , '$1#$2$3$4$5', $css); + + // remove spaces between font families + $css = preg_replace_callback('/font-family:([^;}]+)([;}])/' + ,array($this, '_fontFamilyCB'), $css); + + $css = preg_replace('/@import\\s+url/', '@import url', $css); + + // replace any ws involving newlines with a single newline + $css = preg_replace('/[ \\t]*\\n+\\s*/', "\n", $css); + + // separate common descendent selectors w/ newlines (to limit line lengths) + $css = preg_replace('/([\\w#\\.\\*]+)\\s+([\\w#\\.\\*]+){/', "$1\n$2{", $css); + + // Use newline after 1st numeric value (to limit line lengths). + $css = preg_replace('/ + ((?:padding|margin|border|outline):\\d+(?:px|em)?) # 1 = prop : 1st numeric value + \\s+ + /x' + ,"$1\n", $css); + + // prevent triggering IE6 bug: http://www.crankygeek.com/ie6pebug/ + $css = preg_replace('/:first-l(etter|ine)\\{/', ':first-l$1 {', $css); + + return trim($css); + } + + /** + * Replace what looks like a set of selectors + * + * @param array $m regex matches + * + * @return string + */ + protected function _selectorsCB($m) + { + // remove ws around the combinators + return preg_replace('/\\s*([,>+~])\\s*/', '$1', $m[0]); + } + + /** + * Process a comment and return a replacement + * + * @param array $m regex matches + * + * @return string + */ + protected function _commentCB($m) + { + $hasSurroundingWs = (trim($m[0]) !== $m[1]); + $m = $m[1]; + // $m is the comment content w/o the surrounding tokens, + // but the return value will replace the entire comment. + if ($m === 'keep') { + return '/**/'; + } + if ($m === '" "') { + // component of http://tantek.com/CSS/Examples/midpass.html + return '/*" "*/'; + } + if (preg_match('@";\\}\\s*\\}/\\*\\s+@', $m)) { + // component of http://tantek.com/CSS/Examples/midpass.html + return '/*";}}/* */'; + } + if ($this->_inHack) { + // inversion: feeding only to one browser + if (preg_match('@ + ^/ # comment started like /*/ + \\s* + (\\S[\\s\\S]+?) # has at least some non-ws content + \\s* + /\\* # ends like /*/ or /**/ + @x', $m, $n)) { + // end hack mode after this comment, but preserve the hack and comment content + $this->_inHack = false; + return "/*/{$n[1]}/**/"; + } + } + if (substr($m, -1) === '\\') { // comment ends like \*/ + // begin hack mode and preserve hack + $this->_inHack = true; + return '/*\\*/'; + } + if ($m !== '' && $m[0] === '/') { // comment looks like /*/ foo */ + // begin hack mode and preserve hack + $this->_inHack = true; + return '/*/*/'; + } + if ($this->_inHack) { + // a regular comment ends hack mode but should be preserved + $this->_inHack = false; + return '/**/'; + } + // Issue 107: if there's any surrounding whitespace, it may be important, so + // replace the comment with a single space + return $hasSurroundingWs // remove all other comments + ? ' ' + : ''; + } + + /** + * Process a font-family listing and return a replacement + * + * @param array $m regex matches + * + * @return string + */ + protected function _fontFamilyCB($m) + { + $m[1] = preg_replace('/ + \\s* + ( + "[^"]+" # 1 = family in double qutoes + |\'[^\']+\' # or 1 = family in single quotes + |[\\w\\-]+ # or 1 = unquoted family + ) + \\s* + /x', '$1', $m[1]); + return 'font-family:' . $m[1] . $m[2]; + } +} |