function CSSmin::run

Same name and namespace in other branches

1. 8.x-2.x advagg_css_minify/yui/CSSMin.inc \CSSmin::run() 1 comment
2. 8.x-3.x advagg_css_minify/yui/CSSMin.inc \CSSmin::run() 1 comment

Minifies a string of CSS

Parameters

string $css:

int|bool $linebreakPos:

Return value

string

File

advagg_css_compress/yui/CSSMin.inc, line 81

Class

CSSmin

Code

public function run($css = '', $linebreakPos = false) {
    if (empty($css)) {
        return '';
    }
    if ($this->raisePhpLimits) {
        $this->doRaisePhpLimits();
    }
    $this->comments = array();
    $this->atRuleBlocks = array();
    $this->preservedTokens = array();
    // process data urls
    $css = $this->processDataUrls($css);
    // process comments
    $css = preg_replace_callback('/(?<!\\\\)\\/\\*(.*?)\\*(?<!\\\\)\\//Ss', array(
        $this,
        'processComments',
    ), $css);
    // process strings so their content doesn't get accidentally minified
    $css = preg_replace_callback('/(?:"(?:[^\\\\"]|\\\\.|\\\\)*")|' . "(?:'(?:[^\\\\']|\\\\.|\\\\)*')/S", array(
        $this,
        'processStrings',
    ), $css);
    // Safe chunking: process at rule blocks so after chunking nothing gets stripped out
    $css = preg_replace_callback('/@(?:document|(?:-(?:atsc|khtml|moz|ms|o|wap|webkit)-)?keyframes|media|supports).+?\\}\\s*\\}/si', array(
        $this,
        'processAtRuleBlocks',
    ), $css);
    // Let's divide css code in chunks of {$this->chunkLength} chars aprox.
    // Reason: PHP's PCRE functions like preg_replace have a "backtrack limit"
    // of 100.000 chars by default (php < 5.3.7) so if we're dealing with really
    // long strings and a (sub)pattern matches a number of chars greater than
    // the backtrack limit number (i.e. /(.*)/s) PCRE functions may fail silently
    // returning NULL and $css would be empty.
    $charset = '';
    $charsetRegexp = '/(@charset)( [^;]+;)/i';
    $cssChunks = array();
    $l = strlen($css);
    // if the number of characters is <= {$this->chunkLength}, do not chunk
    if ($l <= $this->chunkLength) {
        $cssChunks[] = $css;
    }
    else {
        // chunk css code securely
        for ($startIndex = 0, $i = $this->chunkLength; $i < $l; $i++) {
            if ($css[$i - 1] === '}' && $i - $startIndex >= $this->chunkLength) {
                $cssChunks[] = $this->strSlice($css, $startIndex, $i);
                $startIndex = $i;
                // Move forward saving iterations when possible!
                if ($startIndex + $this->chunkLength < $l) {
                    $i += $this->chunkLength;
                }
            }
        }
        // Final chunk
        $cssChunks[] = $this->strSlice($css, $startIndex);
    }
    // Minify each chunk
    for ($i = 0, $n = count($cssChunks); $i < $n; $i++) {
        $cssChunks[$i] = $this->minify($cssChunks[$i], $linebreakPos);
        // Keep the first @charset at-rule found
        if (empty($charset) && preg_match($charsetRegexp, $cssChunks[$i], $matches)) {
            $charset = strtolower($matches[1]) . $matches[2];
        }
        // Delete all @charset at-rules
        $cssChunks[$i] = preg_replace($charsetRegexp, '', $cssChunks[$i]);
    }
    // Update the first chunk and push the charset to the top of the file.
    $cssChunks[0] = $charset . $cssChunks[0];
    return trim(implode('', $cssChunks));
}