1<?php
2/**
3 * Class Minify
4 * @package Minify
5 */
6
7/**
8 * Minify - Combines, minifies, and caches JavaScript and CSS files on demand.
9 *
10 * See README for usage instructions (for now).
11 *
12 * This library was inspired by {@link mailto:flashkot@mail.ru jscsscomp by Maxim Martynyuk}
13 * and by the article {@link http://www.hunlock.com/blogs/Supercharged_Javascript "Supercharged JavaScript" by Patrick Hunlock}.
14 *
15 * Requires PHP 5.1.0.
16 * Tested on PHP 5.1.6.
17 *
18 * @package Minify
19 * @author Ryan Grove <ryan@wonko.com>
20 * @author Stephen Clay <steve@mrclay.org>
21 * @copyright 2008 Ryan Grove, Stephen Clay. All rights reserved.
22 * @license http://opensource.org/licenses/bsd-license.php  New BSD License
23 * @link http://code.google.com/p/minify/
24 */
25class Minify {
26
27    const VERSION = '2.2.0';
28    const TYPE_CSS = 'text/css';
29    const TYPE_HTML = 'text/html';
30    // there is some debate over the ideal JS Content-Type, but this is the
31    // Apache default and what Yahoo! uses..
32    const TYPE_JS = 'application/x-javascript';
33    const URL_DEBUG = 'http://code.google.com/p/minify/wiki/Debugging';
34
35    /**
36     * How many hours behind are the file modification times of uploaded files?
37     *
38     * If you upload files from Windows to a non-Windows server, Windows may report
39     * incorrect mtimes for the files. Immediately after modifying and uploading a
40     * file, use the touch command to update the mtime on the server. If the mtime
41     * jumps ahead by a number of hours, set this variable to that number. If the mtime
42     * moves back, this should not be needed.
43     *
44     * @var int $uploaderHoursBehind
45     */
46    public static $uploaderHoursBehind = 0;
47
48    /**
49     * If this string is not empty AND the serve() option 'bubbleCssImports' is
50     * NOT set, then serve() will check CSS files for @import declarations that
51     * appear too late in the combined stylesheet. If found, serve() will prepend
52     * the output with this warning.
53     *
54     * @var string $importWarning
55     */
56    public static $importWarning = "/* See http://code.google.com/p/minify/wiki/CommonProblems#@imports_can_appear_in_invalid_locations_in_combined_CSS_files */\n";
57
58    /**
59     * Has the DOCUMENT_ROOT been set in user code?
60     *
61     * @var bool
62     */
63    public static $isDocRootSet = false;
64
65    /**
66     * Specify a cache object (with identical interface as Minify_Cache_File) or
67     * a path to use with Minify_Cache_File.
68     *
69     * If not called, Minify will not use a cache and, for each 200 response, will
70     * need to recombine files, minify and encode the output.
71     *
72     * @param mixed $cache object with identical interface as Minify_Cache_File or
73     * a directory path, or null to disable caching. (default = '')
74     *
75     * @param bool $fileLocking (default = true) This only applies if the first
76     * parameter is a string.
77     *
78     * @return null
79     */
80    public static function setCache($cache = '', $fileLocking = true)
81    {
82        if (is_string($cache)) {
83            self::$_cache = new Minify_Cache_File($cache, $fileLocking);
84        } else {
85            self::$_cache = $cache;
86        }
87    }
88
89    /**
90     * Serve a request for a minified file.
91     *
92     * Here are the available options and defaults in the base controller:
93     *
94     * 'isPublic' : send "public" instead of "private" in Cache-Control
95     * headers, allowing shared caches to cache the output. (default true)
96     *
97     * 'quiet' : set to true to have serve() return an array rather than sending
98     * any headers/output (default false)
99     *
100     * 'encodeOutput' : set to false to disable content encoding, and not send
101     * the Vary header (default true)
102     *
103     * 'encodeMethod' : generally you should let this be determined by
104     * HTTP_Encoder (leave null), but you can force a particular encoding
105     * to be returned, by setting this to 'gzip' or '' (no encoding)
106     *
107     * 'encodeLevel' : level of encoding compression (0 to 9, default 9)
108     *
109     * 'contentTypeCharset' : appended to the Content-Type header sent. Set to a falsey
110     * value to remove. (default 'utf-8')
111     *
112     * 'maxAge' : set this to the number of seconds the client should use its cache
113     * before revalidating with the server. This sets Cache-Control: max-age and the
114     * Expires header. Unlike the old 'setExpires' setting, this setting will NOT
115     * prevent conditional GETs. Note this has nothing to do with server-side caching.
116     *
117     * 'rewriteCssUris' : If true, serve() will automatically set the 'currentDir'
118     * minifier option to enable URI rewriting in CSS files (default true)
119     *
120     * 'bubbleCssImports' : If true, all @import declarations in combined CSS
121     * files will be move to the top. Note this may alter effective CSS values
122     * due to a change in order. (default false)
123     *
124     * 'debug' : set to true to minify all sources with the 'Lines' controller, which
125     * eases the debugging of combined files. This also prevents 304 responses.
126     * @see Minify_Lines::minify()
127     *
128     * 'concatOnly' : set to true to disable minification and simply concatenate the files.
129     * For JS, no minifier will be used. For CSS, only URI rewriting is still performed.
130     *
131     * 'minifiers' : to override Minify's default choice of minifier function for
132     * a particular content-type, specify your callback under the key of the
133     * content-type:
134     * <code>
135     * // call customCssMinifier($css) for all CSS minification
136     * $options['minifiers'][Minify::TYPE_CSS] = 'customCssMinifier';
137     *
138     * // don't minify Javascript at all
139     * $options['minifiers'][Minify::TYPE_JS] = '';
140     * </code>
141     *
142     * 'minifierOptions' : to send options to the minifier function, specify your options
143     * under the key of the content-type. E.g. To send the CSS minifier an option:
144     * <code>
145     * // give CSS minifier array('optionName' => 'optionValue') as 2nd argument
146     * $options['minifierOptions'][Minify::TYPE_CSS]['optionName'] = 'optionValue';
147     * </code>
148     *
149     * 'contentType' : (optional) this is only needed if your file extension is not
150     * js/css/html. The given content-type will be sent regardless of source file
151     * extension, so this should not be used in a Groups config with other
152     * Javascript/CSS files.
153     *
154     * Any controller options are documented in that controller's setupSources() method.
155     *
156     * @param mixed $controller instance of subclass of Minify_Controller_Base or string
157     * name of controller. E.g. 'Files'
158     *
159     * @param array $options controller/serve options
160     *
161     * @return null|array if the 'quiet' option is set to true, an array
162     * with keys "success" (bool), "statusCode" (int), "content" (string), and
163     * "headers" (array).
164     *
165     * @throws Exception
166     */
167    public static function serve($controller, $options = array())
168    {
169        if (! self::$isDocRootSet && 0 === stripos(PHP_OS, 'win')) {
170            self::setDocRoot();
171        }
172
173        if (is_string($controller)) {
174            // make $controller into object
175            $class = 'Minify_Controller_' . $controller;
176            $controller = new $class();
177            /* @var Minify_Controller_Base $controller */
178        }
179
180        // set up controller sources and mix remaining options with
181        // controller defaults
182        $options = $controller->setupSources($options);
183        $options = $controller->analyzeSources($options);
184        self::$_options = $controller->mixInDefaultOptions($options);
185
186        // check request validity
187        if (! $controller->sources) {
188            // invalid request!
189            if (! self::$_options['quiet']) {
190                self::_errorExit(self::$_options['badRequestHeader'], self::URL_DEBUG);
191            } else {
192                list(,$statusCode) = explode(' ', self::$_options['badRequestHeader']);
193                return array(
194                    'success' => false
195                    ,'statusCode' => (int)$statusCode
196                    ,'content' => ''
197                    ,'headers' => array()
198                );
199            }
200        }
201
202        self::$_controller = $controller;
203
204        if (self::$_options['debug']) {
205            self::_setupDebug($controller->sources);
206            self::$_options['maxAge'] = 0;
207        }
208
209        // determine encoding
210        if (self::$_options['encodeOutput']) {
211            $sendVary = true;
212            if (self::$_options['encodeMethod'] !== null) {
213                // controller specifically requested this
214                $contentEncoding = self::$_options['encodeMethod'];
215            } else {
216                // sniff request header
217                // depending on what the client accepts, $contentEncoding may be
218                // 'x-gzip' while our internal encodeMethod is 'gzip'. Calling
219                // getAcceptedEncoding(false, false) leaves out compress and deflate as options.
220                list(self::$_options['encodeMethod'], $contentEncoding) = HTTP_Encoder::getAcceptedEncoding(false, false);
221                $sendVary = ! HTTP_Encoder::isBuggyIe();
222            }
223        } else {
224            self::$_options['encodeMethod'] = ''; // identity (no encoding)
225        }
226
227        // check client cache
228        $cgOptions = array(
229            'lastModifiedTime' => self::$_options['lastModifiedTime']
230            ,'isPublic' => self::$_options['isPublic']
231            ,'encoding' => self::$_options['encodeMethod']
232        );
233        if (self::$_options['maxAge'] > 0) {
234            $cgOptions['maxAge'] = self::$_options['maxAge'];
235        } elseif (self::$_options['debug']) {
236            $cgOptions['invalidate'] = true;
237        }
238        $cg = new HTTP_ConditionalGet($cgOptions);
239        if ($cg->cacheIsValid) {
240            // client's cache is valid
241            if (! self::$_options['quiet']) {
242                $cg->sendHeaders();
243                return;
244            } else {
245                return array(
246                    'success' => true
247                    ,'statusCode' => 304
248                    ,'content' => ''
249                    ,'headers' => $cg->getHeaders()
250                );
251            }
252        } else {
253            // client will need output
254            $headers = $cg->getHeaders();
255            unset($cg);
256        }
257
258        if (self::$_options['concatOnly']) {
259            foreach ($controller->sources as $key => $source) {
260                if (self::$_options['contentType'] === self::TYPE_JS) {
261                    $source->minifier = "";
262                } elseif (self::$_options['contentType'] === self::TYPE_CSS) {
263                    $source->minifier = array('Minify_CSS', 'minify');
264                    $source->minifyOptions['compress'] = false;
265                }
266            }
267        }
268
269        if (self::$_options['contentType'] === self::TYPE_CSS && self::$_options['rewriteCssUris']) {
270            foreach ($controller->sources as $key => $source) {
271                if ($source->filepath
272                    && !isset($source->minifyOptions['currentDir'])
273                    && !isset($source->minifyOptions['prependRelativePath'])
274                ) {
275                    $source->minifyOptions['currentDir'] = dirname($source->filepath);
276                }
277            }
278        }
279
280        // check server cache
281        if (null !== self::$_cache && ! self::$_options['debug']) {
282            // using cache
283            // the goal is to use only the cache methods to sniff the length and
284            // output the content, as they do not require ever loading the file into
285            // memory.
286            $cacheId = self::_getCacheId();
287            $fullCacheId = (self::$_options['encodeMethod'])
288                ? $cacheId . '.gz'
289                : $cacheId;
290            // check cache for valid entry
291            $cacheIsReady = self::$_cache->isValid($fullCacheId, self::$_options['lastModifiedTime']);
292            if ($cacheIsReady) {
293                $cacheContentLength = self::$_cache->getSize($fullCacheId);
294            } else {
295                // generate & cache content
296                try {
297                    $content = self::_combineMinify();
298                } catch (Exception $e) {
299                    self::$_controller->log($e->getMessage());
300                    if (! self::$_options['quiet']) {
301                        self::_errorExit(self::$_options['errorHeader'], self::URL_DEBUG);
302                    }
303                    throw $e;
304                }
305                self::$_cache->store($cacheId, $content);
306                if (function_exists('gzencode') && self::$_options['encodeMethod']) {
307                    self::$_cache->store($cacheId . '.gz', gzencode($content, self::$_options['encodeLevel']));
308                }
309            }
310        } else {
311            // no cache
312            $cacheIsReady = false;
313            try {
314                $content = self::_combineMinify();
315            } catch (Exception $e) {
316                self::$_controller->log($e->getMessage());
317                if (! self::$_options['quiet']) {
318                    self::_errorExit(self::$_options['errorHeader'], self::URL_DEBUG);
319                }
320                throw $e;
321            }
322        }
323        if (! $cacheIsReady && self::$_options['encodeMethod']) {
324            // still need to encode
325            $content = gzencode($content, self::$_options['encodeLevel']);
326        }
327
328        // add headers
329        $headers['Content-Length'] = $cacheIsReady
330            ? $cacheContentLength
331            : ((function_exists('mb_strlen') && ((int)ini_get('mbstring.func_overload') & 2))
332                ? mb_strlen($content, '8bit')
333                : strlen($content)
334            );
335        $headers['Content-Type'] = self::$_options['contentTypeCharset']
336            ? self::$_options['contentType'] . '; charset=' . self::$_options['contentTypeCharset']
337            : self::$_options['contentType'];
338        if (self::$_options['encodeMethod'] !== '') {
339            $headers['Content-Encoding'] = $contentEncoding;
340        }
341        if (self::$_options['encodeOutput'] && $sendVary) {
342            $headers['Vary'] = 'Accept-Encoding';
343        }
344
345        if (! self::$_options['quiet']) {
346            // output headers & content
347            foreach ($headers as $name => $val) {
348                header($name . ': ' . $val);
349            }
350            if ($cacheIsReady) {
351                self::$_cache->display($fullCacheId);
352            } else {
353                echo $content;
354            }
355        } else {
356            return array(
357                'success' => true
358                ,'statusCode' => 200
359                ,'content' => $cacheIsReady
360                    ? self::$_cache->fetch($fullCacheId)
361                    : $content
362                ,'headers' => $headers
363            );
364        }
365    }
366
367    /**
368     * Return combined minified content for a set of sources
369     *
370     * No internal caching will be used and the content will not be HTTP encoded.
371     *
372     * @param array $sources array of filepaths and/or Minify_Source objects
373     *
374     * @param array $options (optional) array of options for serve. By default
375     * these are already set: quiet = true, encodeMethod = '', lastModifiedTime = 0.
376     *
377     * @return string
378     */
379    public static function combine($sources, $options = array())
380    {
381        $cache = self::$_cache;
382        self::$_cache = null;
383        $options = array_merge(array(
384            'files' => (array)$sources
385            ,'quiet' => true
386            ,'encodeMethod' => ''
387            ,'lastModifiedTime' => 0
388        ), $options);
389        $out = self::serve('Files', $options);
390        self::$_cache = $cache;
391        return $out['content'];
392    }
393
394    /**
395     * Set $_SERVER['DOCUMENT_ROOT']. On IIS, the value is created from SCRIPT_FILENAME and SCRIPT_NAME.
396     *
397     * @param string $docRoot value to use for DOCUMENT_ROOT
398     */
399    public static function setDocRoot($docRoot = '')
400    {
401        self::$isDocRootSet = true;
402        if ($docRoot) {
403            $_SERVER['DOCUMENT_ROOT'] = $docRoot;
404        } elseif (isset($_SERVER['SERVER_SOFTWARE'])
405                  && 0 === strpos($_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/')) {
406            $_SERVER['DOCUMENT_ROOT'] = substr(
407                $_SERVER['SCRIPT_FILENAME']
408                ,0
409                ,strlen($_SERVER['SCRIPT_FILENAME']) - strlen($_SERVER['SCRIPT_NAME']));
410            $_SERVER['DOCUMENT_ROOT'] = rtrim($_SERVER['DOCUMENT_ROOT'], '\\');
411        }
412    }
413
414    /**
415     * Any Minify_Cache_* object or null (i.e. no server cache is used)
416     *
417     * @var Minify_Cache_File
418     */
419    private static $_cache = null;
420
421    /**
422     * Active controller for current request
423     *
424     * @var Minify_Controller_Base
425     */
426    protected static $_controller = null;
427
428    /**
429     * Options for current request
430     *
431     * @var array
432     */
433    protected static $_options = null;
434
435    /**
436     * @param string $header
437     *
438     * @param string $url
439     */
440    protected static function _errorExit($header, $url)
441    {
442        $url = htmlspecialchars($url, ENT_QUOTES);
443        list(,$h1) = explode(' ', $header, 2);
444        $h1 = htmlspecialchars($h1);
445        // FastCGI environments require 3rd arg to header() to be set
446        list(, $code) = explode(' ', $header, 3);
447        header($header, true, $code);
448        header('Content-Type: text/html; charset=utf-8');
449        echo "<h1>$h1</h1>";
450        echo "<p>Please see <a href='$url'>$url</a>.</p>";
451        exit;
452    }
453
454    /**
455     * Set up sources to use Minify_Lines
456     *
457     * @param Minify_Source[] $sources Minify_Source instances
458     */
459    protected static function _setupDebug($sources)
460    {
461        foreach ($sources as $source) {
462            $source->minifier = array('Minify_Lines', 'minify');
463            $id = $source->getId();
464            $source->minifyOptions = array(
465                'id' => (is_file($id) ? basename($id) : $id)
466            );
467        }
468    }
469
470    /**
471     * Combines sources and minifies the result.
472     *
473     * @return string
474     *
475     * @throws Exception
476     */
477    protected static function _combineMinify()
478    {
479        $type = self::$_options['contentType']; // ease readability
480
481        // when combining scripts, make sure all statements separated and
482        // trailing single line comment is terminated
483        $implodeSeparator = ($type === self::TYPE_JS)
484            ? "\n;"
485            : '';
486        // allow the user to pass a particular array of options to each
487        // minifier (designated by type). source objects may still override
488        // these
489        $defaultOptions = isset(self::$_options['minifierOptions'][$type])
490            ? self::$_options['minifierOptions'][$type]
491            : array();
492        // if minifier not set, default is no minification. source objects
493        // may still override this
494        $defaultMinifier = isset(self::$_options['minifiers'][$type])
495            ? self::$_options['minifiers'][$type]
496            : false;
497
498        // process groups of sources with identical minifiers/options
499        $content = array();
500        $i = 0;
501        $l = count(self::$_controller->sources);
502        $groupToProcessTogether = array();
503        $lastMinifier = null;
504        $lastOptions = null;
505        do {
506            // get next source
507            $source = null;
508            if ($i < $l) {
509                $source = self::$_controller->sources[$i];
510                /* @var Minify_Source $source */
511                $sourceContent = $source->getContent();
512
513                // allow the source to override our minifier and options
514                $minifier = (null !== $source->minifier)
515                    ? $source->minifier
516                    : $defaultMinifier;
517                $options = (null !== $source->minifyOptions)
518                    ? array_merge($defaultOptions, $source->minifyOptions)
519                    : $defaultOptions;
520            }
521            // do we need to process our group right now?
522            if ($i > 0                               // yes, we have at least the first group populated
523                && (
524                    ! $source                        // yes, we ran out of sources
525                    || $type === self::TYPE_CSS      // yes, to process CSS individually (avoiding PCRE bugs/limits)
526                    || $minifier !== $lastMinifier   // yes, minifier changed
527                    || $options !== $lastOptions)    // yes, options changed
528                )
529            {
530                // minify previous sources with last settings
531                $imploded = implode($implodeSeparator, $groupToProcessTogether);
532                $groupToProcessTogether = array();
533                if ($lastMinifier) {
534                    try {
535                        $content[] = call_user_func($lastMinifier, $imploded, $lastOptions);
536                    } catch (Exception $e) {
537                        throw new Exception("Exception in minifier: " . $e->getMessage());
538                    }
539                } else {
540                    $content[] = $imploded;
541                }
542            }
543            // add content to the group
544            if ($source) {
545                $groupToProcessTogether[] = $sourceContent;
546                $lastMinifier = $minifier;
547                $lastOptions = $options;
548            }
549            $i++;
550        } while ($source);
551
552        $content = implode($implodeSeparator, $content);
553
554        if ($type === self::TYPE_CSS && false !== strpos($content, '@import')) {
555            $content = self::_handleCssImports($content);
556        }
557
558        // do any post-processing (esp. for editing build URIs)
559        if (self::$_options['postprocessorRequire']) {
560            require_once self::$_options['postprocessorRequire'];
561        }
562        if (self::$_options['postprocessor']) {
563            $content = call_user_func(self::$_options['postprocessor'], $content, $type);
564        }
565        return $content;
566    }
567
568    /**
569     * Make a unique cache id for for this request.
570     *
571     * Any settings that could affect output are taken into consideration
572     *
573     * @param string $prefix
574     *
575     * @return string
576     */
577    protected static function _getCacheId($prefix = 'minify')
578    {
579        $name = preg_replace('/[^a-zA-Z0-9\\.=_,]/', '', self::$_controller->selectionId);
580        $name = preg_replace('/\\.+/', '.', $name);
581        $name = substr($name, 0, 100 - 34 - strlen($prefix));
582        $md5 = md5(serialize(array(
583            Minify_Source::getDigest(self::$_controller->sources)
584            ,self::$_options['minifiers']
585            ,self::$_options['minifierOptions']
586            ,self::$_options['postprocessor']
587            ,self::$_options['bubbleCssImports']
588            ,self::VERSION
589        )));
590        return "{$prefix}_{$name}_{$md5}";
591    }
592
593    /**
594     * Bubble CSS @imports to the top or prepend a warning if an import is detected not at the top.
595     *
596     * @param string $css
597     *
598     * @return string
599     */
600    protected static function _handleCssImports($css)
601    {
602        if (self::$_options['bubbleCssImports']) {
603            // bubble CSS imports
604            preg_match_all('/@import.*?;/', $css, $imports);
605            $css = implode('', $imports[0]) . preg_replace('/@import.*?;/', '', $css);
606        } else if ('' !== self::$importWarning) {
607            // remove comments so we don't mistake { in a comment as a block
608            $noCommentCss = preg_replace('@/\\*[\\s\\S]*?\\*/@', '', $css);
609            $lastImportPos = strrpos($noCommentCss, '@import');
610            $firstBlockPos = strpos($noCommentCss, '{');
611            if (false !== $lastImportPos
612                && false !== $firstBlockPos
613                && $firstBlockPos < $lastImportPos
614            ) {
615                // { appears before @import : prepend warning
616                $css = self::$importWarning . $css;
617            }
618        }
619        return $css;
620    }
621}
622