includes/ResourceLoader.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  * @author Roan Kattouw
  20  * @author Trevor Parscal
  21  */
  22
  23 /**
  24  * Dynamic JavaScript and CSS resource loading system
  25  *
  26  * @example
  27  *      // Registers a module with the resource loading system
  28  *      ResourceLoader::register( 'foo', array(
  29  *              // Script or list of scripts to include when implementating the module (required)
  30  *              'script' => 'resources/foo/foo.js',
  31  *              // List of scripts or lists of scripts to include based on the current language
  32  *              'locales' => array(
  33  *                      'en-gb' => 'resources/foo/locales/en-gb.js',
  34  *              ),
  35  *              // Script or list of scripts to include only when in debug mode
  36  *              'debug' => 'resources/foo/debug.js',
  37  *              // If this module is going to be loaded before the mediawiki module is ready such as jquery or the mediawiki
  38  *              // module itself, it can be included without special loader wrapping - this will also limit the module to not be
  39  *              // able to specify needs, custom loaders, styles, themes or messages (any of the options below) - raw scripts
  40  *              // get registered as 'ready' after the mediawiki module is ready, so they can be named as dependencies
  41  *              'raw' => false,
  42  *              // Modules or list of modules which are needed and should be used when generating loader code
  43  *              'needs' => 'resources/foo/foo.js',
  44  *              // Script or list of scripts which will cause loader code to not be generated - if you are doing something fancy
  45  *              // with your dependencies this gives you a way to use custom registration code
  46  *              'loader' => 'resources/foo/loader.js',
  47  *              // Style-sheets or list of style-sheets to include
  48  *              'style' => 'resources/foo/foo.css',
  49  *              // List of style-sheets or lists of style-sheets to include based on the skin - if no match is found for current
  50  *              // skin, 'default' is used - if default doesn't exist nothing is added
  51  *              'themes' => array(
  52  *                      'default' => 'resources/foo/themes/default/foo.css',
  53  *                      'vector' => 'resources/foo/themes/vector.foo.css',
  54  *              ),
  55  *              // List of keys of messages to include
  56  *              'messages' => array( 'foo-hello', 'foo-goodbye' ),
  57  *              // Subclass of ResourceLoaderModule to use for custom modules
  58  *              'class' => 'ResourceLoaderSiteJSModule',
  59  *      ) );
  60  * @example
  61  *      // Responds to a resource loading request
  62  *      ResourceLoader::respond( $wgRequest, $wgServer . wfScript( 'load' ) );
  63  */
  64 class ResourceLoader {
  65         /* Protected Static Members */
  66
  67         // @var array list of module name/ResourceLoaderModule object pairs
  68         protected static $modules = array();
  69
  70         /* Protected Static Methods */
  71
  72         /**
  73          * Runs text through a filter, caching the filtered result for future calls
  74          *
  75          * @param $filter String: name of filter to run
  76          * @param $data String: text to filter, such as JavaScript or CSS text
  77          * @param $file String: path to file being filtered, (optional: only required for CSS to resolve paths)
  78          * @return String: filtered data
  79          */
  80         protected static function filter( $filter, $data ) {
  81                 global $wgMemc;
  82
  83                 // For empty or whitespace-only things, don't do any processing
  84                 if ( trim( $data ) === '' ) {
  85                         return $data;
  86                 }
  87
  88                 // Try memcached
  89                 $key = wfMemcKey( 'resourceloader', 'filter', $filter, md5( $data ) );
  90                 $cached = $wgMemc->get( $key );
  91
  92                 if ( $cached !== false && $cached !== null ) {
  93                         return $cached;
  94                 }
  95
  96                 // Run the filter
  97                 try {
  98                         switch ( $filter ) {
  99                                 case 'minify-js':
 100                                         $result = JSMin::minify( $data );
 101                                         break;
 102                                 case 'minify-css':
 103                                         $result = CSSMin::minify( $data );
 104                                         break;
 105                                 case 'flip-css':
 106                                         $result = CSSJanus::transform( $data, true, false );
 107                                         break;
 108                                 default:
 109                                         // Don't cache anything, just pass right through
 110                                         return $data;
 111                         }
 112                 } catch ( Exception $exception ) {
 113                         throw new MWException( 'Filter threw an exception: ' . $exception->getMessage() );
 114                 }
 115
 116                 // Save to memcached
 117                 $wgMemc->set( $key, $result );
 118
 119                 return $result;
 120         }
 121
 122         /* Static Methods */
 123
 124         /**
 125          * Registers a module with the ResourceLoader system.
 126          *
 127          * Note that registering the same object under multiple names is not supported and may silently fail in all
 128          * kinds of interesting ways.
 129          *
 130          * @param $name Mixed: string of name of module or array of name/object pairs
 131          * @param $object ResourceLoaderModule: module object (optional when using multiple-registration calling style)
 132          * @return Boolean: false if there were any errors, in which case one or more modules were not registered
 133          *
 134          * @todo We need much more clever error reporting, not just in detailing what happened, but in bringing errors to
 135          * the client in a way that they can easily see them if they want to, such as by using FireBug
 136          */
 137         public static function register( $name, ResourceLoaderModule $object = null ) {
 138                 // Allow multiple modules to be registered in one call
 139                 if ( is_array( $name ) && !isset( $object ) ) {
 140                         foreach ( $name as $key => $value ) {
 141                                 self::register( $key, $value );
 142                         }
 143
 144                         return;
 145                 }
 146
 147                 // Disallow duplicate registrations
 148                 if ( isset( self::$modules[$name] ) ) {
 149                         // A module has already been registered by this name
 150                         throw new MWException( 'Another module has already been registered as ' . $name );
 151                 }
 152                 // Attach module
 153                 self::$modules[$name] = $object;
 154                 $object->setName( $name );
 155         }
 156
 157         /**
 158          * Gets a map of all modules and their options
 159          *
 160          * @return Array: array( modulename => ResourceLoaderModule )
 161          */
 162         public static function getModules() {
 163                 return self::$modules;
 164         }
 165
 166         /**
 167          * Get the ResourceLoaderModule object for a given module name
 168          *
 169          * @param $name String: module name
 170          * @return mixed ResourceLoaderModule or null if not registered
 171          */
 172         public static function getModule( $name ) {
 173                 return isset( self::$modules[$name] ) ? self::$modules[$name] : null;
 174         }
 175
 176         /**
 177          * Gets registration code for all modules, except pre-registered ones listed in self::$preRegisteredModules
 178          *
 179          * @param $context ResourceLoaderContext object
 180          * @return String: JavaScript code for registering all modules with the client loader
 181          */
 182         public static function getModuleRegistrations( ResourceLoaderContext $context ) {
 183                 $scripts = '';
 184                 $registrations = array();
 185
 186                 foreach ( self::$modules as $name => $module ) {
 187                         // Support module loader scripts
 188                         if ( ( $loader = $module->getLoaderScript() ) !== false ) {
 189                                 $scripts .= $loader;
 190                         }
 191                         // Automatically register module
 192                         else {
 193                                 // Modules without dependencies pass two arguments (name, timestamp) to mediaWiki.loader.register()
 194                                 if ( !count( $module->getDependencies() ) ) {
 195                                         $registrations[] = array( $name, $module->getModifiedTime( $context ) );
 196                                 }
 197                                 // Modules with dependencies pass three arguments (name, timestamp, dependencies) to mediaWiki.loader.register()
 198                                 else {
 199                                         $registrations[] = array( $name, $module->getModifiedTime( $context ), $module->getDependencies() );
 200                                 }
 201                         }
 202                 }
 203                 return $scripts . "mediaWiki.loader.register( " . FormatJson::encode( $registrations ) . " );";
 204         }
 205
 206         /**
 207          * Get the highest modification time of all modules, based on a given combination of language code,
 208          * skin name and debug mode flag.
 209          *
 210          * @param $context ResourceLoaderContext object
 211          * @return Integer: UNIX timestamp
 212          */
 213         public static function getHighestModifiedTime( ResourceLoaderContext $context ) {
 214                 $time = 1; // wfTimestamp() treats 0 as 'now', so that's not a suitable choice
 215
 216                 foreach ( self::$modules as $module ) {
 217                         $time = max( $time, $module->getModifiedTime( $context ) );
 218                 }
 219
 220                 return $time;
 221         }
 222
 223         /**
 224          * Outputs a response to a resource load-request, including a content-type header
 225          *
 226          * @param $context ResourceLoaderContext object
 227          */
 228         public static function respond( ResourceLoaderContext $context ) {
 229                 // Split requested modules into two groups, modules and missing
 230                 $modules = array();
 231                 $missing = array();
 232
 233                 foreach ( $context->getModules() as $name ) {
 234                         if ( isset( self::$modules[$name] ) ) {
 235                                 $modules[] = $name;
 236                         } else {
 237                                 $missing[] = $name;
 238                         }
 239                 }
 240
 241                 // Calculate the mtime and caching maxages for this request. We need this, 304 or no 304
 242                 $mtime = 1;
 243                 $maxage = PHP_INT_MAX;
 244                 $smaxage = PHP_INT_MAX;
 245
 246                 foreach ( $modules as $name ) {
 247                         $mtime = max( $mtime, self::$modules[$name]->getModifiedTime( $context ) );
 248                         $maxage = min( $maxage, self::$modules[$name]->getClientMaxage() );
 249                         $smaxage = min( $smaxage, self::$modules[$name]->getServerMaxage() );
 250                 }
 251
 252                 // Output headers
 253                 if ( $context->getOnly() === 'styles' ) {
 254                         header( 'Content-Type: text/css' );
 255                 } else {
 256                         header( 'Content-Type: text/javascript' );
 257                 }
 258
 259                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 260                 $expires = wfTimestamp( TS_RFC2822, min( $maxage, $smaxage ) + time() );
 261                 header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 262                 header( "Expires: $expires" );
 263
 264                 // Check if there's an If-Modified-Since header and respond with a 304 Not Modified if possible
 265                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 266
 267                 if ( $ims !== false && wfTimestamp( TS_UNIX, $ims ) == $mtime ) {
 268                         header( 'HTTP/1.0 304 Not Modified' );
 269                         header( 'Status: 304 Not Modified' );
 270                         return;
 271                 }
 272
 273                 // Use output buffering
 274                 ob_start();
 275
 276                 // Pre-fetch blobs
 277                 $blobs = $context->shouldIncludeMessages() ?
 278                 MessageBlobStore::get( $modules, $context->getLanguage() ) : array();
 279
 280                 // Generate output
 281                 foreach ( $modules as $name ) {
 282                         // Scripts
 283                         $scripts = '';
 284
 285                         if ( $context->shouldIncludeScripts() ) {
 286                                 $scripts .= self::$modules[$name]->getScript( $context );
 287                         }
 288
 289                         // Styles
 290                         $styles = array();
 291
 292                         if (
 293                                 $context->shouldIncludeStyles() && ( count( $styles = self::$modules[$name]->getStyles( $context ) ) )
 294                         ) {
 295                                 foreach ( $styles as $media => $style ) {
 296                                         if ( self::$modules[$name]->getFlip( $context ) ) {
 297                                                 $styles[$media] = self::filter( 'flip-css', $style );
 298                                         }
 299                                         if ( !$context->getDebug() ) {
 300                                                 $styles[$media] = self::filter( 'minify-css', $style );
 301                                         }
 302                                 }
 303                         }
 304
 305                         // Messages
 306                         $messages = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 307
 308                         // Output
 309                         if ( $context->getOnly() === 'styles' ) {
 310                                 if ( $context->getDebug() ) {
 311                                         echo "/* $name */\n";
 312                                         foreach ( $styles as $media => $style ) {
 313                                                 echo "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "\n}\n";
 314                                         }
 315                                 } else {
 316                                         foreach ( $styles as $media => $style ) {
 317                                                 if ( strlen( $style ) ) {
 318                                                         echo "@media $media{" . $style . "}";
 319                                                 }
 320                                         }
 321                                 }
 322                         } else if ( $context->getOnly() === 'scripts' ) {
 323                                 echo $scripts;
 324                         } else if ( $context->getOnly() === 'messages' ) {
 325                                 echo "mediaWiki.msg.set( $messages );\n";
 326                         } else {
 327                                 $styles = FormatJson::encode( $styles );
 328                                 echo "mediaWiki.loader.implement( '$name', function() {{$scripts}},\n$styles,\n$messages );\n";
 329                         }
 330                 }
 331
 332                 // Update the status of script-only modules
 333                 if ( $context->getOnly() === 'scripts' && !in_array( 'startup', $modules ) ) {
 334                         $statuses = array();
 335
 336                         foreach ( $modules as $name ) {
 337                                 $statuses[$name] = 'ready';
 338                         }
 339
 340                         $statuses = FormatJson::encode( $statuses );
 341                         echo "mediaWiki.loader.state( $statuses );\n";
 342                 }
 343
 344                 // Register missing modules
 345                 if ( $context->shouldIncludeScripts() ) {
 346                         foreach ( $missing as $name ) {
 347                                 echo "mediaWiki.loader.register( '$name', null, 'missing' );\n";
 348                         }
 349                 }
 350
 351                 // Output the appropriate header
 352                 if ( $context->getOnly() !== 'styles' ) {
 353                         if ( $context->getDebug() ) {
 354                                 ob_end_flush();
 355                         } else {
 356                                 echo self::filter( 'minify-js', ob_get_clean() );
 357                         }
 358                 }
 359         }
 360 }
 361
 362 // FIXME: Temp hack
 363 require_once "$IP/resources/Resources.php";