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