includes/resourceloader/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  * Most of the documention is on the MediaWiki documentation wiki starting at:
  27  *    http://www.mediawiki.org/wiki/ResourceLoader
  28  */
  29 class ResourceLoader {
  30
  31         /* Protected Static Members */
  32
  33         /** Array: List of module name/ResourceLoaderModule object pairs */
  34         protected $modules = array();
  35         /** Associative array mapping module name to info associative array */
  36         protected $moduleInfos = array();
  37
  38         /* Protected Methods */
  39
  40         /**
  41          * Loads information stored in the database about modules.
  42          *
  43          * This method grabs modules dependencies from the database and updates modules
  44          * objects.
  45          *
  46          * This is not inside the module code because it is much faster to
  47          * request all of the information at once than it is to have each module
  48          * requests its own information. This sacrifice of modularity yields a substantial
  49          * performance improvement.
  50          *
  51          * @param $modules Array: List of module names to preload information for
  52          * @param $context ResourceLoaderContext: Context to load the information within
  53          */
  54         protected function preloadModuleInfo( array $modules, ResourceLoaderContext $context ) {
  55                 if ( !count( $modules ) ) {
  56                         return; // or else Database*::select() will explode, plus it's cheaper!
  57                 }
  58                 $dbr = wfGetDB( DB_SLAVE );
  59                 $skin = $context->getSkin();
  60                 $lang = $context->getLanguage();
  61
  62                 // Get file dependency information
  63                 $res = $dbr->select( 'module_deps', array( 'md_module', 'md_deps' ), array(
  64                                 'md_module' => $modules,
  65                                 'md_skin' => $context->getSkin()
  66                         ), __METHOD__
  67                 );
  68
  69                 // Set modules' dependecies
  70                 $modulesWithDeps = array();
  71                 foreach ( $res as $row ) {
  72                         $this->getModule( $row->md_module )->setFileDependencies( $skin,
  73                                 FormatJson::decode( $row->md_deps, true )
  74                         );
  75                         $modulesWithDeps[] = $row->md_module;
  76                 }
  77
  78                 // Register the absence of a dependency row too
  79                 foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
  80                         $this->getModule( $name )->setFileDependencies( $skin, array() );
  81                 }
  82
  83                 // Get message blob mtimes. Only do this for modules with messages
  84                 $modulesWithMessages = array();
  85                 $modulesWithoutMessages = array();
  86                 foreach ( $modules as $name ) {
  87                         if ( count( $this->getModule( $name )->getMessages() ) ) {
  88                                 $modulesWithMessages[] = $name;
  89                         } else {
  90                                 $modulesWithoutMessages[] = $name;
  91                         }
  92                 }
  93                 if ( count( $modulesWithMessages ) ) {
  94                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
  95                                         'mr_resource' => $modulesWithMessages,
  96                                         'mr_lang' => $lang
  97                                 ), __METHOD__
  98                         );
  99                         foreach ( $res as $row ) {
 100                                 $this->getModule( $row->mr_resource )->setMsgBlobMtime( $lang, $row->mr_timestamp );
 101                         }
 102                 }
 103                 foreach ( $modulesWithoutMessages as $name ) {
 104                         $this->getModule( $name )->setMsgBlobMtime( $lang, 0 );
 105                 }
 106         }
 107
 108         /**
 109          * Runs JavaScript or CSS data through a filter, caching the filtered result for future calls.
 110          *
 111          * Available filters are:
 112          *  - minify-js \see JSMin::minify
 113          *  - minify-css \see CSSMin::minify
 114          *
 115          * If $data is empty, only contains whitespace or the filter was unknown,
 116          * $data is returned unmodified.
 117          *
 118          * @param $filter String: Name of filter to run
 119          * @param $data String: Text to filter, such as JavaScript or CSS text
 120          * @return String: Filtered data
 121          */
 122         protected function filter( $filter, $data ) {
 123                 wfProfileIn( __METHOD__ );
 124
 125                 // For empty/whitespace-only data or for unknown filters, don't perform
 126                 // any caching or processing
 127                 if ( trim( $data ) === ''
 128                         || !in_array( $filter, array( 'minify-js', 'minify-css' ) ) )
 129                 {
 130                         wfProfileOut( __METHOD__ );
 131                         return $data;
 132                 }
 133
 134                 // Try for cache hit
 135                 // Use CACHE_ANYTHING since filtering is very slow compared to DB queries
 136                 $key = wfMemcKey( 'resourceloader', 'filter', $filter, md5( $data ) );
 137                 $cache = wfGetCache( CACHE_ANYTHING );
 138                 $cacheEntry = $cache->get( $key );
 139                 if ( is_string( $cacheEntry ) ) {
 140                         wfProfileOut( __METHOD__ );
 141                         return $cacheEntry;
 142                 }
 143
 144                 // Run the filter - we've already verified one of these will work
 145                 try {
 146                         switch ( $filter ) {
 147                                 case 'minify-js':
 148                                         $result = JSMin::minify( $data );
 149                                         break;
 150                                 case 'minify-css':
 151                                         $result = CSSMin::minify( $data );
 152                                         break;
 153                         }
 154                 } catch ( Exception $exception ) {
 155                         throw new MWException( 'ResourceLoader filter error. ' .
 156                                 'Exception was thrown: ' . $exception->getMessage() );
 157                 }
 158
 159                 // Save filtered text to Memcached
 160                 $cache->set( $key, $result );
 161
 162                 wfProfileOut( __METHOD__ );
 163
 164                 return $result;
 165         }
 166
 167         /* Methods */
 168
 169         /**
 170          * Registers core modules and runs registration hooks.
 171          */
 172         public function __construct() {
 173                 global $IP, $wgResourceModules;
 174
 175                 wfProfileIn( __METHOD__ );
 176
 177                 // Register core modules
 178                 $this->register( include( "$IP/resources/Resources.php" ) );
 179                 // Register extension modules
 180                 wfRunHooks( 'ResourceLoaderRegisterModules', array( &$this ) );
 181                 $this->register( $wgResourceModules );
 182
 183                 wfProfileOut( __METHOD__ );
 184         }
 185
 186         /**
 187          * Registers a module with the ResourceLoader system.
 188          *
 189          * @param $name Mixed: Name of module as a string or List of name/object pairs as an array
 190          * @param $info Module info array. For backwards compatibility with 1.17alpha,
 191          *   this may also be a ResourceLoaderModule object. Optional when using
 192          *   multiple-registration calling style.
 193          * @throws MWException: If a duplicate module registration is attempted
 194          * @throws MWException: If something other than a ResourceLoaderModule is being registered
 195          * @return Boolean: False if there were any errors, in which case one or more modules were not
 196          *     registered
 197          */
 198         public function register( $name, $info = null ) {
 199                 wfProfileIn( __METHOD__ );
 200
 201                 // Allow multiple modules to be registered in one call
 202                 if ( is_array( $name ) ) {
 203                         foreach ( $name as $key => $value ) {
 204                                 $this->register( $key, $value );
 205                         }
 206                         return;
 207                 }
 208
 209                 // Disallow duplicate registrations
 210                 if ( isset( $this->moduleInfos[$name] ) ) {
 211                         // A module has already been registered by this name
 212                         throw new MWException(
 213                                 'ResourceLoader duplicate registration error. ' .
 214                                 'Another module has already been registered as ' . $name
 215                         );
 216                 }
 217
 218                 // Attach module
 219                 if ( is_object( $info ) ) {
 220                         // Old calling convention
 221                         // Validate the input
 222                         if ( !( $info instanceof ResourceLoaderModule ) ) {
 223                                 throw new MWException( 'ResourceLoader invalid module error. ' .
 224                                         'Instances of ResourceLoaderModule expected.' );
 225                         }
 226
 227                         $this->moduleInfos[$name] = array( 'object' => $info );
 228                         $info->setName( $name );
 229                         $this->modules[$name] = $info;
 230                 } else {
 231                         // New calling convention
 232                         $this->moduleInfos[$name] = $info;
 233                 }
 234
 235                 wfProfileOut( __METHOD__ );
 236         }
 237
 238         /**
 239          * Get a list of module names
 240          *
 241          * @return Array: List of module names
 242          */
 243         public function getModuleNames() {
 244                 return array_keys( $this->moduleInfos );
 245         }
 246
 247         /**
 248          * Get the ResourceLoaderModule object for a given module name.
 249          *
 250          * @param $name String: Module name
 251          * @return Mixed: ResourceLoaderModule if module has been registered, null otherwise
 252          */
 253         public function getModule( $name ) {
 254                 if ( !isset( $this->modules[$name] ) ) {
 255                         if ( !isset( $this->moduleInfos[$name] ) ) {
 256                                 // No such module
 257                                 return null;
 258                         }
 259                         // Construct the requested object
 260                         $info = $this->moduleInfos[$name];
 261                         if ( isset( $info['object'] ) ) {
 262                                 // Object given in info array
 263                                 $object = $info['object'];
 264                         } else {
 265                                 if ( !isset( $info['class'] ) ) {
 266                                         $class = 'ResourceLoaderFileModule';
 267                                 } else {
 268                                         $class = $info['class'];
 269                                 }
 270                                 $object = new $class( $info );
 271                         }
 272                         $object->setName( $name );
 273                         $this->modules[$name] = $object;
 274                 }
 275
 276                 return $this->modules[$name];
 277         }
 278
 279         /**
 280          * Outputs a response to a resource load-request, including a content-type header.
 281          *
 282          * @param $context ResourceLoaderContext: Context in which a response should be formed
 283          */
 284         public function respond( ResourceLoaderContext $context ) {
 285                 global $wgResourceLoaderMaxage, $wgCacheEpoch;
 286
 287                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 288                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 289                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 290                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 291                 // the whole thing in our own output buffer to be sure the active buffer
 292                 // doesn't use ob_gzhandler.
 293                 // See http://bugs.php.net/bug.php?id=36514
 294                 ob_start();
 295
 296                 wfProfileIn( __METHOD__ );
 297
 298                 // Split requested modules into two groups, modules and missing
 299                 $modules = array();
 300                 $missing = array();
 301                 foreach ( $context->getModules() as $name ) {
 302                         if ( isset( $this->moduleInfos[$name] ) ) {
 303                                 $modules[$name] = $this->getModule( $name );
 304                         } else {
 305                                 $missing[] = $name;
 306                         }
 307                 }
 308
 309                 // If a version wasn't specified we need a shorter expiry time for updates
 310                 // to propagate to clients quickly
 311                 if ( is_null( $context->getVersion() ) ) {
 312                         $maxage  = $wgResourceLoaderMaxage['unversioned']['client'];
 313                         $smaxage = $wgResourceLoaderMaxage['unversioned']['server'];
 314                 }
 315                 // If a version was specified we can use a longer expiry time since changing
 316                 // version numbers causes cache misses
 317                 else {
 318                         $maxage  = $wgResourceLoaderMaxage['versioned']['client'];
 319                         $smaxage = $wgResourceLoaderMaxage['versioned']['server'];
 320                 }
 321
 322                 // Preload information needed to the mtime calculation below
 323                 $this->preloadModuleInfo( array_keys( $modules ), $context );
 324
 325                 wfProfileIn( __METHOD__.'-getModifiedTime' );
 326
 327                 // To send Last-Modified and support If-Modified-Since, we need to detect
 328                 // the last modified time
 329                 $mtime = wfTimestamp( TS_UNIX, $wgCacheEpoch );
 330                 foreach ( $modules as $module ) {
 331                         // Bypass squid cache if the request includes any private modules
 332                         if ( $module->getGroup() === 'private' ) {
 333                                 $smaxage = 0;
 334                         }
 335                         // Calculate maximum modified time
 336                         $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 337                 }
 338
 339                 wfProfileOut( __METHOD__.'-getModifiedTime' );
 340
 341                 if ( $context->getOnly() === 'styles' ) {
 342                         header( 'Content-Type: text/css' );
 343                 } else {
 344                         header( 'Content-Type: text/javascript' );
 345                 }
 346                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 347                 if ( $context->getDebug() ) {
 348                         header( 'Cache-Control: must-revalidate' );
 349                 } else {
 350                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 351                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, min( $maxage, $smaxage ) + time() ) );
 352                 }
 353
 354                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 355                 // Some clients send "timestamp;length=123". Strip the part after the first ';'
 356                 // so we get a valid timestamp.
 357                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 358                 if ( $ims !== false ) {
 359                         $imsTS = strtok( $ims, ';' );
 360                         if ( $mtime <= wfTimestamp( TS_UNIX, $imsTS ) ) {
 361                                 // There's another bug in ob_gzhandler (see also the comment at
 362                                 // the top of this function) that causes it to gzip even empty
 363                                 // responses, meaning it's impossible to produce a truly empty
 364                                 // response (because the gzip header is always there). This is
 365                                 // a problem because 304 responses have to be completely empty
 366                                 // per the HTTP spec, and Firefox behaves buggily when they're not.
 367                                 // See also http://bugs.php.net/bug.php?id=51579
 368                                 // To work around this, we tear down all output buffering before
 369                                 // sending the 304.
 370                                 while ( ob_get_level() > 0 ) {
 371                                         ob_end_clean();
 372                                 }
 373
 374                                 header( 'HTTP/1.0 304 Not Modified' );
 375                                 header( 'Status: 304 Not Modified' );
 376                                 wfProfileOut( __METHOD__ );
 377                                 return;
 378                         }
 379                 }
 380
 381                 // Generate a response
 382                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 383
 384                 // Capture any PHP warnings from the output buffer and append them to the
 385                 // response in a comment if we're in debug mode.
 386                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 387                         $response .= "/*\n$warnings\n*/";
 388                 }
 389
 390                 // Remove the output buffer and output the response
 391                 ob_end_clean();
 392                 echo $response;
 393
 394                 wfProfileOut( __METHOD__ );
 395         }
 396
 397         /**
 398          * Generates code for a response
 399          *
 400          * @param $context ResourceLoaderContext: Context in which to generate a response
 401          * @param $modules Array: List of module objects keyed by module name
 402          * @param $missing Array: List of unavailable modules (optional)
 403          * @return String: Response data
 404          */
 405         public function makeModuleResponse( ResourceLoaderContext $context,
 406                 array $modules, $missing = array() )
 407         {
 408                 if ( $modules === array() && $missing === array() ) {
 409                         return '/* No modules requested. Max made me put this here */';
 410                 }
 411
 412                 // Pre-fetch blobs
 413                 if ( $context->shouldIncludeMessages() ) {
 414                         $blobs = MessageBlobStore::get( $this, $modules, $context->getLanguage() );
 415                 } else {
 416                         $blobs = array();
 417                 }
 418
 419                 // Generate output
 420                 $out = '';
 421                 foreach ( $modules as $name => $module ) {
 422
 423                         wfProfileIn( __METHOD__ . '-' . $name );
 424
 425                         // Scripts
 426                         $scripts = '';
 427                         if ( $context->shouldIncludeScripts() ) {
 428                                 $scripts .= $module->getScript( $context ) . "\n";
 429                         }
 430
 431                         // Styles
 432                         $styles = array();
 433                         if ( $context->shouldIncludeStyles() ) {
 434                                 $styles = $module->getStyles( $context );
 435                         }
 436
 437                         // Messages
 438                         $messagesBlob = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 439
 440                         // Append output
 441                         switch ( $context->getOnly() ) {
 442                                 case 'scripts':
 443                                         $out .= $scripts;
 444                                         break;
 445                                 case 'styles':
 446                                         $out .= self::makeCombinedStyles( $styles );
 447                                         break;
 448                                 case 'messages':
 449                                         $out .= self::makeMessageSetScript( new XmlJsCode( $messagesBlob ) );
 450                                         break;
 451                                 default:
 452                                         // Minify CSS before embedding in mediaWiki.loader.implement call
 453                                         // (unless in debug mode)
 454                                         if ( !$context->getDebug() ) {
 455                                                 foreach ( $styles as $media => $style ) {
 456                                                         $styles[$media] = $this->filter( 'minify-css', $style );
 457                                                 }
 458                                         }
 459                                         $out .= self::makeLoaderImplementScript( $name, $scripts, $styles,
 460                                                 new XmlJsCode( $messagesBlob ) );
 461                                         break;
 462                         }
 463
 464                         wfProfileOut( __METHOD__ . '-' . $name );
 465                 }
 466
 467                 // Update module states
 468                 if ( $context->shouldIncludeScripts() ) {
 469                         // Set the state of modules loaded as only scripts to ready
 470                         if ( count( $modules ) && $context->getOnly() === 'scripts'
 471                                 && !isset( $modules['startup'] ) )
 472                         {
 473                                 $out .= self::makeLoaderStateScript(
 474                                         array_fill_keys( array_keys( $modules ), 'ready' ) );
 475                         }
 476                         // Set the state of modules which were requested but unavailable as missing
 477                         if ( is_array( $missing ) && count( $missing ) ) {
 478                                 $out .= self::makeLoaderStateScript( array_fill_keys( $missing, 'missing' ) );
 479                         }
 480                 }
 481
 482                 if ( $context->getDebug() ) {
 483                         return $out;
 484                 } else {
 485                         if ( $context->getOnly() === 'styles' ) {
 486                                 return $this->filter( 'minify-css', $out );
 487                         } else {
 488                                 return $this->filter( 'minify-js', $out );
 489                         }
 490                 }
 491         }
 492
 493         /* Static Methods */
 494
 495         /**
 496          * Returns JS code to call to mediaWiki.loader.implement for a module with
 497          * given properties.
 498          *
 499          * @param $name Module name
 500          * @param $scripts Array: List of JavaScript code snippets to be executed after the
 501          *     module is loaded
 502          * @param $styles Array: List of CSS strings keyed by media type
 503          * @param $messages Mixed: List of messages associated with this module. May either be an
 504          *     associative array mapping message key to value, or a JSON-encoded message blob containing
 505          *     the same data, wrapped in an XmlJsCode object.
 506          */
 507         public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
 508                 if ( is_array( $scripts ) ) {
 509                         $scripts = implode( $scripts, "\n" );
 510                 }
 511                 return Xml::encodeJsCall(
 512                         'mediaWiki.loader.implement',
 513                         array(
 514                                 $name,
 515                                 new XmlJsCode( "function() {{$scripts}}" ),
 516                                 (object)$styles,
 517                                 (object)$messages
 518                         ) );
 519         }
 520
 521         /**
 522          * Returns JS code which, when called, will register a given list of messages.
 523          *
 524          * @param $messages Mixed: Either an associative array mapping message key to value, or a
 525          *     JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
 526          */
 527         public static function makeMessageSetScript( $messages ) {
 528                 return Xml::encodeJsCall( 'mediaWiki.messages.set', array( (object)$messages ) );
 529         }
 530
 531         /**
 532          * Combines an associative array mapping media type to CSS into a
 533          * single stylesheet with @media blocks.
 534          *
 535          * @param $styles Array: List of CSS strings keyed by media type
 536          */
 537         public static function makeCombinedStyles( array $styles ) {
 538                 $out = '';
 539                 foreach ( $styles as $media => $style ) {
 540                         $out .= "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "\n}\n";
 541                 }
 542                 return $out;
 543         }
 544
 545         /**
 546          * Returns a JS call to mediaWiki.loader.state, which sets the state of a
 547          * module or modules to a given value. Has two calling conventions:
 548          *
 549          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
 550          *         Set the state of a single module called $name to $state
 551          *
 552          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
 553          *         Set the state of modules with the given names to the given states
 554          */
 555         public static function makeLoaderStateScript( $name, $state = null ) {
 556                 if ( is_array( $name ) ) {
 557                         return Xml::encodeJsCall( 'mediaWiki.loader.state', array( $name ) );
 558                 } else {
 559                         return Xml::encodeJsCall( 'mediaWiki.loader.state', array( $name, $state ) );
 560                 }
 561         }
 562
 563         /**
 564          * Returns JS code which calls the script given by $script. The script will
 565          * be called with local variables name, version, dependencies and group,
 566          * which will have values corresponding to $name, $version, $dependencies
 567          * and $group as supplied.
 568          *
 569          * @param $name String: Module name
 570          * @param $version Integer: Module version number as a timestamp
 571          * @param $dependencies Array: List of module names on which this module depends
 572          * @param $group String: Group which the module is in.
 573          * @param $script String: JavaScript code
 574          */
 575         public static function makeCustomLoaderScript( $name, $version, $dependencies, $group, $script ) {
 576                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 577                 return Xml::encodeJsCall(
 578                         "( function( name, version, dependencies, group ) {\n\t$script\n} )",
 579                         array( $name, $version, $dependencies, $group ) );
 580         }
 581
 582         /**
 583          * Returns JS code which calls mediaWiki.loader.register with the given
 584          * parameters. Has three calling conventions:
 585          *
 586          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version, $dependencies, $group ):
 587          *       Register a single module.
 588          *
 589          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
 590          *       Register modules with the given names.
 591          *
 592          *   - ResourceLoader::makeLoaderRegisterScript( array(
 593          *        array( $name1, $version1, $dependencies1, $group1 ),
 594          *        array( $name2, $version2, $dependencies1, $group2 ),
 595          *        ...
 596          *     ) ):
 597          *        Registers modules with the given names and parameters.
 598          *
 599          * @param $name String: Module name
 600          * @param $version Integer: Module version number as a timestamp
 601          * @param $dependencies Array: List of module names on which this module depends
 602          * @param $group String: group which the module is in.
 603          */
 604         public static function makeLoaderRegisterScript( $name, $version = null,
 605                 $dependencies = null, $group = null )
 606         {
 607                 if ( is_array( $name ) ) {
 608                         return Xml::encodeJsCall( 'mediaWiki.loader.register', array( $name ) );
 609                 } else {
 610                         $version = (int) $version > 1 ? (int) $version : 1;
 611                         return Xml::encodeJsCall( 'mediaWiki.loader.register',
 612                                 array( $name, $version, $dependencies, $group ) );
 613                 }
 614         }
 615
 616         /**
 617          * Returns JS code which runs given JS code if the client-side framework is
 618          * present.
 619          *
 620          * @param $script String: JavaScript code
 621          */
 622         public static function makeLoaderConditionalScript( $script ) {
 623                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 624                 return "if ( window.mediaWiki ) {\n\t$script\n}\n";
 625         }
 626
 627         /**
 628          * Returns JS code which will set the MediaWiki configuration array to
 629          * the given value.
 630          *
 631          * @param $configuration Array: List of configuration values keyed by variable name
 632          */
 633         public static function makeConfigSetScript( array $configuration ) {
 634                 return Xml::encodeJsCall( 'mediaWiki.config.set', array( $configuration ) );
 635         }
 636
 637         /**
 638          * Determine whether debug mode was requested
 639          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
 640          * @return bool
 641          */
 642         public static function inDebugMode() {
 643                 global $wgRequest, $wgResourceLoaderDebug;
 644                 static $retval = null;
 645                 if ( !is_null( $retval ) )
 646                         return $retval;
 647                 return $retval = $wgRequest->getFuzzyBool( 'debug',
 648                         $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug ) );
 649         }
 650 }