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          *  - flip-css \see CSSJanus::transform
 115          *
 116          * If $data is empty, only contains whitespace or the filter was unknown,
 117          * $data is returned unmodified.
 118          *
 119          * @param $filter String: Name of filter to run
 120          * @param $data String: Text to filter, such as JavaScript or CSS text
 121          * @return String: Filtered data
 122          */
 123         protected function filter( $filter, $data ) {
 124                 wfProfileIn( __METHOD__ );
 125
 126                 // For empty/whitespace-only data or for unknown filters, don't perform
 127                 // any caching or processing
 128                 if ( trim( $data ) === ''
 129                         || !in_array( $filter, array( 'minify-js', 'minify-css', 'flip-css' ) ) )
 130                 {
 131                         wfProfileOut( __METHOD__ );
 132                         return $data;
 133                 }
 134
 135                 // Try for cache hit
 136                 // Use CACHE_ANYTHING since filtering is very slow compared to DB queries
 137                 $key = wfMemcKey( 'resourceloader', 'filter', $filter, md5( $data ) );
 138                 $cache = wfGetCache( CACHE_ANYTHING );
 139                 $cacheEntry = $cache->get( $key );
 140                 if ( is_string( $cacheEntry ) ) {
 141                         wfProfileOut( __METHOD__ );
 142                         return $cacheEntry;
 143                 }
 144
 145                 // Run the filter - we've already verified one of these will work
 146                 try {
 147                         switch ( $filter ) {
 148                                 case 'minify-js':
 149                                         $result = JSMin::minify( $data );
 150                                         break;
 151                                 case 'minify-css':
 152                                         $result = CSSMin::minify( $data );
 153                                         break;
 154                                 case 'flip-css':
 155                                         $result = CSSJanus::transform( $data, true, false );
 156                                         break;
 157                         }
 158                 } catch ( Exception $exception ) {
 159                         throw new MWException( 'ResourceLoader filter error. ' .
 160                                 'Exception was thrown: ' . $exception->getMessage() );
 161                 }
 162
 163                 // Save filtered text to Memcached
 164                 $cache->set( $key, $result );
 165
 166                 wfProfileOut( __METHOD__ );
 167
 168                 return $result;
 169         }
 170
 171         /* Methods */
 172
 173         /**
 174          * Registers core modules and runs registration hooks.
 175          */
 176         public function __construct() {
 177                 global $IP, $wgResourceModules;
 178
 179                 wfProfileIn( __METHOD__ );
 180
 181                 // Register core modules
 182                 $this->register( include( "$IP/resources/Resources.php" ) );
 183                 // Register extension modules
 184                 wfRunHooks( 'ResourceLoaderRegisterModules', array( &$this ) );
 185                 $this->register( $wgResourceModules );
 186
 187                 wfProfileOut( __METHOD__ );
 188         }
 189
 190         /**
 191          * Registers a module with the ResourceLoader system.
 192          *
 193          * @param $name Mixed: Name of module as a string or List of name/object pairs as an array
 194          * @param $info Module info array. For backwards compatibility with 1.17alpha,
 195          *   this may also be a ResourceLoaderModule object. Optional when using
 196          *   multiple-registration calling style.
 197          * @throws MWException: If a duplicate module registration is attempted
 198          * @throws MWException: If something other than a ResourceLoaderModule is being registered
 199          * @return Boolean: False if there were any errors, in which case one or more modules were not
 200          *     registered
 201          */
 202         public function register( $name, $info = null ) {
 203                 wfProfileIn( __METHOD__ );
 204
 205                 // Allow multiple modules to be registered in one call
 206                 if ( is_array( $name ) ) {
 207                         foreach ( $name as $key => $value ) {
 208                                 $this->register( $key, $value );
 209                         }
 210                         return;
 211                 }
 212
 213                 // Disallow duplicate registrations
 214                 if ( isset( $this->moduleInfos[$name] ) ) {
 215                         // A module has already been registered by this name
 216                         throw new MWException(
 217                                 'ResourceLoader duplicate registration error. ' .
 218                                 'Another module has already been registered as ' . $name
 219                         );
 220                 }
 221
 222                 // Attach module
 223                 if ( is_object( $info ) ) {
 224                         // Old calling convention
 225                         // Validate the input
 226                         if ( !( $info instanceof ResourceLoaderModule ) ) {
 227                                 throw new MWException( 'ResourceLoader invalid module error. ' .
 228                                         'Instances of ResourceLoaderModule expected.' );
 229                         }
 230
 231                         $this->moduleInfos[$name] = array( 'object' => $info );
 232                         $info->setName( $name );
 233                         $this->modules[$name] = $info;
 234                 } else {
 235                         // New calling convention
 236                         $this->moduleInfos[$name] = $info;
 237                 }
 238
 239                 wfProfileOut( __METHOD__ );
 240         }
 241
 242         /**
 243          * Get a list of module names
 244          *
 245          * @return Array: List of module names
 246          */
 247         public function getModuleNames() {
 248                 return array_keys( $this->moduleInfos );
 249         }
 250
 251         /**
 252          * Get the ResourceLoaderModule object for a given module name.
 253          *
 254          * @param $name String: Module name
 255          * @return Mixed: ResourceLoaderModule if module has been registered, null otherwise
 256          */
 257         public function getModule( $name ) {
 258                 if ( !isset( $this->modules[$name] ) ) {
 259                         if ( !isset( $this->moduleInfos[$name] ) ) {
 260                                 // No such module
 261                                 return null;
 262                         }
 263                         // Construct the requested object
 264                         $info = $this->moduleInfos[$name];
 265                         if ( isset( $info['object'] ) ) {
 266                                 // Object given in info array
 267                                 $object = $info['object'];
 268                         } else {
 269                                 if ( !isset( $info['class'] ) ) {
 270                                         $class = 'ResourceLoaderFileModule';
 271                                 } else {
 272                                         $class = $info['class'];
 273                                 }
 274                                 $object = new $class( $info );
 275                         }
 276                         $object->setName( $name );
 277                         $this->modules[$name] = $object;
 278                 }
 279
 280                 return $this->modules[$name];
 281         }
 282
 283         /**
 284          * Outputs a response to a resource load-request, including a content-type header.
 285          *
 286          * @param $context ResourceLoaderContext: Context in which a response should be formed
 287          */
 288         public function respond( ResourceLoaderContext $context ) {
 289                 global $wgResourceLoaderMaxage, $wgCacheEpoch;
 290
 291                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 292                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 293                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 294                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 295                 // the whole thing in our own output buffer to be sure the active buffer
 296                 // doesn't use ob_gzhandler.
 297                 // See http://bugs.php.net/bug.php?id=36514
 298                 ob_start();
 299
 300                 wfProfileIn( __METHOD__ );
 301
 302                 // Split requested modules into two groups, modules and missing
 303                 $modules = array();
 304                 $missing = array();
 305                 foreach ( $context->getModules() as $name ) {
 306                         if ( isset( $this->moduleInfos[$name] ) ) {
 307                                 $modules[$name] = $this->getModule( $name );
 308                         } else {
 309                                 $missing[] = $name;
 310                         }
 311                 }
 312
 313                 // If a version wasn't specified we need a shorter expiry time for updates
 314                 // to propagate to clients quickly
 315                 if ( is_null( $context->getVersion() ) ) {
 316                         $maxage  = $wgResourceLoaderMaxage['unversioned']['client'];
 317                         $smaxage = $wgResourceLoaderMaxage['unversioned']['server'];
 318                 }
 319                 // If a version was specified we can use a longer expiry time since changing
 320                 // version numbers causes cache misses
 321                 else {
 322                         $maxage  = $wgResourceLoaderMaxage['versioned']['client'];
 323                         $smaxage = $wgResourceLoaderMaxage['versioned']['server'];
 324                 }
 325
 326                 // Preload information needed to the mtime calculation below
 327                 $this->preloadModuleInfo( array_keys( $modules ), $context );
 328
 329                 wfProfileIn( __METHOD__.'-getModifiedTime' );
 330
 331                 // To send Last-Modified and support If-Modified-Since, we need to detect
 332                 // the last modified time
 333                 $mtime = wfTimestamp( TS_UNIX, $wgCacheEpoch );
 334                 foreach ( $modules as $module ) {
 335                         // Bypass squid cache if the request includes any private modules
 336                         if ( $module->getGroup() === 'private' ) {
 337                                 $smaxage = 0;
 338                         }
 339                         // Calculate maximum modified time
 340                         $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 341                 }
 342
 343                 wfProfileOut( __METHOD__.'-getModifiedTime' );
 344
 345                 if ( $context->getOnly() === 'styles' ) {
 346                         header( 'Content-Type: text/css' );
 347                 } else {
 348                         header( 'Content-Type: text/javascript' );
 349                 }
 350                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 351                 if ( $context->getDebug() ) {
 352                         header( 'Cache-Control: must-revalidate' );
 353                 } else {
 354                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 355                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, min( $maxage, $smaxage ) + time() ) );
 356                 }
 357
 358                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 359                 // Some clients send "timestamp;length=123". Strip the part after the first ';'
 360                 // so we get a valid timestamp.
 361                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 362                 if ( $ims !== false ) {
 363                         $imsTS = strtok( $ims, ';' );
 364                         if ( $mtime <= wfTimestamp( TS_UNIX, $imsTS ) ) {
 365                                 // There's another bug in ob_gzhandler (see also the comment at
 366                                 // the top of this function) that causes it to gzip even empty
 367                                 // responses, meaning it's impossible to produce a truly empty
 368                                 // response (because the gzip header is always there). This is
 369                                 // a problem because 304 responses have to be completely empty
 370                                 // per the HTTP spec, and Firefox behaves buggily when they're not.
 371                                 // See also http://bugs.php.net/bug.php?id=51579
 372                                 // To work around this, we tear down all output buffering before
 373                                 // sending the 304.
 374                                 while ( ob_get_level() > 0 ) {
 375                                         ob_end_clean();
 376                                 }
 377
 378                                 header( 'HTTP/1.0 304 Not Modified' );
 379                                 header( 'Status: 304 Not Modified' );
 380                                 wfProfileOut( __METHOD__ );
 381                                 return;
 382                         }
 383                 }
 384
 385                 // Generate a response
 386                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 387
 388                 // Capture any PHP warnings from the output buffer and append them to the
 389                 // response in a comment if we're in debug mode.
 390                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 391                         $response .= "/*\n$warnings\n*/";
 392                 }
 393
 394                 // Remove the output buffer and output the response
 395                 ob_end_clean();
 396                 echo $response;
 397
 398                 wfProfileOut( __METHOD__ );
 399         }
 400
 401         /**
 402          * Generates code for a response
 403          *
 404          * @param $context ResourceLoaderContext: Context in which to generate a response
 405          * @param $modules Array: List of module objects keyed by module name
 406          * @param $missing Array: List of unavailable modules (optional)
 407          * @return String: Response data
 408          */
 409         public function makeModuleResponse( ResourceLoaderContext $context,
 410                 array $modules, $missing = array() )
 411         {
 412                 if ( $modules === array() && $missing === array() ) {
 413                         return '/* No modules requested. Max made me put this here */';
 414                 }
 415
 416                 // Pre-fetch blobs
 417                 if ( $context->shouldIncludeMessages() ) {
 418                         $blobs = MessageBlobStore::get( $this, $modules, $context->getLanguage() );
 419                 } else {
 420                         $blobs = array();
 421                 }
 422
 423                 // Generate output
 424                 $out = '';
 425                 foreach ( $modules as $name => $module ) {
 426
 427                         wfProfileIn( __METHOD__ . '-' . $name );
 428
 429                         // Scripts
 430                         $scripts = '';
 431                         if ( $context->shouldIncludeScripts() ) {
 432                                 $scripts .= $module->getScript( $context ) . "\n";
 433                         }
 434
 435                         // Styles
 436                         $styles = array();
 437                         if ( $context->shouldIncludeStyles() ) {
 438                                 $styles = $module->getStyles( $context );
 439                                 // Flip CSS on a per-module basis
 440                                 if ( $styles && $module->getFlip( $context ) ) {
 441                                         foreach ( $styles as $media => $style ) {
 442                                                 $styles[$media] = $this->filter( 'flip-css', $style );
 443                                         }
 444                                 }
 445                         }
 446
 447                         // Messages
 448                         $messagesBlob = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 449
 450                         // Append output
 451                         switch ( $context->getOnly() ) {
 452                                 case 'scripts':
 453                                         $out .= $scripts;
 454                                         break;
 455                                 case 'styles':
 456                                         $out .= self::makeCombinedStyles( $styles );
 457                                         break;
 458                                 case 'messages':
 459                                         $out .= self::makeMessageSetScript( new XmlJsCode( $messagesBlob ) );
 460                                         break;
 461                                 default:
 462                                         // Minify CSS before embedding in mediaWiki.loader.implement call
 463                                         // (unless in debug mode)
 464                                         if ( !$context->getDebug() ) {
 465                                                 foreach ( $styles as $media => $style ) {
 466                                                         $styles[$media] = $this->filter( 'minify-css', $style );
 467                                                 }
 468                                         }
 469                                         $out .= self::makeLoaderImplementScript( $name, $scripts, $styles,
 470                                                 new XmlJsCode( $messagesBlob ) );
 471                                         break;
 472                         }
 473
 474                         wfProfileOut( __METHOD__ . '-' . $name );
 475                 }
 476
 477                 // Update module states
 478                 if ( $context->shouldIncludeScripts() ) {
 479                         // Set the state of modules loaded as only scripts to ready
 480                         if ( count( $modules ) && $context->getOnly() === 'scripts'
 481                                 && !isset( $modules['startup'] ) )
 482                         {
 483                                 $out .= self::makeLoaderStateScript(
 484                                         array_fill_keys( array_keys( $modules ), 'ready' ) );
 485                         }
 486                         // Set the state of modules which were requested but unavailable as missing
 487                         if ( is_array( $missing ) && count( $missing ) ) {
 488                                 $out .= self::makeLoaderStateScript( array_fill_keys( $missing, 'missing' ) );
 489                         }
 490                 }
 491
 492                 if ( $context->getDebug() ) {
 493                         return $out;
 494                 } else {
 495                         if ( $context->getOnly() === 'styles' ) {
 496                                 return $this->filter( 'minify-css', $out );
 497                         } else {
 498                                 return $this->filter( 'minify-js', $out );
 499                         }
 500                 }
 501         }
 502
 503         /* Static Methods */
 504
 505         /**
 506          * Returns JS code to call to mediaWiki.loader.implement for a module with
 507          * given properties.
 508          *
 509          * @param $name Module name
 510          * @param $scripts Array: List of JavaScript code snippets to be executed after the
 511          *     module is loaded
 512          * @param $styles Array: List of CSS strings keyed by media type
 513          * @param $messages Mixed: List of messages associated with this module. May either be an
 514          *     associative array mapping message key to value, or a JSON-encoded message blob containing
 515          *     the same data, wrapped in an XmlJsCode object.
 516          */
 517         public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
 518                 if ( is_array( $scripts ) ) {
 519                         $scripts = implode( $scripts, "\n" );
 520                 }
 521                 return Xml::encodeJsCall(
 522                         'mediaWiki.loader.implement',
 523                         array(
 524                                 $name,
 525                                 new XmlJsCode( "function() {{$scripts}}" ),
 526                                 (object)$styles,
 527                                 (object)$messages
 528                         ) );
 529         }
 530
 531         /**
 532          * Returns JS code which, when called, will register a given list of messages.
 533          *
 534          * @param $messages Mixed: Either an associative array mapping message key to value, or a
 535          *     JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
 536          */
 537         public static function makeMessageSetScript( $messages ) {
 538                 return Xml::encodeJsCall( 'mediaWiki.messages.set', array( (object)$messages ) );
 539         }
 540
 541         /**
 542          * Combines an associative array mapping media type to CSS into a
 543          * single stylesheet with @media blocks.
 544          *
 545          * @param $styles Array: List of CSS strings keyed by media type
 546          */
 547         public static function makeCombinedStyles( array $styles ) {
 548                 $out = '';
 549                 foreach ( $styles as $media => $style ) {
 550                         $out .= "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "\n}\n";
 551                 }
 552                 return $out;
 553         }
 554
 555         /**
 556          * Returns a JS call to mediaWiki.loader.state, which sets the state of a
 557          * module or modules to a given value. Has two calling conventions:
 558          *
 559          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
 560          *         Set the state of a single module called $name to $state
 561          *
 562          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
 563          *         Set the state of modules with the given names to the given states
 564          */
 565         public static function makeLoaderStateScript( $name, $state = null ) {
 566                 if ( is_array( $name ) ) {
 567                         return Xml::encodeJsCall( 'mediaWiki.loader.state', array( $name ) );
 568                 } else {
 569                         return Xml::encodeJsCall( 'mediaWiki.loader.state', array( $name, $state ) );
 570                 }
 571         }
 572
 573         /**
 574          * Returns JS code which calls the script given by $script. The script will
 575          * be called with local variables name, version, dependencies and group,
 576          * which will have values corresponding to $name, $version, $dependencies
 577          * and $group as supplied.
 578          *
 579          * @param $name String: Module name
 580          * @param $version Integer: Module version number as a timestamp
 581          * @param $dependencies Array: List of module names on which this module depends
 582          * @param $group String: Group which the module is in.
 583          * @param $script String: JavaScript code
 584          */
 585         public static function makeCustomLoaderScript( $name, $version, $dependencies, $group, $script ) {
 586                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 587                 return Xml::encodeJsCall(
 588                         "( function( name, version, dependencies, group ) {\n\t$script\n} )",
 589                         array( $name, $version, $dependencies, $group ) );
 590         }
 591
 592         /**
 593          * Returns JS code which calls mediaWiki.loader.register with the given
 594          * parameters. Has three calling conventions:
 595          *
 596          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version, $dependencies, $group ):
 597          *       Register a single module.
 598          *
 599          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
 600          *       Register modules with the given names.
 601          *
 602          *   - ResourceLoader::makeLoaderRegisterScript( array(
 603          *        array( $name1, $version1, $dependencies1, $group1 ),
 604          *        array( $name2, $version2, $dependencies1, $group2 ),
 605          *        ...
 606          *     ) ):
 607          *        Registers modules with the given names and parameters.
 608          *
 609          * @param $name String: Module name
 610          * @param $version Integer: Module version number as a timestamp
 611          * @param $dependencies Array: List of module names on which this module depends
 612          * @param $group String: group which the module is in.
 613          */
 614         public static function makeLoaderRegisterScript( $name, $version = null,
 615                 $dependencies = null, $group = null )
 616         {
 617                 if ( is_array( $name ) ) {
 618                         return Xml::encodeJsCall( 'mediaWiki.loader.register', array( $name ) );
 619                 } else {
 620                         $version = (int) $version > 1 ? (int) $version : 1;
 621                         return Xml::encodeJsCall( 'mediaWiki.loader.register',
 622                                 array( $name, $version, $dependencies, $group ) );
 623                 }
 624         }
 625
 626         /**
 627          * Returns JS code which runs given JS code if the client-side framework is
 628          * present.
 629          *
 630          * @param $script String: JavaScript code
 631          */
 632         public static function makeLoaderConditionalScript( $script ) {
 633                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 634                 return "if ( window.mediaWiki ) {\n\t$script\n}\n";
 635         }
 636
 637         /**
 638          * Returns JS code which will set the MediaWiki configuration array to
 639          * the given value.
 640          *
 641          * @param $configuration Array: List of configuration values keyed by variable name
 642          */
 643         public static function makeConfigSetScript( array $configuration ) {
 644                 return Xml::encodeJsCall( 'mediaWiki.config.set', array( $configuration ) );
 645         }
 646
 647         /**
 648          * Determine whether debug mode was requested
 649          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
 650          * @return bool
 651          */
 652         public static function inDebugMode() {
 653                 global $wgRequest, $wgResourceLoaderDebug;
 654                 static $retval = null;
 655                 if ( !is_null( $retval ) )
 656                         return $retval;
 657                 return $retval = $wgRequest->getFuzzyBool( 'debug',
 658                         $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug ) );
 659         }
 660 }