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         public 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' dependencies
  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                 foreach ( $modules as $name ) {
  86                         if ( count( $this->getModule( $name )->getMessages() ) ) {
  87                                 $modulesWithMessages[] = $name;
  88                         }
  89                 }
  90                 $modulesWithoutMessages = array_flip( $modules ); // Will be trimmed down by the loop below
  91                 if ( count( $modulesWithMessages ) ) {
  92                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
  93                                         'mr_resource' => $modulesWithMessages,
  94                                         'mr_lang' => $lang
  95                                 ), __METHOD__
  96                         );
  97                         foreach ( $res as $row ) {
  98                                 $this->getModule( $row->mr_resource )->setMsgBlobMtime( $lang, $row->mr_timestamp );
  99                                 unset( $modulesWithoutMessages[$row->mr_resource] );
 100                         }
 101                 }
 102                 foreach ( array_keys( $modulesWithoutMessages ) as $name ) {
 103                         $this->getModule( $name )->setMsgBlobMtime( $lang, 0 );
 104                 }
 105         }
 106
 107         /**
 108          * Runs JavaScript or CSS data through a filter, caching the filtered result for future calls.
 109          *
 110          * Available filters are:
 111          *  - minify-js \see JavaScriptDistiller::stripWhiteSpace
 112          *  - minify-css \see CSSMin::minify
 113          *
 114          * If $data is empty, only contains whitespace or the filter was unknown,
 115          * $data is returned unmodified.
 116          *
 117          * @param $filter String: Name of filter to run
 118          * @param $data String: Text to filter, such as JavaScript or CSS text
 119          * @return String: Filtered data, or a comment containing an error message
 120          */
 121         protected function filter( $filter, $data ) {
 122                 global $wgResourceLoaderMinifyJSVerticalSpace;
 123
 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' ) ) )
 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 = JavaScriptDistiller::stripWhiteSpace(
 150                                                 $data, $wgResourceLoaderMinifyJSVerticalSpace
 151                                         );
 152                                         break;
 153                                 case 'minify-css':
 154                                         $result = CSSMin::minify( $data );
 155                                         break;
 156                         }
 157
 158                         // Save filtered text to Memcached
 159                         $cache->set( $key, $result );
 160                 } catch ( Exception $exception ) {
 161                         // Return exception as a comment
 162                         $result = "/*\n{$exception->__toString()}\n*/\n";
 163                 }
 164
 165                 wfProfileOut( __METHOD__ );
 166
 167                 return $result;
 168         }
 169
 170         /* Methods */
 171
 172         /**
 173          * Registers core modules and runs registration hooks.
 174          */
 175         public function __construct() {
 176                 global $IP, $wgResourceModules;
 177
 178                 wfProfileIn( __METHOD__ );
 179
 180                 // Register core modules
 181                 $this->register( include( "$IP/resources/Resources.php" ) );
 182                 // Register extension modules
 183                 wfRunHooks( 'ResourceLoaderRegisterModules', array( &$this ) );
 184                 $this->register( $wgResourceModules );
 185
 186                 wfProfileOut( __METHOD__ );
 187         }
 188
 189         /**
 190          * Registers a module with the ResourceLoader system.
 191          *
 192          * @param $name Mixed: Name of module as a string or List of name/object pairs as an array
 193          * @param $info Module info array. For backwards compatibility with 1.17alpha,
 194          *   this may also be a ResourceLoaderModule object. Optional when using
 195          *   multiple-registration calling style.
 196          * @throws MWException: If a duplicate module registration is attempted
 197          * @throws MWException: If something other than a ResourceLoaderModule is being registered
 198          * @return Boolean: False if there were any errors, in which case one or more modules were not
 199          *     registered
 200          */
 201         public function register( $name, $info = null ) {
 202                 wfProfileIn( __METHOD__ );
 203
 204                 // Allow multiple modules to be registered in one call
 205                 if ( is_array( $name ) ) {
 206                         foreach ( $name as $key => $value ) {
 207                                 $this->register( $key, $value );
 208                         }
 209                         return;
 210                 }
 211
 212                 // Disallow duplicate registrations
 213                 if ( isset( $this->moduleInfos[$name] ) ) {
 214                         // A module has already been registered by this name
 215                         throw new MWException(
 216                                 'ResourceLoader duplicate registration error. ' .
 217                                 'Another module has already been registered as ' . $name
 218                         );
 219                 }
 220
 221                 // Attach module
 222                 if ( is_object( $info ) ) {
 223                         // Old calling convention
 224                         // Validate the input
 225                         if ( !( $info instanceof ResourceLoaderModule ) ) {
 226                                 throw new MWException( 'ResourceLoader invalid module error. ' .
 227                                         'Instances of ResourceLoaderModule expected.' );
 228                         }
 229
 230                         $this->moduleInfos[$name] = array( 'object' => $info );
 231                         $info->setName( $name );
 232                         $this->modules[$name] = $info;
 233                 } else {
 234                         // New calling convention
 235                         $this->moduleInfos[$name] = $info;
 236                 }
 237
 238                 wfProfileOut( __METHOD__ );
 239         }
 240
 241         /**
 242          * Get a list of module names
 243          *
 244          * @return Array: List of module names
 245          */
 246         public function getModuleNames() {
 247                 return array_keys( $this->moduleInfos );
 248         }
 249
 250         /**
 251          * Get the ResourceLoaderModule object for a given module name.
 252          *
 253          * @param $name String: Module name
 254          * @return Mixed: ResourceLoaderModule if module has been registered, null otherwise
 255          */
 256         public function getModule( $name ) {
 257                 if ( !isset( $this->modules[$name] ) ) {
 258                         if ( !isset( $this->moduleInfos[$name] ) ) {
 259                                 // No such module
 260                                 return null;
 261                         }
 262                         // Construct the requested object
 263                         $info = $this->moduleInfos[$name];
 264                         if ( isset( $info['object'] ) ) {
 265                                 // Object given in info array
 266                                 $object = $info['object'];
 267                         } else {
 268                                 if ( !isset( $info['class'] ) ) {
 269                                         $class = 'ResourceLoaderFileModule';
 270                                 } else {
 271                                         $class = $info['class'];
 272                                 }
 273                                 $object = new $class( $info );
 274                         }
 275                         $object->setName( $name );
 276                         $this->modules[$name] = $object;
 277                 }
 278
 279                 return $this->modules[$name];
 280         }
 281
 282         /**
 283          * Outputs a response to a resource load-request, including a content-type header.
 284          *
 285          * @param $context ResourceLoaderContext: Context in which a response should be formed
 286          */
 287         public function respond( ResourceLoaderContext $context ) {
 288                 global $wgResourceLoaderMaxage, $wgCacheEpoch;
 289
 290                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 291                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 292                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 293                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 294                 // the whole thing in our own output buffer to be sure the active buffer
 295                 // doesn't use ob_gzhandler.
 296                 // See http://bugs.php.net/bug.php?id=36514
 297                 ob_start();
 298
 299                 wfProfileIn( __METHOD__ );
 300                 $exceptions = '';
 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                 try {
 328                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 329                 } catch( Exception $e ) {
 330                         // Add exception to the output as a comment
 331                         $exceptions .= "/*\n{$e->__toString()}\n*/\n";
 332                 }
 333
 334                 wfProfileIn( __METHOD__.'-getModifiedTime' );
 335
 336                 $private = false;
 337                 // To send Last-Modified and support If-Modified-Since, we need to detect
 338                 // the last modified time
 339                 $mtime = wfTimestamp( TS_UNIX, $wgCacheEpoch );
 340                 foreach ( $modules as $module ) {
 341                         try {
 342                                 // Bypass Squid and other shared caches if the request includes any private modules
 343                                 if ( $module->getGroup() === 'private' ) {
 344                                         $private = true;
 345                                 }
 346                                 // Calculate maximum modified time
 347                                 $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 348                         } catch ( Exception $e ) {
 349                                 // Add exception to the output as a comment
 350                                 $exceptions .= "/*\n{$e->__toString()}\n*/\n";
 351                         }
 352                 }
 353
 354                 wfProfileOut( __METHOD__.'-getModifiedTime' );
 355
 356                 if ( $context->getOnly() === 'styles' ) {
 357                         header( 'Content-Type: text/css' );
 358                 } else {
 359                         header( 'Content-Type: text/javascript' );
 360                 }
 361                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 362                 if ( $context->getDebug() ) {
 363                         // Do not cache debug responses
 364                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 365                         header( 'Pragma: no-cache' );
 366                 } else {
 367                         if ( $private ) {
 368                                 header( "Cache-Control: private, max-age=$maxage" );
 369                                 $exp = $maxage;
 370                         } else {
 371                                 header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 372                                 $exp = min( $maxage, $smaxage );
 373                         }
 374                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 375                 }
 376
 377                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 378                 // Some clients send "timestamp;length=123". Strip the part after the first ';'
 379                 // so we get a valid timestamp.
 380                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 381                 if ( $ims !== false ) {
 382                         $imsTS = strtok( $ims, ';' );
 383                         if ( $mtime <= wfTimestamp( TS_UNIX, $imsTS ) ) {
 384                                 // There's another bug in ob_gzhandler (see also the comment at
 385                                 // the top of this function) that causes it to gzip even empty
 386                                 // responses, meaning it's impossible to produce a truly empty
 387                                 // response (because the gzip header is always there). This is
 388                                 // a problem because 304 responses have to be completely empty
 389                                 // per the HTTP spec, and Firefox behaves buggily when they're not.
 390                                 // See also http://bugs.php.net/bug.php?id=51579
 391                                 // To work around this, we tear down all output buffering before
 392                                 // sending the 304.
 393                                 // On some setups, ob_get_level() doesn't seem to go down to zero
 394                                 // no matter how often we call ob_get_clean(), so instead of doing
 395                                 // the more intuitive while ( ob_get_level() > 0 ) ob_get_clean();
 396                                 // we have to be safe here and avoid an infinite loop.
 397                                 for ( $i = 0; $i < ob_get_level(); $i++ ) {
 398                                         ob_end_clean();
 399                                 }
 400
 401                                 header( 'HTTP/1.0 304 Not Modified' );
 402                                 header( 'Status: 304 Not Modified' );
 403                                 wfProfileOut( __METHOD__ );
 404                                 return;
 405                         }
 406                 }
 407
 408                 // Generate a response
 409                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 410
 411                 // Prepend comments indicating exceptions
 412                 $response = $exceptions . $response;
 413
 414                 // Capture any PHP warnings from the output buffer and append them to the
 415                 // response in a comment if we're in debug mode.
 416                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 417                         $response = "/*\n$warnings\n*/\n" . $response;
 418                 }
 419
 420                 // Remove the output buffer and output the response
 421                 ob_end_clean();
 422                 echo $response;
 423
 424                 wfProfileOut( __METHOD__ );
 425         }
 426
 427         /**
 428          * Generates code for a response
 429          *
 430          * @param $context ResourceLoaderContext: Context in which to generate a response
 431          * @param $modules Array: List of module objects keyed by module name
 432          * @param $missing Array: List of unavailable modules (optional)
 433          * @return String: Response data
 434          */
 435         public function makeModuleResponse( ResourceLoaderContext $context,
 436                 array $modules, $missing = array() )
 437         {
 438                 $out = '';
 439                 $exceptions = '';
 440                 if ( $modules === array() && $missing === array() ) {
 441                         return '/* No modules requested. Max made me put this here */';
 442                 }
 443
 444                 // Pre-fetch blobs
 445                 if ( $context->shouldIncludeMessages() ) {
 446                         try {
 447                                 $blobs = MessageBlobStore::get( $this, $modules, $context->getLanguage() );
 448                         } catch ( Exception $e ) {
 449                                 // Add exception to the output as a comment
 450                                 $exceptions .= "/*\n{$e->__toString()}\n*/\n";
 451                         }
 452                 } else {
 453                         $blobs = array();
 454                 }
 455
 456                 // Generate output
 457                 foreach ( $modules as $name => $module ) {
 458                         wfProfileIn( __METHOD__ . '-' . $name );
 459                         try {
 460                                 // Scripts
 461                                 $scripts = '';
 462                                 if ( $context->shouldIncludeScripts() ) {
 463                                         $scripts .= $module->getScript( $context ) . "\n";
 464                                 }
 465
 466                                 // Styles
 467                                 $styles = array();
 468                                 if ( $context->shouldIncludeStyles() ) {
 469                                         $styles = $module->getStyles( $context );
 470                                 }
 471
 472                                 // Messages
 473                                 $messagesBlob = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 474
 475                                 // Append output
 476                                 switch ( $context->getOnly() ) {
 477                                         case 'scripts':
 478                                                 $out .= $scripts;
 479                                                 break;
 480                                         case 'styles':
 481                                                 $out .= self::makeCombinedStyles( $styles );
 482                                                 break;
 483                                         case 'messages':
 484                                                 $out .= self::makeMessageSetScript( new XmlJsCode( $messagesBlob ) );
 485                                                 break;
 486                                         default:
 487                                                 // Minify CSS before embedding in mediaWiki.loader.implement call
 488                                                 // (unless in debug mode)
 489                                                 if ( !$context->getDebug() ) {
 490                                                         foreach ( $styles as $media => $style ) {
 491                                                                 $styles[$media] = $this->filter( 'minify-css', $style );
 492                                                         }
 493                                                 }
 494                                                 $out .= self::makeLoaderImplementScript( $name, $scripts, $styles,
 495                                                         new XmlJsCode( $messagesBlob ) );
 496                                                 break;
 497                                 }
 498                         } catch ( Exception $e ) {
 499                                 // Add exception to the output as a comment
 500                                 $exceptions .= "/*\n{$e->__toString()}\n*/\n";
 501
 502                                 // Register module as missing
 503                                 $missing[] = $name;
 504                                 unset( $modules[$name] );
 505                         }
 506                         wfProfileOut( __METHOD__ . '-' . $name );
 507                 }
 508
 509                 // Update module states
 510                 if ( $context->shouldIncludeScripts() ) {
 511                         // Set the state of modules loaded as only scripts to ready
 512                         if ( count( $modules ) && $context->getOnly() === 'scripts'
 513                                 && !isset( $modules['startup'] ) )
 514                         {
 515                                 $out .= self::makeLoaderStateScript(
 516                                         array_fill_keys( array_keys( $modules ), 'ready' ) );
 517                         }
 518                         // Set the state of modules which were requested but unavailable as missing
 519                         if ( is_array( $missing ) && count( $missing ) ) {
 520                                 $out .= self::makeLoaderStateScript( array_fill_keys( $missing, 'missing' ) );
 521                         }
 522                 }
 523
 524                 if ( $context->getDebug() ) {
 525                         return $exceptions . $out;
 526                 } else {
 527                         if ( $context->getOnly() === 'styles' ) {
 528                                 return $exceptions . $this->filter( 'minify-css', $out );
 529                         } else {
 530                                 return $exceptions . $this->filter( 'minify-js', $out );
 531                         }
 532                 }
 533         }
 534
 535         /* Static Methods */
 536
 537         /**
 538          * Returns JS code to call to mediaWiki.loader.implement for a module with
 539          * given properties.
 540          *
 541          * @param $name Module name
 542          * @param $scripts Array: List of JavaScript code snippets to be executed after the
 543          *     module is loaded
 544          * @param $styles Array: List of CSS strings keyed by media type
 545          * @param $messages Mixed: List of messages associated with this module. May either be an
 546          *     associative array mapping message key to value, or a JSON-encoded message blob containing
 547          *     the same data, wrapped in an XmlJsCode object.
 548          */
 549         public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
 550                 if ( is_array( $scripts ) ) {
 551                         $scripts = implode( $scripts, "\n" );
 552                 }
 553                 return Xml::encodeJsCall(
 554                         'mediaWiki.loader.implement',
 555                         array(
 556                                 $name,
 557                                 new XmlJsCode( "function( $, mw ) {{$scripts}}" ),
 558                                 (object)$styles,
 559                                 (object)$messages
 560                         ) );
 561         }
 562
 563         /**
 564          * Returns JS code which, when called, will register a given list of messages.
 565          *
 566          * @param $messages Mixed: Either an associative array mapping message key to value, or a
 567          *     JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
 568          */
 569         public static function makeMessageSetScript( $messages ) {
 570                 return Xml::encodeJsCall( 'mediaWiki.messages.set', array( (object)$messages ) );
 571         }
 572
 573         /**
 574          * Combines an associative array mapping media type to CSS into a
 575          * single stylesheet with @media blocks.
 576          *
 577          * @param $styles Array: List of CSS strings keyed by media type
 578          */
 579         public static function makeCombinedStyles( array $styles ) {
 580                 $out = '';
 581                 foreach ( $styles as $media => $style ) {
 582                         // Transform the media type based on request params and config
 583                         // The way that this relies on $wgRequest to propagate request params is slightly evil
 584                         $media = OutputPage::transformCssMedia( $media );
 585
 586                         if ( $media === null ) {
 587                                 // Skip
 588                         } else if ( $media === '' || $media == 'all' ) {
 589                                 // Don't output invalid or frivolous @media statements
 590                                 $out .= "$style\n";
 591                         } else {
 592                                 $out .= "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "\n}\n";
 593                         }
 594                 }
 595                 return $out;
 596         }
 597
 598         /**
 599          * Returns a JS call to mediaWiki.loader.state, which sets the state of a
 600          * module or modules to a given value. Has two calling conventions:
 601          *
 602          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
 603          *         Set the state of a single module called $name to $state
 604          *
 605          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
 606          *         Set the state of modules with the given names to the given states
 607          */
 608         public static function makeLoaderStateScript( $name, $state = null ) {
 609                 if ( is_array( $name ) ) {
 610                         return Xml::encodeJsCall( 'mediaWiki.loader.state', array( $name ) );
 611                 } else {
 612                         return Xml::encodeJsCall( 'mediaWiki.loader.state', array( $name, $state ) );
 613                 }
 614         }
 615
 616         /**
 617          * Returns JS code which calls the script given by $script. The script will
 618          * be called with local variables name, version, dependencies and group,
 619          * which will have values corresponding to $name, $version, $dependencies
 620          * and $group as supplied.
 621          *
 622          * @param $name String: Module name
 623          * @param $version Integer: Module version number as a timestamp
 624          * @param $dependencies Array: List of module names on which this module depends
 625          * @param $group String: Group which the module is in.
 626          * @param $script String: JavaScript code
 627          */
 628         public static function makeCustomLoaderScript( $name, $version, $dependencies, $group, $script ) {
 629                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 630                 return Xml::encodeJsCall(
 631                         "( function( name, version, dependencies, group ) {\n\t$script\n} )",
 632                         array( $name, $version, $dependencies, $group ) );
 633         }
 634
 635         /**
 636          * Returns JS code which calls mediaWiki.loader.register with the given
 637          * parameters. Has three calling conventions:
 638          *
 639          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version, $dependencies, $group ):
 640          *       Register a single module.
 641          *
 642          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
 643          *       Register modules with the given names.
 644          *
 645          *   - ResourceLoader::makeLoaderRegisterScript( array(
 646          *        array( $name1, $version1, $dependencies1, $group1 ),
 647          *        array( $name2, $version2, $dependencies1, $group2 ),
 648          *        ...
 649          *     ) ):
 650          *        Registers modules with the given names and parameters.
 651          *
 652          * @param $name String: Module name
 653          * @param $version Integer: Module version number as a timestamp
 654          * @param $dependencies Array: List of module names on which this module depends
 655          * @param $group String: group which the module is in.
 656          */
 657         public static function makeLoaderRegisterScript( $name, $version = null,
 658                 $dependencies = null, $group = null )
 659         {
 660                 if ( is_array( $name ) ) {
 661                         return Xml::encodeJsCall( 'mediaWiki.loader.register', array( $name ) );
 662                 } else {
 663                         $version = (int) $version > 1 ? (int) $version : 1;
 664                         return Xml::encodeJsCall( 'mediaWiki.loader.register',
 665                                 array( $name, $version, $dependencies, $group ) );
 666                 }
 667         }
 668
 669         /**
 670          * Returns JS code which runs given JS code if the client-side framework is
 671          * present.
 672          *
 673          * @param $script String: JavaScript code
 674          */
 675         public static function makeLoaderConditionalScript( $script ) {
 676                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 677                 return "if ( window.mediaWiki ) {\n\t$script\n}\n";
 678         }
 679
 680         /**
 681          * Returns JS code which will set the MediaWiki configuration array to
 682          * the given value.
 683          *
 684          * @param $configuration Array: List of configuration values keyed by variable name
 685          */
 686         public static function makeConfigSetScript( array $configuration ) {
 687                 return Xml::encodeJsCall( 'mediaWiki.config.set', array( $configuration ) );
 688         }
 689
 690         /**
 691          * Determine whether debug mode was requested
 692          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
 693          * @return bool
 694          */
 695         public static function inDebugMode() {
 696                 global $wgRequest, $wgResourceLoaderDebug;
 697                 static $retval = null;
 698                 if ( !is_null( $retval ) )
 699                         return $retval;
 700                 return $retval = $wgRequest->getFuzzyBool( 'debug',
 701                         $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug ) );
 702         }
 703 }