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         protected static $filterCacheVersion = 4;
  33
  34         /** Array: List of module name/ResourceLoaderModule object pairs */
  35         protected $modules = array();
  36         /** Associative array mapping module name to info associative array */
  37         protected $moduleInfos = array();
  38
  39         /* Protected Methods */
  40
  41         /**
  42          * Loads information stored in the database about modules.
  43          *
  44          * This method grabs modules dependencies from the database and updates modules
  45          * objects.
  46          *
  47          * This is not inside the module code because it is much faster to
  48          * request all of the information at once than it is to have each module
  49          * requests its own information. This sacrifice of modularity yields a substantial
  50          * performance improvement.
  51          *
  52          * @param $modules Array: List of module names to preload information for
  53          * @param $context ResourceLoaderContext: Context to load the information within
  54          */
  55         public function preloadModuleInfo( array $modules, ResourceLoaderContext $context ) {
  56                 if ( !count( $modules ) ) {
  57                         return; // or else Database*::select() will explode, plus it's cheaper!
  58                 }
  59                 $dbr = wfGetDB( DB_SLAVE );
  60                 $skin = $context->getSkin();
  61                 $lang = $context->getLanguage();
  62
  63                 // Get file dependency information
  64                 $res = $dbr->select( 'module_deps', array( 'md_module', 'md_deps' ), array(
  65                                 'md_module' => $modules,
  66                                 'md_skin' => $context->getSkin()
  67                         ), __METHOD__
  68                 );
  69
  70                 // Set modules' dependencies
  71                 $modulesWithDeps = array();
  72                 foreach ( $res as $row ) {
  73                         $this->getModule( $row->md_module )->setFileDependencies( $skin,
  74                                 FormatJson::decode( $row->md_deps, true )
  75                         );
  76                         $modulesWithDeps[] = $row->md_module;
  77                 }
  78
  79                 // Register the absence of a dependency row too
  80                 foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
  81                         $this->getModule( $name )->setFileDependencies( $skin, array() );
  82                 }
  83
  84                 // Get message blob mtimes. Only do this for modules with messages
  85                 $modulesWithMessages = array();
  86                 foreach ( $modules as $name ) {
  87                         if ( count( $this->getModule( $name )->getMessages() ) ) {
  88                                 $modulesWithMessages[] = $name;
  89                         }
  90                 }
  91                 $modulesWithoutMessages = array_flip( $modules ); // Will be trimmed down by the loop below
  92                 if ( count( $modulesWithMessages ) ) {
  93                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
  94                                         'mr_resource' => $modulesWithMessages,
  95                                         'mr_lang' => $lang
  96                                 ), __METHOD__
  97                         );
  98                         foreach ( $res as $row ) {
  99                                 $this->getModule( $row->mr_resource )->setMsgBlobMtime( $lang,
 100                                         wfTimestamp( TS_UNIX, $row->mr_timestamp ) );
 101                                 unset( $modulesWithoutMessages[$row->mr_resource] );
 102                         }
 103                 }
 104                 foreach ( array_keys( $modulesWithoutMessages ) as $name ) {
 105                         $this->getModule( $name )->setMsgBlobMtime( $lang, 0 );
 106                 }
 107         }
 108
 109         /**
 110          * Runs JavaScript or CSS data through a filter, caching the filtered result for future calls.
 111          *
 112          * Available filters are:
 113          *  - minify-js \see JavaScriptMinifier::minify
 114          *  - minify-css \see CSSMin::minify
 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, or a comment containing an error message
 122          */
 123         protected function filter( $filter, $data ) {
 124                 global $wgResourceLoaderMinifierStatementsOnOwnLine, $wgResourceLoaderMinifierMaxLineLength;
 125                 wfProfileIn( __METHOD__ );
 126
 127                 // For empty/whitespace-only data or for unknown filters, don't perform
 128                 // any caching or processing
 129                 if ( trim( $data ) === ''
 130                         || !in_array( $filter, array( 'minify-js', 'minify-css' ) ) )
 131                 {
 132                         wfProfileOut( __METHOD__ );
 133                         return $data;
 134                 }
 135
 136                 // Try for cache hit
 137                 // Use CACHE_ANYTHING since filtering is very slow compared to DB queries
 138                 $key = wfMemcKey( 'resourceloader', 'filter', $filter, self::$filterCacheVersion, md5( $data ) );
 139                 $cache = wfGetCache( CACHE_ANYTHING );
 140                 $cacheEntry = $cache->get( $key );
 141                 if ( is_string( $cacheEntry ) ) {
 142                         wfProfileOut( __METHOD__ );
 143                         return $cacheEntry;
 144                 }
 145
 146                 $result = '';
 147                 // Run the filter - we've already verified one of these will work
 148                 try {
 149                         switch ( $filter ) {
 150                                 case 'minify-js':
 151                                         $result = JavaScriptMinifier::minify( $data,
 152                                                 $wgResourceLoaderMinifierStatementsOnOwnLine,
 153                                                 $wgResourceLoaderMinifierMaxLineLength
 154                                         );
 155                                         $result .= "\n\n/* cache key: $key */\n";
 156                                         break;
 157                                 case 'minify-css':
 158                                         $result = CSSMin::minify( $data );
 159                                         $result .= "\n\n/* cache key: $key */\n";
 160                                         break;
 161                         }
 162
 163                         // Save filtered text to Memcached
 164                         $cache->set( $key, $result );
 165                 } catch ( Exception $exception ) {
 166                         // Return exception as a comment
 167                         $result = "/*\n{$exception->__toString()}\n*/\n";
 168                 }
 169
 170                 wfProfileOut( __METHOD__ );
 171
 172                 return $result;
 173         }
 174
 175         /* Methods */
 176
 177         /**
 178          * Registers core modules and runs registration hooks.
 179          */
 180         public function __construct() {
 181                 global $IP, $wgResourceModules;
 182
 183                 wfProfileIn( __METHOD__ );
 184
 185                 // Register core modules
 186                 $this->register( include( "$IP/resources/Resources.php" ) );
 187                 // Register extension modules
 188                 wfRunHooks( 'ResourceLoaderRegisterModules', array( &$this ) );
 189                 $this->register( $wgResourceModules );
 190
 191                 wfProfileOut( __METHOD__ );
 192         }
 193
 194         /**
 195          * Registers a module with the ResourceLoader system.
 196          *
 197          * @param $name Mixed: Name of module as a string or List of name/object pairs as an array
 198          * @param $info Module info array. For backwards compatibility with 1.17alpha,
 199          *   this may also be a ResourceLoaderModule object. Optional when using
 200          *   multiple-registration calling style.
 201          * @throws MWException: If a duplicate module registration is attempted
 202          * @throws MWException: If something other than a ResourceLoaderModule is being registered
 203          * @return Boolean: False if there were any errors, in which case one or more modules were not
 204          *     registered
 205          */
 206         public function register( $name, $info = null ) {
 207                 wfProfileIn( __METHOD__ );
 208
 209                 // Allow multiple modules to be registered in one call
 210                 if ( is_array( $name ) ) {
 211                         foreach ( $name as $key => $value ) {
 212                                 $this->register( $key, $value );
 213                         }
 214                         wfProfileOut( __METHOD__ );
 215                         return;
 216                 }
 217
 218                 // Disallow duplicate registrations
 219                 if ( isset( $this->moduleInfos[$name] ) ) {
 220                         // A module has already been registered by this name
 221                         throw new MWException(
 222                                 'ResourceLoader duplicate registration error. ' .
 223                                 'Another module has already been registered as ' . $name
 224                         );
 225                 }
 226
 227                 // Attach module
 228                 if ( is_object( $info ) ) {
 229                         // Old calling convention
 230                         // Validate the input
 231                         if ( !( $info instanceof ResourceLoaderModule ) ) {
 232                                 throw new MWException( 'ResourceLoader invalid module error. ' .
 233                                         'Instances of ResourceLoaderModule expected.' );
 234                         }
 235
 236                         $this->moduleInfos[$name] = array( 'object' => $info );
 237                         $info->setName( $name );
 238                         $this->modules[$name] = $info;
 239                 } else {
 240                         // New calling convention
 241                         $this->moduleInfos[$name] = $info;
 242                 }
 243
 244                 wfProfileOut( __METHOD__ );
 245         }
 246
 247         /**
 248          * Get a list of module names
 249          *
 250          * @return Array: List of module names
 251          */
 252         public function getModuleNames() {
 253                 return array_keys( $this->moduleInfos );
 254         }
 255
 256         /**
 257          * Get the ResourceLoaderModule object for a given module name.
 258          *
 259          * @param $name String: Module name
 260          * @return ResourceLoaderModule if module has been registered, null otherwise
 261          */
 262         public function getModule( $name ) {
 263                 if ( !isset( $this->modules[$name] ) ) {
 264                         if ( !isset( $this->moduleInfos[$name] ) ) {
 265                                 // No such module
 266                                 return null;
 267                         }
 268                         // Construct the requested object
 269                         $info = $this->moduleInfos[$name];
 270                         if ( isset( $info['object'] ) ) {
 271                                 // Object given in info array
 272                                 $object = $info['object'];
 273                         } else {
 274                                 if ( !isset( $info['class'] ) ) {
 275                                         $class = 'ResourceLoaderFileModule';
 276                                 } else {
 277                                         $class = $info['class'];
 278                                 }
 279                                 $object = new $class( $info );
 280                         }
 281                         $object->setName( $name );
 282                         $this->modules[$name] = $object;
 283                 }
 284
 285                 return $this->modules[$name];
 286         }
 287
 288         /**
 289          * Outputs a response to a resource load-request, including a content-type header.
 290          *
 291          * @param $context ResourceLoaderContext: Context in which a response should be formed
 292          */
 293         public function respond( ResourceLoaderContext $context ) {
 294                 global $wgResourceLoaderMaxage, $wgCacheEpoch;
 295
 296                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 297                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 298                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 299                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 300                 // the whole thing in our own output buffer to be sure the active buffer
 301                 // doesn't use ob_gzhandler.
 302                 // See http://bugs.php.net/bug.php?id=36514
 303                 ob_start();
 304
 305                 wfProfileIn( __METHOD__ );
 306                 $exceptions = '';
 307
 308                 // Split requested modules into two groups, modules and missing
 309                 $modules = array();
 310                 $missing = array();
 311                 foreach ( $context->getModules() as $name ) {
 312                         if ( isset( $this->moduleInfos[$name] ) ) {
 313                                 $modules[$name] = $this->getModule( $name );
 314                         } else {
 315                                 $missing[] = $name;
 316                         }
 317                 }
 318
 319                 // If a version wasn't specified we need a shorter expiry time for updates
 320                 // to propagate to clients quickly
 321                 if ( is_null( $context->getVersion() ) ) {
 322                         $maxage  = $wgResourceLoaderMaxage['unversioned']['client'];
 323                         $smaxage = $wgResourceLoaderMaxage['unversioned']['server'];
 324                 }
 325                 // If a version was specified we can use a longer expiry time since changing
 326                 // version numbers causes cache misses
 327                 else {
 328                         $maxage  = $wgResourceLoaderMaxage['versioned']['client'];
 329                         $smaxage = $wgResourceLoaderMaxage['versioned']['server'];
 330                 }
 331
 332                 // Preload information needed to the mtime calculation below
 333                 try {
 334                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 335                 } catch( Exception $e ) {
 336                         // Add exception to the output as a comment
 337                         $exceptions .= "/*\n{$e->__toString()}\n*/\n";
 338                 }
 339
 340                 wfProfileIn( __METHOD__.'-getModifiedTime' );
 341
 342                 $private = false;
 343                 // To send Last-Modified and support If-Modified-Since, we need to detect
 344                 // the last modified time
 345                 $mtime = wfTimestamp( TS_UNIX, $wgCacheEpoch );
 346                 foreach ( $modules as $module ) {
 347                         try {
 348                                 // Bypass Squid and other shared caches if the request includes any private modules
 349                                 if ( $module->getGroup() === 'private' ) {
 350                                         $private = true;
 351                                 }
 352                                 // Calculate maximum modified time
 353                                 $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 354                         } catch ( Exception $e ) {
 355                                 // Add exception to the output as a comment
 356                                 $exceptions .= "/*\n{$e->__toString()}\n*/\n";
 357                         }
 358                 }
 359
 360                 wfProfileOut( __METHOD__.'-getModifiedTime' );
 361
 362                 if ( $context->getOnly() === 'styles' ) {
 363                         header( 'Content-Type: text/css; charset=utf-8' );
 364                 } else {
 365                         header( 'Content-Type: text/javascript; charset=utf-8' );
 366                 }
 367                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 368                 if ( $context->getDebug() ) {
 369                         // Do not cache debug responses
 370                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 371                         header( 'Pragma: no-cache' );
 372                 } else {
 373                         if ( $private ) {
 374                                 header( "Cache-Control: private, max-age=$maxage" );
 375                                 $exp = $maxage;
 376                         } else {
 377                                 header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 378                                 $exp = min( $maxage, $smaxage );
 379                         }
 380                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 381                 }
 382
 383                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 384                 // Some clients send "timestamp;length=123". Strip the part after the first ';'
 385                 // so we get a valid timestamp.
 386                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 387                 // Never send 304s in debug mode
 388                 if ( $ims !== false && !$context->getDebug() ) {
 389                         $imsTS = strtok( $ims, ';' );
 390                         if ( $mtime <= wfTimestamp( TS_UNIX, $imsTS ) ) {
 391                                 // There's another bug in ob_gzhandler (see also the comment at
 392                                 // the top of this function) that causes it to gzip even empty
 393                                 // responses, meaning it's impossible to produce a truly empty
 394                                 // response (because the gzip header is always there). This is
 395                                 // a problem because 304 responses have to be completely empty
 396                                 // per the HTTP spec, and Firefox behaves buggily when they're not.
 397                                 // See also http://bugs.php.net/bug.php?id=51579
 398                                 // To work around this, we tear down all output buffering before
 399                                 // sending the 304.
 400                                 // On some setups, ob_get_level() doesn't seem to go down to zero
 401                                 // no matter how often we call ob_get_clean(), so instead of doing
 402                                 // the more intuitive while ( ob_get_level() > 0 ) ob_get_clean();
 403                                 // we have to be safe here and avoid an infinite loop.
 404                                 for ( $i = 0; $i < ob_get_level(); $i++ ) {
 405                                         ob_end_clean();
 406                                 }
 407
 408                                 header( 'HTTP/1.0 304 Not Modified' );
 409                                 header( 'Status: 304 Not Modified' );
 410                                 wfProfileOut( __METHOD__ );
 411                                 return;
 412                         }
 413                 }
 414
 415                 // Generate a response
 416                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 417
 418                 // Prepend comments indicating exceptions
 419                 $response = $exceptions . $response;
 420
 421                 // Capture any PHP warnings from the output buffer and append them to the
 422                 // response in a comment if we're in debug mode.
 423                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 424                         $response = "/*\n$warnings\n*/\n" . $response;
 425                 }
 426
 427                 // Remove the output buffer and output the response
 428                 ob_end_clean();
 429                 echo $response;
 430
 431                 wfProfileOut( __METHOD__ );
 432         }
 433
 434         /**
 435          * Generates code for a response
 436          *
 437          * @param $context ResourceLoaderContext: Context in which to generate a response
 438          * @param $modules Array: List of module objects keyed by module name
 439          * @param $missing Array: List of unavailable modules (optional)
 440          * @return String: Response data
 441          */
 442         public function makeModuleResponse( ResourceLoaderContext $context,
 443                 array $modules, $missing = array() )
 444         {
 445                 $out = '';
 446                 $exceptions = '';
 447                 if ( $modules === array() && $missing === array() ) {
 448                         return '/* No modules requested. Max made me put this here */';
 449                 }
 450
 451                 wfProfileIn( __METHOD__ );
 452                 // Pre-fetch blobs
 453                 if ( $context->shouldIncludeMessages() ) {
 454                         try {
 455                                 $blobs = MessageBlobStore::get( $this, $modules, $context->getLanguage() );
 456                         } catch ( Exception $e ) {
 457                                 // Add exception to the output as a comment
 458                                 $exceptions .= "/*\n{$e->__toString()}\n*/\n";
 459                         }
 460                 } else {
 461                         $blobs = array();
 462                 }
 463
 464                 // Generate output
 465                 foreach ( $modules as $name => $module ) {
 466                         wfProfileIn( __METHOD__ . '-' . $name );
 467                         try {
 468                                 // Scripts
 469                                 $scripts = '';
 470                                 if ( $context->shouldIncludeScripts() ) {
 471                                         // bug 27054: Append semicolon to prevent weird bugs
 472                                         // caused by files not terminating their statements right
 473                                         $scripts .= $module->getScript( $context ) . ";\n";
 474                                 }
 475
 476                                 // Styles
 477                                 $styles = array();
 478                                 if ( $context->shouldIncludeStyles() ) {
 479                                         $styles = $module->getStyles( $context );
 480                                 }
 481
 482                                 // Messages
 483                                 $messagesBlob = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 484
 485                                 // Append output
 486                                 switch ( $context->getOnly() ) {
 487                                         case 'scripts':
 488                                                 $out .= $scripts;
 489                                                 break;
 490                                         case 'styles':
 491                                                 $out .= self::makeCombinedStyles( $styles );
 492                                                 break;
 493                                         case 'messages':
 494                                                 $out .= self::makeMessageSetScript( new XmlJsCode( $messagesBlob ) );
 495                                                 break;
 496                                         default:
 497                                                 // Minify CSS before embedding in mw.loader.implement call
 498                                                 // (unless in debug mode)
 499                                                 if ( !$context->getDebug() ) {
 500                                                         foreach ( $styles as $media => $style ) {
 501                                                                 $styles[$media] = $this->filter( 'minify-css', $style );
 502                                                         }
 503                                                 }
 504                                                 $out .= self::makeLoaderImplementScript( $name, $scripts, $styles,
 505                                                         new XmlJsCode( $messagesBlob ) );
 506                                                 break;
 507                                 }
 508                         } catch ( Exception $e ) {
 509                                 // Add exception to the output as a comment
 510                                 $exceptions .= "/*\n{$e->__toString()}\n*/\n";
 511
 512                                 // Register module as missing
 513                                 $missing[] = $name;
 514                                 unset( $modules[$name] );
 515                         }
 516                         wfProfileOut( __METHOD__ . '-' . $name );
 517                 }
 518
 519                 // Update module states
 520                 if ( $context->shouldIncludeScripts() ) {
 521                         // Set the state of modules loaded as only scripts to ready
 522                         if ( count( $modules ) && $context->getOnly() === 'scripts'
 523                                 && !isset( $modules['startup'] ) )
 524                         {
 525                                 $out .= self::makeLoaderStateScript(
 526                                         array_fill_keys( array_keys( $modules ), 'ready' ) );
 527                         }
 528                         // Set the state of modules which were requested but unavailable as missing
 529                         if ( is_array( $missing ) && count( $missing ) ) {
 530                                 $out .= self::makeLoaderStateScript( array_fill_keys( $missing, 'missing' ) );
 531                         }
 532                 }
 533
 534                 if ( !$context->getDebug() ) {
 535                         if ( $context->getOnly() === 'styles' ) {
 536                                 $out = $this->filter( 'minify-css', $out );
 537                         } else {
 538                                 $out = $this->filter( 'minify-js', $out );
 539                         }
 540                 }
 541
 542                 wfProfileOut( __METHOD__ );
 543                 return $exceptions . $out;
 544         }
 545
 546         /* Static Methods */
 547
 548         /**
 549          * Returns JS code to call to mw.loader.implement for a module with
 550          * given properties.
 551          *
 552          * @param $name Module name
 553          * @param $scripts Array: List of JavaScript code snippets to be executed after the
 554          *     module is loaded
 555          * @param $styles Array: List of CSS strings keyed by media type
 556          * @param $messages Mixed: List of messages associated with this module. May either be an
 557          *     associative array mapping message key to value, or a JSON-encoded message blob containing
 558          *     the same data, wrapped in an XmlJsCode object.
 559          */
 560         public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
 561                 if ( is_array( $scripts ) ) {
 562                         $scripts = implode( $scripts, "\n" );
 563                 }
 564                 return Xml::encodeJsCall(
 565                         'mw.loader.implement',
 566                         array(
 567                                 $name,
 568                                 new XmlJsCode( "function( $ ) {{$scripts}}" ),
 569                                 (object)$styles,
 570                                 (object)$messages
 571                         ) );
 572         }
 573
 574         /**
 575          * Returns JS code which, when called, will register a given list of messages.
 576          *
 577          * @param $messages Mixed: Either an associative array mapping message key to value, or a
 578          *     JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
 579          */
 580         public static function makeMessageSetScript( $messages ) {
 581                 return Xml::encodeJsCall( 'mw.messages.set', array( (object)$messages ) );
 582         }
 583
 584         /**
 585          * Combines an associative array mapping media type to CSS into a
 586          * single stylesheet with @media blocks.
 587          *
 588          * @param $styles Array: List of CSS strings keyed by media type
 589          */
 590         public static function makeCombinedStyles( array $styles ) {
 591                 $out = '';
 592                 foreach ( $styles as $media => $style ) {
 593                         // Transform the media type based on request params and config
 594                         // The way that this relies on $wgRequest to propagate request params is slightly evil
 595                         $media = OutputPage::transformCssMedia( $media );
 596
 597                         if ( $media === null ) {
 598                                 // Skip
 599                         } else if ( $media === '' || $media == 'all' ) {
 600                                 // Don't output invalid or frivolous @media statements
 601                                 $out .= "$style\n";
 602                         } else {
 603                                 $out .= "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "\n}\n";
 604                         }
 605                 }
 606                 return $out;
 607         }
 608
 609         /**
 610          * Returns a JS call to mw.loader.state, which sets the state of a
 611          * module or modules to a given value. Has two calling conventions:
 612          *
 613          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
 614          *         Set the state of a single module called $name to $state
 615          *
 616          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
 617          *         Set the state of modules with the given names to the given states
 618          */
 619         public static function makeLoaderStateScript( $name, $state = null ) {
 620                 if ( is_array( $name ) ) {
 621                         return Xml::encodeJsCall( 'mw.loader.state', array( $name ) );
 622                 } else {
 623                         return Xml::encodeJsCall( 'mw.loader.state', array( $name, $state ) );
 624                 }
 625         }
 626
 627         /**
 628          * Returns JS code which calls the script given by $script. The script will
 629          * be called with local variables name, version, dependencies and group,
 630          * which will have values corresponding to $name, $version, $dependencies
 631          * and $group as supplied.
 632          *
 633          * @param $name String: Module name
 634          * @param $version Integer: Module version number as a timestamp
 635          * @param $dependencies Array: List of module names on which this module depends
 636          * @param $group String: Group which the module is in.
 637          * @param $script String: JavaScript code
 638          */
 639         public static function makeCustomLoaderScript( $name, $version, $dependencies, $group, $script ) {
 640                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 641                 return Xml::encodeJsCall(
 642                         "( function( name, version, dependencies, group ) {\n\t$script\n} )",
 643                         array( $name, $version, $dependencies, $group ) );
 644         }
 645
 646         /**
 647          * Returns JS code which calls mw.loader.register with the given
 648          * parameters. Has three calling conventions:
 649          *
 650          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version, $dependencies, $group ):
 651          *       Register a single module.
 652          *
 653          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
 654          *       Register modules with the given names.
 655          *
 656          *   - ResourceLoader::makeLoaderRegisterScript( array(
 657          *        array( $name1, $version1, $dependencies1, $group1 ),
 658          *        array( $name2, $version2, $dependencies1, $group2 ),
 659          *        ...
 660          *     ) ):
 661          *        Registers modules with the given names and parameters.
 662          *
 663          * @param $name String: Module name
 664          * @param $version Integer: Module version number as a timestamp
 665          * @param $dependencies Array: List of module names on which this module depends
 666          * @param $group String: group which the module is in.
 667          */
 668         public static function makeLoaderRegisterScript( $name, $version = null,
 669                 $dependencies = null, $group = null )
 670         {
 671                 if ( is_array( $name ) ) {
 672                         return Xml::encodeJsCall( 'mediaWiki.loader.register', array( $name ) );
 673                 } else {
 674                         $version = (int) $version > 1 ? (int) $version : 1;
 675                         return Xml::encodeJsCall( 'mediaWiki.loader.register',
 676                                 array( $name, $version, $dependencies, $group ) );
 677                 }
 678         }
 679
 680         /**
 681          * Returns JS code which runs given JS code if the client-side framework is
 682          * present.
 683          *
 684          * @param $script String: JavaScript code
 685          */
 686         public static function makeLoaderConditionalScript( $script ) {
 687                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 688                 return "if ( window.mediaWiki ) {\n\t$script\n}\n";
 689         }
 690
 691         /**
 692          * Returns JS code which will set the MediaWiki configuration array to
 693          * the given value.
 694          *
 695          * @param $configuration Array: List of configuration values keyed by variable name
 696          */
 697         public static function makeConfigSetScript( array $configuration ) {
 698                 return Xml::encodeJsCall( 'mediaWiki.config.set', array( $configuration ) );
 699         }
 700
 701         /**
 702          * Determine whether debug mode was requested
 703          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
 704          * @return bool
 705          */
 706         public static function inDebugMode() {
 707                 global $wgRequest, $wgResourceLoaderDebug;
 708                 static $retval = null;
 709                 if ( !is_null( $retval ) )
 710                         return $retval;
 711                 return $retval = $wgRequest->getFuzzyBool( 'debug',
 712                         $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug ) );
 713         }
 714 }