includes/resourceloader/ResourceLoader.php

   1 <?php
   2 /**
   3  * Base class for resource loading system.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @author Roan Kattouw
  22  * @author Trevor Parscal
  23  */
  24
  25 /**
  26  * Dynamic JavaScript and CSS resource loading system.
  27  *
  28  * Most of the documentation is on the MediaWiki documentation wiki starting at:
  29  *    https://www.mediawiki.org/wiki/ResourceLoader
  30  */
  31 class ResourceLoader {
  32         /** @var int */
  33         protected static $filterCacheVersion = 7;
  34
  35         /** @var bool */
  36         protected static $debugMode = null;
  37
  38         /**
  39          * Module name/ResourceLoaderModule object pairs
  40          * @var array
  41          */
  42         protected $modules = array();
  43
  44         /**
  45          * Associative array mapping module name to info associative array
  46          * @var array
  47          */
  48         protected $moduleInfos = array();
  49
  50         /** @var Config $config */
  51         private $config;
  52
  53         /**
  54          * Associative array mapping framework ids to a list of names of test suite modules
  55          * like array( 'qunit' => array( 'mediawiki.tests.qunit.suites', 'ext.foo.tests', .. ), .. )
  56          * @var array
  57          */
  58         protected $testModuleNames = array();
  59
  60         /**
  61          * E.g. array( 'source-id' => 'http://.../load.php' )
  62          * @var array
  63          */
  64         protected $sources = array();
  65
  66         /**
  67          * Errors accumulated during current respond() call.
  68          * @var array
  69          */
  70         protected $errors = array();
  71
  72         /**
  73          * Load information stored in the database about modules.
  74          *
  75          * This method grabs modules dependencies from the database and updates modules
  76          * objects.
  77          *
  78          * This is not inside the module code because it is much faster to
  79          * request all of the information at once than it is to have each module
  80          * requests its own information. This sacrifice of modularity yields a substantial
  81          * performance improvement.
  82          *
  83          * @param array $modules List of module names to preload information for
  84          * @param ResourceLoaderContext $context Context to load the information within
  85          */
  86         public function preloadModuleInfo( array $modules, ResourceLoaderContext $context ) {
  87                 if ( !count( $modules ) ) {
  88                         // Or else Database*::select() will explode, plus it's cheaper!
  89                         return;
  90                 }
  91                 $dbr = wfGetDB( DB_SLAVE );
  92                 $skin = $context->getSkin();
  93                 $lang = $context->getLanguage();
  94
  95                 // Get file dependency information
  96                 $res = $dbr->select( 'module_deps', array( 'md_module', 'md_deps' ), array(
  97                                 'md_module' => $modules,
  98                                 'md_skin' => $skin
  99                         ), __METHOD__
 100                 );
 101
 102                 // Set modules' dependencies
 103                 $modulesWithDeps = array();
 104                 foreach ( $res as $row ) {
 105                         $module = $this->getModule( $row->md_module );
 106                         if ( $module ) {
 107                                 $module->setFileDependencies( $skin, FormatJson::decode( $row->md_deps, true ) );
 108                                 $modulesWithDeps[] = $row->md_module;
 109                         }
 110                 }
 111
 112                 // Register the absence of a dependency row too
 113                 foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
 114                         $module = $this->getModule( $name );
 115                         if ( $module ) {
 116                                 $this->getModule( $name )->setFileDependencies( $skin, array() );
 117                         }
 118                 }
 119
 120                 // Get message blob mtimes. Only do this for modules with messages
 121                 $modulesWithMessages = array();
 122                 foreach ( $modules as $name ) {
 123                         $module = $this->getModule( $name );
 124                         if ( $module && count( $module->getMessages() ) ) {
 125                                 $modulesWithMessages[] = $name;
 126                         }
 127                 }
 128                 $modulesWithoutMessages = array_flip( $modules ); // Will be trimmed down by the loop below
 129                 if ( count( $modulesWithMessages ) ) {
 130                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
 131                                         'mr_resource' => $modulesWithMessages,
 132                                         'mr_lang' => $lang
 133                                 ), __METHOD__
 134                         );
 135                         foreach ( $res as $row ) {
 136                                 $module = $this->getModule( $row->mr_resource );
 137                                 if ( $module ) {
 138                                         $module->setMsgBlobMtime( $lang, wfTimestamp( TS_UNIX, $row->mr_timestamp ) );
 139                                         unset( $modulesWithoutMessages[$row->mr_resource] );
 140                                 }
 141                         }
 142                 }
 143                 foreach ( array_keys( $modulesWithoutMessages ) as $name ) {
 144                         $module = $this->getModule( $name );
 145                         if ( $module ) {
 146                                 $module->setMsgBlobMtime( $lang, 1 );
 147                         }
 148                 }
 149         }
 150
 151         /**
 152          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 153          *
 154          * Available filters are:
 155          *
 156          *    - minify-js \see JavaScriptMinifier::minify
 157          *    - minify-css \see CSSMin::minify
 158          *
 159          * If $data is empty, only contains whitespace or the filter was unknown,
 160          * $data is returned unmodified.
 161          *
 162          * @param string $filter Name of filter to run
 163          * @param string $data Text to filter, such as JavaScript or CSS text
 164          * @param string $cacheReport Whether to include the cache key report
 165          * @return string Filtered data, or a comment containing an error message
 166          */
 167         public function filter( $filter, $data, $cacheReport = true ) {
 168                 wfProfileIn( __METHOD__ );
 169
 170                 // For empty/whitespace-only data or for unknown filters, don't perform
 171                 // any caching or processing
 172                 if ( trim( $data ) === '' || !in_array( $filter, array( 'minify-js', 'minify-css' ) ) ) {
 173                         wfProfileOut( __METHOD__ );
 174                         return $data;
 175                 }
 176
 177                 // Try for cache hit
 178                 // Use CACHE_ANYTHING since filtering is very slow compared to DB queries
 179                 $key = wfMemcKey( 'resourceloader', 'filter', $filter, self::$filterCacheVersion, md5( $data ) );
 180                 $cache = wfGetCache( CACHE_ANYTHING );
 181                 $cacheEntry = $cache->get( $key );
 182                 if ( is_string( $cacheEntry ) ) {
 183                         wfIncrStats( "rl-$filter-cache-hits" );
 184                         wfProfileOut( __METHOD__ );
 185                         return $cacheEntry;
 186                 }
 187
 188                 $result = '';
 189                 // Run the filter - we've already verified one of these will work
 190                 try {
 191                         wfIncrStats( "rl-$filter-cache-misses" );
 192                         switch ( $filter ) {
 193                                 case 'minify-js':
 194                                         $result = JavaScriptMinifier::minify( $data,
 195                                                 $this->config->get( 'ResourceLoaderMinifierStatementsOnOwnLine' ),
 196                                                 $this->config->get( 'ResourceLoaderMinifierMaxLineLength' )
 197                                         );
 198                                         if ( $cacheReport ) {
 199                                                 $result .= "\n/* cache key: $key */";
 200                                         }
 201                                         break;
 202                                 case 'minify-css':
 203                                         $result = CSSMin::minify( $data );
 204                                         if ( $cacheReport ) {
 205                                                 $result .= "\n/* cache key: $key */";
 206                                         }
 207                                         break;
 208                         }
 209
 210                         // Save filtered text to Memcached
 211                         $cache->set( $key, $result );
 212                 } catch ( Exception $e ) {
 213                         MWExceptionHandler::logException( $e );
 214                         wfDebugLog( 'resourceloader', __METHOD__ . ": minification failed: $e" );
 215                         $this->errors[] = self::formatExceptionNoComment( $e );
 216                 }
 217
 218                 wfProfileOut( __METHOD__ );
 219
 220                 return $result;
 221         }
 222
 223         /* Methods */
 224
 225         /**
 226          * Register core modules and runs registration hooks.
 227          * @param Config|null $config
 228          */
 229         public function __construct( Config $config = null ) {
 230                 global $IP;
 231
 232                 wfProfileIn( __METHOD__ );
 233
 234                 if ( $config === null ) {
 235                         wfDebug( __METHOD__ . ' was called without providing a Config instance' );
 236                         $config = ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
 237                 }
 238
 239                 $this->config = $config;
 240
 241                 // Add 'local' source first
 242                 $this->addSource( 'local', wfScript( 'load' ) );
 243
 244                 // Add other sources
 245                 $this->addSource( $config->get( 'ResourceLoaderSources' ) );
 246
 247                 // Register core modules
 248                 $this->register( include "$IP/resources/Resources.php" );
 249                 // Register extension modules
 250                 Hooks::run( 'ResourceLoaderRegisterModules', array( &$this ) );
 251                 $this->register( $config->get( 'ResourceModules' ) );
 252
 253                 if ( $config->get( 'EnableJavaScriptTest' ) === true ) {
 254                         $this->registerTestModules();
 255                 }
 256
 257                 wfProfileOut( __METHOD__ );
 258         }
 259
 260         /**
 261          * @return Config
 262          */
 263         public function getConfig() {
 264                 return $this->config;
 265         }
 266
 267         /**
 268          * Register a module with the ResourceLoader system.
 269          *
 270          * @param mixed $name Name of module as a string or List of name/object pairs as an array
 271          * @param array $info Module info array. For backwards compatibility with 1.17alpha,
 272          *   this may also be a ResourceLoaderModule object. Optional when using
 273          *   multiple-registration calling style.
 274          * @throws MWException If a duplicate module registration is attempted
 275          * @throws MWException If a module name contains illegal characters (pipes or commas)
 276          * @throws MWException If something other than a ResourceLoaderModule is being registered
 277          * @return bool False if there were any errors, in which case one or more modules were
 278          *   not registered
 279          */
 280         public function register( $name, $info = null ) {
 281                 wfProfileIn( __METHOD__ );
 282
 283                 // Allow multiple modules to be registered in one call
 284                 $registrations = is_array( $name ) ? $name : array( $name => $info );
 285                 foreach ( $registrations as $name => $info ) {
 286                         // Disallow duplicate registrations
 287                         if ( isset( $this->moduleInfos[$name] ) ) {
 288                                 wfProfileOut( __METHOD__ );
 289                                 // A module has already been registered by this name
 290                                 throw new MWException(
 291                                         'ResourceLoader duplicate registration error. ' .
 292                                         'Another module has already been registered as ' . $name
 293                                 );
 294                         }
 295
 296                         // Check $name for validity
 297                         if ( !self::isValidModuleName( $name ) ) {
 298                                 wfProfileOut( __METHOD__ );
 299                                 throw new MWException( "ResourceLoader module name '$name' is invalid, "
 300                                         . "see ResourceLoader::isValidModuleName()" );
 301                         }
 302
 303                         // Attach module
 304                         if ( $info instanceof ResourceLoaderModule ) {
 305                                 $this->moduleInfos[$name] = array( 'object' => $info );
 306                                 $info->setName( $name );
 307                                 $this->modules[$name] = $info;
 308                         } elseif ( is_array( $info ) ) {
 309                                 // New calling convention
 310                                 $this->moduleInfos[$name] = $info;
 311                         } else {
 312                                 wfProfileOut( __METHOD__ );
 313                                 throw new MWException(
 314                                         'ResourceLoader module info type error for module \'' . $name .
 315                                         '\': expected ResourceLoaderModule or array (got: ' . gettype( $info ) . ')'
 316                                 );
 317                         }
 318
 319                         // Last-minute changes
 320
 321                         // Apply custom skin-defined styles to existing modules.
 322                         if ( $this->isFileModule( $name ) ) {
 323                                 foreach ( $this->config->get( 'ResourceModuleSkinStyles' ) as $skinName => $skinStyles ) {
 324                                         // If this module already defines skinStyles for this skin, ignore $wgResourceModuleSkinStyles.
 325                                         if ( isset( $this->moduleInfos[$name]['skinStyles'][$skinName] ) ) {
 326                                                 continue;
 327                                         }
 328
 329                                         // If $name is preceded with a '+', the defined style files will be added to 'default'
 330                                         // skinStyles, otherwise 'default' will be ignored as it normally would be.
 331                                         if ( isset( $skinStyles[$name] ) ) {
 332                                                 $paths = (array)$skinStyles[$name];
 333                                                 $styleFiles = array();
 334                                         } elseif ( isset( $skinStyles['+' . $name] ) ) {
 335                                                 $paths = (array)$skinStyles['+' . $name];
 336                                                 $styleFiles = isset( $this->moduleInfos[$name]['skinStyles']['default'] ) ?
 337                                                         $this->moduleInfos[$name]['skinStyles']['default'] :
 338                                                         array();
 339                                         } else {
 340                                                 continue;
 341                                         }
 342
 343                                         // Add new file paths, remapping them to refer to our directories and not use settings
 344                                         // from the module we're modifying. These can come from the base definition or be defined
 345                                         // for each module.
 346                                         list( $localBasePath, $remoteBasePath ) =
 347                                                 ResourceLoaderFileModule::extractBasePaths( $skinStyles );
 348                                         list( $localBasePath, $remoteBasePath ) =
 349                                                 ResourceLoaderFileModule::extractBasePaths( $paths, $localBasePath, $remoteBasePath );
 350
 351                                         foreach ( $paths as $path ) {
 352                                                 $styleFiles[] = new ResourceLoaderFilePath( $path, $localBasePath, $remoteBasePath );
 353                                         }
 354
 355                                         $this->moduleInfos[$name]['skinStyles'][$skinName] = $styleFiles;
 356                                 }
 357                         }
 358                 }
 359
 360                 wfProfileOut( __METHOD__ );
 361         }
 362
 363         /**
 364          */
 365         public function registerTestModules() {
 366                 global $IP;
 367
 368                 if ( $this->config->get( 'EnableJavaScriptTest' ) !== true ) {
 369                         throw new MWException( 'Attempt to register JavaScript test modules '
 370                                 . 'but <code>$wgEnableJavaScriptTest</code> is false. '
 371                                 . 'Edit your <code>LocalSettings.php</code> to enable it.' );
 372                 }
 373
 374                 wfProfileIn( __METHOD__ );
 375
 376                 // Get core test suites
 377                 $testModules = array();
 378                 $testModules['qunit'] = array();
 379                 // Get other test suites (e.g. from extensions)
 380                 Hooks::run( 'ResourceLoaderTestModules', array( &$testModules, &$this ) );
 381
 382                 // Add the testrunner (which configures QUnit) to the dependencies.
 383                 // Since it must be ready before any of the test suites are executed.
 384                 foreach ( $testModules['qunit'] as &$module ) {
 385                         // Make sure all test modules are top-loading so that when QUnit starts
 386                         // on document-ready, it will run once and finish. If some tests arrive
 387                         // later (possibly after QUnit has already finished) they will be ignored.
 388                         $module['position'] = 'top';
 389                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 390                 }
 391
 392                 $testModules['qunit'] =
 393                         ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules['qunit'];
 394
 395                 foreach ( $testModules as $id => $names ) {
 396                         // Register test modules
 397                         $this->register( $testModules[$id] );
 398
 399                         // Keep track of their names so that they can be loaded together
 400                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 401                 }
 402
 403                 wfProfileOut( __METHOD__ );
 404         }
 405
 406         /**
 407          * Add a foreign source of modules.
 408          *
 409          * @param array|string $id Source ID (string), or array( id1 => loadUrl, id2 => loadUrl, ... )
 410          * @param string|array $loadUrl load.php url (string), or array with loadUrl key for
 411          *  backwards-compatibility.
 412          * @throws MWException
 413          */
 414         public function addSource( $id, $loadUrl = null ) {
 415                 // Allow multiple sources to be registered in one call
 416                 if ( is_array( $id ) ) {
 417                         foreach ( $id as $key => $value ) {
 418                                 $this->addSource( $key, $value );
 419                         }
 420                         return;
 421                 }
 422
 423                 // Disallow duplicates
 424                 if ( isset( $this->sources[$id] ) ) {
 425                         throw new MWException(
 426                                 'ResourceLoader duplicate source addition error. ' .
 427                                 'Another source has already been registered as ' . $id
 428                         );
 429                 }
 430
 431                 // Pre 1.24 backwards-compatibility
 432                 if ( is_array( $loadUrl ) ) {
 433                         if ( !isset( $loadUrl['loadScript'] ) ) {
 434                                 throw new MWException(
 435                                         __METHOD__ . ' was passed an array with no "loadScript" key.'
 436                                 );
 437                         }
 438
 439                         $loadUrl = $loadUrl['loadScript'];
 440                 }
 441
 442                 $this->sources[$id] = $loadUrl;
 443         }
 444
 445         /**
 446          * Get a list of module names.
 447          *
 448          * @return array List of module names
 449          */
 450         public function getModuleNames() {
 451                 return array_keys( $this->moduleInfos );
 452         }
 453
 454         /**
 455          * Get a list of test module names for one (or all) frameworks.
 456          *
 457          * If the given framework id is unknkown, or if the in-object variable is not an array,
 458          * then it will return an empty array.
 459          *
 460          * @param string $framework Get only the test module names for one
 461          *   particular framework (optional)
 462          * @return array
 463          */
 464         public function getTestModuleNames( $framework = 'all' ) {
 465                 /** @todo api siteinfo prop testmodulenames modulenames */
 466                 if ( $framework == 'all' ) {
 467                         return $this->testModuleNames;
 468                 } elseif ( isset( $this->testModuleNames[$framework] )
 469                         && is_array( $this->testModuleNames[$framework] )
 470                 ) {
 471                         return $this->testModuleNames[$framework];
 472                 } else {
 473                         return array();
 474                 }
 475         }
 476
 477         /**
 478          * Get the ResourceLoaderModule object for a given module name.
 479          *
 480          * If an array of module parameters exists but a ResourceLoaderModule object has not
 481          * yet been instantiated, this method will instantiate and cache that object such that
 482          * subsequent calls simply return the same object.
 483          *
 484          * @param string $name Module name
 485          * @return ResourceLoaderModule|null If module has been registered, return a
 486          *  ResourceLoaderModule instance. Otherwise, return null.
 487          */
 488         public function getModule( $name ) {
 489                 if ( !isset( $this->modules[$name] ) ) {
 490                         if ( !isset( $this->moduleInfos[$name] ) ) {
 491                                 // No such module
 492                                 return null;
 493                         }
 494                         // Construct the requested object
 495                         $info = $this->moduleInfos[$name];
 496                         /** @var ResourceLoaderModule $object */
 497                         if ( isset( $info['object'] ) ) {
 498                                 // Object given in info array
 499                                 $object = $info['object'];
 500                         } else {
 501                                 if ( !isset( $info['class'] ) ) {
 502                                         $class = 'ResourceLoaderFileModule';
 503                                 } else {
 504                                         $class = $info['class'];
 505                                 }
 506                                 /** @var ResourceLoaderModule $object */
 507                                 $object = new $class( $info );
 508                                 $object->setConfig( $this->getConfig() );
 509                         }
 510                         $object->setName( $name );
 511                         $this->modules[$name] = $object;
 512                 }
 513
 514                 return $this->modules[$name];
 515         }
 516
 517         /**
 518          * Return whether the definition of a module corresponds to a simple ResourceLoaderFileModule.
 519          *
 520          * @param string $name Module name
 521          * @return bool
 522          */
 523         protected function isFileModule( $name ) {
 524                 if ( !isset( $this->moduleInfos[$name] ) ) {
 525                         return false;
 526                 }
 527                 $info = $this->moduleInfos[$name];
 528                 if ( isset( $info['object'] ) || isset( $info['class'] ) ) {
 529                         return false;
 530                 }
 531                 return true;
 532         }
 533
 534         /**
 535          * Get the list of sources.
 536          *
 537          * @return array Like array( id => load.php url, .. )
 538          */
 539         public function getSources() {
 540                 return $this->sources;
 541         }
 542
 543         /**
 544          * Get the URL to the load.php endpoint for the given
 545          * ResourceLoader source
 546          *
 547          * @since 1.24
 548          * @param string $source
 549          * @throws MWException On an invalid $source name
 550          * @return string
 551          */
 552         public function getLoadScript( $source ) {
 553                 if ( !isset( $this->sources[$source] ) ) {
 554                         throw new MWException( "The $source source was never registered in ResourceLoader." );
 555                 }
 556                 return $this->sources[$source];
 557         }
 558
 559         /**
 560          * Output a response to a load request, including the content-type header.
 561          *
 562          * @param ResourceLoaderContext $context Context in which a response should be formed
 563          */
 564         public function respond( ResourceLoaderContext $context ) {
 565                 // Use file cache if enabled and available...
 566                 if ( $this->config->get( 'UseFileCache' ) ) {
 567                         $fileCache = ResourceFileCache::newFromContext( $context );
 568                         if ( $this->tryRespondFromFileCache( $fileCache, $context ) ) {
 569                                 return; // output handled
 570                         }
 571                 }
 572
 573                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 574                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 575                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 576                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 577                 // the whole thing in our own output buffer to be sure the active buffer
 578                 // doesn't use ob_gzhandler.
 579                 // See http://bugs.php.net/bug.php?id=36514
 580                 ob_start();
 581
 582                 wfProfileIn( __METHOD__ );
 583
 584                 // Find out which modules are missing and instantiate the others
 585                 $modules = array();
 586                 $missing = array();
 587                 foreach ( $context->getModules() as $name ) {
 588                         $module = $this->getModule( $name );
 589                         if ( $module ) {
 590                                 // Do not allow private modules to be loaded from the web.
 591                                 // This is a security issue, see bug 34907.
 592                                 if ( $module->getGroup() === 'private' ) {
 593                                         wfDebugLog( 'resourceloader', __METHOD__ . ": request for private module '$name' denied" );
 594                                         $this->errors[] = "Cannot show private module \"$name\"";
 595                                         continue;
 596                                 }
 597                                 $modules[$name] = $module;
 598                         } else {
 599                                 $missing[] = $name;
 600                         }
 601                 }
 602
 603                 // Preload information needed to the mtime calculation below
 604                 try {
 605                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 606                 } catch ( Exception $e ) {
 607                         MWExceptionHandler::logException( $e );
 608                         wfDebugLog( 'resourceloader', __METHOD__ . ": preloading module info failed: $e" );
 609                         $this->errors[] = self::formatExceptionNoComment( $e );
 610                 }
 611
 612                 wfProfileIn( __METHOD__ . '-getModifiedTime' );
 613
 614                 // To send Last-Modified and support If-Modified-Since, we need to detect
 615                 // the last modified time
 616                 $mtime = wfTimestamp( TS_UNIX, $this->config->get( 'CacheEpoch' ) );
 617                 foreach ( $modules as $module ) {
 618                         /**
 619                          * @var $module ResourceLoaderModule
 620                          */
 621                         try {
 622                                 // Calculate maximum modified time
 623                                 $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 624                         } catch ( Exception $e ) {
 625                                 MWExceptionHandler::logException( $e );
 626                                 wfDebugLog( 'resourceloader', __METHOD__ . ": calculating maximum modified time failed: $e" );
 627                                 $this->errors[] = self::formatExceptionNoComment( $e );
 628                         }
 629                 }
 630
 631                 wfProfileOut( __METHOD__ . '-getModifiedTime' );
 632
 633                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 634                 if ( $this->tryRespondLastModified( $context, $mtime ) ) {
 635                         wfProfileOut( __METHOD__ );
 636                         return; // output handled (buffers cleared)
 637                 }
 638
 639                 // Generate a response
 640                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 641
 642                 // Capture any PHP warnings from the output buffer and append them to the
 643                 // error list if we're in debug mode.
 644                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 645                         $this->errors[] = $warnings;
 646                 }
 647
 648                 // Save response to file cache unless there are errors
 649                 if ( isset( $fileCache ) && !$this->errors && !count( $missing ) ) {
 650                         // Cache single modules and images...and other requests if there are enough hits
 651                         if ( ResourceFileCache::useFileCache( $context ) ) {
 652                                 if ( $fileCache->isCacheWorthy() ) {
 653                                         $fileCache->saveText( $response );
 654                                 } else {
 655                                         $fileCache->incrMissesRecent( $context->getRequest() );
 656                                 }
 657                         }
 658                 }
 659
 660                 // Send content type and cache related headers
 661                 $this->sendResponseHeaders( $context, $mtime, (bool)$this->errors );
 662
 663                 // Remove the output buffer and output the response
 664                 ob_end_clean();
 665
 666                 if ( $context->getImageObj() && $this->errors ) {
 667                         // We can't show both the error messages and the response when it's an image.
 668                         $errorText = '';
 669                         foreach ( $this->errors as $error ) {
 670                                 $errorText .= $error . "\n";
 671                         }
 672                         $response = $errorText;
 673                 } elseif ( $this->errors ) {
 674                         // Prepend comments indicating errors
 675                         $errorText = '';
 676                         foreach ( $this->errors as $error ) {
 677                                 $errorText .= self::makeComment( $error );
 678                         }
 679                         $response = $errorText . $response;
 680                 }
 681
 682                 $this->errors = array();
 683                 echo $response;
 684
 685                 wfProfileOut( __METHOD__ );
 686         }
 687
 688         /**
 689          * Send content type and last modified headers to the client.
 690          * @param ResourceLoaderContext $context
 691          * @param string $mtime TS_MW timestamp to use for last-modified
 692          * @param bool $errors Whether there are errors in the response
 693          * @return void
 694          */
 695         protected function sendResponseHeaders( ResourceLoaderContext $context, $mtime, $errors ) {
 696                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 697                 // If a version wasn't specified we need a shorter expiry time for updates
 698                 // to propagate to clients quickly
 699                 // If there were errors, we also need a shorter expiry time so we can recover quickly
 700                 if ( is_null( $context->getVersion() ) || $errors ) {
 701                         $maxage = $rlMaxage['unversioned']['client'];
 702                         $smaxage = $rlMaxage['unversioned']['server'];
 703                 // If a version was specified we can use a longer expiry time since changing
 704                 // version numbers causes cache misses
 705                 } else {
 706                         $maxage = $rlMaxage['versioned']['client'];
 707                         $smaxage = $rlMaxage['versioned']['server'];
 708                 }
 709                 if ( $context->getImageObj() ) {
 710                         // Output different headers if we're outputting textual errors.
 711                         if ( $errors ) {
 712                                 header( 'Content-Type: text/plain; charset=utf-8' );
 713                         } else {
 714                                 $context->getImageObj()->sendResponseHeaders( $context );
 715                         }
 716                 } elseif ( $context->getOnly() === 'styles' ) {
 717                         header( 'Content-Type: text/css; charset=utf-8' );
 718                         header( 'Access-Control-Allow-Origin: *' );
 719                 } else {
 720                         header( 'Content-Type: text/javascript; charset=utf-8' );
 721                 }
 722                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 723                 if ( $context->getDebug() ) {
 724                         // Do not cache debug responses
 725                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 726                         header( 'Pragma: no-cache' );
 727                 } else {
 728                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 729                         $exp = min( $maxage, $smaxage );
 730                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 731                 }
 732         }
 733
 734         /**
 735          * Respond with 304 Last Modified if appropiate.
 736          *
 737          * If there's an If-Modified-Since header, respond with a 304 appropriately
 738          * and clear out the output buffer. If the client cache is too old then do nothing.
 739          *
 740          * @param ResourceLoaderContext $context
 741          * @param string $mtime The TS_MW timestamp to check the header against
 742          * @return bool True if 304 header sent and output handled
 743          */
 744         protected function tryRespondLastModified( ResourceLoaderContext $context, $mtime ) {
 745                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 746                 // Some clients send "timestamp;length=123". Strip the part after the first ';'
 747                 // so we get a valid timestamp.
 748                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 749                 // Never send 304s in debug mode
 750                 if ( $ims !== false && !$context->getDebug() ) {
 751                         $imsTS = strtok( $ims, ';' );
 752                         if ( $mtime <= wfTimestamp( TS_UNIX, $imsTS ) ) {
 753                                 // There's another bug in ob_gzhandler (see also the comment at
 754                                 // the top of this function) that causes it to gzip even empty
 755                                 // responses, meaning it's impossible to produce a truly empty
 756                                 // response (because the gzip header is always there). This is
 757                                 // a problem because 304 responses have to be completely empty
 758                                 // per the HTTP spec, and Firefox behaves buggily when they're not.
 759                                 // See also http://bugs.php.net/bug.php?id=51579
 760                                 // To work around this, we tear down all output buffering before
 761                                 // sending the 304.
 762                                 wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 763
 764                                 header( 'HTTP/1.0 304 Not Modified' );
 765                                 header( 'Status: 304 Not Modified' );
 766                                 return true;
 767                         }
 768                 }
 769                 return false;
 770         }
 771
 772         /**
 773          * Send out code for a response from file cache if possible.
 774          *
 775          * @param ResourceFileCache $fileCache Cache object for this request URL
 776          * @param ResourceLoaderContext $context Context in which to generate a response
 777          * @return bool If this found a cache file and handled the response
 778          */
 779         protected function tryRespondFromFileCache(
 780                 ResourceFileCache $fileCache, ResourceLoaderContext $context
 781         ) {
 782                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 783                 // Buffer output to catch warnings.
 784                 ob_start();
 785                 // Get the maximum age the cache can be
 786                 $maxage = is_null( $context->getVersion() )
 787                         ? $rlMaxage['unversioned']['server']
 788                         : $rlMaxage['versioned']['server'];
 789                 // Minimum timestamp the cache file must have
 790                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 791                 if ( !$good ) {
 792                         try { // RL always hits the DB on file cache miss...
 793                                 wfGetDB( DB_SLAVE );
 794                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 795                                 $good = $fileCache->isCacheGood(); // cache existence check
 796                         }
 797                 }
 798                 if ( $good ) {
 799                         $ts = $fileCache->cacheTimestamp();
 800                         // Send content type and cache headers
 801                         $this->sendResponseHeaders( $context, $ts, false );
 802                         // If there's an If-Modified-Since header, respond with a 304 appropriately
 803                         if ( $this->tryRespondLastModified( $context, $ts ) ) {
 804                                 return false; // output handled (buffers cleared)
 805                         }
 806                         $response = $fileCache->fetchText();
 807                         // Capture any PHP warnings from the output buffer and append them to the
 808                         // response in a comment if we're in debug mode.
 809                         if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 810                                 $response = "/*\n$warnings\n*/\n" . $response;
 811                         }
 812                         // Remove the output buffer and output the response
 813                         ob_end_clean();
 814                         echo $response . "\n/* Cached {$ts} */";
 815                         return true; // cache hit
 816                 }
 817                 // Clear buffer
 818                 ob_end_clean();
 819
 820                 return false; // cache miss
 821         }
 822
 823         /**
 824          * Generate a CSS or JS comment block.
 825          *
 826          * Only use this for public data, not error message details.
 827          *
 828          * @param string $text
 829          * @return string
 830          */
 831         public static function makeComment( $text ) {
 832                 $encText = str_replace( '*/', '* /', $text );
 833                 return "/*\n$encText\n*/\n";
 834         }
 835
 836         /**
 837          * Handle exception display.
 838          *
 839          * @param Exception $e Exception to be shown to the user
 840          * @return string Sanitized text in a CSS/JS comment that can be returned to the user
 841          */
 842         public static function formatException( $e ) {
 843                 return self::makeComment( self::formatExceptionNoComment( $e ) );
 844         }
 845
 846         /**
 847          * Handle exception display.
 848          *
 849          * @since 1.25
 850          * @param Exception $e Exception to be shown to the user
 851          * @return string Sanitized text that can be returned to the user
 852          */
 853         protected static function formatExceptionNoComment( $e ) {
 854                 global $wgShowExceptionDetails;
 855
 856                 if ( $wgShowExceptionDetails ) {
 857                         return $e->__toString();
 858                 } else {
 859                         return wfMessage( 'internalerror' )->text();
 860                 }
 861         }
 862
 863         /**
 864          * Generate code for a response.
 865          *
 866          * @param ResourceLoaderContext $context Context in which to generate a response
 867          * @param array $modules List of module objects keyed by module name
 868          * @param array $missing List of requested module names that are unregistered (optional)
 869          * @return string Response data
 870          */
 871         public function makeModuleResponse( ResourceLoaderContext $context,
 872                 array $modules, array $missing = array()
 873         ) {
 874                 $out = '';
 875                 $states = array();
 876
 877                 if ( !count( $modules ) && !count( $missing ) ) {
 878                         return "/* This file is the Web entry point for MediaWiki's ResourceLoader:
 879    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
 880    no modules were requested. Max made me put this here. */";
 881                 }
 882
 883                 wfProfileIn( __METHOD__ );
 884
 885                 $image = $context->getImageObj();
 886                 if ( $image ) {
 887                         $data = $image->getImageData( $context );
 888                         if ( $data === false ) {
 889                                 $data = '';
 890                                 $this->errors[] = 'Image generation failed';
 891                         }
 892                         wfProfileOut( __METHOD__ );
 893                         return $data;
 894                 }
 895
 896                 // Pre-fetch blobs
 897                 if ( $context->shouldIncludeMessages() ) {
 898                         try {
 899                                 $blobs = MessageBlobStore::getInstance()->get( $this, $modules, $context->getLanguage() );
 900                         } catch ( Exception $e ) {
 901                                 MWExceptionHandler::logException( $e );
 902                                 wfDebugLog(
 903                                         'resourceloader',
 904                                         __METHOD__ . ": pre-fetching blobs from MessageBlobStore failed: $e"
 905                                 );
 906                                 $this->errors[] = self::formatExceptionNoComment( $e );
 907                         }
 908                 } else {
 909                         $blobs = array();
 910                 }
 911
 912                 foreach ( $missing as $name ) {
 913                         $states[$name] = 'missing';
 914                 }
 915
 916                 // Generate output
 917                 $isRaw = false;
 918                 foreach ( $modules as $name => $module ) {
 919                         /**
 920                          * @var $module ResourceLoaderModule
 921                          */
 922
 923                         wfProfileIn( __METHOD__ . '-' . $name );
 924                         try {
 925                                 $scripts = '';
 926                                 if ( $context->shouldIncludeScripts() ) {
 927                                         // If we are in debug mode, we'll want to return an array of URLs if possible
 928                                         // However, we can't do this if the module doesn't support it
 929                                         // We also can't do this if there is an only= parameter, because we have to give
 930                                         // the module a way to return a load.php URL without causing an infinite loop
 931                                         if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
 932                                                 $scripts = $module->getScriptURLsForDebug( $context );
 933                                         } else {
 934                                                 $scripts = $module->getScript( $context );
 935                                                 // rtrim() because there are usually a few line breaks
 936                                                 // after the last ';'. A new line at EOF, a new line
 937                                                 // added by ResourceLoaderFileModule::readScriptFiles, etc.
 938                                                 if ( is_string( $scripts )
 939                                                         && strlen( $scripts )
 940                                                         && substr( rtrim( $scripts ), -1 ) !== ';'
 941                                                 ) {
 942                                                         // Append semicolon to prevent weird bugs caused by files not
 943                                                         // terminating their statements right (bug 27054)
 944                                                         $scripts .= ";\n";
 945                                                 }
 946                                         }
 947                                 }
 948                                 // Styles
 949                                 $styles = array();
 950                                 if ( $context->shouldIncludeStyles() ) {
 951                                         // Don't create empty stylesheets like array( '' => '' ) for modules
 952                                         // that don't *have* any stylesheets (bug 38024).
 953                                         $stylePairs = $module->getStyles( $context );
 954                                         if ( count( $stylePairs ) ) {
 955                                                 // If we are in debug mode without &only= set, we'll want to return an array of URLs
 956                                                 // See comment near shouldIncludeScripts() for more details
 957                                                 if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
 958                                                         $styles = array(
 959                                                                 'url' => $module->getStyleURLsForDebug( $context )
 960                                                         );
 961                                                 } else {
 962                                                         // Minify CSS before embedding in mw.loader.implement call
 963                                                         // (unless in debug mode)
 964                                                         if ( !$context->getDebug() ) {
 965                                                                 foreach ( $stylePairs as $media => $style ) {
 966                                                                         // Can be either a string or an array of strings.
 967                                                                         if ( is_array( $style ) ) {
 968                                                                                 $stylePairs[$media] = array();
 969                                                                                 foreach ( $style as $cssText ) {
 970                                                                                         if ( is_string( $cssText ) ) {
 971                                                                                                 $stylePairs[$media][] = $this->filter( 'minify-css', $cssText );
 972                                                                                         }
 973                                                                                 }
 974                                                                         } elseif ( is_string( $style ) ) {
 975                                                                                 $stylePairs[$media] = $this->filter( 'minify-css', $style );
 976                                                                         }
 977                                                                 }
 978                                                         }
 979                                                         // Wrap styles into @media groups as needed and flatten into a numerical array
 980                                                         $styles = array(
 981                                                                 'css' => self::makeCombinedStyles( $stylePairs )
 982                                                         );
 983                                                 }
 984                                         }
 985                                 }
 986
 987                                 // Messages
 988                                 $messagesBlob = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 989
 990                                 // Append output
 991                                 switch ( $context->getOnly() ) {
 992                                         case 'scripts':
 993                                                 if ( is_string( $scripts ) ) {
 994                                                         // Load scripts raw...
 995                                                         $out .= $scripts;
 996                                                 } elseif ( is_array( $scripts ) ) {
 997                                                         // ...except when $scripts is an array of URLs
 998                                                         $out .= self::makeLoaderImplementScript( $name, $scripts, array(), array() );
 999                                                 }
1000                                                 break;
1001                                         case 'styles':
1002                                                 // We no longer seperate into media, they are all combined now with
1003                                                 // custom media type groups into @media .. {} sections as part of the css string.
1004                                                 // Module returns either an empty array or a numerical array with css strings.
1005                                                 $out .= isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
1006                                                 break;
1007                                         case 'messages':
1008                                                 $out .= self::makeMessageSetScript( new XmlJsCode( $messagesBlob ) );
1009                                                 break;
1010                                         case 'templates':
1011                                                 $out .= Xml::encodeJsCall(
1012                                                         'mw.templates.set',
1013                                                         array( $name, (object)$module->getTemplates() ),
1014                                                         ResourceLoader::inDebugMode()
1015                                                 );
1016                                                 break;
1017                                         default:
1018                                                 $out .= self::makeLoaderImplementScript(
1019                                                         $name,
1020                                                         $scripts,
1021                                                         $styles,
1022                                                         new XmlJsCode( $messagesBlob ),
1023                                                         $module->getTemplates()
1024                                                 );
1025                                                 break;
1026                                 }
1027                         } catch ( Exception $e ) {
1028                                 MWExceptionHandler::logException( $e );
1029                                 wfDebugLog( 'resourceloader', __METHOD__ . ": generating module package failed: $e" );
1030                                 $this->errors[] = self::formatExceptionNoComment( $e );
1031
1032                                 // Respond to client with error-state instead of module implementation
1033                                 $states[$name] = 'error';
1034                                 unset( $modules[$name] );
1035                         }
1036                         $isRaw |= $module->isRaw();
1037                         wfProfileOut( __METHOD__ . '-' . $name );
1038                 }
1039
1040                 // Update module states
1041                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
1042                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
1043                                 // Set the state of modules loaded as only scripts to ready as
1044                                 // they don't have an mw.loader.implement wrapper that sets the state
1045                                 foreach ( $modules as $name => $module ) {
1046                                         $states[$name] = 'ready';
1047                                 }
1048                         }
1049
1050                         // Set the state of modules we didn't respond to with mw.loader.implement
1051                         if ( count( $states ) ) {
1052                                 $out .= self::makeLoaderStateScript( $states );
1053                         }
1054                 } else {
1055                         if ( count( $states ) ) {
1056                                 $this->errors[] = 'Problematic modules: ' .
1057                                         FormatJson::encode( $states, ResourceLoader::inDebugMode() );
1058                         }
1059                 }
1060
1061                 if ( !$context->getDebug() ) {
1062                         if ( $context->getOnly() === 'styles' ) {
1063                                 $out = $this->filter( 'minify-css', $out );
1064                         } else {
1065                                 $out = $this->filter( 'minify-js', $out );
1066                         }
1067                 }
1068
1069                 wfProfileOut( __METHOD__ );
1070                 return $out;
1071         }
1072
1073         /* Static Methods */
1074
1075         /**
1076          * Return JS code that calls mw.loader.implement with given module properties.
1077          *
1078          * @param string $name Module name
1079          * @param mixed $scripts List of URLs to JavaScript files or String of JavaScript code
1080          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1081          *   to CSS files keyed by media type
1082          * @param mixed $messages List of messages associated with this module. May either be an
1083          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1084          *   the same data, wrapped in an XmlJsCode object.
1085          * @param array $templates Keys are name of templates and values are the source of
1086          *   the template.
1087          * @throws MWException
1088          * @return string
1089          */
1090         public static function makeLoaderImplementScript( $name, $scripts, $styles,
1091                 $messages, $templates
1092         ) {
1093                 if ( is_string( $scripts ) ) {
1094                         $scripts = new XmlJsCode( "function ( $, jQuery ) {\n{$scripts}\n}" );
1095                 } elseif ( !is_array( $scripts ) ) {
1096                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1097                 }
1098
1099                 return Xml::encodeJsCall(
1100                         'mw.loader.implement',
1101                         array(
1102                                 $name,
1103                                 $scripts,
1104                                 // Force objects. mw.loader.implement requires them to be javascript objects.
1105                                 // Although these variables are associative arrays, which become javascript
1106                                 // objects through json_encode. In many cases they will be empty arrays, and
1107                                 // PHP/json_encode() consider empty arrays to be numerical arrays and
1108                                 // output javascript "[]" instead of "{}". This fixes that.
1109                                 (object)$styles,
1110                                 (object)$messages,
1111                                 (object)$templates,
1112                         ),
1113                         ResourceLoader::inDebugMode()
1114                 );
1115         }
1116
1117         /**
1118          * Returns JS code which, when called, will register a given list of messages.
1119          *
1120          * @param mixed $messages Either an associative array mapping message key to value, or a
1121          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1122          * @return string
1123          */
1124         public static function makeMessageSetScript( $messages ) {
1125                 return Xml::encodeJsCall(
1126                         'mw.messages.set',
1127                         array( (object)$messages ),
1128                         ResourceLoader::inDebugMode()
1129                 );
1130         }
1131
1132         /**
1133          * Combines an associative array mapping media type to CSS into a
1134          * single stylesheet with "@media" blocks.
1135          *
1136          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1137          * @return array
1138          */
1139         public static function makeCombinedStyles( array $stylePairs ) {
1140                 $out = array();
1141                 foreach ( $stylePairs as $media => $styles ) {
1142                         // ResourceLoaderFileModule::getStyle can return the styles
1143                         // as a string or an array of strings. This is to allow separation in
1144                         // the front-end.
1145                         $styles = (array)$styles;
1146                         foreach ( $styles as $style ) {
1147                                 $style = trim( $style );
1148                                 // Don't output an empty "@media print { }" block (bug 40498)
1149                                 if ( $style !== '' ) {
1150                                         // Transform the media type based on request params and config
1151                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1152                                         $media = OutputPage::transformCssMedia( $media );
1153
1154                                         if ( $media === '' || $media == 'all' ) {
1155                                                 $out[] = $style;
1156                                         } elseif ( is_string( $media ) ) {
1157                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1158                                         }
1159                                         // else: skip
1160                                 }
1161                         }
1162                 }
1163                 return $out;
1164         }
1165
1166         /**
1167          * Returns a JS call to mw.loader.state, which sets the state of a
1168          * module or modules to a given value. Has two calling conventions:
1169          *
1170          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1171          *         Set the state of a single module called $name to $state
1172          *
1173          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
1174          *         Set the state of modules with the given names to the given states
1175          *
1176          * @param string $name
1177          * @param string $state
1178          * @return string
1179          */
1180         public static function makeLoaderStateScript( $name, $state = null ) {
1181                 if ( is_array( $name ) ) {
1182                         return Xml::encodeJsCall(
1183                                 'mw.loader.state',
1184                                 array( $name ),
1185                                 ResourceLoader::inDebugMode()
1186                         );
1187                 } else {
1188                         return Xml::encodeJsCall(
1189                                 'mw.loader.state',
1190                                 array( $name, $state ),
1191                                 ResourceLoader::inDebugMode()
1192                         );
1193                 }
1194         }
1195
1196         /**
1197          * Returns JS code which calls the script given by $script. The script will
1198          * be called with local variables name, version, dependencies and group,
1199          * which will have values corresponding to $name, $version, $dependencies
1200          * and $group as supplied.
1201          *
1202          * @param string $name Module name
1203          * @param int $version Module version number as a timestamp
1204          * @param array $dependencies List of module names on which this module depends
1205          * @param string $group Group which the module is in.
1206          * @param string $source Source of the module, or 'local' if not foreign.
1207          * @param string $script JavaScript code
1208          * @return string
1209          */
1210         public static function makeCustomLoaderScript( $name, $version, $dependencies,
1211                 $group, $source, $script
1212         ) {
1213                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1214                 return Xml::encodeJsCall(
1215                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1216                         array( $name, $version, $dependencies, $group, $source ),
1217                         ResourceLoader::inDebugMode()
1218                 );
1219         }
1220
1221         /**
1222          * Remove empty values from the end of an array.
1223          *
1224          * Values considered empty:
1225          *
1226          * - null
1227          * - empty array
1228          *
1229          * @param Array $array
1230          */
1231         private static function trimArray( Array &$array ) {
1232                 $i = count( $array );
1233                 while ( $i-- ) {
1234                         if ( $array[$i] === null || $array[$i] === array() ) {
1235                                 unset( $array[$i] );
1236                         } else {
1237                                 break;
1238                         }
1239                 }
1240         }
1241
1242         /**
1243          * Returns JS code which calls mw.loader.register with the given
1244          * parameters. Has three calling conventions:
1245          *
1246          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version,
1247          *        $dependencies, $group, $source, $skip
1248          *     ):
1249          *        Register a single module.
1250          *
1251          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
1252          *        Register modules with the given names.
1253          *
1254          *   - ResourceLoader::makeLoaderRegisterScript( array(
1255          *        array( $name1, $version1, $dependencies1, $group1, $source1, $skip1 ),
1256          *        array( $name2, $version2, $dependencies1, $group2, $source2, $skip2 ),
1257          *        ...
1258          *     ) ):
1259          *        Registers modules with the given names and parameters.
1260          *
1261          * @param string $name Module name
1262          * @param int $version Module version number as a timestamp
1263          * @param array $dependencies List of module names on which this module depends
1264          * @param string $group Group which the module is in
1265          * @param string $source Source of the module, or 'local' if not foreign
1266          * @param string $skip Script body of the skip function
1267          * @return string
1268          */
1269         public static function makeLoaderRegisterScript( $name, $version = null,
1270                 $dependencies = null, $group = null, $source = null, $skip = null
1271         ) {
1272                 if ( is_array( $name ) ) {
1273                         // Build module name index
1274                         $index = array();
1275                         foreach ( $name as $i => &$module ) {
1276                                 $index[$module[0]] = $i;
1277                         }
1278
1279                         // Transform dependency names into indexes when possible, they will be resolved by
1280                         // mw.loader.register on the other end
1281                         foreach ( $name as &$module ) {
1282                                 if ( isset( $module[2] ) ) {
1283                                         foreach ( $module[2] as &$dependency ) {
1284                                                 if ( isset( $index[$dependency] ) ) {
1285                                                         $dependency = $index[$dependency];
1286                                                 }
1287                                         }
1288                                 }
1289                         }
1290
1291                         array_walk( $name, array( 'self', 'trimArray' ) );
1292
1293                         return Xml::encodeJsCall(
1294                                 'mw.loader.register',
1295                                 array( $name ),
1296                                 ResourceLoader::inDebugMode()
1297                         );
1298                 } else {
1299                         $registration = array( $name, $version, $dependencies, $group, $source, $skip );
1300                         self::trimArray( $registration );
1301                         return Xml::encodeJsCall(
1302                                 'mw.loader.register',
1303                                 $registration,
1304                                 ResourceLoader::inDebugMode()
1305                         );
1306                 }
1307         }
1308
1309         /**
1310          * Returns JS code which calls mw.loader.addSource() with the given
1311          * parameters. Has two calling conventions:
1312          *
1313          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1314          *       Register a single source
1315          *
1316          *   - ResourceLoader::makeLoaderSourcesScript( array( $id1 => $loadUrl, $id2 => $loadUrl, ... ) );
1317          *       Register sources with the given IDs and properties.
1318          *
1319          * @param string $id Source ID
1320          * @param array $properties Source properties (see addSource())
1321          * @return string
1322          */
1323         public static function makeLoaderSourcesScript( $id, $properties = null ) {
1324                 if ( is_array( $id ) ) {
1325                         return Xml::encodeJsCall(
1326                                 'mw.loader.addSource',
1327                                 array( $id ),
1328                                 ResourceLoader::inDebugMode()
1329                         );
1330                 } else {
1331                         return Xml::encodeJsCall(
1332                                 'mw.loader.addSource',
1333                                 array( $id, $properties ),
1334                                 ResourceLoader::inDebugMode()
1335                         );
1336                 }
1337         }
1338
1339         /**
1340          * Returns JS code which runs given JS code if the client-side framework is
1341          * present.
1342          *
1343          * @param string $script JavaScript code
1344          * @return string
1345          */
1346         public static function makeLoaderConditionalScript( $script ) {
1347                 return "if(window.mw){\n" . trim( $script ) . "\n}";
1348         }
1349
1350         /**
1351          * Returns JS code which will set the MediaWiki configuration array to
1352          * the given value.
1353          *
1354          * @param array $configuration List of configuration values keyed by variable name
1355          * @return string
1356          */
1357         public static function makeConfigSetScript( array $configuration ) {
1358                 return Xml::encodeJsCall(
1359                         'mw.config.set',
1360                         array( $configuration ),
1361                         ResourceLoader::inDebugMode()
1362                 );
1363         }
1364
1365         /**
1366          * Convert an array of module names to a packed query string.
1367          *
1368          * For example, array( 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' )
1369          * becomes 'foo.bar,baz|bar.baz,quux'
1370          * @param array $modules List of module names (strings)
1371          * @return string Packed query string
1372          */
1373         public static function makePackedModulesString( $modules ) {
1374                 $groups = array(); // array( prefix => array( suffixes ) )
1375                 foreach ( $modules as $module ) {
1376                         $pos = strrpos( $module, '.' );
1377                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1378                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1379                         $groups[$prefix][] = $suffix;
1380                 }
1381
1382                 $arr = array();
1383                 foreach ( $groups as $prefix => $suffixes ) {
1384                         $p = $prefix === '' ? '' : $prefix . '.';
1385                         $arr[] = $p . implode( ',', $suffixes );
1386                 }
1387                 $str = implode( '|', $arr );
1388                 return $str;
1389         }
1390
1391         /**
1392          * Determine whether debug mode was requested
1393          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1394          * @return bool
1395          */
1396         public static function inDebugMode() {
1397                 if ( self::$debugMode === null ) {
1398                         global $wgRequest, $wgResourceLoaderDebug;
1399                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1400                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1401                         );
1402                 }
1403                 return self::$debugMode;
1404         }
1405
1406         /**
1407          * Reset static members used for caching.
1408          *
1409          * Global state and $wgRequest are evil, but we're using it right
1410          * now and sometimes we need to be able to force ResourceLoader to
1411          * re-evaluate the context because it has changed (e.g. in the test suite).
1412          */
1413         public static function clearCache() {
1414                 self::$debugMode = null;
1415         }
1416
1417         /**
1418          * Build a load.php URL
1419          *
1420          * @since 1.24
1421          * @param string $source Name of the ResourceLoader source
1422          * @param ResourceLoaderContext $context
1423          * @param array $extraQuery
1424          * @return string URL to load.php. May be protocol-relative (if $wgLoadScript is procol-relative)
1425          */
1426         public function createLoaderURL( $source, ResourceLoaderContext $context,
1427                 $extraQuery = array()
1428         ) {
1429                 $query = self::createLoaderQuery( $context, $extraQuery );
1430                 $script = $this->getLoadScript( $source );
1431
1432                 // Prevent the IE6 extension check from being triggered (bug 28840)
1433                 // by appending a character that's invalid in Windows extensions ('*')
1434                 return wfExpandUrl( wfAppendQuery( $script, $query ) . '&*', PROTO_RELATIVE );
1435         }
1436
1437         /**
1438          * Build a load.php URL
1439          * @deprecated since 1.24, use createLoaderURL instead
1440          * @param array $modules Array of module names (strings)
1441          * @param string $lang Language code
1442          * @param string $skin Skin name
1443          * @param string|null $user User name. If null, the &user= parameter is omitted
1444          * @param string|null $version Versioning timestamp
1445          * @param bool $debug Whether the request should be in debug mode
1446          * @param string|null $only &only= parameter
1447          * @param bool $printable Printable mode
1448          * @param bool $handheld Handheld mode
1449          * @param array $extraQuery Extra query parameters to add
1450          * @return string URL to load.php. May be protocol-relative (if $wgLoadScript is procol-relative)
1451          */
1452         public static function makeLoaderURL( $modules, $lang, $skin, $user = null,
1453                 $version = null, $debug = false, $only = null, $printable = false,
1454                 $handheld = false, $extraQuery = array()
1455         ) {
1456                 global $wgLoadScript;
1457
1458                 $query = self::makeLoaderQuery( $modules, $lang, $skin, $user, $version, $debug,
1459                         $only, $printable, $handheld, $extraQuery
1460                 );
1461
1462                 // Prevent the IE6 extension check from being triggered (bug 28840)
1463                 // by appending a character that's invalid in Windows extensions ('*')
1464                 return wfExpandUrl( wfAppendQuery( $wgLoadScript, $query ) . '&*', PROTO_RELATIVE );
1465         }
1466
1467         /**
1468          * Helper for createLoaderURL()
1469          *
1470          * @since 1.24
1471          * @see makeLoaderQuery
1472          * @param ResourceLoaderContext $context
1473          * @param array $extraQuery
1474          * @return array
1475          */
1476         public static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = array() ) {
1477                 return self::makeLoaderQuery(
1478                         $context->getModules(),
1479                         $context->getLanguage(),
1480                         $context->getSkin(),
1481                         $context->getUser(),
1482                         $context->getVersion(),
1483                         $context->getDebug(),
1484                         $context->getOnly(),
1485                         $context->getRequest()->getBool( 'printable' ),
1486                         $context->getRequest()->getBool( 'handheld' ),
1487                         $extraQuery
1488                 );
1489         }
1490
1491         /**
1492          * Build a query array (array representation of query string) for load.php. Helper
1493          * function for makeLoaderURL().
1494          *
1495          * @param array $modules
1496          * @param string $lang
1497          * @param string $skin
1498          * @param string $user
1499          * @param string $version
1500          * @param bool $debug
1501          * @param string $only
1502          * @param bool $printable
1503          * @param bool $handheld
1504          * @param array $extraQuery
1505          *
1506          * @return array
1507          */
1508         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1509                 $version = null, $debug = false, $only = null, $printable = false,
1510                 $handheld = false, $extraQuery = array()
1511         ) {
1512                 $query = array(
1513                         'modules' => self::makePackedModulesString( $modules ),
1514                         'lang' => $lang,
1515                         'skin' => $skin,
1516                         'debug' => $debug ? 'true' : 'false',
1517                 );
1518                 if ( $user !== null ) {
1519                         $query['user'] = $user;
1520                 }
1521                 if ( $version !== null ) {
1522                         $query['version'] = $version;
1523                 }
1524                 if ( $only !== null ) {
1525                         $query['only'] = $only;
1526                 }
1527                 if ( $printable ) {
1528                         $query['printable'] = 1;
1529                 }
1530                 if ( $handheld ) {
1531                         $query['handheld'] = 1;
1532                 }
1533                 $query += $extraQuery;
1534
1535                 // Make queries uniform in order
1536                 ksort( $query );
1537                 return $query;
1538         }
1539
1540         /**
1541          * Check a module name for validity.
1542          *
1543          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1544          * at most 255 bytes.
1545          *
1546          * @param string $moduleName Module name to check
1547          * @return bool Whether $moduleName is a valid module name
1548          */
1549         public static function isValidModuleName( $moduleName ) {
1550                 return !preg_match( '/[|,!]/', $moduleName ) && strlen( $moduleName ) <= 255;
1551         }
1552
1553         /**
1554          * Returns LESS compiler set up for use with MediaWiki
1555          *
1556          * @param Config $config
1557          * @throws MWException
1558          * @since 1.22
1559          * @return lessc
1560          */
1561         public static function getLessCompiler( Config $config ) {
1562                 // When called from the installer, it is possible that a required PHP extension
1563                 // is missing (at least for now; see bug 47564). If this is the case, throw an
1564                 // exception (caught by the installer) to prevent a fatal error later on.
1565                 if ( !class_exists( 'lessc' ) ) {
1566                         throw new MWException( 'MediaWiki requires the lessphp compiler' );
1567                 }
1568                 if ( !function_exists( 'ctype_digit' ) ) {
1569                         throw new MWException( 'lessc requires the Ctype extension' );
1570                 }
1571
1572                 $less = new lessc();
1573                 $less->setPreserveComments( true );
1574                 $less->setVariables( self::getLessVars( $config ) );
1575                 $less->setImportDir( $config->get( 'ResourceLoaderLESSImportPaths' ) );
1576                 foreach ( $config->get( 'ResourceLoaderLESSFunctions' ) as $name => $func ) {
1577                         $less->registerFunction( $name, $func );
1578                 }
1579                 return $less;
1580         }
1581
1582         /**
1583          * Get global LESS variables.
1584          *
1585          * @param Config $config
1586          * @since 1.22
1587          * @return array Map of variable names to string CSS values.
1588          */
1589         public static function getLessVars( Config $config ) {
1590                 $lessVars = $config->get( 'ResourceLoaderLESSVars' );
1591                 // Sort by key to ensure consistent hashing for cache lookups.
1592                 ksort( $lessVars );
1593                 return $lessVars;
1594         }
1595 }