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 use Psr\Log\LoggerAwareInterface;
  26 use Psr\Log\LoggerInterface;
  27 use Psr\Log\NullLogger;
  28 use WrappedString\WrappedString;
  29
  30 /**
  31  * Dynamic JavaScript and CSS resource loading system.
  32  *
  33  * Most of the documentation is on the MediaWiki documentation wiki starting at:
  34  *    https://www.mediawiki.org/wiki/ResourceLoader
  35  */
  36 class ResourceLoader implements LoggerAwareInterface {
  37         /** @var int */
  38         protected static $filterCacheVersion = 7;
  39
  40         /** @var bool */
  41         protected static $debugMode = null;
  42
  43         /** @var array */
  44         private $lessVars = null;
  45
  46         /**
  47          * Module name/ResourceLoaderModule object pairs
  48          * @var array
  49          */
  50         protected $modules = [];
  51
  52         /**
  53          * Associative array mapping module name to info associative array
  54          * @var array
  55          */
  56         protected $moduleInfos = [];
  57
  58         /** @var Config $config */
  59         private $config;
  60
  61         /**
  62          * Associative array mapping framework ids to a list of names of test suite modules
  63          * like array( 'qunit' => array( 'mediawiki.tests.qunit.suites', 'ext.foo.tests', .. ), .. )
  64          * @var array
  65          */
  66         protected $testModuleNames = [];
  67
  68         /**
  69          * E.g. array( 'source-id' => 'http://.../load.php' )
  70          * @var array
  71          */
  72         protected $sources = [];
  73
  74         /**
  75          * Errors accumulated during current respond() call.
  76          * @var array
  77          */
  78         protected $errors = [];
  79
  80         /**
  81          * @var MessageBlobStore
  82          */
  83         protected $blobStore;
  84
  85         /**
  86          * @var LoggerInterface
  87          */
  88         private $logger;
  89
  90         /** @var string JavaScript / CSS pragma to disable minification. **/
  91         const FILTER_NOMIN = '/*@nomin*/';
  92
  93         /**
  94          * Load information stored in the database about modules.
  95          *
  96          * This method grabs modules dependencies from the database and updates modules
  97          * objects.
  98          *
  99          * This is not inside the module code because it is much faster to
 100          * request all of the information at once than it is to have each module
 101          * requests its own information. This sacrifice of modularity yields a substantial
 102          * performance improvement.
 103          *
 104          * @param array $moduleNames List of module names to preload information for
 105          * @param ResourceLoaderContext $context Context to load the information within
 106          */
 107         public function preloadModuleInfo( array $moduleNames, ResourceLoaderContext $context ) {
 108                 if ( !$moduleNames ) {
 109                         // Or else Database*::select() will explode, plus it's cheaper!
 110                         return;
 111                 }
 112                 $dbr = wfGetDB( DB_SLAVE );
 113                 $skin = $context->getSkin();
 114                 $lang = $context->getLanguage();
 115
 116                 // Batched version of ResourceLoaderModule::getFileDependencies
 117                 $vary = "$skin|$lang";
 118                 $res = $dbr->select( 'module_deps', [ 'md_module', 'md_deps' ], [
 119                                 'md_module' => $moduleNames,
 120                                 'md_skin' => $vary,
 121                         ], __METHOD__
 122                 );
 123
 124                 // Prime in-object cache for file dependencies
 125                 $modulesWithDeps = [];
 126                 foreach ( $res as $row ) {
 127                         $module = $this->getModule( $row->md_module );
 128                         if ( $module ) {
 129                                 $module->setFileDependencies( $context, ResourceLoaderModule::expandRelativePaths(
 130                                         FormatJson::decode( $row->md_deps, true )
 131                                 ) );
 132                                 $modulesWithDeps[] = $row->md_module;
 133                         }
 134                 }
 135                 // Register the absence of a dependency row too
 136                 foreach ( array_diff( $moduleNames, $modulesWithDeps ) as $name ) {
 137                         $module = $this->getModule( $name );
 138                         if ( $module ) {
 139                                 $this->getModule( $name )->setFileDependencies( $context, [] );
 140                         }
 141                 }
 142
 143                 // Prime in-object cache for message blobs for modules with messages
 144                 $modules = [];
 145                 foreach ( $moduleNames as $name ) {
 146                         $module = $this->getModule( $name );
 147                         if ( $module && $module->getMessages() ) {
 148                                 $modules[$name] = $module;
 149                         }
 150                 }
 151                 $store = $this->getMessageBlobStore();
 152                 $blobs = $store->getBlobs( $modules, $lang );
 153                 foreach ( $blobs as $name => $blob ) {
 154                         $modules[$name]->setMessageBlob( $blob, $lang );
 155                 }
 156         }
 157
 158         /**
 159          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 160          *
 161          * Available filters are:
 162          *
 163          *    - minify-js \see JavaScriptMinifier::minify
 164          *    - minify-css \see CSSMin::minify
 165          *
 166          * If $data is empty, only contains whitespace or the filter was unknown,
 167          * $data is returned unmodified.
 168          *
 169          * @param string $filter Name of filter to run
 170          * @param string $data Text to filter, such as JavaScript or CSS text
 171          * @param array $options Keys:
 172          *  - (bool) cache: Whether to allow caching this data. Default: true.
 173          * @return string Filtered data, or a comment containing an error message
 174          */
 175         public static function filter( $filter, $data, array $options = [] ) {
 176                 if ( strpos( $data, ResourceLoader::FILTER_NOMIN ) !== false ) {
 177                         return $data;
 178                 }
 179
 180                 if ( isset( $options['cache'] ) && $options['cache'] === false ) {
 181                         return self::applyFilter( $filter, $data );
 182                 }
 183
 184                 $stats = RequestContext::getMain()->getStats();
 185                 $cache = ObjectCache::getLocalServerInstance( CACHE_ANYTHING );
 186
 187                 $key = $cache->makeGlobalKey(
 188                         'resourceloader',
 189                         'filter',
 190                         $filter,
 191                         self::$filterCacheVersion, md5( $data )
 192                 );
 193
 194                 $result = $cache->get( $key );
 195                 if ( $result === false ) {
 196                         $stats->increment( "resourceloader_cache.$filter.miss" );
 197                         $result = self::applyFilter( $filter, $data );
 198                         $cache->set( $key, $result, 24 * 3600 );
 199                 } else {
 200                         $stats->increment( "resourceloader_cache.$filter.hit" );
 201                 }
 202                 if ( $result === null ) {
 203                         // Cached failure
 204                         $result = $data;
 205                 }
 206
 207                 return $result;
 208         }
 209
 210         private static function applyFilter( $filter, $data ) {
 211                 $data = trim( $data );
 212                 if ( $data ) {
 213                         try {
 214                                 $data = ( $filter === 'minify-css' )
 215                                         ? CSSMin::minify( $data )
 216                                         : JavaScriptMinifier::minify( $data );
 217                         } catch ( Exception $e ) {
 218                                 MWExceptionHandler::logException( $e );
 219                                 return null;
 220                         }
 221                 }
 222                 return $data;
 223         }
 224
 225         /* Methods */
 226
 227         /**
 228          * Register core modules and runs registration hooks.
 229          * @param Config $config [optional]
 230          * @param LoggerInterface $logger [optional]
 231          */
 232         public function __construct( Config $config = null, LoggerInterface $logger = null ) {
 233                 global $IP;
 234
 235                 $this->logger = $logger ?: new NullLogger();
 236
 237                 if ( !$config ) {
 238                         $this->logger->debug( __METHOD__ . ' was called without providing a Config instance' );
 239                         $config = ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
 240                 }
 241                 $this->config = $config;
 242
 243                 // Add 'local' source first
 244                 $this->addSource( 'local', wfScript( 'load' ) );
 245
 246                 // Add other sources
 247                 $this->addSource( $config->get( 'ResourceLoaderSources' ) );
 248
 249                 // Register core modules
 250                 $this->register( include "$IP/resources/Resources.php" );
 251                 $this->register( include "$IP/resources/ResourcesOOUI.php" );
 252                 // Register extension modules
 253                 $this->register( $config->get( 'ResourceModules' ) );
 254                 Hooks::run( 'ResourceLoaderRegisterModules', [ &$this ] );
 255
 256                 if ( $config->get( 'EnableJavaScriptTest' ) === true ) {
 257                         $this->registerTestModules();
 258                 }
 259
 260                 $this->setMessageBlobStore( new MessageBlobStore( $this, $this->logger ) );
 261         }
 262
 263         /**
 264          * @return Config
 265          */
 266         public function getConfig() {
 267                 return $this->config;
 268         }
 269
 270         /**
 271          * @since 1.26
 272          * @param LoggerInterface $logger
 273          */
 274         public function setLogger( LoggerInterface $logger ) {
 275                 $this->logger = $logger;
 276         }
 277
 278         /**
 279          * @since 1.27
 280          * @return LoggerInterface
 281          */
 282         public function getLogger() {
 283                 return $this->logger;
 284         }
 285
 286         /**
 287          * @since 1.26
 288          * @return MessageBlobStore
 289          */
 290         public function getMessageBlobStore() {
 291                 return $this->blobStore;
 292         }
 293
 294         /**
 295          * @since 1.25
 296          * @param MessageBlobStore $blobStore
 297          */
 298         public function setMessageBlobStore( MessageBlobStore $blobStore ) {
 299                 $this->blobStore = $blobStore;
 300         }
 301
 302         /**
 303          * Register a module with the ResourceLoader system.
 304          *
 305          * @param mixed $name Name of module as a string or List of name/object pairs as an array
 306          * @param array $info Module info array. For backwards compatibility with 1.17alpha,
 307          *   this may also be a ResourceLoaderModule object. Optional when using
 308          *   multiple-registration calling style.
 309          * @throws MWException If a duplicate module registration is attempted
 310          * @throws MWException If a module name contains illegal characters (pipes or commas)
 311          * @throws MWException If something other than a ResourceLoaderModule is being registered
 312          * @return bool False if there were any errors, in which case one or more modules were
 313          *   not registered
 314          */
 315         public function register( $name, $info = null ) {
 316                 $moduleSkinStyles = $this->config->get( 'ResourceModuleSkinStyles' );
 317
 318                 // Allow multiple modules to be registered in one call
 319                 $registrations = is_array( $name ) ? $name : [ $name => $info ];
 320                 foreach ( $registrations as $name => $info ) {
 321                         // Warn on duplicate registrations
 322                         if ( isset( $this->moduleInfos[$name] ) ) {
 323                                 // A module has already been registered by this name
 324                                 $this->logger->warning(
 325                                         'ResourceLoader duplicate registration warning. ' .
 326                                         'Another module has already been registered as ' . $name
 327                                 );
 328                         }
 329
 330                         // Check $name for validity
 331                         if ( !self::isValidModuleName( $name ) ) {
 332                                 throw new MWException( "ResourceLoader module name '$name' is invalid, "
 333                                         . "see ResourceLoader::isValidModuleName()" );
 334                         }
 335
 336                         // Attach module
 337                         if ( $info instanceof ResourceLoaderModule ) {
 338                                 $this->moduleInfos[$name] = [ 'object' => $info ];
 339                                 $info->setName( $name );
 340                                 $this->modules[$name] = $info;
 341                         } elseif ( is_array( $info ) ) {
 342                                 // New calling convention
 343                                 $this->moduleInfos[$name] = $info;
 344                         } else {
 345                                 throw new MWException(
 346                                         'ResourceLoader module info type error for module \'' . $name .
 347                                         '\': expected ResourceLoaderModule or array (got: ' . gettype( $info ) . ')'
 348                                 );
 349                         }
 350
 351                         // Last-minute changes
 352
 353                         // Apply custom skin-defined styles to existing modules.
 354                         if ( $this->isFileModule( $name ) ) {
 355                                 foreach ( $moduleSkinStyles as $skinName => $skinStyles ) {
 356                                         // If this module already defines skinStyles for this skin, ignore $wgResourceModuleSkinStyles.
 357                                         if ( isset( $this->moduleInfos[$name]['skinStyles'][$skinName] ) ) {
 358                                                 continue;
 359                                         }
 360
 361                                         // If $name is preceded with a '+', the defined style files will be added to 'default'
 362                                         // skinStyles, otherwise 'default' will be ignored as it normally would be.
 363                                         if ( isset( $skinStyles[$name] ) ) {
 364                                                 $paths = (array)$skinStyles[$name];
 365                                                 $styleFiles = [];
 366                                         } elseif ( isset( $skinStyles['+' . $name] ) ) {
 367                                                 $paths = (array)$skinStyles['+' . $name];
 368                                                 $styleFiles = isset( $this->moduleInfos[$name]['skinStyles']['default'] ) ?
 369                                                         (array)$this->moduleInfos[$name]['skinStyles']['default'] :
 370                                                         [];
 371                                         } else {
 372                                                 continue;
 373                                         }
 374
 375                                         // Add new file paths, remapping them to refer to our directories and not use settings
 376                                         // from the module we're modifying, which come from the base definition.
 377                                         list( $localBasePath, $remoteBasePath ) =
 378                                                 ResourceLoaderFileModule::extractBasePaths( $skinStyles );
 379
 380                                         foreach ( $paths as $path ) {
 381                                                 $styleFiles[] = new ResourceLoaderFilePath( $path, $localBasePath, $remoteBasePath );
 382                                         }
 383
 384                                         $this->moduleInfos[$name]['skinStyles'][$skinName] = $styleFiles;
 385                                 }
 386                         }
 387                 }
 388
 389         }
 390
 391         /**
 392          */
 393         public function registerTestModules() {
 394                 global $IP;
 395
 396                 if ( $this->config->get( 'EnableJavaScriptTest' ) !== true ) {
 397                         throw new MWException( 'Attempt to register JavaScript test modules '
 398                                 . 'but <code>$wgEnableJavaScriptTest</code> is false. '
 399                                 . 'Edit your <code>LocalSettings.php</code> to enable it.' );
 400                 }
 401
 402                 // Get core test suites
 403                 $testModules = [];
 404                 $testModules['qunit'] = [];
 405                 // Get other test suites (e.g. from extensions)
 406                 Hooks::run( 'ResourceLoaderTestModules', [ &$testModules, &$this ] );
 407
 408                 // Add the testrunner (which configures QUnit) to the dependencies.
 409                 // Since it must be ready before any of the test suites are executed.
 410                 foreach ( $testModules['qunit'] as &$module ) {
 411                         // Make sure all test modules are top-loading so that when QUnit starts
 412                         // on document-ready, it will run once and finish. If some tests arrive
 413                         // later (possibly after QUnit has already finished) they will be ignored.
 414                         $module['position'] = 'top';
 415                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 416                 }
 417
 418                 $testModules['qunit'] =
 419                         ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules['qunit'];
 420
 421                 foreach ( $testModules as $id => $names ) {
 422                         // Register test modules
 423                         $this->register( $testModules[$id] );
 424
 425                         // Keep track of their names so that they can be loaded together
 426                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 427                 }
 428
 429         }
 430
 431         /**
 432          * Add a foreign source of modules.
 433          *
 434          * Source IDs are typically the same as the Wiki ID or database name (e.g. lowercase a-z).
 435          *
 436          * @param array|string $id Source ID (string), or array( id1 => loadUrl, id2 => loadUrl, ... )
 437          * @param string|array $loadUrl load.php url (string), or array with loadUrl key for
 438          *  backwards-compatibility.
 439          * @throws MWException
 440          */
 441         public function addSource( $id, $loadUrl = null ) {
 442                 // Allow multiple sources to be registered in one call
 443                 if ( is_array( $id ) ) {
 444                         foreach ( $id as $key => $value ) {
 445                                 $this->addSource( $key, $value );
 446                         }
 447                         return;
 448                 }
 449
 450                 // Disallow duplicates
 451                 if ( isset( $this->sources[$id] ) ) {
 452                         throw new MWException(
 453                                 'ResourceLoader duplicate source addition error. ' .
 454                                 'Another source has already been registered as ' . $id
 455                         );
 456                 }
 457
 458                 // Pre 1.24 backwards-compatibility
 459                 if ( is_array( $loadUrl ) ) {
 460                         if ( !isset( $loadUrl['loadScript'] ) ) {
 461                                 throw new MWException(
 462                                         __METHOD__ . ' was passed an array with no "loadScript" key.'
 463                                 );
 464                         }
 465
 466                         $loadUrl = $loadUrl['loadScript'];
 467                 }
 468
 469                 $this->sources[$id] = $loadUrl;
 470         }
 471
 472         /**
 473          * Get a list of module names.
 474          *
 475          * @return array List of module names
 476          */
 477         public function getModuleNames() {
 478                 return array_keys( $this->moduleInfos );
 479         }
 480
 481         /**
 482          * Get a list of test module names for one (or all) frameworks.
 483          *
 484          * If the given framework id is unknkown, or if the in-object variable is not an array,
 485          * then it will return an empty array.
 486          *
 487          * @param string $framework Get only the test module names for one
 488          *   particular framework (optional)
 489          * @return array
 490          */
 491         public function getTestModuleNames( $framework = 'all' ) {
 492                 /** @todo api siteinfo prop testmodulenames modulenames */
 493                 if ( $framework == 'all' ) {
 494                         return $this->testModuleNames;
 495                 } elseif ( isset( $this->testModuleNames[$framework] )
 496                         && is_array( $this->testModuleNames[$framework] )
 497                 ) {
 498                         return $this->testModuleNames[$framework];
 499                 } else {
 500                         return [];
 501                 }
 502         }
 503
 504         /**
 505          * Check whether a ResourceLoader module is registered
 506          *
 507          * @since 1.25
 508          * @param string $name
 509          * @return bool
 510          */
 511         public function isModuleRegistered( $name ) {
 512                 return isset( $this->moduleInfos[$name] );
 513         }
 514
 515         /**
 516          * Get the ResourceLoaderModule object for a given module name.
 517          *
 518          * If an array of module parameters exists but a ResourceLoaderModule object has not
 519          * yet been instantiated, this method will instantiate and cache that object such that
 520          * subsequent calls simply return the same object.
 521          *
 522          * @param string $name Module name
 523          * @return ResourceLoaderModule|null If module has been registered, return a
 524          *  ResourceLoaderModule instance. Otherwise, return null.
 525          */
 526         public function getModule( $name ) {
 527                 if ( !isset( $this->modules[$name] ) ) {
 528                         if ( !isset( $this->moduleInfos[$name] ) ) {
 529                                 // No such module
 530                                 return null;
 531                         }
 532                         // Construct the requested object
 533                         $info = $this->moduleInfos[$name];
 534                         /** @var ResourceLoaderModule $object */
 535                         if ( isset( $info['object'] ) ) {
 536                                 // Object given in info array
 537                                 $object = $info['object'];
 538                         } else {
 539                                 if ( !isset( $info['class'] ) ) {
 540                                         $class = 'ResourceLoaderFileModule';
 541                                 } else {
 542                                         $class = $info['class'];
 543                                 }
 544                                 /** @var ResourceLoaderModule $object */
 545                                 $object = new $class( $info );
 546                                 $object->setConfig( $this->getConfig() );
 547                                 $object->setLogger( $this->logger );
 548                         }
 549                         $object->setName( $name );
 550                         $this->modules[$name] = $object;
 551                 }
 552
 553                 return $this->modules[$name];
 554         }
 555
 556         /**
 557          * Return whether the definition of a module corresponds to a simple ResourceLoaderFileModule.
 558          *
 559          * @param string $name Module name
 560          * @return bool
 561          */
 562         protected function isFileModule( $name ) {
 563                 if ( !isset( $this->moduleInfos[$name] ) ) {
 564                         return false;
 565                 }
 566                 $info = $this->moduleInfos[$name];
 567                 if ( isset( $info['object'] ) || isset( $info['class'] ) ) {
 568                         return false;
 569                 }
 570                 return true;
 571         }
 572
 573         /**
 574          * Get the list of sources.
 575          *
 576          * @return array Like array( id => load.php url, .. )
 577          */
 578         public function getSources() {
 579                 return $this->sources;
 580         }
 581
 582         /**
 583          * Get the URL to the load.php endpoint for the given
 584          * ResourceLoader source
 585          *
 586          * @since 1.24
 587          * @param string $source
 588          * @throws MWException On an invalid $source name
 589          * @return string
 590          */
 591         public function getLoadScript( $source ) {
 592                 if ( !isset( $this->sources[$source] ) ) {
 593                         throw new MWException( "The $source source was never registered in ResourceLoader." );
 594                 }
 595                 return $this->sources[$source];
 596         }
 597
 598         /**
 599          * @since 1.26
 600          * @param string $value
 601          * @return string Hash
 602          */
 603         public static function makeHash( $value ) {
 604                 // Use base64 to output more entropy in a more compact string (default hex is only base16).
 605                 // The first 8 chars of a base64 encoded digest represent the same binary as
 606                 // the first 12 chars of a hex encoded digest.
 607                 return substr( base64_encode( sha1( $value, true ) ), 0, 8 );
 608         }
 609
 610         /**
 611          * Helper method to get and combine versions of multiple modules.
 612          *
 613          * @since 1.26
 614          * @param ResourceLoaderContext $context
 615          * @param array $modules List of ResourceLoaderModule objects
 616          * @return string Hash
 617          */
 618         public function getCombinedVersion( ResourceLoaderContext $context, array $modules ) {
 619                 if ( !$modules ) {
 620                         return '';
 621                 }
 622                 $hashes = array_map( function ( $module ) use ( $context ) {
 623                         return $this->getModule( $module )->getVersionHash( $context );
 624                 }, $modules );
 625                 return self::makeHash( implode( $hashes ) );
 626         }
 627
 628         /**
 629          * Output a response to a load request, including the content-type header.
 630          *
 631          * @param ResourceLoaderContext $context Context in which a response should be formed
 632          */
 633         public function respond( ResourceLoaderContext $context ) {
 634                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 635                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 636                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 637                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 638                 // the whole thing in our own output buffer to be sure the active buffer
 639                 // doesn't use ob_gzhandler.
 640                 // See http://bugs.php.net/bug.php?id=36514
 641                 ob_start();
 642
 643                 // Find out which modules are missing and instantiate the others
 644                 $modules = [];
 645                 $missing = [];
 646                 foreach ( $context->getModules() as $name ) {
 647                         $module = $this->getModule( $name );
 648                         if ( $module ) {
 649                                 // Do not allow private modules to be loaded from the web.
 650                                 // This is a security issue, see bug 34907.
 651                                 if ( $module->getGroup() === 'private' ) {
 652                                         $this->logger->debug( "Request for private module '$name' denied" );
 653                                         $this->errors[] = "Cannot show private module \"$name\"";
 654                                         continue;
 655                                 }
 656                                 $modules[$name] = $module;
 657                         } else {
 658                                 $missing[] = $name;
 659                         }
 660                 }
 661
 662                 try {
 663                         // Preload for getCombinedVersion() and for batch makeModuleResponse()
 664                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 665                 } catch ( Exception $e ) {
 666                         MWExceptionHandler::logException( $e );
 667                         $this->logger->warning( 'Preloading module info failed: {exception}', [
 668                                 'exception' => $e
 669                         ] );
 670                         $this->errors[] = self::formatExceptionNoComment( $e );
 671                 }
 672
 673                 // Combine versions to propagate cache invalidation
 674                 $versionHash = '';
 675                 try {
 676                         $versionHash = $this->getCombinedVersion( $context, array_keys( $modules ) );
 677                 } catch ( Exception $e ) {
 678                         MWExceptionHandler::logException( $e );
 679                         $this->logger->warning( 'Calculating version hash failed: {exception}', [
 680                                 'exception' => $e
 681                         ] );
 682                         $this->errors[] = self::formatExceptionNoComment( $e );
 683                 }
 684
 685                 // See RFC 2616 § 3.11 Entity Tags
 686                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.11
 687                 $etag = 'W/"' . $versionHash . '"';
 688
 689                 // Try the client-side cache first
 690                 if ( $this->tryRespondNotModified( $context, $etag ) ) {
 691                         return; // output handled (buffers cleared)
 692                 }
 693
 694                 // Use file cache if enabled and available...
 695                 if ( $this->config->get( 'UseFileCache' ) ) {
 696                         $fileCache = ResourceFileCache::newFromContext( $context );
 697                         if ( $this->tryRespondFromFileCache( $fileCache, $context, $etag ) ) {
 698                                 return; // output handled
 699                         }
 700                 }
 701
 702                 // Generate a response
 703                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 704
 705                 // Capture any PHP warnings from the output buffer and append them to the
 706                 // error list if we're in debug mode.
 707                 if ( $context->getDebug() ) {
 708                         $warnings = ob_get_contents();
 709                         if ( strlen( $warnings ) ) {
 710                                 $this->errors[] = $warnings;
 711                         }
 712                 }
 713
 714                 // Save response to file cache unless there are errors
 715                 if ( isset( $fileCache ) && !$this->errors && !count( $missing ) ) {
 716                         // Cache single modules and images...and other requests if there are enough hits
 717                         if ( ResourceFileCache::useFileCache( $context ) ) {
 718                                 if ( $fileCache->isCacheWorthy() ) {
 719                                         $fileCache->saveText( $response );
 720                                 } else {
 721                                         $fileCache->incrMissesRecent( $context->getRequest() );
 722                                 }
 723                         }
 724                 }
 725
 726                 $this->sendResponseHeaders( $context, $etag, (bool)$this->errors );
 727
 728                 // Remove the output buffer and output the response
 729                 ob_end_clean();
 730
 731                 if ( $context->getImageObj() && $this->errors ) {
 732                         // We can't show both the error messages and the response when it's an image.
 733                         $response = implode( "\n\n", $this->errors );
 734                 } elseif ( $this->errors ) {
 735                         $errorText = implode( "\n\n", $this->errors );
 736                         $errorResponse = self::makeComment( $errorText );
 737                         if ( $context->shouldIncludeScripts() ) {
 738                                 $errorResponse .= 'if (window.console && console.error) {'
 739                                         . Xml::encodeJsCall( 'console.error', [ $errorText ] )
 740                                         . "}\n";
 741                         }
 742
 743                         // Prepend error info to the response
 744                         $response = $errorResponse . $response;
 745                 }
 746
 747                 $this->errors = [];
 748                 echo $response;
 749
 750         }
 751
 752         /**
 753          * Send main response headers to the client.
 754          *
 755          * Deals with Content-Type, CORS (for stylesheets), and caching.
 756          *
 757          * @param ResourceLoaderContext $context
 758          * @param string $etag ETag header value
 759          * @param bool $errors Whether there are errors in the response
 760          * @return void
 761          */
 762         protected function sendResponseHeaders( ResourceLoaderContext $context, $etag, $errors ) {
 763                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 764                 // If a version wasn't specified we need a shorter expiry time for updates
 765                 // to propagate to clients quickly
 766                 // If there were errors, we also need a shorter expiry time so we can recover quickly
 767                 if ( is_null( $context->getVersion() ) || $errors ) {
 768                         $maxage = $rlMaxage['unversioned']['client'];
 769                         $smaxage = $rlMaxage['unversioned']['server'];
 770                 // If a version was specified we can use a longer expiry time since changing
 771                 // version numbers causes cache misses
 772                 } else {
 773                         $maxage = $rlMaxage['versioned']['client'];
 774                         $smaxage = $rlMaxage['versioned']['server'];
 775                 }
 776                 if ( $context->getImageObj() ) {
 777                         // Output different headers if we're outputting textual errors.
 778                         if ( $errors ) {
 779                                 header( 'Content-Type: text/plain; charset=utf-8' );
 780                         } else {
 781                                 $context->getImageObj()->sendResponseHeaders( $context );
 782                         }
 783                 } elseif ( $context->getOnly() === 'styles' ) {
 784                         header( 'Content-Type: text/css; charset=utf-8' );
 785                         header( 'Access-Control-Allow-Origin: *' );
 786                 } else {
 787                         header( 'Content-Type: text/javascript; charset=utf-8' );
 788                 }
 789                 // See RFC 2616 § 14.19 ETag
 790                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.19
 791                 header( 'ETag: ' . $etag );
 792                 if ( $context->getDebug() ) {
 793                         // Do not cache debug responses
 794                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 795                         header( 'Pragma: no-cache' );
 796                 } else {
 797                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 798                         $exp = min( $maxage, $smaxage );
 799                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 800                 }
 801         }
 802
 803         /**
 804          * Respond with HTTP 304 Not Modified if appropiate.
 805          *
 806          * If there's an If-None-Match header, respond with a 304 appropriately
 807          * and clear out the output buffer. If the client cache is too old then do nothing.
 808          *
 809          * @param ResourceLoaderContext $context
 810          * @param string $etag ETag header value
 811          * @return bool True if HTTP 304 was sent and output handled
 812          */
 813         protected function tryRespondNotModified( ResourceLoaderContext $context, $etag ) {
 814                 // See RFC 2616 § 14.26 If-None-Match
 815                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
 816                 $clientKeys = $context->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST );
 817                 // Never send 304s in debug mode
 818                 if ( $clientKeys !== false && !$context->getDebug() && in_array( $etag, $clientKeys ) ) {
 819                         // There's another bug in ob_gzhandler (see also the comment at
 820                         // the top of this function) that causes it to gzip even empty
 821                         // responses, meaning it's impossible to produce a truly empty
 822                         // response (because the gzip header is always there). This is
 823                         // a problem because 304 responses have to be completely empty
 824                         // per the HTTP spec, and Firefox behaves buggily when they're not.
 825                         // See also http://bugs.php.net/bug.php?id=51579
 826                         // To work around this, we tear down all output buffering before
 827                         // sending the 304.
 828                         wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 829
 830                         HttpStatus::header( 304 );
 831
 832                         $this->sendResponseHeaders( $context, $etag, false );
 833                         return true;
 834                 }
 835                 return false;
 836         }
 837
 838         /**
 839          * Send out code for a response from file cache if possible.
 840          *
 841          * @param ResourceFileCache $fileCache Cache object for this request URL
 842          * @param ResourceLoaderContext $context Context in which to generate a response
 843          * @param string $etag ETag header value
 844          * @return bool If this found a cache file and handled the response
 845          */
 846         protected function tryRespondFromFileCache(
 847                 ResourceFileCache $fileCache,
 848                 ResourceLoaderContext $context,
 849                 $etag
 850         ) {
 851                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 852                 // Buffer output to catch warnings.
 853                 ob_start();
 854                 // Get the maximum age the cache can be
 855                 $maxage = is_null( $context->getVersion() )
 856                         ? $rlMaxage['unversioned']['server']
 857                         : $rlMaxage['versioned']['server'];
 858                 // Minimum timestamp the cache file must have
 859                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 860                 if ( !$good ) {
 861                         try { // RL always hits the DB on file cache miss...
 862                                 wfGetDB( DB_SLAVE );
 863                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 864                                 $good = $fileCache->isCacheGood(); // cache existence check
 865                         }
 866                 }
 867                 if ( $good ) {
 868                         $ts = $fileCache->cacheTimestamp();
 869                         // Send content type and cache headers
 870                         $this->sendResponseHeaders( $context, $etag, false );
 871                         $response = $fileCache->fetchText();
 872                         // Capture any PHP warnings from the output buffer and append them to the
 873                         // response in a comment if we're in debug mode.
 874                         if ( $context->getDebug() ) {
 875                                 $warnings = ob_get_contents();
 876                                 if ( strlen( $warnings ) ) {
 877                                         $response = self::makeComment( $warnings ) . $response;
 878                                 }
 879                         }
 880                         // Remove the output buffer and output the response
 881                         ob_end_clean();
 882                         echo $response . "\n/* Cached {$ts} */";
 883                         return true; // cache hit
 884                 }
 885                 // Clear buffer
 886                 ob_end_clean();
 887
 888                 return false; // cache miss
 889         }
 890
 891         /**
 892          * Generate a CSS or JS comment block.
 893          *
 894          * Only use this for public data, not error message details.
 895          *
 896          * @param string $text
 897          * @return string
 898          */
 899         public static function makeComment( $text ) {
 900                 $encText = str_replace( '*/', '* /', $text );
 901                 return "/*\n$encText\n*/\n";
 902         }
 903
 904         /**
 905          * Handle exception display.
 906          *
 907          * @param Exception $e Exception to be shown to the user
 908          * @return string Sanitized text in a CSS/JS comment that can be returned to the user
 909          */
 910         public static function formatException( $e ) {
 911                 return self::makeComment( self::formatExceptionNoComment( $e ) );
 912         }
 913
 914         /**
 915          * Handle exception display.
 916          *
 917          * @since 1.25
 918          * @param Exception $e Exception to be shown to the user
 919          * @return string Sanitized text that can be returned to the user
 920          */
 921         protected static function formatExceptionNoComment( $e ) {
 922                 global $wgShowExceptionDetails;
 923
 924                 if ( !$wgShowExceptionDetails ) {
 925                         return MWExceptionHandler::getPublicLogMessage( $e );
 926                 }
 927
 928                 return MWExceptionHandler::getLogMessage( $e );
 929         }
 930
 931         /**
 932          * Generate code for a response.
 933          *
 934          * @param ResourceLoaderContext $context Context in which to generate a response
 935          * @param ResourceLoaderModule[] $modules List of module objects keyed by module name
 936          * @param string[] $missing List of requested module names that are unregistered (optional)
 937          * @return string Response data
 938          */
 939         public function makeModuleResponse( ResourceLoaderContext $context,
 940                 array $modules, array $missing = []
 941         ) {
 942                 $out = '';
 943                 $states = [];
 944
 945                 if ( !count( $modules ) && !count( $missing ) ) {
 946                         return <<<MESSAGE
 947 /* This file is the Web entry point for MediaWiki's ResourceLoader:
 948    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
 949    no modules were requested. Max made me put this here. */
 950 MESSAGE;
 951                 }
 952
 953                 $image = $context->getImageObj();
 954                 if ( $image ) {
 955                         $data = $image->getImageData( $context );
 956                         if ( $data === false ) {
 957                                 $data = '';
 958                                 $this->errors[] = 'Image generation failed';
 959                         }
 960                         return $data;
 961                 }
 962
 963                 foreach ( $missing as $name ) {
 964                         $states[$name] = 'missing';
 965                 }
 966
 967                 // Generate output
 968                 $isRaw = false;
 969
 970                 $filter = $context->getOnly() === 'styles' ? 'minify-css' : 'minify-js';
 971
 972                 foreach ( $modules as $name => $module ) {
 973                         try {
 974                                 $content = $module->getModuleContent( $context );
 975                                 $strContent = '';
 976
 977                                 // Append output
 978                                 switch ( $context->getOnly() ) {
 979                                         case 'scripts':
 980                                                 $scripts = $content['scripts'];
 981                                                 if ( is_string( $scripts ) ) {
 982                                                         // Load scripts raw...
 983                                                         $strContent = $scripts;
 984                                                 } elseif ( is_array( $scripts ) ) {
 985                                                         // ...except when $scripts is an array of URLs
 986                                                         $strContent = self::makeLoaderImplementScript( $name, $scripts, [], [], [] );
 987                                                 }
 988                                                 break;
 989                                         case 'styles':
 990                                                 $styles = $content['styles'];
 991                                                 // We no longer seperate into media, they are all combined now with
 992                                                 // custom media type groups into @media .. {} sections as part of the css string.
 993                                                 // Module returns either an empty array or a numerical array with css strings.
 994                                                 $strContent = isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
 995                                                 break;
 996                                         default:
 997                                                 $strContent = self::makeLoaderImplementScript(
 998                                                         $name,
 999                                                         isset( $content['scripts'] ) ? $content['scripts'] : '',
1000                                                         isset( $content['styles'] ) ? $content['styles'] : [],
1001                                                         isset( $content['messagesBlob'] ) ? new XmlJsCode( $content['messagesBlob'] ) : [],
1002                                                         isset( $content['templates'] ) ? $content['templates'] : []
1003                                                 );
1004                                                 break;
1005                                 }
1006
1007                                 if ( !$context->getDebug() ) {
1008                                         $strContent = self::filter( $filter, $strContent );
1009                                 }
1010
1011                                 $out .= $strContent;
1012
1013                         } catch ( Exception $e ) {
1014                                 MWExceptionHandler::logException( $e );
1015                                 $this->logger->warning( 'Generating module package failed: {exception}', [
1016                                         'exception' => $e
1017                                 ] );
1018                                 $this->errors[] = self::formatExceptionNoComment( $e );
1019
1020                                 // Respond to client with error-state instead of module implementation
1021                                 $states[$name] = 'error';
1022                                 unset( $modules[$name] );
1023                         }
1024                         $isRaw |= $module->isRaw();
1025                 }
1026
1027                 // Update module states
1028                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
1029                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
1030                                 // Set the state of modules loaded as only scripts to ready as
1031                                 // they don't have an mw.loader.implement wrapper that sets the state
1032                                 foreach ( $modules as $name => $module ) {
1033                                         $states[$name] = 'ready';
1034                                 }
1035                         }
1036
1037                         // Set the state of modules we didn't respond to with mw.loader.implement
1038                         if ( count( $states ) ) {
1039                                 $stateScript = self::makeLoaderStateScript( $states );
1040                                 if ( !$context->getDebug() ) {
1041                                         $stateScript = self::filter( 'minify-js', $stateScript );
1042                                 }
1043                                 $out .= $stateScript;
1044                         }
1045                 } else {
1046                         if ( count( $states ) ) {
1047                                 $this->errors[] = 'Problematic modules: ' .
1048                                         FormatJson::encode( $states, ResourceLoader::inDebugMode() );
1049                         }
1050                 }
1051
1052                 return $out;
1053         }
1054
1055         /**
1056          * Get names of modules that use a certain message.
1057          *
1058          * @param string $messageKey
1059          * @return array List of module names
1060          */
1061         public function getModulesByMessage( $messageKey ) {
1062                 $moduleNames = [];
1063                 foreach ( $this->getModuleNames() as $moduleName ) {
1064                         $module = $this->getModule( $moduleName );
1065                         if ( in_array( $messageKey, $module->getMessages() ) ) {
1066                                 $moduleNames[] = $moduleName;
1067                         }
1068                 }
1069                 return $moduleNames;
1070         }
1071
1072         /* Static Methods */
1073
1074         /**
1075          * Return JS code that calls mw.loader.implement with given module properties.
1076          *
1077          * @param string $name Module name
1078          * @param mixed $scripts List of URLs to JavaScript files or String of JavaScript code
1079          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1080          *   to CSS files keyed by media type
1081          * @param mixed $messages List of messages associated with this module. May either be an
1082          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1083          *   the same data, wrapped in an XmlJsCode object.
1084          * @param array $templates Keys are name of templates and values are the source of
1085          *   the template.
1086          * @throws MWException
1087          * @return string
1088          */
1089         public static function makeLoaderImplementScript(
1090                 $name, $scripts, $styles, $messages, $templates
1091         ) {
1092                 if ( is_string( $scripts ) ) {
1093                         // Site and user module are a legacy scripts that run in the global scope (no closure).
1094                         // Transportation as string instructs mw.loader.implement to use globalEval.
1095                         if ( $name === 'site' || $name === 'user' ) {
1096                                 // Minify manually because the general makeModuleResponse() minification won't be
1097                                 // effective here due to the script being a string instead of a function. (T107377)
1098                                 if ( !ResourceLoader::inDebugMode() ) {
1099                                         $scripts = self::filter( 'minify-js', $scripts );
1100                                 }
1101                         } else {
1102                                 $scripts = new XmlJsCode( "function ( $, jQuery, require, module ) {\n{$scripts}\n}" );
1103                         }
1104                 } elseif ( !is_array( $scripts ) ) {
1105                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1106                 }
1107                 // mw.loader.implement requires 'styles', 'messages' and 'templates' to be objects (not
1108                 // arrays). json_encode considers empty arrays to be numerical and outputs "[]" instead
1109                 // of "{}". Force them to objects.
1110                 $module = [
1111                         $name,
1112                         $scripts,
1113                         (object)$styles,
1114                         (object)$messages,
1115                         (object)$templates,
1116                 ];
1117                 self::trimArray( $module );
1118
1119                 return Xml::encodeJsCall( 'mw.loader.implement', $module, ResourceLoader::inDebugMode() );
1120         }
1121
1122         /**
1123          * Returns JS code which, when called, will register a given list of messages.
1124          *
1125          * @param mixed $messages Either an associative array mapping message key to value, or a
1126          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1127          * @return string
1128          */
1129         public static function makeMessageSetScript( $messages ) {
1130                 return Xml::encodeJsCall(
1131                         'mw.messages.set',
1132                         [ (object)$messages ],
1133                         ResourceLoader::inDebugMode()
1134                 );
1135         }
1136
1137         /**
1138          * Combines an associative array mapping media type to CSS into a
1139          * single stylesheet with "@media" blocks.
1140          *
1141          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1142          * @return array
1143          */
1144         public static function makeCombinedStyles( array $stylePairs ) {
1145                 $out = [];
1146                 foreach ( $stylePairs as $media => $styles ) {
1147                         // ResourceLoaderFileModule::getStyle can return the styles
1148                         // as a string or an array of strings. This is to allow separation in
1149                         // the front-end.
1150                         $styles = (array)$styles;
1151                         foreach ( $styles as $style ) {
1152                                 $style = trim( $style );
1153                                 // Don't output an empty "@media print { }" block (bug 40498)
1154                                 if ( $style !== '' ) {
1155                                         // Transform the media type based on request params and config
1156                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1157                                         $media = OutputPage::transformCssMedia( $media );
1158
1159                                         if ( $media === '' || $media == 'all' ) {
1160                                                 $out[] = $style;
1161                                         } elseif ( is_string( $media ) ) {
1162                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1163                                         }
1164                                         // else: skip
1165                                 }
1166                         }
1167                 }
1168                 return $out;
1169         }
1170
1171         /**
1172          * Returns a JS call to mw.loader.state, which sets the state of a
1173          * module or modules to a given value. Has two calling conventions:
1174          *
1175          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1176          *         Set the state of a single module called $name to $state
1177          *
1178          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
1179          *         Set the state of modules with the given names to the given states
1180          *
1181          * @param string $name
1182          * @param string $state
1183          * @return string
1184          */
1185         public static function makeLoaderStateScript( $name, $state = null ) {
1186                 if ( is_array( $name ) ) {
1187                         return Xml::encodeJsCall(
1188                                 'mw.loader.state',
1189                                 [ $name ],
1190                                 ResourceLoader::inDebugMode()
1191                         );
1192                 } else {
1193                         return Xml::encodeJsCall(
1194                                 'mw.loader.state',
1195                                 [ $name, $state ],
1196                                 ResourceLoader::inDebugMode()
1197                         );
1198                 }
1199         }
1200
1201         /**
1202          * Returns JS code which calls the script given by $script. The script will
1203          * be called with local variables name, version, dependencies and group,
1204          * which will have values corresponding to $name, $version, $dependencies
1205          * and $group as supplied.
1206          *
1207          * @param string $name Module name
1208          * @param string $version Module version hash
1209          * @param array $dependencies List of module names on which this module depends
1210          * @param string $group Group which the module is in.
1211          * @param string $source Source of the module, or 'local' if not foreign.
1212          * @param string $script JavaScript code
1213          * @return string
1214          */
1215         public static function makeCustomLoaderScript( $name, $version, $dependencies,
1216                 $group, $source, $script
1217         ) {
1218                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1219                 return Xml::encodeJsCall(
1220                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1221                         [ $name, $version, $dependencies, $group, $source ],
1222                         ResourceLoader::inDebugMode()
1223                 );
1224         }
1225
1226         private static function isEmptyObject( stdClass $obj ) {
1227                 foreach ( $obj as $key => $value ) {
1228                         return false;
1229                 }
1230                 return true;
1231         }
1232
1233         /**
1234          * Remove empty values from the end of an array.
1235          *
1236          * Values considered empty:
1237          *
1238          * - null
1239          * - array()
1240          * - new XmlJsCode( '{}' )
1241          * - new stdClass() // (object) array()
1242          *
1243          * @param Array $array
1244          */
1245         private static function trimArray( array &$array ) {
1246                 $i = count( $array );
1247                 while ( $i-- ) {
1248                         if ( $array[$i] === null
1249                                 || $array[$i] === []
1250                                 || ( $array[$i] instanceof XmlJsCode && $array[$i]->value === '{}' )
1251                                 || ( $array[$i] instanceof stdClass && self::isEmptyObject( $array[$i] ) )
1252                         ) {
1253                                 unset( $array[$i] );
1254                         } else {
1255                                 break;
1256                         }
1257                 }
1258         }
1259
1260         /**
1261          * Returns JS code which calls mw.loader.register with the given
1262          * parameters. Has three calling conventions:
1263          *
1264          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version,
1265          *        $dependencies, $group, $source, $skip
1266          *     ):
1267          *        Register a single module.
1268          *
1269          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
1270          *        Register modules with the given names.
1271          *
1272          *   - ResourceLoader::makeLoaderRegisterScript( array(
1273          *        array( $name1, $version1, $dependencies1, $group1, $source1, $skip1 ),
1274          *        array( $name2, $version2, $dependencies1, $group2, $source2, $skip2 ),
1275          *        ...
1276          *     ) ):
1277          *        Registers modules with the given names and parameters.
1278          *
1279          * @param string $name Module name
1280          * @param string $version Module version hash
1281          * @param array $dependencies List of module names on which this module depends
1282          * @param string $group Group which the module is in
1283          * @param string $source Source of the module, or 'local' if not foreign
1284          * @param string $skip Script body of the skip function
1285          * @return string
1286          */
1287         public static function makeLoaderRegisterScript( $name, $version = null,
1288                 $dependencies = null, $group = null, $source = null, $skip = null
1289         ) {
1290                 if ( is_array( $name ) ) {
1291                         // Build module name index
1292                         $index = [];
1293                         foreach ( $name as $i => &$module ) {
1294                                 $index[$module[0]] = $i;
1295                         }
1296
1297                         // Transform dependency names into indexes when possible, they will be resolved by
1298                         // mw.loader.register on the other end
1299                         foreach ( $name as &$module ) {
1300                                 if ( isset( $module[2] ) ) {
1301                                         foreach ( $module[2] as &$dependency ) {
1302                                                 if ( isset( $index[$dependency] ) ) {
1303                                                         $dependency = $index[$dependency];
1304                                                 }
1305                                         }
1306                                 }
1307                         }
1308
1309                         array_walk( $name, [ 'self', 'trimArray' ] );
1310
1311                         return Xml::encodeJsCall(
1312                                 'mw.loader.register',
1313                                 [ $name ],
1314                                 ResourceLoader::inDebugMode()
1315                         );
1316                 } else {
1317                         $registration = [ $name, $version, $dependencies, $group, $source, $skip ];
1318                         self::trimArray( $registration );
1319                         return Xml::encodeJsCall(
1320                                 'mw.loader.register',
1321                                 $registration,
1322                                 ResourceLoader::inDebugMode()
1323                         );
1324                 }
1325         }
1326
1327         /**
1328          * Returns JS code which calls mw.loader.addSource() with the given
1329          * parameters. Has two calling conventions:
1330          *
1331          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1332          *       Register a single source
1333          *
1334          *   - ResourceLoader::makeLoaderSourcesScript( array( $id1 => $loadUrl, $id2 => $loadUrl, ... ) );
1335          *       Register sources with the given IDs and properties.
1336          *
1337          * @param string $id Source ID
1338          * @param array $properties Source properties (see addSource())
1339          * @return string
1340          */
1341         public static function makeLoaderSourcesScript( $id, $properties = null ) {
1342                 if ( is_array( $id ) ) {
1343                         return Xml::encodeJsCall(
1344                                 'mw.loader.addSource',
1345                                 [ $id ],
1346                                 ResourceLoader::inDebugMode()
1347                         );
1348                 } else {
1349                         return Xml::encodeJsCall(
1350                                 'mw.loader.addSource',
1351                                 [ $id, $properties ],
1352                                 ResourceLoader::inDebugMode()
1353                         );
1354                 }
1355         }
1356
1357         /**
1358          * Returns JS code which runs given JS code if the client-side framework is
1359          * present.
1360          *
1361          * @deprecated since 1.25; use makeInlineScript instead
1362          * @param string $script JavaScript code
1363          * @return string
1364          */
1365         public static function makeLoaderConditionalScript( $script ) {
1366                 return '(window.RLQ=window.RLQ||[]).push(function(){' .
1367                         trim( $script ) . '});';
1368         }
1369
1370         /**
1371          * Construct an inline script tag with given JS code.
1372          *
1373          * The code will be wrapped in a closure, and it will be executed by ResourceLoader
1374          * only if the client has adequate support for MediaWiki JavaScript code.
1375          *
1376          * @param string $script JavaScript code
1377          * @return WrappedString HTML
1378          */
1379         public static function makeInlineScript( $script ) {
1380                 $js = self::makeLoaderConditionalScript( $script );
1381                 return new WrappedString(
1382                         Html::inlineScript( $js ),
1383                         '<script>(window.RLQ=window.RLQ||[]).push(function(){',
1384                         '});</script>'
1385                 );
1386         }
1387
1388         /**
1389          * Returns JS code which will set the MediaWiki configuration array to
1390          * the given value.
1391          *
1392          * @param array $configuration List of configuration values keyed by variable name
1393          * @return string
1394          */
1395         public static function makeConfigSetScript( array $configuration ) {
1396                 return Xml::encodeJsCall(
1397                         'mw.config.set',
1398                         [ $configuration ],
1399                         ResourceLoader::inDebugMode()
1400                 );
1401         }
1402
1403         /**
1404          * Convert an array of module names to a packed query string.
1405          *
1406          * For example, array( 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' )
1407          * becomes 'foo.bar,baz|bar.baz,quux'
1408          * @param array $modules List of module names (strings)
1409          * @return string Packed query string
1410          */
1411         public static function makePackedModulesString( $modules ) {
1412                 $groups = []; // array( prefix => array( suffixes ) )
1413                 foreach ( $modules as $module ) {
1414                         $pos = strrpos( $module, '.' );
1415                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1416                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1417                         $groups[$prefix][] = $suffix;
1418                 }
1419
1420                 $arr = [];
1421                 foreach ( $groups as $prefix => $suffixes ) {
1422                         $p = $prefix === '' ? '' : $prefix . '.';
1423                         $arr[] = $p . implode( ',', $suffixes );
1424                 }
1425                 $str = implode( '|', $arr );
1426                 return $str;
1427         }
1428
1429         /**
1430          * Determine whether debug mode was requested
1431          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1432          * @return bool
1433          */
1434         public static function inDebugMode() {
1435                 if ( self::$debugMode === null ) {
1436                         global $wgRequest, $wgResourceLoaderDebug;
1437                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1438                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1439                         );
1440                 }
1441                 return self::$debugMode;
1442         }
1443
1444         /**
1445          * Reset static members used for caching.
1446          *
1447          * Global state and $wgRequest are evil, but we're using it right
1448          * now and sometimes we need to be able to force ResourceLoader to
1449          * re-evaluate the context because it has changed (e.g. in the test suite).
1450          */
1451         public static function clearCache() {
1452                 self::$debugMode = null;
1453         }
1454
1455         /**
1456          * Build a load.php URL
1457          *
1458          * @since 1.24
1459          * @param string $source Name of the ResourceLoader source
1460          * @param ResourceLoaderContext $context
1461          * @param array $extraQuery
1462          * @return string URL to load.php. May be protocol-relative if $wgLoadScript is, too.
1463          */
1464         public function createLoaderURL( $source, ResourceLoaderContext $context,
1465                 $extraQuery = []
1466         ) {
1467                 $query = self::createLoaderQuery( $context, $extraQuery );
1468                 $script = $this->getLoadScript( $source );
1469
1470                 return wfAppendQuery( $script, $query );
1471         }
1472
1473         /**
1474          * Build a load.php URL
1475          * @deprecated since 1.24 Use createLoaderURL() instead
1476          * @param array $modules Array of module names (strings)
1477          * @param string $lang Language code
1478          * @param string $skin Skin name
1479          * @param string|null $user User name. If null, the &user= parameter is omitted
1480          * @param string|null $version Versioning timestamp
1481          * @param bool $debug Whether the request should be in debug mode
1482          * @param string|null $only &only= parameter
1483          * @param bool $printable Printable mode
1484          * @param bool $handheld Handheld mode
1485          * @param array $extraQuery Extra query parameters to add
1486          * @return string URL to load.php. May be protocol-relative if $wgLoadScript is, too.
1487          */
1488         public static function makeLoaderURL( $modules, $lang, $skin, $user = null,
1489                 $version = null, $debug = false, $only = null, $printable = false,
1490                 $handheld = false, $extraQuery = []
1491         ) {
1492                 global $wgLoadScript;
1493
1494                 $query = self::makeLoaderQuery( $modules, $lang, $skin, $user, $version, $debug,
1495                         $only, $printable, $handheld, $extraQuery
1496                 );
1497
1498                 return wfAppendQuery( $wgLoadScript, $query );
1499         }
1500
1501         /**
1502          * Helper for createLoaderURL()
1503          *
1504          * @since 1.24
1505          * @see makeLoaderQuery
1506          * @param ResourceLoaderContext $context
1507          * @param array $extraQuery
1508          * @return array
1509          */
1510         public static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = [] ) {
1511                 return self::makeLoaderQuery(
1512                         $context->getModules(),
1513                         $context->getLanguage(),
1514                         $context->getSkin(),
1515                         $context->getUser(),
1516                         $context->getVersion(),
1517                         $context->getDebug(),
1518                         $context->getOnly(),
1519                         $context->getRequest()->getBool( 'printable' ),
1520                         $context->getRequest()->getBool( 'handheld' ),
1521                         $extraQuery
1522                 );
1523         }
1524
1525         /**
1526          * Build a query array (array representation of query string) for load.php. Helper
1527          * function for makeLoaderURL().
1528          *
1529          * @param array $modules
1530          * @param string $lang
1531          * @param string $skin
1532          * @param string $user
1533          * @param string $version
1534          * @param bool $debug
1535          * @param string $only
1536          * @param bool $printable
1537          * @param bool $handheld
1538          * @param array $extraQuery
1539          *
1540          * @return array
1541          */
1542         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1543                 $version = null, $debug = false, $only = null, $printable = false,
1544                 $handheld = false, $extraQuery = []
1545         ) {
1546                 $query = [
1547                         'modules' => self::makePackedModulesString( $modules ),
1548                         'lang' => $lang,
1549                         'skin' => $skin,
1550                         'debug' => $debug ? 'true' : 'false',
1551                 ];
1552                 if ( $user !== null ) {
1553                         $query['user'] = $user;
1554                 }
1555                 if ( $version !== null ) {
1556                         $query['version'] = $version;
1557                 }
1558                 if ( $only !== null ) {
1559                         $query['only'] = $only;
1560                 }
1561                 if ( $printable ) {
1562                         $query['printable'] = 1;
1563                 }
1564                 if ( $handheld ) {
1565                         $query['handheld'] = 1;
1566                 }
1567                 $query += $extraQuery;
1568
1569                 // Make queries uniform in order
1570                 ksort( $query );
1571                 return $query;
1572         }
1573
1574         /**
1575          * Check a module name for validity.
1576          *
1577          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1578          * at most 255 bytes.
1579          *
1580          * @param string $moduleName Module name to check
1581          * @return bool Whether $moduleName is a valid module name
1582          */
1583         public static function isValidModuleName( $moduleName ) {
1584                 return strcspn( $moduleName, '!,|', 0, 255 ) === strlen( $moduleName );
1585         }
1586
1587         /**
1588          * Returns LESS compiler set up for use with MediaWiki
1589          *
1590          * @since 1.27
1591          * @param array $extraVars Associative array of extra (i.e., other than the
1592          *   globally-configured ones) that should be used for compilation.
1593          * @throws MWException
1594          * @return Less_Parser
1595          */
1596         public function getLessCompiler( $extraVars = [] ) {
1597                 // When called from the installer, it is possible that a required PHP extension
1598                 // is missing (at least for now; see bug 47564). If this is the case, throw an
1599                 // exception (caught by the installer) to prevent a fatal error later on.
1600                 if ( !class_exists( 'Less_Parser' ) ) {
1601                         throw new MWException( 'MediaWiki requires the less.php parser' );
1602                 }
1603
1604                 $parser = new Less_Parser;
1605                 $parser->ModifyVars( array_merge( $this->getLessVars(), $extraVars ) );
1606                 $parser->SetImportDirs(
1607                         array_fill_keys( $this->config->get( 'ResourceLoaderLESSImportPaths' ), '' )
1608                 );
1609                 $parser->SetOption( 'relativeUrls', false );
1610                 $parser->SetCacheDir( $this->config->get( 'CacheDirectory' ) ?: wfTempDir() );
1611
1612                 return $parser;
1613         }
1614
1615         /**
1616          * Get global LESS variables.
1617          *
1618          * @since 1.27
1619          * @return array Map of variable names to string CSS values.
1620          */
1621         public function getLessVars() {
1622                 if ( !$this->lessVars ) {
1623                         $lessVars = $this->config->get( 'ResourceLoaderLESSVars' );
1624                         Hooks::run( 'ResourceLoaderGetLessVars', [ &$lessVars ] );
1625                         $this->lessVars = $lessVars;
1626                 }
1627                 return $this->lessVars;
1628         }
1629 }