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         protected $config;
  60
  61         /**
  62          * Associative array mapping framework ids to a list of names of test suite modules
  63          * like [ 'qunit' => [ 'mediawiki.tests.qunit.suites', 'ext.foo.tests', ... ], ... ]
  64          * @var array
  65          */
  66         protected $testModuleNames = [];
  67
  68         /**
  69          * E.g. [ '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_REPLICA );
 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                 // Batched version of ResourceLoaderWikiModule::getTitleInfo
 144                 ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $moduleNames );
 145
 146                 // Prime in-object cache for message blobs for modules with messages
 147                 $modules = [];
 148                 foreach ( $moduleNames as $name ) {
 149                         $module = $this->getModule( $name );
 150                         if ( $module && $module->getMessages() ) {
 151                                 $modules[$name] = $module;
 152                         }
 153                 }
 154                 $store = $this->getMessageBlobStore();
 155                 $blobs = $store->getBlobs( $modules, $lang );
 156                 foreach ( $blobs as $name => $blob ) {
 157                         $modules[$name]->setMessageBlob( $blob, $lang );
 158                 }
 159         }
 160
 161         /**
 162          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 163          *
 164          * Available filters are:
 165          *
 166          *    - minify-js \see JavaScriptMinifier::minify
 167          *    - minify-css \see CSSMin::minify
 168          *
 169          * If $data is empty, only contains whitespace or the filter was unknown,
 170          * $data is returned unmodified.
 171          *
 172          * @param string $filter Name of filter to run
 173          * @param string $data Text to filter, such as JavaScript or CSS text
 174          * @param array $options Keys:
 175          *  - (bool) cache: Whether to allow caching this data. Default: true.
 176          * @return string Filtered data, or a comment containing an error message
 177          */
 178         public static function filter( $filter, $data, array $options = [] ) {
 179                 if ( strpos( $data, ResourceLoader::FILTER_NOMIN ) !== false ) {
 180                         return $data;
 181                 }
 182
 183                 if ( isset( $options['cache'] ) && $options['cache'] === false ) {
 184                         return self::applyFilter( $filter, $data );
 185                 }
 186
 187                 $stats = RequestContext::getMain()->getStats();
 188                 $cache = ObjectCache::getLocalServerInstance( CACHE_ANYTHING );
 189
 190                 $key = $cache->makeGlobalKey(
 191                         'resourceloader',
 192                         'filter',
 193                         $filter,
 194                         self::$filterCacheVersion, md5( $data )
 195                 );
 196
 197                 $result = $cache->get( $key );
 198                 if ( $result === false ) {
 199                         $stats->increment( "resourceloader_cache.$filter.miss" );
 200                         $result = self::applyFilter( $filter, $data );
 201                         $cache->set( $key, $result, 24 * 3600 );
 202                 } else {
 203                         $stats->increment( "resourceloader_cache.$filter.hit" );
 204                 }
 205                 if ( $result === null ) {
 206                         // Cached failure
 207                         $result = $data;
 208                 }
 209
 210                 return $result;
 211         }
 212
 213         private static function applyFilter( $filter, $data ) {
 214                 $data = trim( $data );
 215                 if ( $data ) {
 216                         try {
 217                                 $data = ( $filter === 'minify-css' )
 218                                         ? CSSMin::minify( $data )
 219                                         : JavaScriptMinifier::minify( $data );
 220                         } catch ( Exception $e ) {
 221                                 MWExceptionHandler::logException( $e );
 222                                 return null;
 223                         }
 224                 }
 225                 return $data;
 226         }
 227
 228         /* Methods */
 229
 230         /**
 231          * Register core modules and runs registration hooks.
 232          * @param Config $config [optional]
 233          * @param LoggerInterface $logger [optional]
 234          */
 235         public function __construct( Config $config = null, LoggerInterface $logger = null ) {
 236                 global $IP;
 237
 238                 $this->logger = $logger ?: new NullLogger();
 239
 240                 if ( !$config ) {
 241                         $this->logger->debug( __METHOD__ . ' was called without providing a Config instance' );
 242                         $config = ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
 243                 }
 244                 $this->config = $config;
 245
 246                 // Add 'local' source first
 247                 $this->addSource( 'local', $config->get( 'LoadScript' ) );
 248
 249                 // Add other sources
 250                 $this->addSource( $config->get( 'ResourceLoaderSources' ) );
 251
 252                 // Register core modules
 253                 $this->register( include "$IP/resources/Resources.php" );
 254                 $this->register( include "$IP/resources/ResourcesOOUI.php" );
 255                 // Register extension modules
 256                 $this->register( $config->get( 'ResourceModules' ) );
 257                 Hooks::run( 'ResourceLoaderRegisterModules', [ &$this ] );
 258
 259                 if ( $config->get( 'EnableJavaScriptTest' ) === true ) {
 260                         $this->registerTestModules();
 261                 }
 262
 263                 $this->setMessageBlobStore( new MessageBlobStore( $this, $this->logger ) );
 264         }
 265
 266         /**
 267          * @return Config
 268          */
 269         public function getConfig() {
 270                 return $this->config;
 271         }
 272
 273         /**
 274          * @since 1.26
 275          * @param LoggerInterface $logger
 276          */
 277         public function setLogger( LoggerInterface $logger ) {
 278                 $this->logger = $logger;
 279         }
 280
 281         /**
 282          * @since 1.27
 283          * @return LoggerInterface
 284          */
 285         public function getLogger() {
 286                 return $this->logger;
 287         }
 288
 289         /**
 290          * @since 1.26
 291          * @return MessageBlobStore
 292          */
 293         public function getMessageBlobStore() {
 294                 return $this->blobStore;
 295         }
 296
 297         /**
 298          * @since 1.25
 299          * @param MessageBlobStore $blobStore
 300          */
 301         public function setMessageBlobStore( MessageBlobStore $blobStore ) {
 302                 $this->blobStore = $blobStore;
 303         }
 304
 305         /**
 306          * Register a module with the ResourceLoader system.
 307          *
 308          * @param mixed $name Name of module as a string or List of name/object pairs as an array
 309          * @param array $info Module info array. For backwards compatibility with 1.17alpha,
 310          *   this may also be a ResourceLoaderModule object. Optional when using
 311          *   multiple-registration calling style.
 312          * @throws MWException If a duplicate module registration is attempted
 313          * @throws MWException If a module name contains illegal characters (pipes or commas)
 314          * @throws MWException If something other than a ResourceLoaderModule is being registered
 315          * @return bool False if there were any errors, in which case one or more modules were
 316          *   not registered
 317          */
 318         public function register( $name, $info = null ) {
 319                 $moduleSkinStyles = $this->config->get( 'ResourceModuleSkinStyles' );
 320
 321                 // Allow multiple modules to be registered in one call
 322                 $registrations = is_array( $name ) ? $name : [ $name => $info ];
 323                 foreach ( $registrations as $name => $info ) {
 324                         // Warn on duplicate registrations
 325                         if ( isset( $this->moduleInfos[$name] ) ) {
 326                                 // A module has already been registered by this name
 327                                 $this->logger->warning(
 328                                         'ResourceLoader duplicate registration warning. ' .
 329                                         'Another module has already been registered as ' . $name
 330                                 );
 331                         }
 332
 333                         // Check $name for validity
 334                         if ( !self::isValidModuleName( $name ) ) {
 335                                 throw new MWException( "ResourceLoader module name '$name' is invalid, "
 336                                         . "see ResourceLoader::isValidModuleName()" );
 337                         }
 338
 339                         // Attach module
 340                         if ( $info instanceof ResourceLoaderModule ) {
 341                                 $this->moduleInfos[$name] = [ 'object' => $info ];
 342                                 $info->setName( $name );
 343                                 $this->modules[$name] = $info;
 344                         } elseif ( is_array( $info ) ) {
 345                                 // New calling convention
 346                                 $this->moduleInfos[$name] = $info;
 347                         } else {
 348                                 throw new MWException(
 349                                         'ResourceLoader module info type error for module \'' . $name .
 350                                         '\': expected ResourceLoaderModule or array (got: ' . gettype( $info ) . ')'
 351                                 );
 352                         }
 353
 354                         // Last-minute changes
 355
 356                         // Apply custom skin-defined styles to existing modules.
 357                         if ( $this->isFileModule( $name ) ) {
 358                                 foreach ( $moduleSkinStyles as $skinName => $skinStyles ) {
 359                                         // If this module already defines skinStyles for this skin, ignore $wgResourceModuleSkinStyles.
 360                                         if ( isset( $this->moduleInfos[$name]['skinStyles'][$skinName] ) ) {
 361                                                 continue;
 362                                         }
 363
 364                                         // If $name is preceded with a '+', the defined style files will be added to 'default'
 365                                         // skinStyles, otherwise 'default' will be ignored as it normally would be.
 366                                         if ( isset( $skinStyles[$name] ) ) {
 367                                                 $paths = (array)$skinStyles[$name];
 368                                                 $styleFiles = [];
 369                                         } elseif ( isset( $skinStyles['+' . $name] ) ) {
 370                                                 $paths = (array)$skinStyles['+' . $name];
 371                                                 $styleFiles = isset( $this->moduleInfos[$name]['skinStyles']['default'] ) ?
 372                                                         (array)$this->moduleInfos[$name]['skinStyles']['default'] :
 373                                                         [];
 374                                         } else {
 375                                                 continue;
 376                                         }
 377
 378                                         // Add new file paths, remapping them to refer to our directories and not use settings
 379                                         // from the module we're modifying, which come from the base definition.
 380                                         list( $localBasePath, $remoteBasePath ) =
 381                                                 ResourceLoaderFileModule::extractBasePaths( $skinStyles );
 382
 383                                         foreach ( $paths as $path ) {
 384                                                 $styleFiles[] = new ResourceLoaderFilePath( $path, $localBasePath, $remoteBasePath );
 385                                         }
 386
 387                                         $this->moduleInfos[$name]['skinStyles'][$skinName] = $styleFiles;
 388                                 }
 389                         }
 390                 }
 391
 392         }
 393
 394         /**
 395          */
 396         public function registerTestModules() {
 397                 global $IP;
 398
 399                 if ( $this->config->get( 'EnableJavaScriptTest' ) !== true ) {
 400                         throw new MWException( 'Attempt to register JavaScript test modules '
 401                                 . 'but <code>$wgEnableJavaScriptTest</code> is false. '
 402                                 . 'Edit your <code>LocalSettings.php</code> to enable it.' );
 403                 }
 404
 405                 // Get core test suites
 406                 $testModules = [];
 407                 $testModules['qunit'] = [];
 408                 // Get other test suites (e.g. from extensions)
 409                 Hooks::run( 'ResourceLoaderTestModules', [ &$testModules, &$this ] );
 410
 411                 // Add the testrunner (which configures QUnit) to the dependencies.
 412                 // Since it must be ready before any of the test suites are executed.
 413                 foreach ( $testModules['qunit'] as &$module ) {
 414                         // Make sure all test modules are top-loading so that when QUnit starts
 415                         // on document-ready, it will run once and finish. If some tests arrive
 416                         // later (possibly after QUnit has already finished) they will be ignored.
 417                         $module['position'] = 'top';
 418                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 419                 }
 420
 421                 $testModules['qunit'] =
 422                         ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules['qunit'];
 423
 424                 foreach ( $testModules as $id => $names ) {
 425                         // Register test modules
 426                         $this->register( $testModules[$id] );
 427
 428                         // Keep track of their names so that they can be loaded together
 429                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 430                 }
 431
 432         }
 433
 434         /**
 435          * Add a foreign source of modules.
 436          *
 437          * Source IDs are typically the same as the Wiki ID or database name (e.g. lowercase a-z).
 438          *
 439          * @param array|string $id Source ID (string), or [ id1 => loadUrl, id2 => loadUrl, ... ]
 440          * @param string|array $loadUrl load.php url (string), or array with loadUrl key for
 441          *  backwards-compatibility.
 442          * @throws MWException
 443          */
 444         public function addSource( $id, $loadUrl = null ) {
 445                 // Allow multiple sources to be registered in one call
 446                 if ( is_array( $id ) ) {
 447                         foreach ( $id as $key => $value ) {
 448                                 $this->addSource( $key, $value );
 449                         }
 450                         return;
 451                 }
 452
 453                 // Disallow duplicates
 454                 if ( isset( $this->sources[$id] ) ) {
 455                         throw new MWException(
 456                                 'ResourceLoader duplicate source addition error. ' .
 457                                 'Another source has already been registered as ' . $id
 458                         );
 459                 }
 460
 461                 // Pre 1.24 backwards-compatibility
 462                 if ( is_array( $loadUrl ) ) {
 463                         if ( !isset( $loadUrl['loadScript'] ) ) {
 464                                 throw new MWException(
 465                                         __METHOD__ . ' was passed an array with no "loadScript" key.'
 466                                 );
 467                         }
 468
 469                         $loadUrl = $loadUrl['loadScript'];
 470                 }
 471
 472                 $this->sources[$id] = $loadUrl;
 473         }
 474
 475         /**
 476          * Get a list of module names.
 477          *
 478          * @return array List of module names
 479          */
 480         public function getModuleNames() {
 481                 return array_keys( $this->moduleInfos );
 482         }
 483
 484         /**
 485          * Get a list of test module names for one (or all) frameworks.
 486          *
 487          * If the given framework id is unknkown, or if the in-object variable is not an array,
 488          * then it will return an empty array.
 489          *
 490          * @param string $framework Get only the test module names for one
 491          *   particular framework (optional)
 492          * @return array
 493          */
 494         public function getTestModuleNames( $framework = 'all' ) {
 495                 /** @todo api siteinfo prop testmodulenames modulenames */
 496                 if ( $framework == 'all' ) {
 497                         return $this->testModuleNames;
 498                 } elseif ( isset( $this->testModuleNames[$framework] )
 499                         && is_array( $this->testModuleNames[$framework] )
 500                 ) {
 501                         return $this->testModuleNames[$framework];
 502                 } else {
 503                         return [];
 504                 }
 505         }
 506
 507         /**
 508          * Check whether a ResourceLoader module is registered
 509          *
 510          * @since 1.25
 511          * @param string $name
 512          * @return bool
 513          */
 514         public function isModuleRegistered( $name ) {
 515                 return isset( $this->moduleInfos[$name] );
 516         }
 517
 518         /**
 519          * Get the ResourceLoaderModule object for a given module name.
 520          *
 521          * If an array of module parameters exists but a ResourceLoaderModule object has not
 522          * yet been instantiated, this method will instantiate and cache that object such that
 523          * subsequent calls simply return the same object.
 524          *
 525          * @param string $name Module name
 526          * @return ResourceLoaderModule|null If module has been registered, return a
 527          *  ResourceLoaderModule instance. Otherwise, return null.
 528          */
 529         public function getModule( $name ) {
 530                 if ( !isset( $this->modules[$name] ) ) {
 531                         if ( !isset( $this->moduleInfos[$name] ) ) {
 532                                 // No such module
 533                                 return null;
 534                         }
 535                         // Construct the requested object
 536                         $info = $this->moduleInfos[$name];
 537                         /** @var ResourceLoaderModule $object */
 538                         if ( isset( $info['object'] ) ) {
 539                                 // Object given in info array
 540                                 $object = $info['object'];
 541                         } else {
 542                                 if ( !isset( $info['class'] ) ) {
 543                                         $class = 'ResourceLoaderFileModule';
 544                                 } else {
 545                                         $class = $info['class'];
 546                                 }
 547                                 /** @var ResourceLoaderModule $object */
 548                                 $object = new $class( $info );
 549                                 $object->setConfig( $this->getConfig() );
 550                                 $object->setLogger( $this->logger );
 551                         }
 552                         $object->setName( $name );
 553                         $this->modules[$name] = $object;
 554                 }
 555
 556                 return $this->modules[$name];
 557         }
 558
 559         /**
 560          * Return whether the definition of a module corresponds to a simple ResourceLoaderFileModule.
 561          *
 562          * @param string $name Module name
 563          * @return bool
 564          */
 565         protected function isFileModule( $name ) {
 566                 if ( !isset( $this->moduleInfos[$name] ) ) {
 567                         return false;
 568                 }
 569                 $info = $this->moduleInfos[$name];
 570                 if ( isset( $info['object'] ) || isset( $info['class'] ) ) {
 571                         return false;
 572                 }
 573                 return true;
 574         }
 575
 576         /**
 577          * Get the list of sources.
 578          *
 579          * @return array Like [ id => load.php url, ... ]
 580          */
 581         public function getSources() {
 582                 return $this->sources;
 583         }
 584
 585         /**
 586          * Get the URL to the load.php endpoint for the given
 587          * ResourceLoader source
 588          *
 589          * @since 1.24
 590          * @param string $source
 591          * @throws MWException On an invalid $source name
 592          * @return string
 593          */
 594         public function getLoadScript( $source ) {
 595                 if ( !isset( $this->sources[$source] ) ) {
 596                         throw new MWException( "The $source source was never registered in ResourceLoader." );
 597                 }
 598                 return $this->sources[$source];
 599         }
 600
 601         /**
 602          * @since 1.26
 603          * @param string $value
 604          * @return string Hash
 605          */
 606         public static function makeHash( $value ) {
 607                 $hash = hash( 'fnv132', $value );
 608                 return Wikimedia\base_convert( $hash, 16, 36, 7 );
 609         }
 610
 611         /**
 612          * Helper method to get and combine versions of multiple modules.
 613          *
 614          * @since 1.26
 615          * @param ResourceLoaderContext $context
 616          * @param string[] $modules List of known module names
 617          * @return string Hash
 618          */
 619         public function getCombinedVersion( ResourceLoaderContext $context, array $moduleNames ) {
 620                 if ( !$moduleNames ) {
 621                         return '';
 622                 }
 623                 $hashes = array_map( function ( $module ) use ( $context ) {
 624                         return $this->getModule( $module )->getVersionHash( $context );
 625                 }, $moduleNames );
 626                 return self::makeHash( implode( '', $hashes ) );
 627         }
 628
 629         /**
 630          * Get the expected value of the 'version' query parameter.
 631          *
 632          * This is used by respond() to set a short Cache-Control header for requests with
 633          * information newer than the current server has. This avoids pollution of edge caches.
 634          * Typically during deployment. (T117587)
 635          *
 636          * This MUST match return value of `mw.loader#getCombinedVersion()` client-side.
 637          *
 638          * @since 1.28
 639          * @param ResourceLoaderContext $context
 640          * @param string[] $modules List of module names
 641          * @return string Hash
 642          */
 643         public function makeVersionQuery( ResourceLoaderContext $context ) {
 644                 // As of MediaWiki 1.28, the server and client use the same algorithm for combining
 645                 // version hashes. There is no technical reason for this to be same, and for years the
 646                 // implementations differed. If getCombinedVersion in PHP (used for StartupModule and
 647                 // E-Tag headers) differs in the future from getCombinedVersion in JS (used for 'version'
 648                 // query parameter), then this method must continue to match the JS one.
 649                 $moduleNames = [];
 650                 foreach ( $context->getModules() as $name ) {
 651                         if ( !$this->getModule( $name ) ) {
 652                                 // If a versioned request contains a missing module, the version is a mismatch
 653                                 // as the client considered a module (and version) we don't have.
 654                                 return '';
 655                         }
 656                         $moduleNames[] = $name;
 657                 }
 658                 return $this->getCombinedVersion( $context, $moduleNames );
 659         }
 660
 661         /**
 662          * Output a response to a load request, including the content-type header.
 663          *
 664          * @param ResourceLoaderContext $context Context in which a response should be formed
 665          */
 666         public function respond( ResourceLoaderContext $context ) {
 667                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 668                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 669                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 670                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 671                 // the whole thing in our own output buffer to be sure the active buffer
 672                 // doesn't use ob_gzhandler.
 673                 // See http://bugs.php.net/bug.php?id=36514
 674                 ob_start();
 675
 676                 // Find out which modules are missing and instantiate the others
 677                 $modules = [];
 678                 $missing = [];
 679                 foreach ( $context->getModules() as $name ) {
 680                         $module = $this->getModule( $name );
 681                         if ( $module ) {
 682                                 // Do not allow private modules to be loaded from the web.
 683                                 // This is a security issue, see bug 34907.
 684                                 if ( $module->getGroup() === 'private' ) {
 685                                         $this->logger->debug( "Request for private module '$name' denied" );
 686                                         $this->errors[] = "Cannot show private module \"$name\"";
 687                                         continue;
 688                                 }
 689                                 $modules[$name] = $module;
 690                         } else {
 691                                 $missing[] = $name;
 692                         }
 693                 }
 694
 695                 try {
 696                         // Preload for getCombinedVersion() and for batch makeModuleResponse()
 697                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 698                 } catch ( Exception $e ) {
 699                         MWExceptionHandler::logException( $e );
 700                         $this->logger->warning( 'Preloading module info failed: {exception}', [
 701                                 'exception' => $e
 702                         ] );
 703                         $this->errors[] = self::formatExceptionNoComment( $e );
 704                 }
 705
 706                 // Combine versions to propagate cache invalidation
 707                 $versionHash = '';
 708                 try {
 709                         $versionHash = $this->getCombinedVersion( $context, array_keys( $modules ) );
 710                 } catch ( Exception $e ) {
 711                         MWExceptionHandler::logException( $e );
 712                         $this->logger->warning( 'Calculating version hash failed: {exception}', [
 713                                 'exception' => $e
 714                         ] );
 715                         $this->errors[] = self::formatExceptionNoComment( $e );
 716                 }
 717
 718                 // See RFC 2616 § 3.11 Entity Tags
 719                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.11
 720                 $etag = 'W/"' . $versionHash . '"';
 721
 722                 // Try the client-side cache first
 723                 if ( $this->tryRespondNotModified( $context, $etag ) ) {
 724                         return; // output handled (buffers cleared)
 725                 }
 726
 727                 // Use file cache if enabled and available...
 728                 if ( $this->config->get( 'UseFileCache' ) ) {
 729                         $fileCache = ResourceFileCache::newFromContext( $context );
 730                         if ( $this->tryRespondFromFileCache( $fileCache, $context, $etag ) ) {
 731                                 return; // output handled
 732                         }
 733                 }
 734
 735                 // Generate a response
 736                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 737
 738                 // Capture any PHP warnings from the output buffer and append them to the
 739                 // error list if we're in debug mode.
 740                 if ( $context->getDebug() ) {
 741                         $warnings = ob_get_contents();
 742                         if ( strlen( $warnings ) ) {
 743                                 $this->errors[] = $warnings;
 744                         }
 745                 }
 746
 747                 // Save response to file cache unless there are errors
 748                 if ( isset( $fileCache ) && !$this->errors && !count( $missing ) ) {
 749                         // Cache single modules and images...and other requests if there are enough hits
 750                         if ( ResourceFileCache::useFileCache( $context ) ) {
 751                                 if ( $fileCache->isCacheWorthy() ) {
 752                                         $fileCache->saveText( $response );
 753                                 } else {
 754                                         $fileCache->incrMissesRecent( $context->getRequest() );
 755                                 }
 756                         }
 757                 }
 758
 759                 $this->sendResponseHeaders( $context, $etag, (bool)$this->errors );
 760
 761                 // Remove the output buffer and output the response
 762                 ob_end_clean();
 763
 764                 if ( $context->getImageObj() && $this->errors ) {
 765                         // We can't show both the error messages and the response when it's an image.
 766                         $response = implode( "\n\n", $this->errors );
 767                 } elseif ( $this->errors ) {
 768                         $errorText = implode( "\n\n", $this->errors );
 769                         $errorResponse = self::makeComment( $errorText );
 770                         if ( $context->shouldIncludeScripts() ) {
 771                                 $errorResponse .= 'if (window.console && console.error) {'
 772                                         . Xml::encodeJsCall( 'console.error', [ $errorText ] )
 773                                         . "}\n";
 774                         }
 775
 776                         // Prepend error info to the response
 777                         $response = $errorResponse . $response;
 778                 }
 779
 780                 $this->errors = [];
 781                 echo $response;
 782
 783         }
 784
 785         /**
 786          * Send main response headers to the client.
 787          *
 788          * Deals with Content-Type, CORS (for stylesheets), and caching.
 789          *
 790          * @param ResourceLoaderContext $context
 791          * @param string $etag ETag header value
 792          * @param bool $errors Whether there are errors in the response
 793          * @return void
 794          */
 795         protected function sendResponseHeaders( ResourceLoaderContext $context, $etag, $errors ) {
 796                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 797                 // Use a short cache expiry so that updates propagate to clients quickly, if:
 798                 // - No version specified (shared resources, e.g. stylesheets)
 799                 // - There were errors (recover quickly)
 800                 // - Version mismatch (T117587, T47877)
 801                 if ( is_null( $context->getVersion() )
 802                         || $errors
 803                         || $context->getVersion() !== $this->makeVersionQuery( $context )
 804                 ) {
 805                         $maxage = $rlMaxage['unversioned']['client'];
 806                         $smaxage = $rlMaxage['unversioned']['server'];
 807                 // If a version was specified we can use a longer expiry time since changing
 808                 // version numbers causes cache misses
 809                 } else {
 810                         $maxage = $rlMaxage['versioned']['client'];
 811                         $smaxage = $rlMaxage['versioned']['server'];
 812                 }
 813                 if ( $context->getImageObj() ) {
 814                         // Output different headers if we're outputting textual errors.
 815                         if ( $errors ) {
 816                                 header( 'Content-Type: text/plain; charset=utf-8' );
 817                         } else {
 818                                 $context->getImageObj()->sendResponseHeaders( $context );
 819                         }
 820                 } elseif ( $context->getOnly() === 'styles' ) {
 821                         header( 'Content-Type: text/css; charset=utf-8' );
 822                         header( 'Access-Control-Allow-Origin: *' );
 823                 } else {
 824                         header( 'Content-Type: text/javascript; charset=utf-8' );
 825                 }
 826                 // See RFC 2616 § 14.19 ETag
 827                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.19
 828                 header( 'ETag: ' . $etag );
 829                 if ( $context->getDebug() ) {
 830                         // Do not cache debug responses
 831                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 832                         header( 'Pragma: no-cache' );
 833                 } else {
 834                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 835                         $exp = min( $maxage, $smaxage );
 836                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 837                 }
 838         }
 839
 840         /**
 841          * Respond with HTTP 304 Not Modified if appropiate.
 842          *
 843          * If there's an If-None-Match header, respond with a 304 appropriately
 844          * and clear out the output buffer. If the client cache is too old then do nothing.
 845          *
 846          * @param ResourceLoaderContext $context
 847          * @param string $etag ETag header value
 848          * @return bool True if HTTP 304 was sent and output handled
 849          */
 850         protected function tryRespondNotModified( ResourceLoaderContext $context, $etag ) {
 851                 // See RFC 2616 § 14.26 If-None-Match
 852                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
 853                 $clientKeys = $context->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST );
 854                 // Never send 304s in debug mode
 855                 if ( $clientKeys !== false && !$context->getDebug() && in_array( $etag, $clientKeys ) ) {
 856                         // There's another bug in ob_gzhandler (see also the comment at
 857                         // the top of this function) that causes it to gzip even empty
 858                         // responses, meaning it's impossible to produce a truly empty
 859                         // response (because the gzip header is always there). This is
 860                         // a problem because 304 responses have to be completely empty
 861                         // per the HTTP spec, and Firefox behaves buggily when they're not.
 862                         // See also http://bugs.php.net/bug.php?id=51579
 863                         // To work around this, we tear down all output buffering before
 864                         // sending the 304.
 865                         wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 866
 867                         HttpStatus::header( 304 );
 868
 869                         $this->sendResponseHeaders( $context, $etag, false );
 870                         return true;
 871                 }
 872                 return false;
 873         }
 874
 875         /**
 876          * Send out code for a response from file cache if possible.
 877          *
 878          * @param ResourceFileCache $fileCache Cache object for this request URL
 879          * @param ResourceLoaderContext $context Context in which to generate a response
 880          * @param string $etag ETag header value
 881          * @return bool If this found a cache file and handled the response
 882          */
 883         protected function tryRespondFromFileCache(
 884                 ResourceFileCache $fileCache,
 885                 ResourceLoaderContext $context,
 886                 $etag
 887         ) {
 888                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 889                 // Buffer output to catch warnings.
 890                 ob_start();
 891                 // Get the maximum age the cache can be
 892                 $maxage = is_null( $context->getVersion() )
 893                         ? $rlMaxage['unversioned']['server']
 894                         : $rlMaxage['versioned']['server'];
 895                 // Minimum timestamp the cache file must have
 896                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 897                 if ( !$good ) {
 898                         try { // RL always hits the DB on file cache miss...
 899                                 wfGetDB( DB_REPLICA );
 900                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 901                                 $good = $fileCache->isCacheGood(); // cache existence check
 902                         }
 903                 }
 904                 if ( $good ) {
 905                         $ts = $fileCache->cacheTimestamp();
 906                         // Send content type and cache headers
 907                         $this->sendResponseHeaders( $context, $etag, false );
 908                         $response = $fileCache->fetchText();
 909                         // Capture any PHP warnings from the output buffer and append them to the
 910                         // response in a comment if we're in debug mode.
 911                         if ( $context->getDebug() ) {
 912                                 $warnings = ob_get_contents();
 913                                 if ( strlen( $warnings ) ) {
 914                                         $response = self::makeComment( $warnings ) . $response;
 915                                 }
 916                         }
 917                         // Remove the output buffer and output the response
 918                         ob_end_clean();
 919                         echo $response . "\n/* Cached {$ts} */";
 920                         return true; // cache hit
 921                 }
 922                 // Clear buffer
 923                 ob_end_clean();
 924
 925                 return false; // cache miss
 926         }
 927
 928         /**
 929          * Generate a CSS or JS comment block.
 930          *
 931          * Only use this for public data, not error message details.
 932          *
 933          * @param string $text
 934          * @return string
 935          */
 936         public static function makeComment( $text ) {
 937                 $encText = str_replace( '*/', '* /', $text );
 938                 return "/*\n$encText\n*/\n";
 939         }
 940
 941         /**
 942          * Handle exception display.
 943          *
 944          * @param Exception $e Exception to be shown to the user
 945          * @return string Sanitized text in a CSS/JS comment that can be returned to the user
 946          */
 947         public static function formatException( $e ) {
 948                 return self::makeComment( self::formatExceptionNoComment( $e ) );
 949         }
 950
 951         /**
 952          * Handle exception display.
 953          *
 954          * @since 1.25
 955          * @param Exception $e Exception to be shown to the user
 956          * @return string Sanitized text that can be returned to the user
 957          */
 958         protected static function formatExceptionNoComment( $e ) {
 959                 global $wgShowExceptionDetails;
 960
 961                 if ( !$wgShowExceptionDetails ) {
 962                         return MWExceptionHandler::getPublicLogMessage( $e );
 963                 }
 964
 965                 return MWExceptionHandler::getLogMessage( $e );
 966         }
 967
 968         /**
 969          * Generate code for a response.
 970          *
 971          * @param ResourceLoaderContext $context Context in which to generate a response
 972          * @param ResourceLoaderModule[] $modules List of module objects keyed by module name
 973          * @param string[] $missing List of requested module names that are unregistered (optional)
 974          * @return string Response data
 975          */
 976         public function makeModuleResponse( ResourceLoaderContext $context,
 977                 array $modules, array $missing = []
 978         ) {
 979                 $out = '';
 980                 $states = [];
 981
 982                 if ( !count( $modules ) && !count( $missing ) ) {
 983                         return <<<MESSAGE
 984 /* This file is the Web entry point for MediaWiki's ResourceLoader:
 985    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
 986    no modules were requested. Max made me put this here. */
 987 MESSAGE;
 988                 }
 989
 990                 $image = $context->getImageObj();
 991                 if ( $image ) {
 992                         $data = $image->getImageData( $context );
 993                         if ( $data === false ) {
 994                                 $data = '';
 995                                 $this->errors[] = 'Image generation failed';
 996                         }
 997                         return $data;
 998                 }
 999
1000                 foreach ( $missing as $name ) {
1001                         $states[$name] = 'missing';
1002                 }
1003
1004                 // Generate output
1005                 $isRaw = false;
1006
1007                 $filter = $context->getOnly() === 'styles' ? 'minify-css' : 'minify-js';
1008
1009                 foreach ( $modules as $name => $module ) {
1010                         try {
1011                                 $content = $module->getModuleContent( $context );
1012                                 $implementKey = $name . '@' . $module->getVersionHash( $context );
1013                                 $strContent = '';
1014
1015                                 // Append output
1016                                 switch ( $context->getOnly() ) {
1017                                         case 'scripts':
1018                                                 $scripts = $content['scripts'];
1019                                                 if ( is_string( $scripts ) ) {
1020                                                         // Load scripts raw...
1021                                                         $strContent = $scripts;
1022                                                 } elseif ( is_array( $scripts ) ) {
1023                                                         // ...except when $scripts is an array of URLs
1024                                                         $strContent = self::makeLoaderImplementScript( $implementKey, $scripts, [], [], [] );
1025                                                 }
1026                                                 break;
1027                                         case 'styles':
1028                                                 $styles = $content['styles'];
1029                                                 // We no longer seperate into media, they are all combined now with
1030                                                 // custom media type groups into @media .. {} sections as part of the css string.
1031                                                 // Module returns either an empty array or a numerical array with css strings.
1032                                                 $strContent = isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
1033                                                 break;
1034                                         default:
1035                                                 $scripts = isset( $content['scripts'] ) ? $content['scripts'] : '';
1036                                                 if ( is_string( $scripts ) ) {
1037                                                         if ( $name === 'site' || $name === 'user' ) {
1038                                                                 // Legacy scripts that run in the global scope without a closure.
1039                                                                 // mw.loader.implement will use globalEval if scripts is a string.
1040                                                                 // Minify manually here, because general response minification is
1041                                                                 // not effective due it being a string literal, not a function.
1042                                                                 if ( !ResourceLoader::inDebugMode() ) {
1043                                                                         $scripts = self::filter( 'minify-js', $scripts ); // T107377
1044                                                                 }
1045                                                         } else {
1046                                                                 $scripts = new XmlJsCode( $scripts );
1047                                                         }
1048                                                 }
1049                                                 $strContent = self::makeLoaderImplementScript(
1050                                                         $implementKey,
1051                                                         $scripts,
1052                                                         isset( $content['styles'] ) ? $content['styles'] : [],
1053                                                         isset( $content['messagesBlob'] ) ? new XmlJsCode( $content['messagesBlob'] ) : [],
1054                                                         isset( $content['templates'] ) ? $content['templates'] : []
1055                                                 );
1056                                                 break;
1057                                 }
1058
1059                                 if ( !$context->getDebug() ) {
1060                                         $strContent = self::filter( $filter, $strContent );
1061                                 }
1062
1063                                 $out .= $strContent;
1064
1065                         } catch ( Exception $e ) {
1066                                 MWExceptionHandler::logException( $e );
1067                                 $this->logger->warning( 'Generating module package failed: {exception}', [
1068                                         'exception' => $e
1069                                 ] );
1070                                 $this->errors[] = self::formatExceptionNoComment( $e );
1071
1072                                 // Respond to client with error-state instead of module implementation
1073                                 $states[$name] = 'error';
1074                                 unset( $modules[$name] );
1075                         }
1076                         $isRaw |= $module->isRaw();
1077                 }
1078
1079                 // Update module states
1080                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
1081                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
1082                                 // Set the state of modules loaded as only scripts to ready as
1083                                 // they don't have an mw.loader.implement wrapper that sets the state
1084                                 foreach ( $modules as $name => $module ) {
1085                                         $states[$name] = 'ready';
1086                                 }
1087                         }
1088
1089                         // Set the state of modules we didn't respond to with mw.loader.implement
1090                         if ( count( $states ) ) {
1091                                 $stateScript = self::makeLoaderStateScript( $states );
1092                                 if ( !$context->getDebug() ) {
1093                                         $stateScript = self::filter( 'minify-js', $stateScript );
1094                                 }
1095                                 $out .= $stateScript;
1096                         }
1097                 } else {
1098                         if ( count( $states ) ) {
1099                                 $this->errors[] = 'Problematic modules: ' .
1100                                         FormatJson::encode( $states, ResourceLoader::inDebugMode() );
1101                         }
1102                 }
1103
1104                 return $out;
1105         }
1106
1107         /**
1108          * Get names of modules that use a certain message.
1109          *
1110          * @param string $messageKey
1111          * @return array List of module names
1112          */
1113         public function getModulesByMessage( $messageKey ) {
1114                 $moduleNames = [];
1115                 foreach ( $this->getModuleNames() as $moduleName ) {
1116                         $module = $this->getModule( $moduleName );
1117                         if ( in_array( $messageKey, $module->getMessages() ) ) {
1118                                 $moduleNames[] = $moduleName;
1119                         }
1120                 }
1121                 return $moduleNames;
1122         }
1123
1124         /* Static Methods */
1125
1126         /**
1127          * Return JS code that calls mw.loader.implement with given module properties.
1128          *
1129          * @param string $name Module name or implement key (format "`[name]@[version]`")
1130          * @param XmlJsCode|array|string $scripts Code as XmlJsCode (to be wrapped in a closure),
1131          *  list of URLs to JavaScript files, or a string of JavaScript for `$.globalEval`.
1132          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1133          *   to CSS files keyed by media type
1134          * @param mixed $messages List of messages associated with this module. May either be an
1135          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1136          *   the same data, wrapped in an XmlJsCode object.
1137          * @param array $templates Keys are name of templates and values are the source of
1138          *   the template.
1139          * @throws MWException
1140          * @return string
1141          */
1142         protected static function makeLoaderImplementScript(
1143                 $name, $scripts, $styles, $messages, $templates
1144         ) {
1145
1146                 if ( $scripts instanceof XmlJsCode ) {
1147                         $scripts = new XmlJsCode( "function ( $, jQuery, require, module ) {\n{$scripts->value}\n}" );
1148                 } elseif ( !is_string( $scripts ) && !is_array( $scripts ) ) {
1149                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1150                 }
1151                 // mw.loader.implement requires 'styles', 'messages' and 'templates' to be objects (not
1152                 // arrays). json_encode considers empty arrays to be numerical and outputs "[]" instead
1153                 // of "{}". Force them to objects.
1154                 $module = [
1155                         $name,
1156                         $scripts,
1157                         (object)$styles,
1158                         (object)$messages,
1159                         (object)$templates,
1160                 ];
1161                 self::trimArray( $module );
1162
1163                 return Xml::encodeJsCall( 'mw.loader.implement', $module, ResourceLoader::inDebugMode() );
1164         }
1165
1166         /**
1167          * Returns JS code which, when called, will register a given list of messages.
1168          *
1169          * @param mixed $messages Either an associative array mapping message key to value, or a
1170          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1171          * @return string
1172          */
1173         public static function makeMessageSetScript( $messages ) {
1174                 return Xml::encodeJsCall(
1175                         'mw.messages.set',
1176                         [ (object)$messages ],
1177                         ResourceLoader::inDebugMode()
1178                 );
1179         }
1180
1181         /**
1182          * Combines an associative array mapping media type to CSS into a
1183          * single stylesheet with "@media" blocks.
1184          *
1185          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1186          * @return array
1187          */
1188         public static function makeCombinedStyles( array $stylePairs ) {
1189                 $out = [];
1190                 foreach ( $stylePairs as $media => $styles ) {
1191                         // ResourceLoaderFileModule::getStyle can return the styles
1192                         // as a string or an array of strings. This is to allow separation in
1193                         // the front-end.
1194                         $styles = (array)$styles;
1195                         foreach ( $styles as $style ) {
1196                                 $style = trim( $style );
1197                                 // Don't output an empty "@media print { }" block (bug 40498)
1198                                 if ( $style !== '' ) {
1199                                         // Transform the media type based on request params and config
1200                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1201                                         $media = OutputPage::transformCssMedia( $media );
1202
1203                                         if ( $media === '' || $media == 'all' ) {
1204                                                 $out[] = $style;
1205                                         } elseif ( is_string( $media ) ) {
1206                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1207                                         }
1208                                         // else: skip
1209                                 }
1210                         }
1211                 }
1212                 return $out;
1213         }
1214
1215         /**
1216          * Returns a JS call to mw.loader.state, which sets the state of a
1217          * module or modules to a given value. Has two calling conventions:
1218          *
1219          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1220          *         Set the state of a single module called $name to $state
1221          *
1222          *    - ResourceLoader::makeLoaderStateScript( [ $name => $state, ... ] ):
1223          *         Set the state of modules with the given names to the given states
1224          *
1225          * @param string $name
1226          * @param string $state
1227          * @return string
1228          */
1229         public static function makeLoaderStateScript( $name, $state = null ) {
1230                 if ( is_array( $name ) ) {
1231                         return Xml::encodeJsCall(
1232                                 'mw.loader.state',
1233                                 [ $name ],
1234                                 ResourceLoader::inDebugMode()
1235                         );
1236                 } else {
1237                         return Xml::encodeJsCall(
1238                                 'mw.loader.state',
1239                                 [ $name, $state ],
1240                                 ResourceLoader::inDebugMode()
1241                         );
1242                 }
1243         }
1244
1245         /**
1246          * Returns JS code which calls the script given by $script. The script will
1247          * be called with local variables name, version, dependencies and group,
1248          * which will have values corresponding to $name, $version, $dependencies
1249          * and $group as supplied.
1250          *
1251          * @param string $name Module name
1252          * @param string $version Module version hash
1253          * @param array $dependencies List of module names on which this module depends
1254          * @param string $group Group which the module is in.
1255          * @param string $source Source of the module, or 'local' if not foreign.
1256          * @param string $script JavaScript code
1257          * @return string
1258          */
1259         public static function makeCustomLoaderScript( $name, $version, $dependencies,
1260                 $group, $source, $script
1261         ) {
1262                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1263                 return Xml::encodeJsCall(
1264                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1265                         [ $name, $version, $dependencies, $group, $source ],
1266                         ResourceLoader::inDebugMode()
1267                 );
1268         }
1269
1270         private static function isEmptyObject( stdClass $obj ) {
1271                 foreach ( $obj as $key => $value ) {
1272                         return false;
1273                 }
1274                 return true;
1275         }
1276
1277         /**
1278          * Remove empty values from the end of an array.
1279          *
1280          * Values considered empty:
1281          *
1282          * - null
1283          * - []
1284          * - new XmlJsCode( '{}' )
1285          * - new stdClass() // (object) []
1286          *
1287          * @param Array $array
1288          */
1289         private static function trimArray( array &$array ) {
1290                 $i = count( $array );
1291                 while ( $i-- ) {
1292                         if ( $array[$i] === null
1293                                 || $array[$i] === []
1294                                 || ( $array[$i] instanceof XmlJsCode && $array[$i]->value === '{}' )
1295                                 || ( $array[$i] instanceof stdClass && self::isEmptyObject( $array[$i] ) )
1296                         ) {
1297                                 unset( $array[$i] );
1298                         } else {
1299                                 break;
1300                         }
1301                 }
1302         }
1303
1304         /**
1305          * Returns JS code which calls mw.loader.register with the given
1306          * parameters. Has three calling conventions:
1307          *
1308          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version,
1309          *        $dependencies, $group, $source, $skip
1310          *     ):
1311          *        Register a single module.
1312          *
1313          *   - ResourceLoader::makeLoaderRegisterScript( [ $name1, $name2 ] ):
1314          *        Register modules with the given names.
1315          *
1316          *   - ResourceLoader::makeLoaderRegisterScript( [
1317          *        [ $name1, $version1, $dependencies1, $group1, $source1, $skip1 ],
1318          *        [ $name2, $version2, $dependencies1, $group2, $source2, $skip2 ],
1319          *        ...
1320          *     ] ):
1321          *        Registers modules with the given names and parameters.
1322          *
1323          * @param string $name Module name
1324          * @param string $version Module version hash
1325          * @param array $dependencies List of module names on which this module depends
1326          * @param string $group Group which the module is in
1327          * @param string $source Source of the module, or 'local' if not foreign
1328          * @param string $skip Script body of the skip function
1329          * @return string
1330          */
1331         public static function makeLoaderRegisterScript( $name, $version = null,
1332                 $dependencies = null, $group = null, $source = null, $skip = null
1333         ) {
1334                 if ( is_array( $name ) ) {
1335                         // Build module name index
1336                         $index = [];
1337                         foreach ( $name as $i => &$module ) {
1338                                 $index[$module[0]] = $i;
1339                         }
1340
1341                         // Transform dependency names into indexes when possible, they will be resolved by
1342                         // mw.loader.register on the other end
1343                         foreach ( $name as &$module ) {
1344                                 if ( isset( $module[2] ) ) {
1345                                         foreach ( $module[2] as &$dependency ) {
1346                                                 if ( isset( $index[$dependency] ) ) {
1347                                                         $dependency = $index[$dependency];
1348                                                 }
1349                                         }
1350                                 }
1351                         }
1352
1353                         array_walk( $name, [ 'self', 'trimArray' ] );
1354
1355                         return Xml::encodeJsCall(
1356                                 'mw.loader.register',
1357                                 [ $name ],
1358                                 ResourceLoader::inDebugMode()
1359                         );
1360                 } else {
1361                         $registration = [ $name, $version, $dependencies, $group, $source, $skip ];
1362                         self::trimArray( $registration );
1363                         return Xml::encodeJsCall(
1364                                 'mw.loader.register',
1365                                 $registration,
1366                                 ResourceLoader::inDebugMode()
1367                         );
1368                 }
1369         }
1370
1371         /**
1372          * Returns JS code which calls mw.loader.addSource() with the given
1373          * parameters. Has two calling conventions:
1374          *
1375          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1376          *       Register a single source
1377          *
1378          *   - ResourceLoader::makeLoaderSourcesScript( [ $id1 => $loadUrl, $id2 => $loadUrl, ... ] );
1379          *       Register sources with the given IDs and properties.
1380          *
1381          * @param string $id Source ID
1382          * @param string $loadUrl load.php url
1383          * @return string
1384          */
1385         public static function makeLoaderSourcesScript( $id, $loadUrl = null ) {
1386                 if ( is_array( $id ) ) {
1387                         return Xml::encodeJsCall(
1388                                 'mw.loader.addSource',
1389                                 [ $id ],
1390                                 ResourceLoader::inDebugMode()
1391                         );
1392                 } else {
1393                         return Xml::encodeJsCall(
1394                                 'mw.loader.addSource',
1395                                 [ $id, $loadUrl ],
1396                                 ResourceLoader::inDebugMode()
1397                         );
1398                 }
1399         }
1400
1401         /**
1402          * Returns JS code which runs given JS code if the client-side framework is
1403          * present.
1404          *
1405          * @deprecated since 1.25; use makeInlineScript instead
1406          * @param string $script JavaScript code
1407          * @return string
1408          */
1409         public static function makeLoaderConditionalScript( $script ) {
1410                 return '(window.RLQ=window.RLQ||[]).push(function(){' .
1411                         trim( $script ) . '});';
1412         }
1413
1414         /**
1415          * Construct an inline script tag with given JS code.
1416          *
1417          * The code will be wrapped in a closure, and it will be executed by ResourceLoader
1418          * only if the client has adequate support for MediaWiki JavaScript code.
1419          *
1420          * @param string $script JavaScript code
1421          * @return WrappedString HTML
1422          */
1423         public static function makeInlineScript( $script ) {
1424                 $js = self::makeLoaderConditionalScript( $script );
1425                 return new WrappedString(
1426                         Html::inlineScript( $js ),
1427                         '<script>(window.RLQ=window.RLQ||[]).push(function(){',
1428                         '});</script>'
1429                 );
1430         }
1431
1432         /**
1433          * Returns JS code which will set the MediaWiki configuration array to
1434          * the given value.
1435          *
1436          * @param array $configuration List of configuration values keyed by variable name
1437          * @param bool $pretty Pretty-print with extra whitespace
1438          * @return string
1439          */
1440         public static function makeConfigSetScript( array $configuration, $pretty = null ) {
1441                 return Xml::encodeJsCall(
1442                         'mw.config.set',
1443                         [ $configuration ],
1444                         ( $pretty === null ) ? ResourceLoader::inDebugMode() : $pretty
1445                 );
1446         }
1447
1448         /**
1449          * Convert an array of module names to a packed query string.
1450          *
1451          * For example, [ 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' ]
1452          * becomes 'foo.bar,baz|bar.baz,quux'
1453          * @param array $modules List of module names (strings)
1454          * @return string Packed query string
1455          */
1456         public static function makePackedModulesString( $modules ) {
1457                 $groups = []; // [ prefix => [ suffixes ] ]
1458                 foreach ( $modules as $module ) {
1459                         $pos = strrpos( $module, '.' );
1460                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1461                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1462                         $groups[$prefix][] = $suffix;
1463                 }
1464
1465                 $arr = [];
1466                 foreach ( $groups as $prefix => $suffixes ) {
1467                         $p = $prefix === '' ? '' : $prefix . '.';
1468                         $arr[] = $p . implode( ',', $suffixes );
1469                 }
1470                 $str = implode( '|', $arr );
1471                 return $str;
1472         }
1473
1474         /**
1475          * Determine whether debug mode was requested
1476          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1477          * @return bool
1478          */
1479         public static function inDebugMode() {
1480                 if ( self::$debugMode === null ) {
1481                         global $wgRequest, $wgResourceLoaderDebug;
1482                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1483                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1484                         );
1485                 }
1486                 return self::$debugMode;
1487         }
1488
1489         /**
1490          * Reset static members used for caching.
1491          *
1492          * Global state and $wgRequest are evil, but we're using it right
1493          * now and sometimes we need to be able to force ResourceLoader to
1494          * re-evaluate the context because it has changed (e.g. in the test suite).
1495          */
1496         public static function clearCache() {
1497                 self::$debugMode = null;
1498         }
1499
1500         /**
1501          * Build a load.php URL
1502          *
1503          * @since 1.24
1504          * @param string $source Name of the ResourceLoader source
1505          * @param ResourceLoaderContext $context
1506          * @param array $extraQuery
1507          * @return string URL to load.php. May be protocol-relative if $wgLoadScript is, too.
1508          */
1509         public function createLoaderURL( $source, ResourceLoaderContext $context,
1510                 $extraQuery = []
1511         ) {
1512                 $query = self::createLoaderQuery( $context, $extraQuery );
1513                 $script = $this->getLoadScript( $source );
1514
1515                 return wfAppendQuery( $script, $query );
1516         }
1517
1518         /**
1519          * Helper for createLoaderURL()
1520          *
1521          * @since 1.24
1522          * @see makeLoaderQuery
1523          * @param ResourceLoaderContext $context
1524          * @param array $extraQuery
1525          * @return array
1526          */
1527         protected static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = [] ) {
1528                 return self::makeLoaderQuery(
1529                         $context->getModules(),
1530                         $context->getLanguage(),
1531                         $context->getSkin(),
1532                         $context->getUser(),
1533                         $context->getVersion(),
1534                         $context->getDebug(),
1535                         $context->getOnly(),
1536                         $context->getRequest()->getBool( 'printable' ),
1537                         $context->getRequest()->getBool( 'handheld' ),
1538                         $extraQuery
1539                 );
1540         }
1541
1542         /**
1543          * Build a query array (array representation of query string) for load.php. Helper
1544          * function for createLoaderURL().
1545          *
1546          * @param array $modules
1547          * @param string $lang
1548          * @param string $skin
1549          * @param string $user
1550          * @param string $version
1551          * @param bool $debug
1552          * @param string $only
1553          * @param bool $printable
1554          * @param bool $handheld
1555          * @param array $extraQuery
1556          *
1557          * @return array
1558          */
1559         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1560                 $version = null, $debug = false, $only = null, $printable = false,
1561                 $handheld = false, $extraQuery = []
1562         ) {
1563                 $query = [
1564                         'modules' => self::makePackedModulesString( $modules ),
1565                         'lang' => $lang,
1566                         'skin' => $skin,
1567                         'debug' => $debug ? 'true' : 'false',
1568                 ];
1569                 if ( $user !== null ) {
1570                         $query['user'] = $user;
1571                 }
1572                 if ( $version !== null ) {
1573                         $query['version'] = $version;
1574                 }
1575                 if ( $only !== null ) {
1576                         $query['only'] = $only;
1577                 }
1578                 if ( $printable ) {
1579                         $query['printable'] = 1;
1580                 }
1581                 if ( $handheld ) {
1582                         $query['handheld'] = 1;
1583                 }
1584                 $query += $extraQuery;
1585
1586                 // Make queries uniform in order
1587                 ksort( $query );
1588                 return $query;
1589         }
1590
1591         /**
1592          * Check a module name for validity.
1593          *
1594          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1595          * at most 255 bytes.
1596          *
1597          * @param string $moduleName Module name to check
1598          * @return bool Whether $moduleName is a valid module name
1599          */
1600         public static function isValidModuleName( $moduleName ) {
1601                 return strcspn( $moduleName, '!,|', 0, 255 ) === strlen( $moduleName );
1602         }
1603
1604         /**
1605          * Returns LESS compiler set up for use with MediaWiki
1606          *
1607          * @since 1.27
1608          * @param array $extraVars Associative array of extra (i.e., other than the
1609          *   globally-configured ones) that should be used for compilation.
1610          * @throws MWException
1611          * @return Less_Parser
1612          */
1613         public function getLessCompiler( $extraVars = [] ) {
1614                 // When called from the installer, it is possible that a required PHP extension
1615                 // is missing (at least for now; see bug 47564). If this is the case, throw an
1616                 // exception (caught by the installer) to prevent a fatal error later on.
1617                 if ( !class_exists( 'Less_Parser' ) ) {
1618                         throw new MWException( 'MediaWiki requires the less.php parser' );
1619                 }
1620
1621                 $parser = new Less_Parser;
1622                 $parser->ModifyVars( array_merge( $this->getLessVars(), $extraVars ) );
1623                 $parser->SetImportDirs(
1624                         array_fill_keys( $this->config->get( 'ResourceLoaderLESSImportPaths' ), '' )
1625                 );
1626                 $parser->SetOption( 'relativeUrls', false );
1627
1628                 return $parser;
1629         }
1630
1631         /**
1632          * Get global LESS variables.
1633          *
1634          * @since 1.27
1635          * @return array Map of variable names to string CSS values.
1636          */
1637         public function getLessVars() {
1638                 if ( !$this->lessVars ) {
1639                         $lessVars = $this->config->get( 'ResourceLoaderLESSVars' );
1640                         Hooks::run( 'ResourceLoaderGetLessVars', [ &$lessVars ] );
1641                         $this->lessVars = $lessVars;
1642                 }
1643                 return $this->lessVars;
1644         }
1645 }