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                 // 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', $config->get( 'LoadScript' ) );
 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 [ 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 [ 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                 $hash = hash( 'fnv132', $value );
 605                 return Wikimedia\base_convert( $hash, 16, 36, 7 );
 606         }
 607
 608         /**
 609          * Helper method to get and combine versions of multiple modules.
 610          *
 611          * @since 1.26
 612          * @param ResourceLoaderContext $context
 613          * @param string[] $modules List of known module names
 614          * @return string Hash
 615          */
 616         public function getCombinedVersion( ResourceLoaderContext $context, array $moduleNames ) {
 617                 if ( !$moduleNames ) {
 618                         return '';
 619                 }
 620                 $hashes = array_map( function ( $module ) use ( $context ) {
 621                         return $this->getModule( $module )->getVersionHash( $context );
 622                 }, $moduleNames );
 623                 return self::makeHash( implode( '', $hashes ) );
 624         }
 625
 626         /**
 627          * Get the expected value of the 'version' query parameter.
 628          *
 629          * This is used by respond() to set a short Cache-Control header for requests with
 630          * information newer than the current server has. This avoids pollution of edge caches.
 631          * Typically during deployment. (T117587)
 632          *
 633          * This MUST match return value of `mw.loader#getCombinedVersion()` client-side.
 634          *
 635          * @since 1.28
 636          * @param ResourceLoaderContext $context
 637          * @param string[] $modules List of module names
 638          * @return string Hash
 639          */
 640         public function getExpectedVersionQuery( ResourceLoaderContext $context ) {
 641                 // As of MediaWiki 1.28, the server and client use the same algorithm for combining
 642                 // version hashes. There is no technical reason for this to be same, and for years the
 643                 // implementations differed. If getCombinedVersion in PHP (used for StartupModule and
 644                 // E-Tag headers) differs in the future from getCombinedVersion in JS (used for 'version'
 645                 // query parameter), then this method must continue to match the JS one.
 646                 $moduleNames = [];
 647                 foreach ( $context->getModules() as $name ) {
 648                         if ( !$this->getModule( $name ) ) {
 649                                 // If a versioned request contains a missing module, the version is a mismatch
 650                                 // as the client considered a module (and version) we don't have.
 651                                 return '';
 652                         }
 653                         $moduleNames[] = $name;
 654                 }
 655                 return $this->getCombinedVersion( $context, $moduleNames );
 656         }
 657
 658         /**
 659          * Output a response to a load request, including the content-type header.
 660          *
 661          * @param ResourceLoaderContext $context Context in which a response should be formed
 662          */
 663         public function respond( ResourceLoaderContext $context ) {
 664                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 665                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 666                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 667                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 668                 // the whole thing in our own output buffer to be sure the active buffer
 669                 // doesn't use ob_gzhandler.
 670                 // See http://bugs.php.net/bug.php?id=36514
 671                 ob_start();
 672
 673                 // Find out which modules are missing and instantiate the others
 674                 $modules = [];
 675                 $missing = [];
 676                 foreach ( $context->getModules() as $name ) {
 677                         $module = $this->getModule( $name );
 678                         if ( $module ) {
 679                                 // Do not allow private modules to be loaded from the web.
 680                                 // This is a security issue, see bug 34907.
 681                                 if ( $module->getGroup() === 'private' ) {
 682                                         $this->logger->debug( "Request for private module '$name' denied" );
 683                                         $this->errors[] = "Cannot show private module \"$name\"";
 684                                         continue;
 685                                 }
 686                                 $modules[$name] = $module;
 687                         } else {
 688                                 $missing[] = $name;
 689                         }
 690                 }
 691
 692                 try {
 693                         // Preload for getCombinedVersion() and for batch makeModuleResponse()
 694                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 695                 } catch ( Exception $e ) {
 696                         MWExceptionHandler::logException( $e );
 697                         $this->logger->warning( 'Preloading module info failed: {exception}', [
 698                                 'exception' => $e
 699                         ] );
 700                         $this->errors[] = self::formatExceptionNoComment( $e );
 701                 }
 702
 703                 // Combine versions to propagate cache invalidation
 704                 $versionHash = '';
 705                 try {
 706                         $versionHash = $this->getCombinedVersion( $context, array_keys( $modules ) );
 707                 } catch ( Exception $e ) {
 708                         MWExceptionHandler::logException( $e );
 709                         $this->logger->warning( 'Calculating version hash failed: {exception}', [
 710                                 'exception' => $e
 711                         ] );
 712                         $this->errors[] = self::formatExceptionNoComment( $e );
 713                 }
 714
 715                 // See RFC 2616 § 3.11 Entity Tags
 716                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.11
 717                 $etag = 'W/"' . $versionHash . '"';
 718
 719                 // Try the client-side cache first
 720                 if ( $this->tryRespondNotModified( $context, $etag ) ) {
 721                         return; // output handled (buffers cleared)
 722                 }
 723
 724                 // Use file cache if enabled and available...
 725                 if ( $this->config->get( 'UseFileCache' ) ) {
 726                         $fileCache = ResourceFileCache::newFromContext( $context );
 727                         if ( $this->tryRespondFromFileCache( $fileCache, $context, $etag ) ) {
 728                                 return; // output handled
 729                         }
 730                 }
 731
 732                 // Generate a response
 733                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 734
 735                 // Capture any PHP warnings from the output buffer and append them to the
 736                 // error list if we're in debug mode.
 737                 if ( $context->getDebug() ) {
 738                         $warnings = ob_get_contents();
 739                         if ( strlen( $warnings ) ) {
 740                                 $this->errors[] = $warnings;
 741                         }
 742                 }
 743
 744                 // Save response to file cache unless there are errors
 745                 if ( isset( $fileCache ) && !$this->errors && !count( $missing ) ) {
 746                         // Cache single modules and images...and other requests if there are enough hits
 747                         if ( ResourceFileCache::useFileCache( $context ) ) {
 748                                 if ( $fileCache->isCacheWorthy() ) {
 749                                         $fileCache->saveText( $response );
 750                                 } else {
 751                                         $fileCache->incrMissesRecent( $context->getRequest() );
 752                                 }
 753                         }
 754                 }
 755
 756                 $this->sendResponseHeaders( $context, $etag, (bool)$this->errors );
 757
 758                 // Remove the output buffer and output the response
 759                 ob_end_clean();
 760
 761                 if ( $context->getImageObj() && $this->errors ) {
 762                         // We can't show both the error messages and the response when it's an image.
 763                         $response = implode( "\n\n", $this->errors );
 764                 } elseif ( $this->errors ) {
 765                         $errorText = implode( "\n\n", $this->errors );
 766                         $errorResponse = self::makeComment( $errorText );
 767                         if ( $context->shouldIncludeScripts() ) {
 768                                 $errorResponse .= 'if (window.console && console.error) {'
 769                                         . Xml::encodeJsCall( 'console.error', [ $errorText ] )
 770                                         . "}\n";
 771                         }
 772
 773                         // Prepend error info to the response
 774                         $response = $errorResponse . $response;
 775                 }
 776
 777                 $this->errors = [];
 778                 echo $response;
 779
 780         }
 781
 782         /**
 783          * Send main response headers to the client.
 784          *
 785          * Deals with Content-Type, CORS (for stylesheets), and caching.
 786          *
 787          * @param ResourceLoaderContext $context
 788          * @param string $etag ETag header value
 789          * @param bool $errors Whether there are errors in the response
 790          * @return void
 791          */
 792         protected function sendResponseHeaders( ResourceLoaderContext $context, $etag, $errors ) {
 793                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 794                 // Use a short cache expiry so that updates propagate to clients quickly, if:
 795                 // - No version specified (shared resources, e.g. stylesheets)
 796                 // - There were errors (recover quickly)
 797                 // - Version mismatch (T117587, T47877)
 798                 if ( is_null( $context->getVersion() )
 799                         || $errors
 800                         || $context->getVersion() !== $this->getExpectedVersionQuery( $context )
 801                 ) {
 802                         $maxage = $rlMaxage['unversioned']['client'];
 803                         $smaxage = $rlMaxage['unversioned']['server'];
 804                 // If a version was specified we can use a longer expiry time since changing
 805                 // version numbers causes cache misses
 806                 } else {
 807                         $maxage = $rlMaxage['versioned']['client'];
 808                         $smaxage = $rlMaxage['versioned']['server'];
 809                 }
 810                 if ( $context->getImageObj() ) {
 811                         // Output different headers if we're outputting textual errors.
 812                         if ( $errors ) {
 813                                 header( 'Content-Type: text/plain; charset=utf-8' );
 814                         } else {
 815                                 $context->getImageObj()->sendResponseHeaders( $context );
 816                         }
 817                 } elseif ( $context->getOnly() === 'styles' ) {
 818                         header( 'Content-Type: text/css; charset=utf-8' );
 819                         header( 'Access-Control-Allow-Origin: *' );
 820                 } else {
 821                         header( 'Content-Type: text/javascript; charset=utf-8' );
 822                 }
 823                 // See RFC 2616 § 14.19 ETag
 824                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.19
 825                 header( 'ETag: ' . $etag );
 826                 if ( $context->getDebug() ) {
 827                         // Do not cache debug responses
 828                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 829                         header( 'Pragma: no-cache' );
 830                 } else {
 831                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 832                         $exp = min( $maxage, $smaxage );
 833                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 834                 }
 835         }
 836
 837         /**
 838          * Respond with HTTP 304 Not Modified if appropiate.
 839          *
 840          * If there's an If-None-Match header, respond with a 304 appropriately
 841          * and clear out the output buffer. If the client cache is too old then do nothing.
 842          *
 843          * @param ResourceLoaderContext $context
 844          * @param string $etag ETag header value
 845          * @return bool True if HTTP 304 was sent and output handled
 846          */
 847         protected function tryRespondNotModified( ResourceLoaderContext $context, $etag ) {
 848                 // See RFC 2616 § 14.26 If-None-Match
 849                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
 850                 $clientKeys = $context->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST );
 851                 // Never send 304s in debug mode
 852                 if ( $clientKeys !== false && !$context->getDebug() && in_array( $etag, $clientKeys ) ) {
 853                         // There's another bug in ob_gzhandler (see also the comment at
 854                         // the top of this function) that causes it to gzip even empty
 855                         // responses, meaning it's impossible to produce a truly empty
 856                         // response (because the gzip header is always there). This is
 857                         // a problem because 304 responses have to be completely empty
 858                         // per the HTTP spec, and Firefox behaves buggily when they're not.
 859                         // See also http://bugs.php.net/bug.php?id=51579
 860                         // To work around this, we tear down all output buffering before
 861                         // sending the 304.
 862                         wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 863
 864                         HttpStatus::header( 304 );
 865
 866                         $this->sendResponseHeaders( $context, $etag, false );
 867                         return true;
 868                 }
 869                 return false;
 870         }
 871
 872         /**
 873          * Send out code for a response from file cache if possible.
 874          *
 875          * @param ResourceFileCache $fileCache Cache object for this request URL
 876          * @param ResourceLoaderContext $context Context in which to generate a response
 877          * @param string $etag ETag header value
 878          * @return bool If this found a cache file and handled the response
 879          */
 880         protected function tryRespondFromFileCache(
 881                 ResourceFileCache $fileCache,
 882                 ResourceLoaderContext $context,
 883                 $etag
 884         ) {
 885                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 886                 // Buffer output to catch warnings.
 887                 ob_start();
 888                 // Get the maximum age the cache can be
 889                 $maxage = is_null( $context->getVersion() )
 890                         ? $rlMaxage['unversioned']['server']
 891                         : $rlMaxage['versioned']['server'];
 892                 // Minimum timestamp the cache file must have
 893                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 894                 if ( !$good ) {
 895                         try { // RL always hits the DB on file cache miss...
 896                                 wfGetDB( DB_REPLICA );
 897                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 898                                 $good = $fileCache->isCacheGood(); // cache existence check
 899                         }
 900                 }
 901                 if ( $good ) {
 902                         $ts = $fileCache->cacheTimestamp();
 903                         // Send content type and cache headers
 904                         $this->sendResponseHeaders( $context, $etag, false );
 905                         $response = $fileCache->fetchText();
 906                         // Capture any PHP warnings from the output buffer and append them to the
 907                         // response in a comment if we're in debug mode.
 908                         if ( $context->getDebug() ) {
 909                                 $warnings = ob_get_contents();
 910                                 if ( strlen( $warnings ) ) {
 911                                         $response = self::makeComment( $warnings ) . $response;
 912                                 }
 913                         }
 914                         // Remove the output buffer and output the response
 915                         ob_end_clean();
 916                         echo $response . "\n/* Cached {$ts} */";
 917                         return true; // cache hit
 918                 }
 919                 // Clear buffer
 920                 ob_end_clean();
 921
 922                 return false; // cache miss
 923         }
 924
 925         /**
 926          * Generate a CSS or JS comment block.
 927          *
 928          * Only use this for public data, not error message details.
 929          *
 930          * @param string $text
 931          * @return string
 932          */
 933         public static function makeComment( $text ) {
 934                 $encText = str_replace( '*/', '* /', $text );
 935                 return "/*\n$encText\n*/\n";
 936         }
 937
 938         /**
 939          * Handle exception display.
 940          *
 941          * @param Exception $e Exception to be shown to the user
 942          * @return string Sanitized text in a CSS/JS comment that can be returned to the user
 943          */
 944         public static function formatException( $e ) {
 945                 return self::makeComment( self::formatExceptionNoComment( $e ) );
 946         }
 947
 948         /**
 949          * Handle exception display.
 950          *
 951          * @since 1.25
 952          * @param Exception $e Exception to be shown to the user
 953          * @return string Sanitized text that can be returned to the user
 954          */
 955         protected static function formatExceptionNoComment( $e ) {
 956                 global $wgShowExceptionDetails;
 957
 958                 if ( !$wgShowExceptionDetails ) {
 959                         return MWExceptionHandler::getPublicLogMessage( $e );
 960                 }
 961
 962                 return MWExceptionHandler::getLogMessage( $e );
 963         }
 964
 965         /**
 966          * Generate code for a response.
 967          *
 968          * @param ResourceLoaderContext $context Context in which to generate a response
 969          * @param ResourceLoaderModule[] $modules List of module objects keyed by module name
 970          * @param string[] $missing List of requested module names that are unregistered (optional)
 971          * @return string Response data
 972          */
 973         public function makeModuleResponse( ResourceLoaderContext $context,
 974                 array $modules, array $missing = []
 975         ) {
 976                 $out = '';
 977                 $states = [];
 978
 979                 if ( !count( $modules ) && !count( $missing ) ) {
 980                         return <<<MESSAGE
 981 /* This file is the Web entry point for MediaWiki's ResourceLoader:
 982    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
 983    no modules were requested. Max made me put this here. */
 984 MESSAGE;
 985                 }
 986
 987                 $image = $context->getImageObj();
 988                 if ( $image ) {
 989                         $data = $image->getImageData( $context );
 990                         if ( $data === false ) {
 991                                 $data = '';
 992                                 $this->errors[] = 'Image generation failed';
 993                         }
 994                         return $data;
 995                 }
 996
 997                 foreach ( $missing as $name ) {
 998                         $states[$name] = 'missing';
 999                 }
1000
1001                 // Generate output
1002                 $isRaw = false;
1003
1004                 $filter = $context->getOnly() === 'styles' ? 'minify-css' : 'minify-js';
1005
1006                 foreach ( $modules as $name => $module ) {
1007                         try {
1008                                 $content = $module->getModuleContent( $context );
1009                                 $strContent = '';
1010
1011                                 // Append output
1012                                 switch ( $context->getOnly() ) {
1013                                         case 'scripts':
1014                                                 $scripts = $content['scripts'];
1015                                                 if ( is_string( $scripts ) ) {
1016                                                         // Load scripts raw...
1017                                                         $strContent = $scripts;
1018                                                 } elseif ( is_array( $scripts ) ) {
1019                                                         // ...except when $scripts is an array of URLs
1020                                                         $strContent = self::makeLoaderImplementScript( $name, $scripts, [], [], [] );
1021                                                 }
1022                                                 break;
1023                                         case 'styles':
1024                                                 $styles = $content['styles'];
1025                                                 // We no longer seperate into media, they are all combined now with
1026                                                 // custom media type groups into @media .. {} sections as part of the css string.
1027                                                 // Module returns either an empty array or a numerical array with css strings.
1028                                                 $strContent = isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
1029                                                 break;
1030                                         default:
1031                                                 $strContent = self::makeLoaderImplementScript(
1032                                                         $name,
1033                                                         isset( $content['scripts'] ) ? $content['scripts'] : '',
1034                                                         isset( $content['styles'] ) ? $content['styles'] : [],
1035                                                         isset( $content['messagesBlob'] ) ? new XmlJsCode( $content['messagesBlob'] ) : [],
1036                                                         isset( $content['templates'] ) ? $content['templates'] : []
1037                                                 );
1038                                                 break;
1039                                 }
1040
1041                                 if ( !$context->getDebug() ) {
1042                                         $strContent = self::filter( $filter, $strContent );
1043                                 }
1044
1045                                 $out .= $strContent;
1046
1047                         } catch ( Exception $e ) {
1048                                 MWExceptionHandler::logException( $e );
1049                                 $this->logger->warning( 'Generating module package failed: {exception}', [
1050                                         'exception' => $e
1051                                 ] );
1052                                 $this->errors[] = self::formatExceptionNoComment( $e );
1053
1054                                 // Respond to client with error-state instead of module implementation
1055                                 $states[$name] = 'error';
1056                                 unset( $modules[$name] );
1057                         }
1058                         $isRaw |= $module->isRaw();
1059                 }
1060
1061                 // Update module states
1062                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
1063                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
1064                                 // Set the state of modules loaded as only scripts to ready as
1065                                 // they don't have an mw.loader.implement wrapper that sets the state
1066                                 foreach ( $modules as $name => $module ) {
1067                                         $states[$name] = 'ready';
1068                                 }
1069                         }
1070
1071                         // Set the state of modules we didn't respond to with mw.loader.implement
1072                         if ( count( $states ) ) {
1073                                 $stateScript = self::makeLoaderStateScript( $states );
1074                                 if ( !$context->getDebug() ) {
1075                                         $stateScript = self::filter( 'minify-js', $stateScript );
1076                                 }
1077                                 $out .= $stateScript;
1078                         }
1079                 } else {
1080                         if ( count( $states ) ) {
1081                                 $this->errors[] = 'Problematic modules: ' .
1082                                         FormatJson::encode( $states, ResourceLoader::inDebugMode() );
1083                         }
1084                 }
1085
1086                 return $out;
1087         }
1088
1089         /**
1090          * Get names of modules that use a certain message.
1091          *
1092          * @param string $messageKey
1093          * @return array List of module names
1094          */
1095         public function getModulesByMessage( $messageKey ) {
1096                 $moduleNames = [];
1097                 foreach ( $this->getModuleNames() as $moduleName ) {
1098                         $module = $this->getModule( $moduleName );
1099                         if ( in_array( $messageKey, $module->getMessages() ) ) {
1100                                 $moduleNames[] = $moduleName;
1101                         }
1102                 }
1103                 return $moduleNames;
1104         }
1105
1106         /* Static Methods */
1107
1108         /**
1109          * Return JS code that calls mw.loader.implement with given module properties.
1110          *
1111          * @param string $name Module name
1112          * @param mixed $scripts List of URLs to JavaScript files or String of JavaScript code
1113          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1114          *   to CSS files keyed by media type
1115          * @param mixed $messages List of messages associated with this module. May either be an
1116          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1117          *   the same data, wrapped in an XmlJsCode object.
1118          * @param array $templates Keys are name of templates and values are the source of
1119          *   the template.
1120          * @throws MWException
1121          * @return string
1122          */
1123         public static function makeLoaderImplementScript(
1124                 $name, $scripts, $styles, $messages, $templates
1125         ) {
1126                 if ( is_string( $scripts ) ) {
1127                         // Site and user module are a legacy scripts that run in the global scope (no closure).
1128                         // Transportation as string instructs mw.loader.implement to use globalEval.
1129                         if ( $name === 'site' || $name === 'user' ) {
1130                                 // Minify manually because the general makeModuleResponse() minification won't be
1131                                 // effective here due to the script being a string instead of a function. (T107377)
1132                                 if ( !ResourceLoader::inDebugMode() ) {
1133                                         $scripts = self::filter( 'minify-js', $scripts );
1134                                 }
1135                         } else {
1136                                 $scripts = new XmlJsCode( "function ( $, jQuery, require, module ) {\n{$scripts}\n}" );
1137                         }
1138                 } elseif ( !is_array( $scripts ) ) {
1139                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1140                 }
1141                 // mw.loader.implement requires 'styles', 'messages' and 'templates' to be objects (not
1142                 // arrays). json_encode considers empty arrays to be numerical and outputs "[]" instead
1143                 // of "{}". Force them to objects.
1144                 $module = [
1145                         $name,
1146                         $scripts,
1147                         (object)$styles,
1148                         (object)$messages,
1149                         (object)$templates,
1150                 ];
1151                 self::trimArray( $module );
1152
1153                 return Xml::encodeJsCall( 'mw.loader.implement', $module, ResourceLoader::inDebugMode() );
1154         }
1155
1156         /**
1157          * Returns JS code which, when called, will register a given list of messages.
1158          *
1159          * @param mixed $messages Either an associative array mapping message key to value, or a
1160          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1161          * @return string
1162          */
1163         public static function makeMessageSetScript( $messages ) {
1164                 return Xml::encodeJsCall(
1165                         'mw.messages.set',
1166                         [ (object)$messages ],
1167                         ResourceLoader::inDebugMode()
1168                 );
1169         }
1170
1171         /**
1172          * Combines an associative array mapping media type to CSS into a
1173          * single stylesheet with "@media" blocks.
1174          *
1175          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1176          * @return array
1177          */
1178         public static function makeCombinedStyles( array $stylePairs ) {
1179                 $out = [];
1180                 foreach ( $stylePairs as $media => $styles ) {
1181                         // ResourceLoaderFileModule::getStyle can return the styles
1182                         // as a string or an array of strings. This is to allow separation in
1183                         // the front-end.
1184                         $styles = (array)$styles;
1185                         foreach ( $styles as $style ) {
1186                                 $style = trim( $style );
1187                                 // Don't output an empty "@media print { }" block (bug 40498)
1188                                 if ( $style !== '' ) {
1189                                         // Transform the media type based on request params and config
1190                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1191                                         $media = OutputPage::transformCssMedia( $media );
1192
1193                                         if ( $media === '' || $media == 'all' ) {
1194                                                 $out[] = $style;
1195                                         } elseif ( is_string( $media ) ) {
1196                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1197                                         }
1198                                         // else: skip
1199                                 }
1200                         }
1201                 }
1202                 return $out;
1203         }
1204
1205         /**
1206          * Returns a JS call to mw.loader.state, which sets the state of a
1207          * module or modules to a given value. Has two calling conventions:
1208          *
1209          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1210          *         Set the state of a single module called $name to $state
1211          *
1212          *    - ResourceLoader::makeLoaderStateScript( [ $name => $state, ... ] ):
1213          *         Set the state of modules with the given names to the given states
1214          *
1215          * @param string $name
1216          * @param string $state
1217          * @return string
1218          */
1219         public static function makeLoaderStateScript( $name, $state = null ) {
1220                 if ( is_array( $name ) ) {
1221                         return Xml::encodeJsCall(
1222                                 'mw.loader.state',
1223                                 [ $name ],
1224                                 ResourceLoader::inDebugMode()
1225                         );
1226                 } else {
1227                         return Xml::encodeJsCall(
1228                                 'mw.loader.state',
1229                                 [ $name, $state ],
1230                                 ResourceLoader::inDebugMode()
1231                         );
1232                 }
1233         }
1234
1235         /**
1236          * Returns JS code which calls the script given by $script. The script will
1237          * be called with local variables name, version, dependencies and group,
1238          * which will have values corresponding to $name, $version, $dependencies
1239          * and $group as supplied.
1240          *
1241          * @param string $name Module name
1242          * @param string $version Module version hash
1243          * @param array $dependencies List of module names on which this module depends
1244          * @param string $group Group which the module is in.
1245          * @param string $source Source of the module, or 'local' if not foreign.
1246          * @param string $script JavaScript code
1247          * @return string
1248          */
1249         public static function makeCustomLoaderScript( $name, $version, $dependencies,
1250                 $group, $source, $script
1251         ) {
1252                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1253                 return Xml::encodeJsCall(
1254                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1255                         [ $name, $version, $dependencies, $group, $source ],
1256                         ResourceLoader::inDebugMode()
1257                 );
1258         }
1259
1260         private static function isEmptyObject( stdClass $obj ) {
1261                 foreach ( $obj as $key => $value ) {
1262                         return false;
1263                 }
1264                 return true;
1265         }
1266
1267         /**
1268          * Remove empty values from the end of an array.
1269          *
1270          * Values considered empty:
1271          *
1272          * - null
1273          * - array()
1274          * - new XmlJsCode( '{}' )
1275          * - new stdClass() // (object) array()
1276          *
1277          * @param Array $array
1278          */
1279         private static function trimArray( array &$array ) {
1280                 $i = count( $array );
1281                 while ( $i-- ) {
1282                         if ( $array[$i] === null
1283                                 || $array[$i] === []
1284                                 || ( $array[$i] instanceof XmlJsCode && $array[$i]->value === '{}' )
1285                                 || ( $array[$i] instanceof stdClass && self::isEmptyObject( $array[$i] ) )
1286                         ) {
1287                                 unset( $array[$i] );
1288                         } else {
1289                                 break;
1290                         }
1291                 }
1292         }
1293
1294         /**
1295          * Returns JS code which calls mw.loader.register with the given
1296          * parameters. Has three calling conventions:
1297          *
1298          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version,
1299          *        $dependencies, $group, $source, $skip
1300          *     ):
1301          *        Register a single module.
1302          *
1303          *   - ResourceLoader::makeLoaderRegisterScript( [ $name1, $name2 ] ):
1304          *        Register modules with the given names.
1305          *
1306          *   - ResourceLoader::makeLoaderRegisterScript( [
1307          *        [ $name1, $version1, $dependencies1, $group1, $source1, $skip1 ],
1308          *        [ $name2, $version2, $dependencies1, $group2, $source2, $skip2 ],
1309          *        ...
1310          *     ] ):
1311          *        Registers modules with the given names and parameters.
1312          *
1313          * @param string $name Module name
1314          * @param string $version Module version hash
1315          * @param array $dependencies List of module names on which this module depends
1316          * @param string $group Group which the module is in
1317          * @param string $source Source of the module, or 'local' if not foreign
1318          * @param string $skip Script body of the skip function
1319          * @return string
1320          */
1321         public static function makeLoaderRegisterScript( $name, $version = null,
1322                 $dependencies = null, $group = null, $source = null, $skip = null
1323         ) {
1324                 if ( is_array( $name ) ) {
1325                         // Build module name index
1326                         $index = [];
1327                         foreach ( $name as $i => &$module ) {
1328                                 $index[$module[0]] = $i;
1329                         }
1330
1331                         // Transform dependency names into indexes when possible, they will be resolved by
1332                         // mw.loader.register on the other end
1333                         foreach ( $name as &$module ) {
1334                                 if ( isset( $module[2] ) ) {
1335                                         foreach ( $module[2] as &$dependency ) {
1336                                                 if ( isset( $index[$dependency] ) ) {
1337                                                         $dependency = $index[$dependency];
1338                                                 }
1339                                         }
1340                                 }
1341                         }
1342
1343                         array_walk( $name, [ 'self', 'trimArray' ] );
1344
1345                         return Xml::encodeJsCall(
1346                                 'mw.loader.register',
1347                                 [ $name ],
1348                                 ResourceLoader::inDebugMode()
1349                         );
1350                 } else {
1351                         $registration = [ $name, $version, $dependencies, $group, $source, $skip ];
1352                         self::trimArray( $registration );
1353                         return Xml::encodeJsCall(
1354                                 'mw.loader.register',
1355                                 $registration,
1356                                 ResourceLoader::inDebugMode()
1357                         );
1358                 }
1359         }
1360
1361         /**
1362          * Returns JS code which calls mw.loader.addSource() with the given
1363          * parameters. Has two calling conventions:
1364          *
1365          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1366          *       Register a single source
1367          *
1368          *   - ResourceLoader::makeLoaderSourcesScript( [ $id1 => $loadUrl, $id2 => $loadUrl, ... ] );
1369          *       Register sources with the given IDs and properties.
1370          *
1371          * @param string $id Source ID
1372          * @param string $loadUrl load.php url
1373          * @return string
1374          */
1375         public static function makeLoaderSourcesScript( $id, $loadUrl = null ) {
1376                 if ( is_array( $id ) ) {
1377                         return Xml::encodeJsCall(
1378                                 'mw.loader.addSource',
1379                                 [ $id ],
1380                                 ResourceLoader::inDebugMode()
1381                         );
1382                 } else {
1383                         return Xml::encodeJsCall(
1384                                 'mw.loader.addSource',
1385                                 [ $id, $loadUrl ],
1386                                 ResourceLoader::inDebugMode()
1387                         );
1388                 }
1389         }
1390
1391         /**
1392          * Returns JS code which runs given JS code if the client-side framework is
1393          * present.
1394          *
1395          * @deprecated since 1.25; use makeInlineScript instead
1396          * @param string $script JavaScript code
1397          * @return string
1398          */
1399         public static function makeLoaderConditionalScript( $script ) {
1400                 return '(window.RLQ=window.RLQ||[]).push(function(){' .
1401                         trim( $script ) . '});';
1402         }
1403
1404         /**
1405          * Construct an inline script tag with given JS code.
1406          *
1407          * The code will be wrapped in a closure, and it will be executed by ResourceLoader
1408          * only if the client has adequate support for MediaWiki JavaScript code.
1409          *
1410          * @param string $script JavaScript code
1411          * @return WrappedString HTML
1412          */
1413         public static function makeInlineScript( $script ) {
1414                 $js = self::makeLoaderConditionalScript( $script );
1415                 return new WrappedString(
1416                         Html::inlineScript( $js ),
1417                         '<script>(window.RLQ=window.RLQ||[]).push(function(){',
1418                         '});</script>'
1419                 );
1420         }
1421
1422         /**
1423          * Returns JS code which will set the MediaWiki configuration array to
1424          * the given value.
1425          *
1426          * @param array $configuration List of configuration values keyed by variable name
1427          * @param bool $pretty Pretty-print with extra whitespace
1428          * @return string
1429          */
1430         public static function makeConfigSetScript( array $configuration, $pretty = null ) {
1431                 return Xml::encodeJsCall(
1432                         'mw.config.set',
1433                         [ $configuration ],
1434                         ( $pretty === null ) ? ResourceLoader::inDebugMode() : $pretty
1435                 );
1436         }
1437
1438         /**
1439          * Convert an array of module names to a packed query string.
1440          *
1441          * For example, [ 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' ]
1442          * becomes 'foo.bar,baz|bar.baz,quux'
1443          * @param array $modules List of module names (strings)
1444          * @return string Packed query string
1445          */
1446         public static function makePackedModulesString( $modules ) {
1447                 $groups = []; // [ prefix => [ suffixes ] ]
1448                 foreach ( $modules as $module ) {
1449                         $pos = strrpos( $module, '.' );
1450                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1451                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1452                         $groups[$prefix][] = $suffix;
1453                 }
1454
1455                 $arr = [];
1456                 foreach ( $groups as $prefix => $suffixes ) {
1457                         $p = $prefix === '' ? '' : $prefix . '.';
1458                         $arr[] = $p . implode( ',', $suffixes );
1459                 }
1460                 $str = implode( '|', $arr );
1461                 return $str;
1462         }
1463
1464         /**
1465          * Determine whether debug mode was requested
1466          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1467          * @return bool
1468          */
1469         public static function inDebugMode() {
1470                 if ( self::$debugMode === null ) {
1471                         global $wgRequest, $wgResourceLoaderDebug;
1472                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1473                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1474                         );
1475                 }
1476                 return self::$debugMode;
1477         }
1478
1479         /**
1480          * Reset static members used for caching.
1481          *
1482          * Global state and $wgRequest are evil, but we're using it right
1483          * now and sometimes we need to be able to force ResourceLoader to
1484          * re-evaluate the context because it has changed (e.g. in the test suite).
1485          */
1486         public static function clearCache() {
1487                 self::$debugMode = null;
1488         }
1489
1490         /**
1491          * Build a load.php URL
1492          *
1493          * @since 1.24
1494          * @param string $source Name of the ResourceLoader source
1495          * @param ResourceLoaderContext $context
1496          * @param array $extraQuery
1497          * @return string URL to load.php. May be protocol-relative if $wgLoadScript is, too.
1498          */
1499         public function createLoaderURL( $source, ResourceLoaderContext $context,
1500                 $extraQuery = []
1501         ) {
1502                 $query = self::createLoaderQuery( $context, $extraQuery );
1503                 $script = $this->getLoadScript( $source );
1504
1505                 return wfAppendQuery( $script, $query );
1506         }
1507
1508         /**
1509          * Helper for createLoaderURL()
1510          *
1511          * @since 1.24
1512          * @see makeLoaderQuery
1513          * @param ResourceLoaderContext $context
1514          * @param array $extraQuery
1515          * @return array
1516          */
1517         protected static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = [] ) {
1518                 return self::makeLoaderQuery(
1519                         $context->getModules(),
1520                         $context->getLanguage(),
1521                         $context->getSkin(),
1522                         $context->getUser(),
1523                         $context->getVersion(),
1524                         $context->getDebug(),
1525                         $context->getOnly(),
1526                         $context->getRequest()->getBool( 'printable' ),
1527                         $context->getRequest()->getBool( 'handheld' ),
1528                         $extraQuery
1529                 );
1530         }
1531
1532         /**
1533          * Build a query array (array representation of query string) for load.php. Helper
1534          * function for createLoaderURL().
1535          *
1536          * @param array $modules
1537          * @param string $lang
1538          * @param string $skin
1539          * @param string $user
1540          * @param string $version
1541          * @param bool $debug
1542          * @param string $only
1543          * @param bool $printable
1544          * @param bool $handheld
1545          * @param array $extraQuery
1546          *
1547          * @return array
1548          */
1549         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1550                 $version = null, $debug = false, $only = null, $printable = false,
1551                 $handheld = false, $extraQuery = []
1552         ) {
1553                 $query = [
1554                         'modules' => self::makePackedModulesString( $modules ),
1555                         'lang' => $lang,
1556                         'skin' => $skin,
1557                         'debug' => $debug ? 'true' : 'false',
1558                 ];
1559                 if ( $user !== null ) {
1560                         $query['user'] = $user;
1561                 }
1562                 if ( $version !== null ) {
1563                         $query['version'] = $version;
1564                 }
1565                 if ( $only !== null ) {
1566                         $query['only'] = $only;
1567                 }
1568                 if ( $printable ) {
1569                         $query['printable'] = 1;
1570                 }
1571                 if ( $handheld ) {
1572                         $query['handheld'] = 1;
1573                 }
1574                 $query += $extraQuery;
1575
1576                 // Make queries uniform in order
1577                 ksort( $query );
1578                 return $query;
1579         }
1580
1581         /**
1582          * Check a module name for validity.
1583          *
1584          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1585          * at most 255 bytes.
1586          *
1587          * @param string $moduleName Module name to check
1588          * @return bool Whether $moduleName is a valid module name
1589          */
1590         public static function isValidModuleName( $moduleName ) {
1591                 return strcspn( $moduleName, '!,|', 0, 255 ) === strlen( $moduleName );
1592         }
1593
1594         /**
1595          * Returns LESS compiler set up for use with MediaWiki
1596          *
1597          * @since 1.27
1598          * @param array $extraVars Associative array of extra (i.e., other than the
1599          *   globally-configured ones) that should be used for compilation.
1600          * @throws MWException
1601          * @return Less_Parser
1602          */
1603         public function getLessCompiler( $extraVars = [] ) {
1604                 // When called from the installer, it is possible that a required PHP extension
1605                 // is missing (at least for now; see bug 47564). If this is the case, throw an
1606                 // exception (caught by the installer) to prevent a fatal error later on.
1607                 if ( !class_exists( 'Less_Parser' ) ) {
1608                         throw new MWException( 'MediaWiki requires the less.php parser' );
1609                 }
1610
1611                 $parser = new Less_Parser;
1612                 $parser->ModifyVars( array_merge( $this->getLessVars(), $extraVars ) );
1613                 $parser->SetImportDirs(
1614                         array_fill_keys( $this->config->get( 'ResourceLoaderLESSImportPaths' ), '' )
1615                 );
1616                 $parser->SetOption( 'relativeUrls', false );
1617
1618                 return $parser;
1619         }
1620
1621         /**
1622          * Get global LESS variables.
1623          *
1624          * @since 1.27
1625          * @return array Map of variable names to string CSS values.
1626          */
1627         public function getLessVars() {
1628                 if ( !$this->lessVars ) {
1629                         $lessVars = $this->config->get( 'ResourceLoaderLESSVars' );
1630                         Hooks::run( 'ResourceLoaderGetLessVars', [ &$lessVars ] );
1631                         $this->lessVars = $lessVars;
1632                 }
1633                 return $this->lessVars;
1634         }
1635 }