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 MediaWiki\MediaWikiServices;
  26 use Psr\Log\LoggerAwareInterface;
  27 use Psr\Log\LoggerInterface;
  28 use Psr\Log\NullLogger;
  29 use WrappedString\WrappedString;
  30
  31 /**
  32  * Dynamic JavaScript and CSS resource loading system.
  33  *
  34  * Most of the documentation is on the MediaWiki documentation wiki starting at:
  35  *    https://www.mediawiki.org/wiki/ResourceLoader
  36  */
  37 class ResourceLoader implements LoggerAwareInterface {
  38         /** @var int */
  39         protected static $filterCacheVersion = 7;
  40
  41         /** @var bool */
  42         protected static $debugMode = null;
  43
  44         /** @var array */
  45         private $lessVars = null;
  46
  47         /**
  48          * Module name/ResourceLoaderModule object pairs
  49          * @var array
  50          */
  51         protected $modules = [];
  52
  53         /**
  54          * Associative array mapping module name to info associative array
  55          * @var array
  56          */
  57         protected $moduleInfos = [];
  58
  59         /** @var Config $config */
  60         protected $config;
  61
  62         /**
  63          * Associative array mapping framework ids to a list of names of test suite modules
  64          * like [ 'qunit' => [ 'mediawiki.tests.qunit.suites', 'ext.foo.tests', ... ], ... ]
  65          * @var array
  66          */
  67         protected $testModuleNames = [];
  68
  69         /**
  70          * E.g. [ 'source-id' => 'http://.../load.php' ]
  71          * @var array
  72          */
  73         protected $sources = [];
  74
  75         /**
  76          * Errors accumulated during current respond() call.
  77          * @var array
  78          */
  79         protected $errors = [];
  80
  81         /**
  82          * @var MessageBlobStore
  83          */
  84         protected $blobStore;
  85
  86         /**
  87          * @var LoggerInterface
  88          */
  89         private $logger;
  90
  91         /** @var string JavaScript / CSS pragma to disable minification. **/
  92         const FILTER_NOMIN = '/*@nomin*/';
  93
  94         /**
  95          * Load information stored in the database about modules.
  96          *
  97          * This method grabs modules dependencies from the database and updates modules
  98          * objects.
  99          *
 100          * This is not inside the module code because it is much faster to
 101          * request all of the information at once than it is to have each module
 102          * requests its own information. This sacrifice of modularity yields a substantial
 103          * performance improvement.
 104          *
 105          * @param array $moduleNames List of module names to preload information for
 106          * @param ResourceLoaderContext $context Context to load the information within
 107          */
 108         public function preloadModuleInfo( array $moduleNames, ResourceLoaderContext $context ) {
 109                 if ( !$moduleNames ) {
 110                         // Or else Database*::select() will explode, plus it's cheaper!
 111                         return;
 112                 }
 113                 $dbr = wfGetDB( DB_REPLICA );
 114                 $skin = $context->getSkin();
 115                 $lang = $context->getLanguage();
 116
 117                 // Batched version of ResourceLoaderModule::getFileDependencies
 118                 $vary = "$skin|$lang";
 119                 $res = $dbr->select( 'module_deps', [ 'md_module', 'md_deps' ], [
 120                                 'md_module' => $moduleNames,
 121                                 'md_skin' => $vary,
 122                         ], __METHOD__
 123                 );
 124
 125                 // Prime in-object cache for file dependencies
 126                 $modulesWithDeps = [];
 127                 foreach ( $res as $row ) {
 128                         $module = $this->getModule( $row->md_module );
 129                         if ( $module ) {
 130                                 $module->setFileDependencies( $context, ResourceLoaderModule::expandRelativePaths(
 131                                         FormatJson::decode( $row->md_deps, true )
 132                                 ) );
 133                                 $modulesWithDeps[] = $row->md_module;
 134                         }
 135                 }
 136                 // Register the absence of a dependency row too
 137                 foreach ( array_diff( $moduleNames, $modulesWithDeps ) as $name ) {
 138                         $module = $this->getModule( $name );
 139                         if ( $module ) {
 140                                 $this->getModule( $name )->setFileDependencies( $context, [] );
 141                         }
 142                 }
 143
 144                 // Batched version of ResourceLoaderWikiModule::getTitleInfo
 145                 ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $moduleNames );
 146
 147                 // Prime in-object cache for message blobs for modules with messages
 148                 $modules = [];
 149                 foreach ( $moduleNames as $name ) {
 150                         $module = $this->getModule( $name );
 151                         if ( $module && $module->getMessages() ) {
 152                                 $modules[$name] = $module;
 153                         }
 154                 }
 155                 $store = $this->getMessageBlobStore();
 156                 $blobs = $store->getBlobs( $modules, $lang );
 157                 foreach ( $blobs as $name => $blob ) {
 158                         $modules[$name]->setMessageBlob( $blob, $lang );
 159                 }
 160         }
 161
 162         /**
 163          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 164          *
 165          * Available filters are:
 166          *
 167          *    - minify-js \see JavaScriptMinifier::minify
 168          *    - minify-css \see CSSMin::minify
 169          *
 170          * If $data is empty, only contains whitespace or the filter was unknown,
 171          * $data is returned unmodified.
 172          *
 173          * @param string $filter Name of filter to run
 174          * @param string $data Text to filter, such as JavaScript or CSS text
 175          * @param array $options Keys:
 176          *  - (bool) cache: Whether to allow caching this data. Default: true.
 177          * @return string Filtered data, or a comment containing an error message
 178          */
 179         public static function filter( $filter, $data, array $options = [] ) {
 180                 if ( strpos( $data, ResourceLoader::FILTER_NOMIN ) !== false ) {
 181                         return $data;
 182                 }
 183
 184                 if ( isset( $options['cache'] ) && $options['cache'] === false ) {
 185                         return self::applyFilter( $filter, $data );
 186                 }
 187
 188                 $stats = RequestContext::getMain()->getStats();
 189                 $cache = ObjectCache::getLocalServerInstance( CACHE_ANYTHING );
 190
 191                 $key = $cache->makeGlobalKey(
 192                         'resourceloader',
 193                         'filter',
 194                         $filter,
 195                         self::$filterCacheVersion, md5( $data )
 196                 );
 197
 198                 $result = $cache->get( $key );
 199                 if ( $result === false ) {
 200                         $stats->increment( "resourceloader_cache.$filter.miss" );
 201                         $result = self::applyFilter( $filter, $data );
 202                         $cache->set( $key, $result, 24 * 3600 );
 203                 } else {
 204                         $stats->increment( "resourceloader_cache.$filter.hit" );
 205                 }
 206                 if ( $result === null ) {
 207                         // Cached failure
 208                         $result = $data;
 209                 }
 210
 211                 return $result;
 212         }
 213
 214         private static function applyFilter( $filter, $data ) {
 215                 $data = trim( $data );
 216                 if ( $data ) {
 217                         try {
 218                                 $data = ( $filter === 'minify-css' )
 219                                         ? CSSMin::minify( $data )
 220                                         : JavaScriptMinifier::minify( $data );
 221                         } catch ( Exception $e ) {
 222                                 MWExceptionHandler::logException( $e );
 223                                 return null;
 224                         }
 225                 }
 226                 return $data;
 227         }
 228
 229         /* Methods */
 230
 231         /**
 232          * Register core modules and runs registration hooks.
 233          * @param Config $config [optional]
 234          * @param LoggerInterface $logger [optional]
 235          */
 236         public function __construct( Config $config = null, LoggerInterface $logger = null ) {
 237                 global $IP;
 238
 239                 $this->logger = $logger ?: new NullLogger();
 240
 241                 if ( !$config ) {
 242                         $this->logger->debug( __METHOD__ . ' was called without providing a Config instance' );
 243                         $config = MediaWikiServices::getInstance()->getMainConfig();
 244                 }
 245                 $this->config = $config;
 246
 247                 // Add 'local' source first
 248                 $this->addSource( 'local', $config->get( 'LoadScript' ) );
 249
 250                 // Add other sources
 251                 $this->addSource( $config->get( 'ResourceLoaderSources' ) );
 252
 253                 // Register core modules
 254                 $this->register( include "$IP/resources/Resources.php" );
 255                 $this->register( include "$IP/resources/ResourcesOOUI.php" );
 256                 // Register extension modules
 257                 $this->register( $config->get( 'ResourceModules' ) );
 258                 Hooks::run( 'ResourceLoaderRegisterModules', [ &$this ] );
 259
 260                 if ( $config->get( 'EnableJavaScriptTest' ) === true ) {
 261                         $this->registerTestModules();
 262                 }
 263
 264                 $this->setMessageBlobStore( new MessageBlobStore( $this, $this->logger ) );
 265         }
 266
 267         /**
 268          * @return Config
 269          */
 270         public function getConfig() {
 271                 return $this->config;
 272         }
 273
 274         /**
 275          * @since 1.26
 276          * @param LoggerInterface $logger
 277          */
 278         public function setLogger( LoggerInterface $logger ) {
 279                 $this->logger = $logger;
 280         }
 281
 282         /**
 283          * @since 1.27
 284          * @return LoggerInterface
 285          */
 286         public function getLogger() {
 287                 return $this->logger;
 288         }
 289
 290         /**
 291          * @since 1.26
 292          * @return MessageBlobStore
 293          */
 294         public function getMessageBlobStore() {
 295                 return $this->blobStore;
 296         }
 297
 298         /**
 299          * @since 1.25
 300          * @param MessageBlobStore $blobStore
 301          */
 302         public function setMessageBlobStore( MessageBlobStore $blobStore ) {
 303                 $this->blobStore = $blobStore;
 304         }
 305
 306         /**
 307          * Register a module with the ResourceLoader system.
 308          *
 309          * @param mixed $name Name of module as a string or List of name/object pairs as an array
 310          * @param array $info Module info array. For backwards compatibility with 1.17alpha,
 311          *   this may also be a ResourceLoaderModule object. Optional when using
 312          *   multiple-registration calling style.
 313          * @throws MWException If a duplicate module registration is attempted
 314          * @throws MWException If a module name contains illegal characters (pipes or commas)
 315          * @throws MWException If something other than a ResourceLoaderModule is being registered
 316          * @return bool False if there were any errors, in which case one or more modules were
 317          *   not registered
 318          */
 319         public function register( $name, $info = null ) {
 320                 $moduleSkinStyles = $this->config->get( 'ResourceModuleSkinStyles' );
 321
 322                 // Allow multiple modules to be registered in one call
 323                 $registrations = is_array( $name ) ? $name : [ $name => $info ];
 324                 foreach ( $registrations as $name => $info ) {
 325                         // Warn on duplicate registrations
 326                         if ( isset( $this->moduleInfos[$name] ) ) {
 327                                 // A module has already been registered by this name
 328                                 $this->logger->warning(
 329                                         'ResourceLoader duplicate registration warning. ' .
 330                                         'Another module has already been registered as ' . $name
 331                                 );
 332                         }
 333
 334                         // Check $name for validity
 335                         if ( !self::isValidModuleName( $name ) ) {
 336                                 throw new MWException( "ResourceLoader module name '$name' is invalid, "
 337                                         . "see ResourceLoader::isValidModuleName()" );
 338                         }
 339
 340                         // Attach module
 341                         if ( $info instanceof ResourceLoaderModule ) {
 342                                 $this->moduleInfos[$name] = [ 'object' => $info ];
 343                                 $info->setName( $name );
 344                                 $this->modules[$name] = $info;
 345                         } elseif ( is_array( $info ) ) {
 346                                 // New calling convention
 347                                 $this->moduleInfos[$name] = $info;
 348                         } else {
 349                                 throw new MWException(
 350                                         'ResourceLoader module info type error for module \'' . $name .
 351                                         '\': expected ResourceLoaderModule or array (got: ' . gettype( $info ) . ')'
 352                                 );
 353                         }
 354
 355                         // Last-minute changes
 356
 357                         // Apply custom skin-defined styles to existing modules.
 358                         if ( $this->isFileModule( $name ) ) {
 359                                 foreach ( $moduleSkinStyles as $skinName => $skinStyles ) {
 360                                         // If this module already defines skinStyles for this skin, ignore $wgResourceModuleSkinStyles.
 361                                         if ( isset( $this->moduleInfos[$name]['skinStyles'][$skinName] ) ) {
 362                                                 continue;
 363                                         }
 364
 365                                         // If $name is preceded with a '+', the defined style files will be added to 'default'
 366                                         // skinStyles, otherwise 'default' will be ignored as it normally would be.
 367                                         if ( isset( $skinStyles[$name] ) ) {
 368                                                 $paths = (array)$skinStyles[$name];
 369                                                 $styleFiles = [];
 370                                         } elseif ( isset( $skinStyles['+' . $name] ) ) {
 371                                                 $paths = (array)$skinStyles['+' . $name];
 372                                                 $styleFiles = isset( $this->moduleInfos[$name]['skinStyles']['default'] ) ?
 373                                                         (array)$this->moduleInfos[$name]['skinStyles']['default'] :
 374                                                         [];
 375                                         } else {
 376                                                 continue;
 377                                         }
 378
 379                                         // Add new file paths, remapping them to refer to our directories and not use settings
 380                                         // from the module we're modifying, which come from the base definition.
 381                                         list( $localBasePath, $remoteBasePath ) =
 382                                                 ResourceLoaderFileModule::extractBasePaths( $skinStyles );
 383
 384                                         foreach ( $paths as $path ) {
 385                                                 $styleFiles[] = new ResourceLoaderFilePath( $path, $localBasePath, $remoteBasePath );
 386                                         }
 387
 388                                         $this->moduleInfos[$name]['skinStyles'][$skinName] = $styleFiles;
 389                                 }
 390                         }
 391                 }
 392         }
 393
 394         public function registerTestModules() {
 395                 global $IP;
 396
 397                 if ( $this->config->get( 'EnableJavaScriptTest' ) !== true ) {
 398                         throw new MWException( 'Attempt to register JavaScript test modules '
 399                                 . 'but <code>$wgEnableJavaScriptTest</code> is false. '
 400                                 . 'Edit your <code>LocalSettings.php</code> to enable it.' );
 401                 }
 402
 403                 // Get core test suites
 404                 $testModules = [];
 405                 $testModules['qunit'] = [];
 406                 // Get other test suites (e.g. from extensions)
 407                 Hooks::run( 'ResourceLoaderTestModules', [ &$testModules, &$this ] );
 408
 409                 // Add the testrunner (which configures QUnit) to the dependencies.
 410                 // Since it must be ready before any of the test suites are executed.
 411                 foreach ( $testModules['qunit'] as &$module ) {
 412                         // Make sure all test modules are top-loading so that when QUnit starts
 413                         // on document-ready, it will run once and finish. If some tests arrive
 414                         // later (possibly after QUnit has already finished) they will be ignored.
 415                         $module['position'] = 'top';
 416                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 417                 }
 418
 419                 $testModules['qunit'] =
 420                         ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules['qunit'];
 421
 422                 foreach ( $testModules as $id => $names ) {
 423                         // Register test modules
 424                         $this->register( $testModules[$id] );
 425
 426                         // Keep track of their names so that they can be loaded together
 427                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 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 makeVersionQuery( 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 https://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                 // https://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          * Send main response headers to the client.
 783          *
 784          * Deals with Content-Type, CORS (for stylesheets), and caching.
 785          *
 786          * @param ResourceLoaderContext $context
 787          * @param string $etag ETag header value
 788          * @param bool $errors Whether there are errors in the response
 789          * @return void
 790          */
 791         protected function sendResponseHeaders( ResourceLoaderContext $context, $etag, $errors ) {
 792                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 793                 // Use a short cache expiry so that updates propagate to clients quickly, if:
 794                 // - No version specified (shared resources, e.g. stylesheets)
 795                 // - There were errors (recover quickly)
 796                 // - Version mismatch (T117587, T47877)
 797                 if ( is_null( $context->getVersion() )
 798                         || $errors
 799                         || $context->getVersion() !== $this->makeVersionQuery( $context )
 800                 ) {
 801                         $maxage = $rlMaxage['unversioned']['client'];
 802                         $smaxage = $rlMaxage['unversioned']['server'];
 803                 // If a version was specified we can use a longer expiry time since changing
 804                 // version numbers causes cache misses
 805                 } else {
 806                         $maxage = $rlMaxage['versioned']['client'];
 807                         $smaxage = $rlMaxage['versioned']['server'];
 808                 }
 809                 if ( $context->getImageObj() ) {
 810                         // Output different headers if we're outputting textual errors.
 811                         if ( $errors ) {
 812                                 header( 'Content-Type: text/plain; charset=utf-8' );
 813                         } else {
 814                                 $context->getImageObj()->sendResponseHeaders( $context );
 815                         }
 816                 } elseif ( $context->getOnly() === 'styles' ) {
 817                         header( 'Content-Type: text/css; charset=utf-8' );
 818                         header( 'Access-Control-Allow-Origin: *' );
 819                 } else {
 820                         header( 'Content-Type: text/javascript; charset=utf-8' );
 821                 }
 822                 // See RFC 2616 § 14.19 ETag
 823                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.19
 824                 header( 'ETag: ' . $etag );
 825                 if ( $context->getDebug() ) {
 826                         // Do not cache debug responses
 827                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 828                         header( 'Pragma: no-cache' );
 829                 } else {
 830                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 831                         $exp = min( $maxage, $smaxage );
 832                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 833                 }
 834         }
 835
 836         /**
 837          * Respond with HTTP 304 Not Modified if appropiate.
 838          *
 839          * If there's an If-None-Match header, respond with a 304 appropriately
 840          * and clear out the output buffer. If the client cache is too old then do nothing.
 841          *
 842          * @param ResourceLoaderContext $context
 843          * @param string $etag ETag header value
 844          * @return bool True if HTTP 304 was sent and output handled
 845          */
 846         protected function tryRespondNotModified( ResourceLoaderContext $context, $etag ) {
 847                 // See RFC 2616 § 14.26 If-None-Match
 848                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
 849                 $clientKeys = $context->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST );
 850                 // Never send 304s in debug mode
 851                 if ( $clientKeys !== false && !$context->getDebug() && in_array( $etag, $clientKeys ) ) {
 852                         // There's another bug in ob_gzhandler (see also the comment at
 853                         // the top of this function) that causes it to gzip even empty
 854                         // responses, meaning it's impossible to produce a truly empty
 855                         // response (because the gzip header is always there). This is
 856                         // a problem because 304 responses have to be completely empty
 857                         // per the HTTP spec, and Firefox behaves buggily when they're not.
 858                         // See also https://bugs.php.net/bug.php?id=51579
 859                         // To work around this, we tear down all output buffering before
 860                         // sending the 304.
 861                         wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 862
 863                         HttpStatus::header( 304 );
 864
 865                         $this->sendResponseHeaders( $context, $etag, false );
 866                         return true;
 867                 }
 868                 return false;
 869         }
 870
 871         /**
 872          * Send out code for a response from file cache if possible.
 873          *
 874          * @param ResourceFileCache $fileCache Cache object for this request URL
 875          * @param ResourceLoaderContext $context Context in which to generate a response
 876          * @param string $etag ETag header value
 877          * @return bool If this found a cache file and handled the response
 878          */
 879         protected function tryRespondFromFileCache(
 880                 ResourceFileCache $fileCache,
 881                 ResourceLoaderContext $context,
 882                 $etag
 883         ) {
 884                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 885                 // Buffer output to catch warnings.
 886                 ob_start();
 887                 // Get the maximum age the cache can be
 888                 $maxage = is_null( $context->getVersion() )
 889                         ? $rlMaxage['unversioned']['server']
 890                         : $rlMaxage['versioned']['server'];
 891                 // Minimum timestamp the cache file must have
 892                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 893                 if ( !$good ) {
 894                         try { // RL always hits the DB on file cache miss...
 895                                 wfGetDB( DB_REPLICA );
 896                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 897                                 $good = $fileCache->isCacheGood(); // cache existence check
 898                         }
 899                 }
 900                 if ( $good ) {
 901                         $ts = $fileCache->cacheTimestamp();
 902                         // Send content type and cache headers
 903                         $this->sendResponseHeaders( $context, $etag, false );
 904                         $response = $fileCache->fetchText();
 905                         // Capture any PHP warnings from the output buffer and append them to the
 906                         // response in a comment if we're in debug mode.
 907                         if ( $context->getDebug() ) {
 908                                 $warnings = ob_get_contents();
 909                                 if ( strlen( $warnings ) ) {
 910                                         $response = self::makeComment( $warnings ) . $response;
 911                                 }
 912                         }
 913                         // Remove the output buffer and output the response
 914                         ob_end_clean();
 915                         echo $response . "\n/* Cached {$ts} */";
 916                         return true; // cache hit
 917                 }
 918                 // Clear buffer
 919                 ob_end_clean();
 920
 921                 return false; // cache miss
 922         }
 923
 924         /**
 925          * Generate a CSS or JS comment block.
 926          *
 927          * Only use this for public data, not error message details.
 928          *
 929          * @param string $text
 930          * @return string
 931          */
 932         public static function makeComment( $text ) {
 933                 $encText = str_replace( '*/', '* /', $text );
 934                 return "/*\n$encText\n*/\n";
 935         }
 936
 937         /**
 938          * Handle exception display.
 939          *
 940          * @param Exception $e Exception to be shown to the user
 941          * @return string Sanitized text in a CSS/JS comment that can be returned to the user
 942          */
 943         public static function formatException( $e ) {
 944                 return self::makeComment( self::formatExceptionNoComment( $e ) );
 945         }
 946
 947         /**
 948          * Handle exception display.
 949          *
 950          * @since 1.25
 951          * @param Exception $e Exception to be shown to the user
 952          * @return string Sanitized text that can be returned to the user
 953          */
 954         protected static function formatExceptionNoComment( $e ) {
 955                 global $wgShowExceptionDetails;
 956
 957                 if ( !$wgShowExceptionDetails ) {
 958                         return MWExceptionHandler::getPublicLogMessage( $e );
 959                 }
 960
 961                 return MWExceptionHandler::getLogMessage( $e );
 962         }
 963
 964         /**
 965          * Generate code for a response.
 966          *
 967          * @param ResourceLoaderContext $context Context in which to generate a response
 968          * @param ResourceLoaderModule[] $modules List of module objects keyed by module name
 969          * @param string[] $missing List of requested module names that are unregistered (optional)
 970          * @return string Response data
 971          */
 972         public function makeModuleResponse( ResourceLoaderContext $context,
 973                 array $modules, array $missing = []
 974         ) {
 975                 $out = '';
 976                 $states = [];
 977
 978                 if ( !count( $modules ) && !count( $missing ) ) {
 979                         return <<<MESSAGE
 980 /* This file is the Web entry point for MediaWiki's ResourceLoader:
 981    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
 982    no modules were requested. Max made me put this here. */
 983 MESSAGE;
 984                 }
 985
 986                 $image = $context->getImageObj();
 987                 if ( $image ) {
 988                         $data = $image->getImageData( $context );
 989                         if ( $data === false ) {
 990                                 $data = '';
 991                                 $this->errors[] = 'Image generation failed';
 992                         }
 993                         return $data;
 994                 }
 995
 996                 foreach ( $missing as $name ) {
 997                         $states[$name] = 'missing';
 998                 }
 999
1000                 // Generate output
1001                 $isRaw = false;
1002
1003                 $filter = $context->getOnly() === 'styles' ? 'minify-css' : 'minify-js';
1004
1005                 foreach ( $modules as $name => $module ) {
1006                         try {
1007                                 $content = $module->getModuleContent( $context );
1008                                 $implementKey = $name . '@' . $module->getVersionHash( $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( $implementKey, $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                                                 $scripts = isset( $content['scripts'] ) ? $content['scripts'] : '';
1032                                                 if ( is_string( $scripts ) ) {
1033                                                         if ( $name === 'site' || $name === 'user' ) {
1034                                                                 // Legacy scripts that run in the global scope without a closure.
1035                                                                 // mw.loader.implement will use globalEval if scripts is a string.
1036                                                                 // Minify manually here, because general response minification is
1037                                                                 // not effective due it being a string literal, not a function.
1038                                                                 if ( !ResourceLoader::inDebugMode() ) {
1039                                                                         $scripts = self::filter( 'minify-js', $scripts ); // T107377
1040                                                                 }
1041                                                         } else {
1042                                                                 $scripts = new XmlJsCode( $scripts );
1043                                                         }
1044                                                 }
1045                                                 $strContent = self::makeLoaderImplementScript(
1046                                                         $implementKey,
1047                                                         $scripts,
1048                                                         isset( $content['styles'] ) ? $content['styles'] : [],
1049                                                         isset( $content['messagesBlob'] ) ? new XmlJsCode( $content['messagesBlob'] ) : [],
1050                                                         isset( $content['templates'] ) ? $content['templates'] : []
1051                                                 );
1052                                                 break;
1053                                 }
1054
1055                                 if ( !$context->getDebug() ) {
1056                                         $strContent = self::filter( $filter, $strContent );
1057                                 }
1058
1059                                 $out .= $strContent;
1060
1061                         } catch ( Exception $e ) {
1062                                 MWExceptionHandler::logException( $e );
1063                                 $this->logger->warning( 'Generating module package failed: {exception}', [
1064                                         'exception' => $e
1065                                 ] );
1066                                 $this->errors[] = self::formatExceptionNoComment( $e );
1067
1068                                 // Respond to client with error-state instead of module implementation
1069                                 $states[$name] = 'error';
1070                                 unset( $modules[$name] );
1071                         }
1072                         $isRaw |= $module->isRaw();
1073                 }
1074
1075                 // Update module states
1076                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
1077                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
1078                                 // Set the state of modules loaded as only scripts to ready as
1079                                 // they don't have an mw.loader.implement wrapper that sets the state
1080                                 foreach ( $modules as $name => $module ) {
1081                                         $states[$name] = 'ready';
1082                                 }
1083                         }
1084
1085                         // Set the state of modules we didn't respond to with mw.loader.implement
1086                         if ( count( $states ) ) {
1087                                 $stateScript = self::makeLoaderStateScript( $states );
1088                                 if ( !$context->getDebug() ) {
1089                                         $stateScript = self::filter( 'minify-js', $stateScript );
1090                                 }
1091                                 $out .= $stateScript;
1092                         }
1093                 } else {
1094                         if ( count( $states ) ) {
1095                                 $this->errors[] = 'Problematic modules: ' .
1096                                         FormatJson::encode( $states, ResourceLoader::inDebugMode() );
1097                         }
1098                 }
1099
1100                 return $out;
1101         }
1102
1103         /**
1104          * Get names of modules that use a certain message.
1105          *
1106          * @param string $messageKey
1107          * @return array List of module names
1108          */
1109         public function getModulesByMessage( $messageKey ) {
1110                 $moduleNames = [];
1111                 foreach ( $this->getModuleNames() as $moduleName ) {
1112                         $module = $this->getModule( $moduleName );
1113                         if ( in_array( $messageKey, $module->getMessages() ) ) {
1114                                 $moduleNames[] = $moduleName;
1115                         }
1116                 }
1117                 return $moduleNames;
1118         }
1119
1120         /* Static Methods */
1121
1122         /**
1123          * Return JS code that calls mw.loader.implement with given module properties.
1124          *
1125          * @param string $name Module name or implement key (format "`[name]@[version]`")
1126          * @param XmlJsCode|array|string $scripts Code as XmlJsCode (to be wrapped in a closure),
1127          *  list of URLs to JavaScript files, or a string of JavaScript for `$.globalEval`.
1128          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1129          *   to CSS files keyed by media type
1130          * @param mixed $messages List of messages associated with this module. May either be an
1131          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1132          *   the same data, wrapped in an XmlJsCode object.
1133          * @param array $templates Keys are name of templates and values are the source of
1134          *   the template.
1135          * @throws MWException
1136          * @return string
1137          */
1138         protected static function makeLoaderImplementScript(
1139                 $name, $scripts, $styles, $messages, $templates
1140         ) {
1141                 if ( $scripts instanceof XmlJsCode ) {
1142                         $scripts = new XmlJsCode( "function ( $, jQuery, require, module ) {\n{$scripts->value}\n}" );
1143                 } elseif ( !is_string( $scripts ) && !is_array( $scripts ) ) {
1144                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1145                 }
1146                 // mw.loader.implement requires 'styles', 'messages' and 'templates' to be objects (not
1147                 // arrays). json_encode considers empty arrays to be numerical and outputs "[]" instead
1148                 // of "{}". Force them to objects.
1149                 $module = [
1150                         $name,
1151                         $scripts,
1152                         (object)$styles,
1153                         (object)$messages,
1154                         (object)$templates,
1155                 ];
1156                 self::trimArray( $module );
1157
1158                 return Xml::encodeJsCall( 'mw.loader.implement', $module, ResourceLoader::inDebugMode() );
1159         }
1160
1161         /**
1162          * Returns JS code which, when called, will register a given list of messages.
1163          *
1164          * @param mixed $messages Either an associative array mapping message key to value, or a
1165          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1166          * @return string
1167          */
1168         public static function makeMessageSetScript( $messages ) {
1169                 return Xml::encodeJsCall(
1170                         'mw.messages.set',
1171                         [ (object)$messages ],
1172                         ResourceLoader::inDebugMode()
1173                 );
1174         }
1175
1176         /**
1177          * Combines an associative array mapping media type to CSS into a
1178          * single stylesheet with "@media" blocks.
1179          *
1180          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1181          * @return array
1182          */
1183         public static function makeCombinedStyles( array $stylePairs ) {
1184                 $out = [];
1185                 foreach ( $stylePairs as $media => $styles ) {
1186                         // ResourceLoaderFileModule::getStyle can return the styles
1187                         // as a string or an array of strings. This is to allow separation in
1188                         // the front-end.
1189                         $styles = (array)$styles;
1190                         foreach ( $styles as $style ) {
1191                                 $style = trim( $style );
1192                                 // Don't output an empty "@media print { }" block (bug 40498)
1193                                 if ( $style !== '' ) {
1194                                         // Transform the media type based on request params and config
1195                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1196                                         $media = OutputPage::transformCssMedia( $media );
1197
1198                                         if ( $media === '' || $media == 'all' ) {
1199                                                 $out[] = $style;
1200                                         } elseif ( is_string( $media ) ) {
1201                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1202                                         }
1203                                         // else: skip
1204                                 }
1205                         }
1206                 }
1207                 return $out;
1208         }
1209
1210         /**
1211          * Returns a JS call to mw.loader.state, which sets the state of a
1212          * module or modules to a given value. Has two calling conventions:
1213          *
1214          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1215          *         Set the state of a single module called $name to $state
1216          *
1217          *    - ResourceLoader::makeLoaderStateScript( [ $name => $state, ... ] ):
1218          *         Set the state of modules with the given names to the given states
1219          *
1220          * @param string $name
1221          * @param string $state
1222          * @return string
1223          */
1224         public static function makeLoaderStateScript( $name, $state = null ) {
1225                 if ( is_array( $name ) ) {
1226                         return Xml::encodeJsCall(
1227                                 'mw.loader.state',
1228                                 [ $name ],
1229                                 ResourceLoader::inDebugMode()
1230                         );
1231                 } else {
1232                         return Xml::encodeJsCall(
1233                                 'mw.loader.state',
1234                                 [ $name, $state ],
1235                                 ResourceLoader::inDebugMode()
1236                         );
1237                 }
1238         }
1239
1240         /**
1241          * Returns JS code which calls the script given by $script. The script will
1242          * be called with local variables name, version, dependencies and group,
1243          * which will have values corresponding to $name, $version, $dependencies
1244          * and $group as supplied.
1245          *
1246          * @param string $name Module name
1247          * @param string $version Module version hash
1248          * @param array $dependencies List of module names on which this module depends
1249          * @param string $group Group which the module is in.
1250          * @param string $source Source of the module, or 'local' if not foreign.
1251          * @param string $script JavaScript code
1252          * @return string
1253          */
1254         public static function makeCustomLoaderScript( $name, $version, $dependencies,
1255                 $group, $source, $script
1256         ) {
1257                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1258                 return Xml::encodeJsCall(
1259                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1260                         [ $name, $version, $dependencies, $group, $source ],
1261                         ResourceLoader::inDebugMode()
1262                 );
1263         }
1264
1265         private static function isEmptyObject( stdClass $obj ) {
1266                 foreach ( $obj as $key => $value ) {
1267                         return false;
1268                 }
1269                 return true;
1270         }
1271
1272         /**
1273          * Remove empty values from the end of an array.
1274          *
1275          * Values considered empty:
1276          *
1277          * - null
1278          * - []
1279          * - new XmlJsCode( '{}' )
1280          * - new stdClass() // (object) []
1281          *
1282          * @param Array $array
1283          */
1284         private static function trimArray( array &$array ) {
1285                 $i = count( $array );
1286                 while ( $i-- ) {
1287                         if ( $array[$i] === null
1288                                 || $array[$i] === []
1289                                 || ( $array[$i] instanceof XmlJsCode && $array[$i]->value === '{}' )
1290                                 || ( $array[$i] instanceof stdClass && self::isEmptyObject( $array[$i] ) )
1291                         ) {
1292                                 unset( $array[$i] );
1293                         } else {
1294                                 break;
1295                         }
1296                 }
1297         }
1298
1299         /**
1300          * Returns JS code which calls mw.loader.register with the given
1301          * parameters. Has three calling conventions:
1302          *
1303          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version,
1304          *        $dependencies, $group, $source, $skip
1305          *     ):
1306          *        Register a single module.
1307          *
1308          *   - ResourceLoader::makeLoaderRegisterScript( [ $name1, $name2 ] ):
1309          *        Register modules with the given names.
1310          *
1311          *   - ResourceLoader::makeLoaderRegisterScript( [
1312          *        [ $name1, $version1, $dependencies1, $group1, $source1, $skip1 ],
1313          *        [ $name2, $version2, $dependencies1, $group2, $source2, $skip2 ],
1314          *        ...
1315          *     ] ):
1316          *        Registers modules with the given names and parameters.
1317          *
1318          * @param string $name Module name
1319          * @param string $version Module version hash
1320          * @param array $dependencies List of module names on which this module depends
1321          * @param string $group Group which the module is in
1322          * @param string $source Source of the module, or 'local' if not foreign
1323          * @param string $skip Script body of the skip function
1324          * @return string
1325          */
1326         public static function makeLoaderRegisterScript( $name, $version = null,
1327                 $dependencies = null, $group = null, $source = null, $skip = null
1328         ) {
1329                 if ( is_array( $name ) ) {
1330                         // Build module name index
1331                         $index = [];
1332                         foreach ( $name as $i => &$module ) {
1333                                 $index[$module[0]] = $i;
1334                         }
1335
1336                         // Transform dependency names into indexes when possible, they will be resolved by
1337                         // mw.loader.register on the other end
1338                         foreach ( $name as &$module ) {
1339                                 if ( isset( $module[2] ) ) {
1340                                         foreach ( $module[2] as &$dependency ) {
1341                                                 if ( isset( $index[$dependency] ) ) {
1342                                                         $dependency = $index[$dependency];
1343                                                 }
1344                                         }
1345                                 }
1346                         }
1347
1348                         array_walk( $name, [ 'self', 'trimArray' ] );
1349
1350                         return Xml::encodeJsCall(
1351                                 'mw.loader.register',
1352                                 [ $name ],
1353                                 ResourceLoader::inDebugMode()
1354                         );
1355                 } else {
1356                         $registration = [ $name, $version, $dependencies, $group, $source, $skip ];
1357                         self::trimArray( $registration );
1358                         return Xml::encodeJsCall(
1359                                 'mw.loader.register',
1360                                 $registration,
1361                                 ResourceLoader::inDebugMode()
1362                         );
1363                 }
1364         }
1365
1366         /**
1367          * Returns JS code which calls mw.loader.addSource() with the given
1368          * parameters. Has two calling conventions:
1369          *
1370          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1371          *       Register a single source
1372          *
1373          *   - ResourceLoader::makeLoaderSourcesScript( [ $id1 => $loadUrl, $id2 => $loadUrl, ... ] );
1374          *       Register sources with the given IDs and properties.
1375          *
1376          * @param string $id Source ID
1377          * @param string $loadUrl load.php url
1378          * @return string
1379          */
1380         public static function makeLoaderSourcesScript( $id, $loadUrl = null ) {
1381                 if ( is_array( $id ) ) {
1382                         return Xml::encodeJsCall(
1383                                 'mw.loader.addSource',
1384                                 [ $id ],
1385                                 ResourceLoader::inDebugMode()
1386                         );
1387                 } else {
1388                         return Xml::encodeJsCall(
1389                                 'mw.loader.addSource',
1390                                 [ $id, $loadUrl ],
1391                                 ResourceLoader::inDebugMode()
1392                         );
1393                 }
1394         }
1395
1396         /**
1397          * Returns JS code which runs given JS code if the client-side framework is
1398          * present.
1399          *
1400          * @deprecated since 1.25; use makeInlineScript instead
1401          * @param string $script JavaScript code
1402          * @return string
1403          */
1404         public static function makeLoaderConditionalScript( $script ) {
1405                 return '(window.RLQ=window.RLQ||[]).push(function(){' .
1406                         trim( $script ) . '});';
1407         }
1408
1409         /**
1410          * Construct an inline script tag with given JS code.
1411          *
1412          * The code will be wrapped in a closure, and it will be executed by ResourceLoader
1413          * only if the client has adequate support for MediaWiki JavaScript code.
1414          *
1415          * @param string $script JavaScript code
1416          * @return WrappedString HTML
1417          */
1418         public static function makeInlineScript( $script ) {
1419                 $js = self::makeLoaderConditionalScript( $script );
1420                 return new WrappedString(
1421                         Html::inlineScript( $js ),
1422                         '<script>(window.RLQ=window.RLQ||[]).push(function(){',
1423                         '});</script>'
1424                 );
1425         }
1426
1427         /**
1428          * Returns JS code which will set the MediaWiki configuration array to
1429          * the given value.
1430          *
1431          * @param array $configuration List of configuration values keyed by variable name
1432          * @return string
1433          */
1434         public static function makeConfigSetScript( array $configuration ) {
1435                 return Xml::encodeJsCall(
1436                         'mw.config.set',
1437                         [ $configuration ],
1438                         ResourceLoader::inDebugMode()
1439                 );
1440         }
1441
1442         /**
1443          * Convert an array of module names to a packed query string.
1444          *
1445          * For example, [ 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' ]
1446          * becomes 'foo.bar,baz|bar.baz,quux'
1447          * @param array $modules List of module names (strings)
1448          * @return string Packed query string
1449          */
1450         public static function makePackedModulesString( $modules ) {
1451                 $groups = []; // [ prefix => [ suffixes ] ]
1452                 foreach ( $modules as $module ) {
1453                         $pos = strrpos( $module, '.' );
1454                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1455                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1456                         $groups[$prefix][] = $suffix;
1457                 }
1458
1459                 $arr = [];
1460                 foreach ( $groups as $prefix => $suffixes ) {
1461                         $p = $prefix === '' ? '' : $prefix . '.';
1462                         $arr[] = $p . implode( ',', $suffixes );
1463                 }
1464                 $str = implode( '|', $arr );
1465                 return $str;
1466         }
1467
1468         /**
1469          * Determine whether debug mode was requested
1470          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1471          * @return bool
1472          */
1473         public static function inDebugMode() {
1474                 if ( self::$debugMode === null ) {
1475                         global $wgRequest, $wgResourceLoaderDebug;
1476                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1477                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1478                         );
1479                 }
1480                 return self::$debugMode;
1481         }
1482
1483         /**
1484          * Reset static members used for caching.
1485          *
1486          * Global state and $wgRequest are evil, but we're using it right
1487          * now and sometimes we need to be able to force ResourceLoader to
1488          * re-evaluate the context because it has changed (e.g. in the test suite).
1489          */
1490         public static function clearCache() {
1491                 self::$debugMode = null;
1492         }
1493
1494         /**
1495          * Build a load.php URL
1496          *
1497          * @since 1.24
1498          * @param string $source Name of the ResourceLoader source
1499          * @param ResourceLoaderContext $context
1500          * @param array $extraQuery
1501          * @return string URL to load.php. May be protocol-relative if $wgLoadScript is, too.
1502          */
1503         public function createLoaderURL( $source, ResourceLoaderContext $context,
1504                 $extraQuery = []
1505         ) {
1506                 $query = self::createLoaderQuery( $context, $extraQuery );
1507                 $script = $this->getLoadScript( $source );
1508
1509                 return wfAppendQuery( $script, $query );
1510         }
1511
1512         /**
1513          * Helper for createLoaderURL()
1514          *
1515          * @since 1.24
1516          * @see makeLoaderQuery
1517          * @param ResourceLoaderContext $context
1518          * @param array $extraQuery
1519          * @return array
1520          */
1521         protected static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = [] ) {
1522                 return self::makeLoaderQuery(
1523                         $context->getModules(),
1524                         $context->getLanguage(),
1525                         $context->getSkin(),
1526                         $context->getUser(),
1527                         $context->getVersion(),
1528                         $context->getDebug(),
1529                         $context->getOnly(),
1530                         $context->getRequest()->getBool( 'printable' ),
1531                         $context->getRequest()->getBool( 'handheld' ),
1532                         $extraQuery
1533                 );
1534         }
1535
1536         /**
1537          * Build a query array (array representation of query string) for load.php. Helper
1538          * function for createLoaderURL().
1539          *
1540          * @param array $modules
1541          * @param string $lang
1542          * @param string $skin
1543          * @param string $user
1544          * @param string $version
1545          * @param bool $debug
1546          * @param string $only
1547          * @param bool $printable
1548          * @param bool $handheld
1549          * @param array $extraQuery
1550          *
1551          * @return array
1552          */
1553         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1554                 $version = null, $debug = false, $only = null, $printable = false,
1555                 $handheld = false, $extraQuery = []
1556         ) {
1557                 $query = [
1558                         'modules' => self::makePackedModulesString( $modules ),
1559                         'lang' => $lang,
1560                         'skin' => $skin,
1561                         'debug' => $debug ? 'true' : 'false',
1562                 ];
1563                 if ( $user !== null ) {
1564                         $query['user'] = $user;
1565                 }
1566                 if ( $version !== null ) {
1567                         $query['version'] = $version;
1568                 }
1569                 if ( $only !== null ) {
1570                         $query['only'] = $only;
1571                 }
1572                 if ( $printable ) {
1573                         $query['printable'] = 1;
1574                 }
1575                 if ( $handheld ) {
1576                         $query['handheld'] = 1;
1577                 }
1578                 $query += $extraQuery;
1579
1580                 // Make queries uniform in order
1581                 ksort( $query );
1582                 return $query;
1583         }
1584
1585         /**
1586          * Check a module name for validity.
1587          *
1588          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1589          * at most 255 bytes.
1590          *
1591          * @param string $moduleName Module name to check
1592          * @return bool Whether $moduleName is a valid module name
1593          */
1594         public static function isValidModuleName( $moduleName ) {
1595                 return strcspn( $moduleName, '!,|', 0, 255 ) === strlen( $moduleName );
1596         }
1597
1598         /**
1599          * Returns LESS compiler set up for use with MediaWiki
1600          *
1601          * @since 1.27
1602          * @param array $extraVars Associative array of extra (i.e., other than the
1603          *   globally-configured ones) that should be used for compilation.
1604          * @throws MWException
1605          * @return Less_Parser
1606          */
1607         public function getLessCompiler( $extraVars = [] ) {
1608                 // When called from the installer, it is possible that a required PHP extension
1609                 // is missing (at least for now; see bug 47564). If this is the case, throw an
1610                 // exception (caught by the installer) to prevent a fatal error later on.
1611                 if ( !class_exists( 'Less_Parser' ) ) {
1612                         throw new MWException( 'MediaWiki requires the less.php parser' );
1613                 }
1614
1615                 $parser = new Less_Parser;
1616                 $parser->ModifyVars( array_merge( $this->getLessVars(), $extraVars ) );
1617                 $parser->SetImportDirs(
1618                         array_fill_keys( $this->config->get( 'ResourceLoaderLESSImportPaths' ), '' )
1619                 );
1620                 $parser->SetOption( 'relativeUrls', false );
1621
1622                 return $parser;
1623         }
1624
1625         /**
1626          * Get global LESS variables.
1627          *
1628          * @since 1.27
1629          * @return array Map of variable names to string CSS values.
1630          */
1631         public function getLessVars() {
1632                 if ( !$this->lessVars ) {
1633                         $lessVars = $this->config->get( 'ResourceLoaderLESSVars' );
1634                         Hooks::run( 'ResourceLoaderGetLessVars', [ &$lessVars ] );
1635                         $this->lessVars = $lessVars;
1636                 }
1637                 return $this->lessVars;
1638         }
1639 }