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 Wikimedia\Rdbms\DBConnectionError;
  30 use Wikimedia\WrappedString;
  31
  32 /**
  33  * Dynamic JavaScript and CSS resource loading system.
  34  *
  35  * Most of the documentation is on the MediaWiki documentation wiki starting at:
  36  *    https://www.mediawiki.org/wiki/ResourceLoader
  37  */
  38 class ResourceLoader implements LoggerAwareInterface {
  39         /** @var int */
  40         const CACHE_VERSION = 8;
  41
  42         /** @var bool */
  43         protected static $debugMode = null;
  44
  45         /**
  46          * Module name/ResourceLoaderModule object pairs
  47          * @var array
  48          */
  49         protected $modules = [];
  50
  51         /**
  52          * Associative array mapping module name to info associative array
  53          * @var array
  54          */
  55         protected $moduleInfos = [];
  56
  57         /** @var Config $config */
  58         protected $config;
  59
  60         /**
  61          * Associative array mapping framework ids to a list of names of test suite modules
  62          * like [ 'qunit' => [ 'mediawiki.tests.qunit.suites', 'ext.foo.tests', ... ], ... ]
  63          * @var array
  64          */
  65         protected $testModuleNames = [];
  66
  67         /**
  68          * E.g. [ 'source-id' => 'http://.../load.php' ]
  69          * @var array
  70          */
  71         protected $sources = [];
  72
  73         /**
  74          * Errors accumulated during current respond() call.
  75          * @var array
  76          */
  77         protected $errors = [];
  78
  79         /**
  80          * List of extra HTTP response headers provided by loaded modules.
  81          *
  82          * Populated by makeModuleResponse().
  83          *
  84          * @var array
  85          */
  86         protected $extraHeaders = [];
  87
  88         /**
  89          * @var MessageBlobStore
  90          */
  91         protected $blobStore;
  92
  93         /**
  94          * @var LoggerInterface
  95          */
  96         private $logger;
  97
  98         /** @var string JavaScript / CSS pragma to disable minification. **/
  99         const FILTER_NOMIN = '/*@nomin*/';
 100
 101         /**
 102          * Load information stored in the database about modules.
 103          *
 104          * This method grabs modules dependencies from the database and updates modules
 105          * objects.
 106          *
 107          * This is not inside the module code because it is much faster to
 108          * request all of the information at once than it is to have each module
 109          * requests its own information. This sacrifice of modularity yields a substantial
 110          * performance improvement.
 111          *
 112          * @param array $moduleNames List of module names to preload information for
 113          * @param ResourceLoaderContext $context Context to load the information within
 114          */
 115         public function preloadModuleInfo( array $moduleNames, ResourceLoaderContext $context ) {
 116                 if ( !$moduleNames ) {
 117                         // Or else Database*::select() will explode, plus it's cheaper!
 118                         return;
 119                 }
 120                 $dbr = wfGetDB( DB_REPLICA );
 121                 $lang = $context->getLanguage();
 122
 123                 // Batched version of ResourceLoaderModule::getFileDependencies
 124                 $vary = ResourceLoaderModule::getVary( $context );
 125                 $res = $dbr->select( 'module_deps', [ 'md_module', 'md_deps' ], [
 126                                 'md_module' => $moduleNames,
 127                                 'md_skin' => $vary,
 128                         ], __METHOD__
 129                 );
 130
 131                 // Prime in-object cache for file dependencies
 132                 $modulesWithDeps = [];
 133                 foreach ( $res as $row ) {
 134                         $module = $this->getModule( $row->md_module );
 135                         if ( $module ) {
 136                                 $module->setFileDependencies( $context, ResourceLoaderModule::expandRelativePaths(
 137                                         json_decode( $row->md_deps, true )
 138                                 ) );
 139                                 $modulesWithDeps[] = $row->md_module;
 140                         }
 141                 }
 142                 // Register the absence of a dependency row too
 143                 foreach ( array_diff( $moduleNames, $modulesWithDeps ) as $name ) {
 144                         $module = $this->getModule( $name );
 145                         if ( $module ) {
 146                                 $this->getModule( $name )->setFileDependencies( $context, [] );
 147                         }
 148                 }
 149
 150                 // Batched version of ResourceLoaderWikiModule::getTitleInfo
 151                 ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $moduleNames );
 152
 153                 // Prime in-object cache for message blobs for modules with messages
 154                 $modules = [];
 155                 foreach ( $moduleNames as $name ) {
 156                         $module = $this->getModule( $name );
 157                         if ( $module && $module->getMessages() ) {
 158                                 $modules[$name] = $module;
 159                         }
 160                 }
 161                 $store = $this->getMessageBlobStore();
 162                 $blobs = $store->getBlobs( $modules, $lang );
 163                 foreach ( $blobs as $name => $blob ) {
 164                         $modules[$name]->setMessageBlob( $blob, $lang );
 165                 }
 166         }
 167
 168         /**
 169          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 170          *
 171          * Available filters are:
 172          *
 173          *    - minify-js \see JavaScriptMinifier::minify
 174          *    - minify-css \see CSSMin::minify
 175          *
 176          * If $data is empty, only contains whitespace or the filter was unknown,
 177          * $data is returned unmodified.
 178          *
 179          * @param string $filter Name of filter to run
 180          * @param string $data Text to filter, such as JavaScript or CSS text
 181          * @param array $options Keys:
 182          *  - (bool) cache: Whether to allow caching this data. Default: true.
 183          * @return string Filtered data, or a comment containing an error message
 184          */
 185         public static function filter( $filter, $data, array $options = [] ) {
 186                 if ( strpos( $data, self::FILTER_NOMIN ) !== false ) {
 187                         return $data;
 188                 }
 189
 190                 if ( isset( $options['cache'] ) && $options['cache'] === false ) {
 191                         return self::applyFilter( $filter, $data );
 192                 }
 193
 194                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
 195                 $cache = ObjectCache::getLocalServerInstance( CACHE_ANYTHING );
 196
 197                 $key = $cache->makeGlobalKey(
 198                         'resourceloader-filter',
 199                         $filter,
 200                         self::CACHE_VERSION,
 201                         md5( $data )
 202                 );
 203
 204                 $result = $cache->get( $key );
 205                 if ( $result === false ) {
 206                         $stats->increment( "resourceloader_cache.$filter.miss" );
 207                         $result = self::applyFilter( $filter, $data );
 208                         $cache->set( $key, $result, 24 * 3600 );
 209                 } else {
 210                         $stats->increment( "resourceloader_cache.$filter.hit" );
 211                 }
 212                 if ( $result === null ) {
 213                         // Cached failure
 214                         $result = $data;
 215                 }
 216
 217                 return $result;
 218         }
 219
 220         private static function applyFilter( $filter, $data ) {
 221                 $data = trim( $data );
 222                 if ( $data ) {
 223                         try {
 224                                 $data = ( $filter === 'minify-css' )
 225                                         ? CSSMin::minify( $data )
 226                                         : JavaScriptMinifier::minify( $data );
 227                         } catch ( Exception $e ) {
 228                                 MWExceptionHandler::logException( $e );
 229                                 return null;
 230                         }
 231                 }
 232                 return $data;
 233         }
 234
 235         /**
 236          * Register core modules and runs registration hooks.
 237          * @param Config|null $config
 238          * @param LoggerInterface|null $logger [optional]
 239          */
 240         public function __construct( Config $config = null, LoggerInterface $logger = null ) {
 241                 $this->logger = $logger ?: new NullLogger();
 242
 243                 if ( !$config ) {
 244                         wfDeprecated( __METHOD__ . ' without a Config instance', '1.34' );
 245                         $config = MediaWikiServices::getInstance()->getMainConfig();
 246                 }
 247                 $this->config = $config;
 248
 249                 // Add 'local' source first
 250                 $this->addSource( 'local', $config->get( 'LoadScript' ) );
 251
 252                 // Special module that always exists
 253                 $this->register( 'startup', [ 'class' => ResourceLoaderStartUpModule::class ] );
 254
 255                 $this->setMessageBlobStore( new MessageBlobStore( $this, $this->logger ) );
 256         }
 257
 258         /**
 259          * @return Config
 260          */
 261         public function getConfig() {
 262                 return $this->config;
 263         }
 264
 265         /**
 266          * @since 1.26
 267          * @param LoggerInterface $logger
 268          */
 269         public function setLogger( LoggerInterface $logger ) {
 270                 $this->logger = $logger;
 271         }
 272
 273         /**
 274          * @since 1.27
 275          * @return LoggerInterface
 276          */
 277         public function getLogger() {
 278                 return $this->logger;
 279         }
 280
 281         /**
 282          * @since 1.26
 283          * @return MessageBlobStore
 284          */
 285         public function getMessageBlobStore() {
 286                 return $this->blobStore;
 287         }
 288
 289         /**
 290          * @since 1.25
 291          * @param MessageBlobStore $blobStore
 292          */
 293         public function setMessageBlobStore( MessageBlobStore $blobStore ) {
 294                 $this->blobStore = $blobStore;
 295         }
 296
 297         /**
 298          * Register a module with the ResourceLoader system.
 299          *
 300          * @param mixed $name Name of module as a string or List of name/object pairs as an array
 301          * @param array|null $info Module info array. For backwards compatibility with 1.17alpha,
 302          *   this may also be a ResourceLoaderModule object. Optional when using
 303          *   multiple-registration calling style.
 304          * @throws MWException If a duplicate module registration is attempted
 305          * @throws MWException If a module name contains illegal characters (pipes or commas)
 306          * @throws MWException If something other than a ResourceLoaderModule is being registered
 307          */
 308         public function register( $name, $info = null ) {
 309                 $moduleSkinStyles = $this->config->get( 'ResourceModuleSkinStyles' );
 310
 311                 // Allow multiple modules to be registered in one call
 312                 $registrations = is_array( $name ) ? $name : [ $name => $info ];
 313                 foreach ( $registrations as $name => $info ) {
 314                         // Warn on duplicate registrations
 315                         if ( isset( $this->moduleInfos[$name] ) ) {
 316                                 // A module has already been registered by this name
 317                                 $this->logger->warning(
 318                                         'ResourceLoader duplicate registration warning. ' .
 319                                         'Another module has already been registered as ' . $name
 320                                 );
 321                         }
 322
 323                         // Check $name for validity
 324                         if ( !self::isValidModuleName( $name ) ) {
 325                                 throw new MWException( "ResourceLoader module name '$name' is invalid, "
 326                                         . "see ResourceLoader::isValidModuleName()" );
 327                         }
 328
 329                         // Attach module
 330                         if ( $info instanceof ResourceLoaderModule ) {
 331                                 $this->moduleInfos[$name] = [ 'object' => $info ];
 332                                 $info->setName( $name );
 333                                 $this->modules[$name] = $info;
 334                         } elseif ( is_array( $info ) ) {
 335                                 // New calling convention
 336                                 $this->moduleInfos[$name] = $info;
 337                         } else {
 338                                 throw new MWException(
 339                                         'ResourceLoader module info type error for module \'' . $name .
 340                                         '\': expected ResourceLoaderModule or array (got: ' . gettype( $info ) . ')'
 341                                 );
 342                         }
 343
 344                         // Last-minute changes
 345
 346                         // Apply custom skin-defined styles to existing modules.
 347                         if ( $this->isFileModule( $name ) ) {
 348                                 foreach ( $moduleSkinStyles as $skinName => $skinStyles ) {
 349                                         // If this module already defines skinStyles for this skin, ignore $wgResourceModuleSkinStyles.
 350                                         if ( isset( $this->moduleInfos[$name]['skinStyles'][$skinName] ) ) {
 351                                                 continue;
 352                                         }
 353
 354                                         // If $name is preceded with a '+', the defined style files will be added to 'default'
 355                                         // skinStyles, otherwise 'default' will be ignored as it normally would be.
 356                                         if ( isset( $skinStyles[$name] ) ) {
 357                                                 $paths = (array)$skinStyles[$name];
 358                                                 $styleFiles = [];
 359                                         } elseif ( isset( $skinStyles['+' . $name] ) ) {
 360                                                 $paths = (array)$skinStyles['+' . $name];
 361                                                 $styleFiles = isset( $this->moduleInfos[$name]['skinStyles']['default'] ) ?
 362                                                         (array)$this->moduleInfos[$name]['skinStyles']['default'] :
 363                                                         [];
 364                                         } else {
 365                                                 continue;
 366                                         }
 367
 368                                         // Add new file paths, remapping them to refer to our directories and not use settings
 369                                         // from the module we're modifying, which come from the base definition.
 370                                         list( $localBasePath, $remoteBasePath ) =
 371                                                 ResourceLoaderFileModule::extractBasePaths( $skinStyles );
 372
 373                                         foreach ( $paths as $path ) {
 374                                                 $styleFiles[] = new ResourceLoaderFilePath( $path, $localBasePath, $remoteBasePath );
 375                                         }
 376
 377                                         $this->moduleInfos[$name]['skinStyles'][$skinName] = $styleFiles;
 378                                 }
 379                         }
 380                 }
 381         }
 382
 383         /**
 384          * @internal For use by ServiceWiring only
 385          */
 386         public function registerTestModules() {
 387                 global $IP;
 388
 389                 if ( $this->config->get( 'EnableJavaScriptTest' ) !== true ) {
 390                         throw new MWException( 'Attempt to register JavaScript test modules '
 391                                 . 'but <code>$wgEnableJavaScriptTest</code> is false. '
 392                                 . 'Edit your <code>LocalSettings.php</code> to enable it.' );
 393                 }
 394
 395                 $testModules = [
 396                         'qunit' => [],
 397                 ];
 398
 399                 // Get test suites from extensions
 400                 // Avoid PHP 7.1 warning from passing $this by reference
 401                 $rl = $this;
 402                 Hooks::run( 'ResourceLoaderTestModules', [ &$testModules, &$rl ] );
 403                 $extRegistry = ExtensionRegistry::getInstance();
 404                 // In case of conflict, the deprecated hook has precedence.
 405                 $testModules['qunit'] += $extRegistry->getAttribute( 'QUnitTestModules' );
 406
 407                 // Add the QUnit testrunner as implicit dependency to extension test suites.
 408                 foreach ( $testModules['qunit'] as &$module ) {
 409                         // Shuck any single-module dependency as an array
 410                         if ( isset( $module['dependencies'] ) && is_string( $module['dependencies'] ) ) {
 411                                 $module['dependencies'] = [ $module['dependencies'] ];
 412                         }
 413
 414                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 415                 }
 416
 417                 // Get core test suites
 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          * Add a foreign source of modules.
 432          *
 433          * Source IDs are typically the same as the Wiki ID or database name (e.g. lowercase a-z).
 434          *
 435          * @param array|string $id Source ID (string), or [ id1 => loadUrl, id2 => loadUrl, ... ]
 436          * @param string|array|null $loadUrl load.php url (string), or array with loadUrl key for
 437          *  backwards-compatibility.
 438          * @throws MWException
 439          */
 440         public function addSource( $id, $loadUrl = null ) {
 441                 // Allow multiple sources to be registered in one call
 442                 if ( is_array( $id ) ) {
 443                         foreach ( $id as $key => $value ) {
 444                                 $this->addSource( $key, $value );
 445                         }
 446                         return;
 447                 }
 448
 449                 // Disallow duplicates
 450                 if ( isset( $this->sources[$id] ) ) {
 451                         throw new MWException(
 452                                 'ResourceLoader duplicate source addition error. ' .
 453                                 'Another source has already been registered as ' . $id
 454                         );
 455                 }
 456
 457                 // Pre 1.24 backwards-compatibility
 458                 if ( is_array( $loadUrl ) ) {
 459                         if ( !isset( $loadUrl['loadScript'] ) ) {
 460                                 throw new MWException(
 461                                         __METHOD__ . ' was passed an array with no "loadScript" key.'
 462                                 );
 463                         }
 464
 465                         $loadUrl = $loadUrl['loadScript'];
 466                 }
 467
 468                 $this->sources[$id] = $loadUrl;
 469         }
 470
 471         /**
 472          * Get a list of module names.
 473          *
 474          * @return array List of module names
 475          */
 476         public function getModuleNames() {
 477                 return array_keys( $this->moduleInfos );
 478         }
 479
 480         /**
 481          * Get a list of test module names for one (or all) frameworks.
 482          *
 483          * If the given framework id is unknkown, or if the in-object variable is not an array,
 484          * then it will return an empty array.
 485          *
 486          * @param string $framework Get only the test module names for one
 487          *   particular framework (optional)
 488          * @return array
 489          */
 490         public function getTestModuleNames( $framework = 'all' ) {
 491                 /** @todo api siteinfo prop testmodulenames modulenames */
 492                 if ( $framework == 'all' ) {
 493                         return $this->testModuleNames;
 494                 } elseif ( isset( $this->testModuleNames[$framework] )
 495                         && is_array( $this->testModuleNames[$framework] )
 496                 ) {
 497                         return $this->testModuleNames[$framework];
 498                 } else {
 499                         return [];
 500                 }
 501         }
 502
 503         /**
 504          * Check whether a ResourceLoader module is registered
 505          *
 506          * @since 1.25
 507          * @param string $name
 508          * @return bool
 509          */
 510         public function isModuleRegistered( $name ) {
 511                 return isset( $this->moduleInfos[$name] );
 512         }
 513
 514         /**
 515          * Get the ResourceLoaderModule object for a given module name.
 516          *
 517          * If an array of module parameters exists but a ResourceLoaderModule object has not
 518          * yet been instantiated, this method will instantiate and cache that object such that
 519          * subsequent calls simply return the same object.
 520          *
 521          * @param string $name Module name
 522          * @return ResourceLoaderModule|null If module has been registered, return a
 523          *  ResourceLoaderModule instance. Otherwise, return null.
 524          */
 525         public function getModule( $name ) {
 526                 if ( !isset( $this->modules[$name] ) ) {
 527                         if ( !isset( $this->moduleInfos[$name] ) ) {
 528                                 // No such module
 529                                 return null;
 530                         }
 531                         // Construct the requested object
 532                         $info = $this->moduleInfos[$name];
 533                         /** @var ResourceLoaderModule $object */
 534                         if ( isset( $info['object'] ) ) {
 535                                 // Object given in info array
 536                                 $object = $info['object'];
 537                         } elseif ( isset( $info['factory'] ) ) {
 538                                 $object = call_user_func( $info['factory'], $info );
 539                                 $object->setConfig( $this->getConfig() );
 540                                 $object->setLogger( $this->logger );
 541                         } else {
 542                                 $class = $info['class'] ?? ResourceLoaderFileModule::class;
 543                                 /** @var ResourceLoaderModule $object */
 544                                 $object = new $class( $info );
 545                                 $object->setConfig( $this->getConfig() );
 546                                 $object->setLogger( $this->logger );
 547                         }
 548                         $object->setName( $name );
 549                         $this->modules[$name] = $object;
 550                 }
 551
 552                 return $this->modules[$name];
 553         }
 554
 555         /**
 556          * Whether the module is a ResourceLoaderFileModule (including subclasses).
 557          *
 558          * @param string $name Module name
 559          * @return bool
 560          */
 561         protected function isFileModule( $name ) {
 562                 if ( !isset( $this->moduleInfos[$name] ) ) {
 563                         return false;
 564                 }
 565                 $info = $this->moduleInfos[$name];
 566                 if ( isset( $info['object'] ) ) {
 567                         return false;
 568                 }
 569                 return (
 570                         // The implied default for 'class' is ResourceLoaderFileModule
 571                         !isset( $info['class'] ) ||
 572                         // Explicit default
 573                         $info['class'] === ResourceLoaderFileModule::class ||
 574                         is_subclass_of( $info['class'], ResourceLoaderFileModule::class )
 575                 );
 576         }
 577
 578         /**
 579          * Get the list of sources.
 580          *
 581          * @return array Like [ id => load.php url, ... ]
 582          */
 583         public function getSources() {
 584                 return $this->sources;
 585         }
 586
 587         /**
 588          * Get the URL to the load.php endpoint for the given
 589          * ResourceLoader source
 590          *
 591          * @since 1.24
 592          * @param string $source
 593          * @throws MWException On an invalid $source name
 594          * @return string
 595          */
 596         public function getLoadScript( $source ) {
 597                 if ( !isset( $this->sources[$source] ) ) {
 598                         throw new MWException( "The $source source was never registered in ResourceLoader." );
 599                 }
 600                 return $this->sources[$source];
 601         }
 602
 603         /**
 604          * @since 1.26
 605          * @param string $value
 606          * @return string Hash
 607          */
 608         public static function makeHash( $value ) {
 609                 $hash = hash( 'fnv132', $value );
 610                 return Wikimedia\base_convert( $hash, 16, 36, 7 );
 611         }
 612
 613         /**
 614          * Add an error to the 'errors' array and log it.
 615          *
 616          * @private For internal use by ResourceLoader and ResourceLoaderStartUpModule.
 617          * @since 1.29
 618          * @param Exception $e
 619          * @param string $msg
 620          * @param array $context
 621          */
 622         public function outputErrorAndLog( Exception $e, $msg, array $context = [] ) {
 623                 MWExceptionHandler::logException( $e );
 624                 $this->logger->warning(
 625                         $msg,
 626                         $context + [ 'exception' => $e ]
 627                 );
 628                 $this->errors[] = self::formatExceptionNoComment( $e );
 629         }
 630
 631         /**
 632          * Helper method to get and combine versions of multiple modules.
 633          *
 634          * @since 1.26
 635          * @param ResourceLoaderContext $context
 636          * @param string[] $moduleNames List of known module names
 637          * @return string Hash
 638          */
 639         public function getCombinedVersion( ResourceLoaderContext $context, array $moduleNames ) {
 640                 if ( !$moduleNames ) {
 641                         return '';
 642                 }
 643                 $hashes = array_map( function ( $module ) use ( $context ) {
 644                         try {
 645                                 return $this->getModule( $module )->getVersionHash( $context );
 646                         } catch ( Exception $e ) {
 647                                 // If modules fail to compute a version, don't fail the request (T152266)
 648                                 // and still compute versions of other modules.
 649                                 $this->outputErrorAndLog( $e,
 650                                         'Calculating version for "{module}" failed: {exception}',
 651                                         [
 652                                                 'module' => $module,
 653                                         ]
 654                                 );
 655                                 return '';
 656                         }
 657                 }, $moduleNames );
 658                 return self::makeHash( implode( '', $hashes ) );
 659         }
 660
 661         /**
 662          * Get the expected value of the 'version' query parameter.
 663          *
 664          * This is used by respond() to set a short Cache-Control header for requests with
 665          * information newer than the current server has. This avoids pollution of edge caches.
 666          * Typically during deployment. (T117587)
 667          *
 668          * This MUST match return value of `mw.loader#getCombinedVersion()` client-side.
 669          *
 670          * @since 1.28
 671          * @param ResourceLoaderContext $context
 672          * @return string Hash
 673          */
 674         public function makeVersionQuery( ResourceLoaderContext $context ) {
 675                 // As of MediaWiki 1.28, the server and client use the same algorithm for combining
 676                 // version hashes. There is no technical reason for this to be same, and for years the
 677                 // implementations differed. If getCombinedVersion in PHP (used for StartupModule and
 678                 // E-Tag headers) differs in the future from getCombinedVersion in JS (used for 'version'
 679                 // query parameter), then this method must continue to match the JS one.
 680                 $moduleNames = [];
 681                 foreach ( $context->getModules() as $name ) {
 682                         if ( !$this->getModule( $name ) ) {
 683                                 // If a versioned request contains a missing module, the version is a mismatch
 684                                 // as the client considered a module (and version) we don't have.
 685                                 return '';
 686                         }
 687                         $moduleNames[] = $name;
 688                 }
 689                 return $this->getCombinedVersion( $context, $moduleNames );
 690         }
 691
 692         /**
 693          * Output a response to a load request, including the content-type header.
 694          *
 695          * @param ResourceLoaderContext $context Context in which a response should be formed
 696          */
 697         public function respond( ResourceLoaderContext $context ) {
 698                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 699                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 700                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 701                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 702                 // the whole thing in our own output buffer to be sure the active buffer
 703                 // doesn't use ob_gzhandler.
 704                 // See https://bugs.php.net/bug.php?id=36514
 705                 ob_start();
 706
 707                 $this->measureResponseTime( RequestContext::getMain()->getTiming() );
 708
 709                 // Find out which modules are missing and instantiate the others
 710                 $modules = [];
 711                 $missing = [];
 712                 foreach ( $context->getModules() as $name ) {
 713                         $module = $this->getModule( $name );
 714                         if ( $module ) {
 715                                 // Do not allow private modules to be loaded from the web.
 716                                 // This is a security issue, see T36907.
 717                                 if ( $module->getGroup() === 'private' ) {
 718                                         $this->logger->debug( "Request for private module '$name' denied" );
 719                                         $this->errors[] = "Cannot show private module \"$name\"";
 720                                         continue;
 721                                 }
 722                                 $modules[$name] = $module;
 723                         } else {
 724                                 $missing[] = $name;
 725                         }
 726                 }
 727
 728                 try {
 729                         // Preload for getCombinedVersion() and for batch makeModuleResponse()
 730                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 731                 } catch ( Exception $e ) {
 732                         $this->outputErrorAndLog( $e, 'Preloading module info failed: {exception}' );
 733                 }
 734
 735                 // Combine versions to propagate cache invalidation
 736                 $versionHash = '';
 737                 try {
 738                         $versionHash = $this->getCombinedVersion( $context, array_keys( $modules ) );
 739                 } catch ( Exception $e ) {
 740                         $this->outputErrorAndLog( $e, 'Calculating version hash failed: {exception}' );
 741                 }
 742
 743                 // See RFC 2616 § 3.11 Entity Tags
 744                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.11
 745                 $etag = 'W/"' . $versionHash . '"';
 746
 747                 // Try the client-side cache first
 748                 if ( $this->tryRespondNotModified( $context, $etag ) ) {
 749                         return; // output handled (buffers cleared)
 750                 }
 751
 752                 // Use file cache if enabled and available...
 753                 if ( $this->config->get( 'UseFileCache' ) ) {
 754                         $fileCache = ResourceFileCache::newFromContext( $context );
 755                         if ( $this->tryRespondFromFileCache( $fileCache, $context, $etag ) ) {
 756                                 return; // output handled
 757                         }
 758                 }
 759
 760                 // Generate a response
 761                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 762
 763                 // Capture any PHP warnings from the output buffer and append them to the
 764                 // error list if we're in debug mode.
 765                 if ( $context->getDebug() ) {
 766                         $warnings = ob_get_contents();
 767                         if ( strlen( $warnings ) ) {
 768                                 $this->errors[] = $warnings;
 769                         }
 770                 }
 771
 772                 // Save response to file cache unless there are errors
 773                 if ( isset( $fileCache ) && !$this->errors && $missing === [] ) {
 774                         // Cache single modules and images...and other requests if there are enough hits
 775                         if ( ResourceFileCache::useFileCache( $context ) ) {
 776                                 if ( $fileCache->isCacheWorthy() ) {
 777                                         $fileCache->saveText( $response );
 778                                 } else {
 779                                         $fileCache->incrMissesRecent( $context->getRequest() );
 780                                 }
 781                         }
 782                 }
 783
 784                 $this->sendResponseHeaders( $context, $etag, (bool)$this->errors, $this->extraHeaders );
 785
 786                 // Remove the output buffer and output the response
 787                 ob_end_clean();
 788
 789                 if ( $context->getImageObj() && $this->errors ) {
 790                         // We can't show both the error messages and the response when it's an image.
 791                         $response = implode( "\n\n", $this->errors );
 792                 } elseif ( $this->errors ) {
 793                         $errorText = implode( "\n\n", $this->errors );
 794                         $errorResponse = self::makeComment( $errorText );
 795                         if ( $context->shouldIncludeScripts() ) {
 796                                 $errorResponse .= 'if (window.console && console.error) {'
 797                                         . Xml::encodeJsCall( 'console.error', [ $errorText ] )
 798                                         . "}\n";
 799                         }
 800
 801                         // Prepend error info to the response
 802                         $response = $errorResponse . $response;
 803                 }
 804
 805                 $this->errors = [];
 806                 echo $response;
 807         }
 808
 809         protected function measureResponseTime( Timing $timing ) {
 810                 DeferredUpdates::addCallableUpdate( function () use ( $timing ) {
 811                         $measure = $timing->measure( 'responseTime', 'requestStart', 'requestShutdown' );
 812                         if ( $measure !== false ) {
 813                                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
 814                                 $stats->timing( 'resourceloader.responseTime', $measure['duration'] * 1000 );
 815                         }
 816                 } );
 817         }
 818
 819         /**
 820          * Send main response headers to the client.
 821          *
 822          * Deals with Content-Type, CORS (for stylesheets), and caching.
 823          *
 824          * @param ResourceLoaderContext $context
 825          * @param string $etag ETag header value
 826          * @param bool $errors Whether there are errors in the response
 827          * @param string[] $extra Array of extra HTTP response headers
 828          * @return void
 829          */
 830         protected function sendResponseHeaders(
 831                 ResourceLoaderContext $context, $etag, $errors, array $extra = []
 832         ) {
 833                 \MediaWiki\HeaderCallback::warnIfHeadersSent();
 834                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 835                 // Use a short cache expiry so that updates propagate to clients quickly, if:
 836                 // - No version specified (shared resources, e.g. stylesheets)
 837                 // - There were errors (recover quickly)
 838                 // - Version mismatch (T117587, T47877)
 839                 if ( is_null( $context->getVersion() )
 840                         || $errors
 841                         || $context->getVersion() !== $this->makeVersionQuery( $context )
 842                 ) {
 843                         $maxage = $rlMaxage['unversioned']['client'];
 844                         $smaxage = $rlMaxage['unversioned']['server'];
 845                 // If a version was specified we can use a longer expiry time since changing
 846                 // version numbers causes cache misses
 847                 } else {
 848                         $maxage = $rlMaxage['versioned']['client'];
 849                         $smaxage = $rlMaxage['versioned']['server'];
 850                 }
 851                 if ( $context->getImageObj() ) {
 852                         // Output different headers if we're outputting textual errors.
 853                         if ( $errors ) {
 854                                 header( 'Content-Type: text/plain; charset=utf-8' );
 855                         } else {
 856                                 $context->getImageObj()->sendResponseHeaders( $context );
 857                         }
 858                 } elseif ( $context->getOnly() === 'styles' ) {
 859                         header( 'Content-Type: text/css; charset=utf-8' );
 860                         header( 'Access-Control-Allow-Origin: *' );
 861                 } else {
 862                         header( 'Content-Type: text/javascript; charset=utf-8' );
 863                 }
 864                 // See RFC 2616 § 14.19 ETag
 865                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.19
 866                 header( 'ETag: ' . $etag );
 867                 if ( $context->getDebug() ) {
 868                         // Do not cache debug responses
 869                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 870                         header( 'Pragma: no-cache' );
 871                 } else {
 872                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 873                         $exp = min( $maxage, $smaxage );
 874                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 875                 }
 876                 foreach ( $extra as $header ) {
 877                         header( $header );
 878                 }
 879         }
 880
 881         /**
 882          * Respond with HTTP 304 Not Modified if appropiate.
 883          *
 884          * If there's an If-None-Match header, respond with a 304 appropriately
 885          * and clear out the output buffer. If the client cache is too old then do nothing.
 886          *
 887          * @param ResourceLoaderContext $context
 888          * @param string $etag ETag header value
 889          * @return bool True if HTTP 304 was sent and output handled
 890          */
 891         protected function tryRespondNotModified( ResourceLoaderContext $context, $etag ) {
 892                 // See RFC 2616 § 14.26 If-None-Match
 893                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
 894                 $clientKeys = $context->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST );
 895                 // Never send 304s in debug mode
 896                 if ( $clientKeys !== false && !$context->getDebug() && in_array( $etag, $clientKeys ) ) {
 897                         // There's another bug in ob_gzhandler (see also the comment at
 898                         // the top of this function) that causes it to gzip even empty
 899                         // responses, meaning it's impossible to produce a truly empty
 900                         // response (because the gzip header is always there). This is
 901                         // a problem because 304 responses have to be completely empty
 902                         // per the HTTP spec, and Firefox behaves buggily when they're not.
 903                         // See also https://bugs.php.net/bug.php?id=51579
 904                         // To work around this, we tear down all output buffering before
 905                         // sending the 304.
 906                         wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 907
 908                         HttpStatus::header( 304 );
 909
 910                         $this->sendResponseHeaders( $context, $etag, false );
 911                         return true;
 912                 }
 913                 return false;
 914         }
 915
 916         /**
 917          * Send out code for a response from file cache if possible.
 918          *
 919          * @param ResourceFileCache $fileCache Cache object for this request URL
 920          * @param ResourceLoaderContext $context Context in which to generate a response
 921          * @param string $etag ETag header value
 922          * @return bool If this found a cache file and handled the response
 923          */
 924         protected function tryRespondFromFileCache(
 925                 ResourceFileCache $fileCache,
 926                 ResourceLoaderContext $context,
 927                 $etag
 928         ) {
 929                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 930                 // Buffer output to catch warnings.
 931                 ob_start();
 932                 // Get the maximum age the cache can be
 933                 $maxage = is_null( $context->getVersion() )
 934                         ? $rlMaxage['unversioned']['server']
 935                         : $rlMaxage['versioned']['server'];
 936                 // Minimum timestamp the cache file must have
 937                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 938                 if ( !$good ) {
 939                         try { // RL always hits the DB on file cache miss...
 940                                 wfGetDB( DB_REPLICA );
 941                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 942                                 $good = $fileCache->isCacheGood(); // cache existence check
 943                         }
 944                 }
 945                 if ( $good ) {
 946                         $ts = $fileCache->cacheTimestamp();
 947                         // Send content type and cache headers
 948                         $this->sendResponseHeaders( $context, $etag, false );
 949                         $response = $fileCache->fetchText();
 950                         // Capture any PHP warnings from the output buffer and append them to the
 951                         // response in a comment if we're in debug mode.
 952                         if ( $context->getDebug() ) {
 953                                 $warnings = ob_get_contents();
 954                                 if ( strlen( $warnings ) ) {
 955                                         $response = self::makeComment( $warnings ) . $response;
 956                                 }
 957                         }
 958                         // Remove the output buffer and output the response
 959                         ob_end_clean();
 960                         echo $response . "\n/* Cached {$ts} */";
 961                         return true; // cache hit
 962                 }
 963                 // Clear buffer
 964                 ob_end_clean();
 965
 966                 return false; // cache miss
 967         }
 968
 969         /**
 970          * Generate a CSS or JS comment block.
 971          *
 972          * Only use this for public data, not error message details.
 973          *
 974          * @param string $text
 975          * @return string
 976          */
 977         public static function makeComment( $text ) {
 978                 $encText = str_replace( '*/', '* /', $text );
 979                 return "/*\n$encText\n*/\n";
 980         }
 981
 982         /**
 983          * Handle exception display.
 984          *
 985          * @param Exception $e Exception to be shown to the user
 986          * @return string Sanitized text in a CSS/JS comment that can be returned to the user
 987          */
 988         public static function formatException( $e ) {
 989                 return self::makeComment( self::formatExceptionNoComment( $e ) );
 990         }
 991
 992         /**
 993          * Handle exception display.
 994          *
 995          * @since 1.25
 996          * @param Exception $e Exception to be shown to the user
 997          * @return string Sanitized text that can be returned to the user
 998          */
 999         protected static function formatExceptionNoComment( $e ) {
1000                 global $wgShowExceptionDetails;
1001
1002                 if ( !$wgShowExceptionDetails ) {
1003                         return MWExceptionHandler::getPublicLogMessage( $e );
1004                 }
1005
1006                 return MWExceptionHandler::getLogMessage( $e ) .
1007                         "\nBacktrace:\n" .
1008                         MWExceptionHandler::getRedactedTraceAsString( $e );
1009         }
1010
1011         /**
1012          * Generate code for a response.
1013          *
1014          * Calling this method also populates the `errors` and `headers` members,
1015          * later used by respond().
1016          *
1017          * @param ResourceLoaderContext $context Context in which to generate a response
1018          * @param ResourceLoaderModule[] $modules List of module objects keyed by module name
1019          * @param string[] $missing List of requested module names that are unregistered (optional)
1020          * @return string Response data
1021          */
1022         public function makeModuleResponse( ResourceLoaderContext $context,
1023                 array $modules, array $missing = []
1024         ) {
1025                 $out = '';
1026                 $states = [];
1027
1028                 if ( $modules === [] && $missing === [] ) {
1029                         return <<<MESSAGE
1030 /* This file is the Web entry point for MediaWiki's ResourceLoader:
1031    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
1032    no modules were requested. Max made me put this here. */
1033 MESSAGE;
1034                 }
1035
1036                 $image = $context->getImageObj();
1037                 if ( $image ) {
1038                         $data = $image->getImageData( $context );
1039                         if ( $data === false ) {
1040                                 $data = '';
1041                                 $this->errors[] = 'Image generation failed';
1042                         }
1043                         return $data;
1044                 }
1045
1046                 foreach ( $missing as $name ) {
1047                         $states[$name] = 'missing';
1048                 }
1049
1050                 // Generate output
1051                 $isRaw = false;
1052
1053                 $filter = $context->getOnly() === 'styles' ? 'minify-css' : 'minify-js';
1054
1055                 foreach ( $modules as $name => $module ) {
1056                         try {
1057                                 $content = $module->getModuleContent( $context );
1058                                 $implementKey = $name . '@' . $module->getVersionHash( $context );
1059                                 $strContent = '';
1060
1061                                 if ( isset( $content['headers'] ) ) {
1062                                         $this->extraHeaders = array_merge( $this->extraHeaders, $content['headers'] );
1063                                 }
1064
1065                                 // Append output
1066                                 switch ( $context->getOnly() ) {
1067                                         case 'scripts':
1068                                                 $scripts = $content['scripts'];
1069                                                 if ( is_string( $scripts ) ) {
1070                                                         // Load scripts raw...
1071                                                         $strContent = $scripts;
1072                                                 } elseif ( is_array( $scripts ) ) {
1073                                                         // ...except when $scripts is an array of URLs or an associative array
1074                                                         $strContent = self::makeLoaderImplementScript( $implementKey, $scripts, [], [], [] );
1075                                                 }
1076                                                 break;
1077                                         case 'styles':
1078                                                 $styles = $content['styles'];
1079                                                 // We no longer separate into media, they are all combined now with
1080                                                 // custom media type groups into @media .. {} sections as part of the css string.
1081                                                 // Module returns either an empty array or a numerical array with css strings.
1082                                                 $strContent = isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
1083                                                 break;
1084                                         default:
1085                                                 $scripts = $content['scripts'] ?? '';
1086                                                 if ( is_string( $scripts ) ) {
1087                                                         if ( $name === 'site' || $name === 'user' ) {
1088                                                                 // Legacy scripts that run in the global scope without a closure.
1089                                                                 // mw.loader.implement will use globalEval if scripts is a string.
1090                                                                 // Minify manually here, because general response minification is
1091                                                                 // not effective due it being a string literal, not a function.
1092                                                                 if ( !$context->getDebug() ) {
1093                                                                         $scripts = self::filter( 'minify-js', $scripts ); // T107377
1094                                                                 }
1095                                                         } else {
1096                                                                 $scripts = new XmlJsCode( $scripts );
1097                                                         }
1098                                                 }
1099                                                 $strContent = self::makeLoaderImplementScript(
1100                                                         $implementKey,
1101                                                         $scripts,
1102                                                         $content['styles'] ?? [],
1103                                                         isset( $content['messagesBlob'] ) ? new XmlJsCode( $content['messagesBlob'] ) : [],
1104                                                         $content['templates'] ?? []
1105                                                 );
1106                                                 break;
1107                                 }
1108
1109                                 if ( !$context->getDebug() ) {
1110                                         $strContent = self::filter( $filter, $strContent );
1111                                 } else {
1112                                         // In debug mode, separate each response by a new line.
1113                                         // For example, between 'mw.loader.implement();' statements.
1114                                         $strContent = $this->ensureNewline( $strContent );
1115                                 }
1116
1117                                 if ( $context->getOnly() === 'scripts' ) {
1118                                         // Use a linebreak between module scripts (T162719)
1119                                         $out .= $this->ensureNewline( $strContent );
1120                                 } else {
1121                                         $out .= $strContent;
1122                                 }
1123
1124                         } catch ( Exception $e ) {
1125                                 $this->outputErrorAndLog( $e, 'Generating module package failed: {exception}' );
1126
1127                                 // Respond to client with error-state instead of module implementation
1128                                 $states[$name] = 'error';
1129                                 unset( $modules[$name] );
1130                         }
1131                         $isRaw |= $module->isRaw();
1132                 }
1133
1134                 // Update module states
1135                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
1136                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
1137                                 // Set the state of modules loaded as only scripts to ready as
1138                                 // they don't have an mw.loader.implement wrapper that sets the state
1139                                 foreach ( $modules as $name => $module ) {
1140                                         $states[$name] = 'ready';
1141                                 }
1142                         }
1143
1144                         // Set the state of modules we didn't respond to with mw.loader.implement
1145                         if ( count( $states ) ) {
1146                                 $stateScript = self::makeLoaderStateScript( $states );
1147                                 if ( !$context->getDebug() ) {
1148                                         $stateScript = self::filter( 'minify-js', $stateScript );
1149                                 }
1150                                 // Use a linebreak between module script and state script (T162719)
1151                                 $out = $this->ensureNewline( $out ) . $stateScript;
1152                         }
1153                 } elseif ( $states ) {
1154                         $this->errors[] = 'Problematic modules: '
1155                                 . self::encodeJsonForScript( $states );
1156                 }
1157
1158                 return $out;
1159         }
1160
1161         /**
1162          * Ensure the string is either empty or ends in a line break
1163          * @param string $str
1164          * @return string
1165          */
1166         private function ensureNewline( $str ) {
1167                 $end = substr( $str, -1 );
1168                 if ( $end === false || $end === '' || $end === "\n" ) {
1169                         return $str;
1170                 }
1171                 return $str . "\n";
1172         }
1173
1174         /**
1175          * Get names of modules that use a certain message.
1176          *
1177          * @param string $messageKey
1178          * @return array List of module names
1179          */
1180         public function getModulesByMessage( $messageKey ) {
1181                 $moduleNames = [];
1182                 foreach ( $this->getModuleNames() as $moduleName ) {
1183                         $module = $this->getModule( $moduleName );
1184                         if ( in_array( $messageKey, $module->getMessages() ) ) {
1185                                 $moduleNames[] = $moduleName;
1186                         }
1187                 }
1188                 return $moduleNames;
1189         }
1190
1191         /**
1192          * Return JS code that calls mw.loader.implement with given module properties.
1193          *
1194          * @param string $name Module name or implement key (format "`[name]@[version]`")
1195          * @param XmlJsCode|array|string $scripts Code as XmlJsCode (to be wrapped in a closure),
1196          *  list of URLs to JavaScript files, string of JavaScript for `$.globalEval`, or array with
1197          *  'files' and 'main' properties (see ResourceLoaderModule::getScript())
1198          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1199          *   to CSS files keyed by media type
1200          * @param mixed $messages List of messages associated with this module. May either be an
1201          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1202          *   the same data, wrapped in an XmlJsCode object.
1203          * @param array $templates Keys are name of templates and values are the source of
1204          *   the template.
1205          * @throws MWException
1206          * @return string JavaScript code
1207          */
1208         protected static function makeLoaderImplementScript(
1209                 $name, $scripts, $styles, $messages, $templates
1210         ) {
1211                 if ( $scripts instanceof XmlJsCode ) {
1212                         if ( $scripts->value === '' ) {
1213                                 $scripts = null;
1214                         } elseif ( self::inDebugMode() ) {
1215                                 $scripts = new XmlJsCode( "function ( $, jQuery, require, module ) {\n{$scripts->value}\n}" );
1216                         } else {
1217                                 $scripts = new XmlJsCode( 'function($,jQuery,require,module){' . $scripts->value . '}' );
1218                         }
1219                 } elseif ( is_array( $scripts ) && isset( $scripts['files'] ) ) {
1220                         $files = $scripts['files'];
1221                         foreach ( $files as $path => &$file ) {
1222                                 // $file is changed (by reference) from a descriptor array to the content of the file
1223                                 // All of these essentially do $file = $file['content'];, some just have wrapping around it
1224                                 if ( $file['type'] === 'script' ) {
1225                                         // Multi-file modules only get two parameters ($ and jQuery are being phased out)
1226                                         if ( self::inDebugMode() ) {
1227                                                 $file = new XmlJsCode( "function ( require, module ) {\n{$file['content']}\n}" );
1228                                         } else {
1229                                                 $file = new XmlJsCode( 'function(require,module){' . $file['content'] . '}' );
1230                                         }
1231                                 } else {
1232                                         $file = $file['content'];
1233                                 }
1234                         }
1235                         $scripts = XmlJsCode::encodeObject( [
1236                                 'main' => $scripts['main'],
1237                                 'files' => XmlJsCode::encodeObject( $files, self::inDebugMode() )
1238                         ], self::inDebugMode() );
1239                 } elseif ( !is_string( $scripts ) && !is_array( $scripts ) ) {
1240                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1241                 }
1242
1243                 // mw.loader.implement requires 'styles', 'messages' and 'templates' to be objects (not
1244                 // arrays). json_encode considers empty arrays to be numerical and outputs "[]" instead
1245                 // of "{}". Force them to objects.
1246                 $module = [
1247                         $name,
1248                         $scripts,
1249                         (object)$styles,
1250                         (object)$messages,
1251                         (object)$templates
1252                 ];
1253                 self::trimArray( $module );
1254
1255                 return Xml::encodeJsCall( 'mw.loader.implement', $module, self::inDebugMode() );
1256         }
1257
1258         /**
1259          * Returns JS code which, when called, will register a given list of messages.
1260          *
1261          * @param mixed $messages Either an associative array mapping message key to value, or a
1262          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1263          * @return string JavaScript code
1264          */
1265         public static function makeMessageSetScript( $messages ) {
1266                 return Xml::encodeJsCall(
1267                         'mw.messages.set',
1268                         [ (object)$messages ],
1269                         self::inDebugMode()
1270                 );
1271         }
1272
1273         /**
1274          * Combines an associative array mapping media type to CSS into a
1275          * single stylesheet with "@media" blocks.
1276          *
1277          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1278          * @return array
1279          */
1280         public static function makeCombinedStyles( array $stylePairs ) {
1281                 $out = [];
1282                 foreach ( $stylePairs as $media => $styles ) {
1283                         // ResourceLoaderFileModule::getStyle can return the styles
1284                         // as a string or an array of strings. This is to allow separation in
1285                         // the front-end.
1286                         $styles = (array)$styles;
1287                         foreach ( $styles as $style ) {
1288                                 $style = trim( $style );
1289                                 // Don't output an empty "@media print { }" block (T42498)
1290                                 if ( $style !== '' ) {
1291                                         // Transform the media type based on request params and config
1292                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1293                                         $media = OutputPage::transformCssMedia( $media );
1294
1295                                         if ( $media === '' || $media == 'all' ) {
1296                                                 $out[] = $style;
1297                                         } elseif ( is_string( $media ) ) {
1298                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1299                                         }
1300                                         // else: skip
1301                                 }
1302                         }
1303                 }
1304                 return $out;
1305         }
1306
1307         /**
1308          * Wrapper around json_encode that avoids needless escapes,
1309          * and pretty-prints in debug mode.
1310          *
1311          * @internal
1312          * @since 1.32
1313          * @param bool|string|array $data
1314          * @return string JSON
1315          */
1316         public static function encodeJsonForScript( $data ) {
1317                 // Keep output as small as possible by disabling needless escape modes
1318                 // that PHP uses by default.
1319                 // However, while most module scripts are only served on HTTP responses
1320                 // for JavaScript, some modules can also be embedded in the HTML as inline
1321                 // scripts. This, and the fact that we sometimes need to export strings
1322                 // containing user-generated content and labels that may genuinely contain
1323                 // a sequences like "</script>", we need to encode either '/' or '<'.
1324                 // By default PHP escapes '/'. Let's escape '<' instead which is less common
1325                 // and allows URLs to mostly remain readable.
1326                 $jsonFlags = JSON_UNESCAPED_SLASHES |
1327                         JSON_UNESCAPED_UNICODE |
1328                         JSON_HEX_TAG |
1329                         JSON_HEX_AMP;
1330                 if ( self::inDebugMode() ) {
1331                         $jsonFlags |= JSON_PRETTY_PRINT;
1332                 }
1333                 return json_encode( $data, $jsonFlags );
1334         }
1335
1336         /**
1337          * Returns a JS call to mw.loader.state, which sets the state of one
1338          * ore more modules to a given value. Has two calling conventions:
1339          *
1340          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1341          *         Set the state of a single module called $name to $state
1342          *
1343          *    - ResourceLoader::makeLoaderStateScript( [ $name => $state, ... ] ):
1344          *         Set the state of modules with the given names to the given states
1345          *
1346          * @param array|string $states
1347          * @param string|null $state
1348          * @return string JavaScript code
1349          */
1350         public static function makeLoaderStateScript( $states, $state = null ) {
1351                 if ( !is_array( $states ) ) {
1352                         $states = [ $states => $state ];
1353                 }
1354                 return Xml::encodeJsCall(
1355                         'mw.loader.state',
1356                         [ $states ],
1357                         self::inDebugMode()
1358                 );
1359         }
1360
1361         private static function isEmptyObject( stdClass $obj ) {
1362                 foreach ( $obj as $key => $value ) {
1363                         return false;
1364                 }
1365                 return true;
1366         }
1367
1368         /**
1369          * Remove empty values from the end of an array.
1370          *
1371          * Values considered empty:
1372          *
1373          * - null
1374          * - []
1375          * - new XmlJsCode( '{}' )
1376          * - new stdClass() // (object) []
1377          *
1378          * @param array $array
1379          */
1380         private static function trimArray( array &$array ) {
1381                 $i = count( $array );
1382                 while ( $i-- ) {
1383                         if ( $array[$i] === null
1384                                 || $array[$i] === []
1385                                 || ( $array[$i] instanceof XmlJsCode && $array[$i]->value === '{}' )
1386                                 || ( $array[$i] instanceof stdClass && self::isEmptyObject( $array[$i] ) )
1387                         ) {
1388                                 unset( $array[$i] );
1389                         } else {
1390                                 break;
1391                         }
1392                 }
1393         }
1394
1395         /**
1396          * Returns JS code which calls mw.loader.register with the given
1397          * parameter.
1398          *
1399          * @par Example
1400          * @code
1401          *
1402          *     ResourceLoader::makeLoaderRegisterScript( [
1403          *        [ $name1, $version1, $dependencies1, $group1, $source1, $skip1 ],
1404          *        [ $name2, $version2, $dependencies1, $group2, $source2, $skip2 ],
1405          *        ...
1406          *     ] ):
1407          * @endcode
1408          *
1409          * @internal
1410          * @since 1.32
1411          * @param array $modules Array of module registration arrays, each containing
1412          *  - string: module name
1413          *  - string: module version
1414          *  - array|null: List of dependencies (optional)
1415          *  - string|null: Module group (optional)
1416          *  - string|null: Name of foreign module source, or 'local' (optional)
1417          *  - string|null: Script body of a skip function (optional)
1418          * @return string JavaScript code
1419          */
1420         public static function makeLoaderRegisterScript( array $modules ) {
1421                 // Optimisation: Transform dependency names into indexes when possible
1422                 // to produce smaller output. They are expanded by mw.loader.register on
1423                 // the other end using resolveIndexedDependencies().
1424                 $index = [];
1425                 foreach ( $modules as $i => &$module ) {
1426                         // Build module name index
1427                         $index[$module[0]] = $i;
1428                 }
1429                 foreach ( $modules as &$module ) {
1430                         if ( isset( $module[2] ) ) {
1431                                 foreach ( $module[2] as &$dependency ) {
1432                                         if ( isset( $index[$dependency] ) ) {
1433                                                 // Replace module name in dependency list with index
1434                                                 $dependency = $index[$dependency];
1435                                         }
1436                                 }
1437                         }
1438                 }
1439
1440                 array_walk( $modules, [ self::class, 'trimArray' ] );
1441
1442                 return Xml::encodeJsCall(
1443                         'mw.loader.register',
1444                         [ $modules ],
1445                         self::inDebugMode()
1446                 );
1447         }
1448
1449         /**
1450          * Returns JS code which calls mw.loader.addSource() with the given
1451          * parameters. Has two calling conventions:
1452          *
1453          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1454          *       Register a single source
1455          *
1456          *   - ResourceLoader::makeLoaderSourcesScript( [ $id1 => $loadUrl, $id2 => $loadUrl, ... ] );
1457          *       Register sources with the given IDs and properties.
1458          *
1459          * @param string|array $sources Source ID
1460          * @param string|null $loadUrl load.php url
1461          * @return string JavaScript code
1462          */
1463         public static function makeLoaderSourcesScript( $sources, $loadUrl = null ) {
1464                 if ( !is_array( $sources ) ) {
1465                         $sources = [ $sources => $loadUrl ];
1466                 }
1467                 return Xml::encodeJsCall(
1468                         'mw.loader.addSource',
1469                         [ $sources ],
1470                         self::inDebugMode()
1471                 );
1472         }
1473
1474         /**
1475          * Wraps JavaScript code to run after the startup module.
1476          *
1477          * @param string $script JavaScript code
1478          * @return string JavaScript code
1479          */
1480         public static function makeLoaderConditionalScript( $script ) {
1481                 // Adds a function to lazy-created RLQ
1482                 return '(RLQ=window.RLQ||[]).push(function(){' .
1483                         trim( $script ) . '});';
1484         }
1485
1486         /**
1487          * Wraps JavaScript code to run after a required module.
1488          *
1489          * @since 1.32
1490          * @param string|string[] $modules Module name(s)
1491          * @param string $script JavaScript code
1492          * @return string JavaScript code
1493          */
1494         public static function makeInlineCodeWithModule( $modules, $script ) {
1495                 // Adds an array to lazy-created RLQ
1496                 return '(RLQ=window.RLQ||[]).push(['
1497                         . self::encodeJsonForScript( $modules ) . ','
1498                         . 'function(){' . trim( $script ) . '}'
1499                         . ']);';
1500         }
1501
1502         /**
1503          * Returns an HTML script tag that runs given JS code after startup and base modules.
1504          *
1505          * The code will be wrapped in a closure, and it will be executed by ResourceLoader's
1506          * startup module if the client has adequate support for MediaWiki JavaScript code.
1507          *
1508          * @param string $script JavaScript code
1509          * @param string|null $nonce [optional] Content-Security-Policy nonce
1510          *  (from OutputPage::getCSPNonce)
1511          * @return string|WrappedString HTML
1512          */
1513         public static function makeInlineScript( $script, $nonce = null ) {
1514                 $js = self::makeLoaderConditionalScript( $script );
1515                 $escNonce = '';
1516                 if ( $nonce === null ) {
1517                         wfWarn( __METHOD__ . " did not get nonce. Will break CSP" );
1518                 } elseif ( $nonce !== false ) {
1519                         // If it was false, CSP is disabled, so no nonce attribute.
1520                         // Nonce should be only base64 characters, so should be safe,
1521                         // but better to be safely escaped than sorry.
1522                         $escNonce = ' nonce="' . htmlspecialchars( $nonce ) . '"';
1523                 }
1524
1525                 return new WrappedString(
1526                         Html::inlineScript( $js, $nonce ),
1527                         "<script$escNonce>(RLQ=window.RLQ||[]).push(function(){",
1528                         '});</script>'
1529                 );
1530         }
1531
1532         /**
1533          * Returns JS code which will set the MediaWiki configuration array to
1534          * the given value.
1535          *
1536          * @param array $configuration List of configuration values keyed by variable name
1537          * @return string JavaScript code
1538          * @throws Exception
1539          */
1540         public static function makeConfigSetScript( array $configuration ) {
1541                 $js = Xml::encodeJsCall(
1542                         'mw.config.set',
1543                         [ $configuration ],
1544                         self::inDebugMode()
1545                 );
1546                 if ( $js === false ) {
1547                         $e = new Exception(
1548                                 'JSON serialization of config data failed. ' .
1549                                 'This usually means the config data is not valid UTF-8.'
1550                         );
1551                         MWExceptionHandler::logException( $e );
1552                         $js = Xml::encodeJsCall( 'mw.log.error', [ $e->__toString() ] );
1553                 }
1554                 return $js;
1555         }
1556
1557         /**
1558          * Convert an array of module names to a packed query string.
1559          *
1560          * For example, `[ 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' ]`
1561          * becomes `'foo.bar,baz|bar.baz,quux'`.
1562          *
1563          * This process is reversed by ResourceLoader::expandModuleNames().
1564          * See also mw.loader#buildModulesString() which is a port of this, used
1565          * on the client-side.
1566          *
1567          * @param array $modules List of module names (strings)
1568          * @return string Packed query string
1569          */
1570         public static function makePackedModulesString( $modules ) {
1571                 $moduleMap = []; // [ prefix => [ suffixes ] ]
1572                 foreach ( $modules as $module ) {
1573                         $pos = strrpos( $module, '.' );
1574                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1575                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1576                         $moduleMap[$prefix][] = $suffix;
1577                 }
1578
1579                 $arr = [];
1580                 foreach ( $moduleMap as $prefix => $suffixes ) {
1581                         $p = $prefix === '' ? '' : $prefix . '.';
1582                         $arr[] = $p . implode( ',', $suffixes );
1583                 }
1584                 return implode( '|', $arr );
1585         }
1586
1587         /**
1588          * Expand a string of the form `jquery.foo,bar|jquery.ui.baz,quux` to
1589          * an array of module names like `[ 'jquery.foo', 'jquery.bar',
1590          * 'jquery.ui.baz', 'jquery.ui.quux' ]`.
1591          *
1592          * This process is reversed by ResourceLoader::makePackedModulesString().
1593          *
1594          * @since 1.33
1595          * @param string $modules Packed module name list
1596          * @return array Array of module names
1597          */
1598         public static function expandModuleNames( $modules ) {
1599                 $retval = [];
1600                 $exploded = explode( '|', $modules );
1601                 foreach ( $exploded as $group ) {
1602                         if ( strpos( $group, ',' ) === false ) {
1603                                 // This is not a set of modules in foo.bar,baz notation
1604                                 // but a single module
1605                                 $retval[] = $group;
1606                         } else {
1607                                 // This is a set of modules in foo.bar,baz notation
1608                                 $pos = strrpos( $group, '.' );
1609                                 if ( $pos === false ) {
1610                                         // Prefixless modules, i.e. without dots
1611                                         $retval = array_merge( $retval, explode( ',', $group ) );
1612                                 } else {
1613                                         // We have a prefix and a bunch of suffixes
1614                                         $prefix = substr( $group, 0, $pos ); // 'foo'
1615                                         $suffixes = explode( ',', substr( $group, $pos + 1 ) ); // [ 'bar', 'baz' ]
1616                                         foreach ( $suffixes as $suffix ) {
1617                                                 $retval[] = "$prefix.$suffix";
1618                                         }
1619                                 }
1620                         }
1621                 }
1622                 return $retval;
1623         }
1624
1625         /**
1626          * Determine whether debug mode was requested
1627          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1628          * @return bool
1629          */
1630         public static function inDebugMode() {
1631                 if ( self::$debugMode === null ) {
1632                         global $wgRequest, $wgResourceLoaderDebug;
1633                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1634                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1635                         );
1636                 }
1637                 return self::$debugMode;
1638         }
1639
1640         /**
1641          * Reset static members used for caching.
1642          *
1643          * Global state and $wgRequest are evil, but we're using it right
1644          * now and sometimes we need to be able to force ResourceLoader to
1645          * re-evaluate the context because it has changed (e.g. in the test suite).
1646          *
1647          * @internal For use by unit tests
1648          * @codeCoverageIgnore
1649          */
1650         public static function clearCache() {
1651                 self::$debugMode = null;
1652         }
1653
1654         /**
1655          * Build a load.php URL
1656          *
1657          * @since 1.24
1658          * @param string $source Name of the ResourceLoader source
1659          * @param ResourceLoaderContext $context
1660          * @param array $extraQuery
1661          * @return string URL to load.php. May be protocol-relative if $wgLoadScript is, too.
1662          */
1663         public function createLoaderURL( $source, ResourceLoaderContext $context,
1664                 $extraQuery = []
1665         ) {
1666                 $query = self::createLoaderQuery( $context, $extraQuery );
1667                 $script = $this->getLoadScript( $source );
1668
1669                 return wfAppendQuery( $script, $query );
1670         }
1671
1672         /**
1673          * Helper for createLoaderURL()
1674          *
1675          * @since 1.24
1676          * @see makeLoaderQuery
1677          * @param ResourceLoaderContext $context
1678          * @param array $extraQuery
1679          * @return array
1680          */
1681         protected static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = [] ) {
1682                 return self::makeLoaderQuery(
1683                         $context->getModules(),
1684                         $context->getLanguage(),
1685                         $context->getSkin(),
1686                         $context->getUser(),
1687                         $context->getVersion(),
1688                         $context->getDebug(),
1689                         $context->getOnly(),
1690                         $context->getRequest()->getBool( 'printable' ),
1691                         $context->getRequest()->getBool( 'handheld' ),
1692                         $extraQuery
1693                 );
1694         }
1695
1696         /**
1697          * Build a query array (array representation of query string) for load.php. Helper
1698          * function for createLoaderURL().
1699          *
1700          * @param array $modules
1701          * @param string $lang
1702          * @param string $skin
1703          * @param string|null $user
1704          * @param string|null $version
1705          * @param bool $debug
1706          * @param string|null $only
1707          * @param bool $printable
1708          * @param bool $handheld
1709          * @param array $extraQuery
1710          * @return array
1711          */
1712         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1713                 $version = null, $debug = false, $only = null, $printable = false,
1714                 $handheld = false, $extraQuery = []
1715         ) {
1716                 $query = [
1717                         'modules' => self::makePackedModulesString( $modules ),
1718                 ];
1719                 // Keep urls short by omitting query parameters that
1720                 // match the defaults assumed by ResourceLoaderContext.
1721                 // Note: This relies on the defaults either being insignificant or forever constant,
1722                 // as otherwise cached urls could change in meaning when the defaults change.
1723                 if ( $lang !== ResourceLoaderContext::DEFAULT_LANG ) {
1724                         $query['lang'] = $lang;
1725                 }
1726                 if ( $skin !== ResourceLoaderContext::DEFAULT_SKIN ) {
1727                         $query['skin'] = $skin;
1728                 }
1729                 if ( $debug === true ) {
1730                         $query['debug'] = 'true';
1731                 }
1732                 if ( $user !== null ) {
1733                         $query['user'] = $user;
1734                 }
1735                 if ( $version !== null ) {
1736                         $query['version'] = $version;
1737                 }
1738                 if ( $only !== null ) {
1739                         $query['only'] = $only;
1740                 }
1741                 if ( $printable ) {
1742                         $query['printable'] = 1;
1743                 }
1744                 if ( $handheld ) {
1745                         $query['handheld'] = 1;
1746                 }
1747                 $query += $extraQuery;
1748
1749                 // Make queries uniform in order
1750                 ksort( $query );
1751                 return $query;
1752         }
1753
1754         /**
1755          * Check a module name for validity.
1756          *
1757          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1758          * at most 255 bytes.
1759          *
1760          * @param string $moduleName Module name to check
1761          * @return bool Whether $moduleName is a valid module name
1762          */
1763         public static function isValidModuleName( $moduleName ) {
1764                 return strcspn( $moduleName, '!,|', 0, 255 ) === strlen( $moduleName );
1765         }
1766
1767         /**
1768          * Returns LESS compiler set up for use with MediaWiki
1769          *
1770          * @since 1.27
1771          * @param array $vars Associative array of variables that should be used
1772          *  for compilation. Since 1.32, this method no longer automatically includes
1773          *  global LESS vars from ResourceLoader::getLessVars (T191937).
1774          * @throws MWException
1775          * @return Less_Parser
1776          */
1777         public function getLessCompiler( $vars = [] ) {
1778                 global $IP;
1779                 // When called from the installer, it is possible that a required PHP extension
1780                 // is missing (at least for now; see T49564). If this is the case, throw an
1781                 // exception (caught by the installer) to prevent a fatal error later on.
1782                 if ( !class_exists( 'Less_Parser' ) ) {
1783                         throw new MWException( 'MediaWiki requires the less.php parser' );
1784                 }
1785
1786                 $parser = new Less_Parser;
1787                 $parser->ModifyVars( $vars );
1788                 $parser->SetImportDirs( [
1789                         "$IP/resources/src/mediawiki.less/" => '',
1790                 ] );
1791                 $parser->SetOption( 'relativeUrls', false );
1792
1793                 return $parser;
1794         }
1795
1796         /**
1797          * Get global LESS variables.
1798          *
1799          * @since 1.27
1800          * @deprecated since 1.32 Use ResourceLoderModule::getLessVars() instead.
1801          * @return array Map of variable names to string CSS values.
1802          */
1803         public function getLessVars() {
1804                 return [];
1805         }
1806 }