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                 $skin = $context->getSkin();
 122                 $lang = $context->getLanguage();
 123
 124                 // Batched version of ResourceLoaderModule::getFileDependencies
 125                 $vary = "$skin|$lang";
 126                 $res = $dbr->select( 'module_deps', [ 'md_module', 'md_deps' ], [
 127                                 'md_module' => $moduleNames,
 128                                 'md_skin' => $vary,
 129                         ], __METHOD__
 130                 );
 131
 132                 // Prime in-object cache for file dependencies
 133                 $modulesWithDeps = [];
 134                 foreach ( $res as $row ) {
 135                         $module = $this->getModule( $row->md_module );
 136                         if ( $module ) {
 137                                 $module->setFileDependencies( $context, ResourceLoaderModule::expandRelativePaths(
 138                                         json_decode( $row->md_deps, true )
 139                                 ) );
 140                                 $modulesWithDeps[] = $row->md_module;
 141                         }
 142                 }
 143                 // Register the absence of a dependency row too
 144                 foreach ( array_diff( $moduleNames, $modulesWithDeps ) as $name ) {
 145                         $module = $this->getModule( $name );
 146                         if ( $module ) {
 147                                 $this->getModule( $name )->setFileDependencies( $context, [] );
 148                         }
 149                 }
 150
 151                 // Batched version of ResourceLoaderWikiModule::getTitleInfo
 152                 ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $moduleNames );
 153
 154                 // Prime in-object cache for message blobs for modules with messages
 155                 $modules = [];
 156                 foreach ( $moduleNames as $name ) {
 157                         $module = $this->getModule( $name );
 158                         if ( $module && $module->getMessages() ) {
 159                                 $modules[$name] = $module;
 160                         }
 161                 }
 162                 $store = $this->getMessageBlobStore();
 163                 $blobs = $store->getBlobs( $modules, $lang );
 164                 foreach ( $blobs as $name => $blob ) {
 165                         $modules[$name]->setMessageBlob( $blob, $lang );
 166                 }
 167         }
 168
 169         /**
 170          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 171          *
 172          * Available filters are:
 173          *
 174          *    - minify-js \see JavaScriptMinifier::minify
 175          *    - minify-css \see CSSMin::minify
 176          *
 177          * If $data is empty, only contains whitespace or the filter was unknown,
 178          * $data is returned unmodified.
 179          *
 180          * @param string $filter Name of filter to run
 181          * @param string $data Text to filter, such as JavaScript or CSS text
 182          * @param array $options Keys:
 183          *  - (bool) cache: Whether to allow caching this data. Default: true.
 184          * @return string Filtered data, or a comment containing an error message
 185          */
 186         public static function filter( $filter, $data, array $options = [] ) {
 187                 if ( strpos( $data, self::FILTER_NOMIN ) !== false ) {
 188                         return $data;
 189                 }
 190
 191                 if ( isset( $options['cache'] ) && $options['cache'] === false ) {
 192                         return self::applyFilter( $filter, $data );
 193                 }
 194
 195                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
 196                 $cache = ObjectCache::getLocalServerInstance( CACHE_ANYTHING );
 197
 198                 $key = $cache->makeGlobalKey(
 199                         'resourceloader',
 200                         'filter',
 201                         $filter,
 202                         self::CACHE_VERSION,
 203                         md5( $data )
 204                 );
 205
 206                 $result = $cache->get( $key );
 207                 if ( $result === false ) {
 208                         $stats->increment( "resourceloader_cache.$filter.miss" );
 209                         $result = self::applyFilter( $filter, $data );
 210                         $cache->set( $key, $result, 24 * 3600 );
 211                 } else {
 212                         $stats->increment( "resourceloader_cache.$filter.hit" );
 213                 }
 214                 if ( $result === null ) {
 215                         // Cached failure
 216                         $result = $data;
 217                 }
 218
 219                 return $result;
 220         }
 221
 222         private static function applyFilter( $filter, $data ) {
 223                 $data = trim( $data );
 224                 if ( $data ) {
 225                         try {
 226                                 $data = ( $filter === 'minify-css' )
 227                                         ? CSSMin::minify( $data )
 228                                         : JavaScriptMinifier::minify( $data );
 229                         } catch ( Exception $e ) {
 230                                 MWExceptionHandler::logException( $e );
 231                                 return null;
 232                         }
 233                 }
 234                 return $data;
 235         }
 236
 237         /**
 238          * Register core modules and runs registration hooks.
 239          * @param Config|null $config [optional]
 240          * @param LoggerInterface|null $logger [optional]
 241          */
 242         public function __construct( Config $config = null, LoggerInterface $logger = null ) {
 243                 $this->logger = $logger ?: new NullLogger();
 244
 245                 if ( !$config ) {
 246                         // TODO: Deprecate and remove.
 247                         $this->logger->debug( __METHOD__ . ' was called without providing a Config instance' );
 248                         $config = MediaWikiServices::getInstance()->getMainConfig();
 249                 }
 250                 $this->config = $config;
 251
 252                 // Add 'local' source first
 253                 $this->addSource( 'local', $config->get( 'LoadScript' ) );
 254
 255                 // Special module that always exists
 256                 $this->register( 'startup', [ 'class' => ResourceLoaderStartUpModule::class ] );
 257
 258                 $this->setMessageBlobStore( new MessageBlobStore( $this, $this->logger ) );
 259         }
 260
 261         /**
 262          * @return Config
 263          */
 264         public function getConfig() {
 265                 return $this->config;
 266         }
 267
 268         /**
 269          * @since 1.26
 270          * @param LoggerInterface $logger
 271          */
 272         public function setLogger( LoggerInterface $logger ) {
 273                 $this->logger = $logger;
 274         }
 275
 276         /**
 277          * @since 1.27
 278          * @return LoggerInterface
 279          */
 280         public function getLogger() {
 281                 return $this->logger;
 282         }
 283
 284         /**
 285          * @since 1.26
 286          * @return MessageBlobStore
 287          */
 288         public function getMessageBlobStore() {
 289                 return $this->blobStore;
 290         }
 291
 292         /**
 293          * @since 1.25
 294          * @param MessageBlobStore $blobStore
 295          */
 296         public function setMessageBlobStore( MessageBlobStore $blobStore ) {
 297                 $this->blobStore = $blobStore;
 298         }
 299
 300         /**
 301          * Register a module with the ResourceLoader system.
 302          *
 303          * @param mixed $name Name of module as a string or List of name/object pairs as an array
 304          * @param array|null $info Module info array. For backwards compatibility with 1.17alpha,
 305          *   this may also be a ResourceLoaderModule object. Optional when using
 306          *   multiple-registration calling style.
 307          * @throws MWException If a duplicate module registration is attempted
 308          * @throws MWException If a module name contains illegal characters (pipes or commas)
 309          * @throws MWException If something other than a ResourceLoaderModule is being registered
 310          */
 311         public function register( $name, $info = null ) {
 312                 $moduleSkinStyles = $this->config->get( 'ResourceModuleSkinStyles' );
 313
 314                 // Allow multiple modules to be registered in one call
 315                 $registrations = is_array( $name ) ? $name : [ $name => $info ];
 316                 foreach ( $registrations as $name => $info ) {
 317                         // Warn on duplicate registrations
 318                         if ( isset( $this->moduleInfos[$name] ) ) {
 319                                 // A module has already been registered by this name
 320                                 $this->logger->warning(
 321                                         'ResourceLoader duplicate registration warning. ' .
 322                                         'Another module has already been registered as ' . $name
 323                                 );
 324                         }
 325
 326                         // Check $name for validity
 327                         if ( !self::isValidModuleName( $name ) ) {
 328                                 throw new MWException( "ResourceLoader module name '$name' is invalid, "
 329                                         . "see ResourceLoader::isValidModuleName()" );
 330                         }
 331
 332                         // Attach module
 333                         if ( $info instanceof ResourceLoaderModule ) {
 334                                 $this->moduleInfos[$name] = [ 'object' => $info ];
 335                                 $info->setName( $name );
 336                                 $this->modules[$name] = $info;
 337                         } elseif ( is_array( $info ) ) {
 338                                 // New calling convention
 339                                 $this->moduleInfos[$name] = $info;
 340                         } else {
 341                                 throw new MWException(
 342                                         'ResourceLoader module info type error for module \'' . $name .
 343                                         '\': expected ResourceLoaderModule or array (got: ' . gettype( $info ) . ')'
 344                                 );
 345                         }
 346
 347                         // Last-minute changes
 348
 349                         // Apply custom skin-defined styles to existing modules.
 350                         if ( $this->isFileModule( $name ) ) {
 351                                 foreach ( $moduleSkinStyles as $skinName => $skinStyles ) {
 352                                         // If this module already defines skinStyles for this skin, ignore $wgResourceModuleSkinStyles.
 353                                         if ( isset( $this->moduleInfos[$name]['skinStyles'][$skinName] ) ) {
 354                                                 continue;
 355                                         }
 356
 357                                         // If $name is preceded with a '+', the defined style files will be added to 'default'
 358                                         // skinStyles, otherwise 'default' will be ignored as it normally would be.
 359                                         if ( isset( $skinStyles[$name] ) ) {
 360                                                 $paths = (array)$skinStyles[$name];
 361                                                 $styleFiles = [];
 362                                         } elseif ( isset( $skinStyles['+' . $name] ) ) {
 363                                                 $paths = (array)$skinStyles['+' . $name];
 364                                                 $styleFiles = isset( $this->moduleInfos[$name]['skinStyles']['default'] ) ?
 365                                                         (array)$this->moduleInfos[$name]['skinStyles']['default'] :
 366                                                         [];
 367                                         } else {
 368                                                 continue;
 369                                         }
 370
 371                                         // Add new file paths, remapping them to refer to our directories and not use settings
 372                                         // from the module we're modifying, which come from the base definition.
 373                                         list( $localBasePath, $remoteBasePath ) =
 374                                                 ResourceLoaderFileModule::extractBasePaths( $skinStyles );
 375
 376                                         foreach ( $paths as $path ) {
 377                                                 $styleFiles[] = new ResourceLoaderFilePath( $path, $localBasePath, $remoteBasePath );
 378                                         }
 379
 380                                         $this->moduleInfos[$name]['skinStyles'][$skinName] = $styleFiles;
 381                                 }
 382                         }
 383                 }
 384         }
 385
 386         /**
 387          * @internal For use by ServiceWiring only
 388          */
 389         public function registerTestModules() {
 390                 global $IP;
 391
 392                 if ( $this->config->get( 'EnableJavaScriptTest' ) !== true ) {
 393                         throw new MWException( 'Attempt to register JavaScript test modules '
 394                                 . 'but <code>$wgEnableJavaScriptTest</code> is false. '
 395                                 . 'Edit your <code>LocalSettings.php</code> to enable it.' );
 396                 }
 397
 398                 $testModules = [
 399                         'qunit' => [],
 400                 ];
 401
 402                 // Get test suites from extensions
 403                 // Avoid PHP 7.1 warning from passing $this by reference
 404                 $rl = $this;
 405                 Hooks::run( 'ResourceLoaderTestModules', [ &$testModules, &$rl ] );
 406                 $extRegistry = ExtensionRegistry::getInstance();
 407                 // In case of conflict, the deprecated hook has precedence.
 408                 $testModules['qunit'] += $extRegistry->getAttribute( 'QUnitTestModules' );
 409
 410                 // Add the QUnit testrunner as implicit dependency to extension test suites.
 411                 foreach ( $testModules['qunit'] as &$module ) {
 412                         // Shuck any single-module dependency as an array
 413                         if ( isset( $module['dependencies'] ) && is_string( $module['dependencies'] ) ) {
 414                                 $module['dependencies'] = [ $module['dependencies'] ];
 415                         }
 416
 417                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 418                 }
 419
 420                 // Get core test suites
 421                 $testModules['qunit'] =
 422                         ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules['qunit'];
 423
 424                 foreach ( $testModules as $id => $names ) {
 425                         // Register test modules
 426                         $this->register( $testModules[$id] );
 427
 428                         // Keep track of their names so that they can be loaded together
 429                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 430                 }
 431         }
 432
 433         /**
 434          * Add a foreign source of modules.
 435          *
 436          * Source IDs are typically the same as the Wiki ID or database name (e.g. lowercase a-z).
 437          *
 438          * @param array|string $id Source ID (string), or [ id1 => loadUrl, id2 => loadUrl, ... ]
 439          * @param string|array|null $loadUrl load.php url (string), or array with loadUrl key for
 440          *  backwards-compatibility.
 441          * @throws MWException
 442          */
 443         public function addSource( $id, $loadUrl = null ) {
 444                 // Allow multiple sources to be registered in one call
 445                 if ( is_array( $id ) ) {
 446                         foreach ( $id as $key => $value ) {
 447                                 $this->addSource( $key, $value );
 448                         }
 449                         return;
 450                 }
 451
 452                 // Disallow duplicates
 453                 if ( isset( $this->sources[$id] ) ) {
 454                         throw new MWException(
 455                                 'ResourceLoader duplicate source addition error. ' .
 456                                 'Another source has already been registered as ' . $id
 457                         );
 458                 }
 459
 460                 // Pre 1.24 backwards-compatibility
 461                 if ( is_array( $loadUrl ) ) {
 462                         if ( !isset( $loadUrl['loadScript'] ) ) {
 463                                 throw new MWException(
 464                                         __METHOD__ . ' was passed an array with no "loadScript" key.'
 465                                 );
 466                         }
 467
 468                         $loadUrl = $loadUrl['loadScript'];
 469                 }
 470
 471                 $this->sources[$id] = $loadUrl;
 472         }
 473
 474         /**
 475          * Get a list of module names.
 476          *
 477          * @return array List of module names
 478          */
 479         public function getModuleNames() {
 480                 return array_keys( $this->moduleInfos );
 481         }
 482
 483         /**
 484          * Get a list of test module names for one (or all) frameworks.
 485          *
 486          * If the given framework id is unknkown, or if the in-object variable is not an array,
 487          * then it will return an empty array.
 488          *
 489          * @param string $framework Get only the test module names for one
 490          *   particular framework (optional)
 491          * @return array
 492          */
 493         public function getTestModuleNames( $framework = 'all' ) {
 494                 /** @todo api siteinfo prop testmodulenames modulenames */
 495                 if ( $framework == 'all' ) {
 496                         return $this->testModuleNames;
 497                 } elseif ( isset( $this->testModuleNames[$framework] )
 498                         && is_array( $this->testModuleNames[$framework] )
 499                 ) {
 500                         return $this->testModuleNames[$framework];
 501                 } else {
 502                         return [];
 503                 }
 504         }
 505
 506         /**
 507          * Check whether a ResourceLoader module is registered
 508          *
 509          * @since 1.25
 510          * @param string $name
 511          * @return bool
 512          */
 513         public function isModuleRegistered( $name ) {
 514                 return isset( $this->moduleInfos[$name] );
 515         }
 516
 517         /**
 518          * Get the ResourceLoaderModule object for a given module name.
 519          *
 520          * If an array of module parameters exists but a ResourceLoaderModule object has not
 521          * yet been instantiated, this method will instantiate and cache that object such that
 522          * subsequent calls simply return the same object.
 523          *
 524          * @param string $name Module name
 525          * @return ResourceLoaderModule|null If module has been registered, return a
 526          *  ResourceLoaderModule instance. Otherwise, return null.
 527          */
 528         public function getModule( $name ) {
 529                 if ( !isset( $this->modules[$name] ) ) {
 530                         if ( !isset( $this->moduleInfos[$name] ) ) {
 531                                 // No such module
 532                                 return null;
 533                         }
 534                         // Construct the requested object
 535                         $info = $this->moduleInfos[$name];
 536                         /** @var ResourceLoaderModule $object */
 537                         if ( isset( $info['object'] ) ) {
 538                                 // Object given in info array
 539                                 $object = $info['object'];
 540                         } elseif ( isset( $info['factory'] ) ) {
 541                                 $object = call_user_func( $info['factory'], $info );
 542                                 $object->setConfig( $this->getConfig() );
 543                                 $object->setLogger( $this->logger );
 544                         } else {
 545                                 $class = $info['class'] ?? ResourceLoaderFileModule::class;
 546                                 /** @var ResourceLoaderModule $object */
 547                                 $object = new $class( $info );
 548                                 $object->setConfig( $this->getConfig() );
 549                                 $object->setLogger( $this->logger );
 550                         }
 551                         $object->setName( $name );
 552                         $this->modules[$name] = $object;
 553                 }
 554
 555                 return $this->modules[$name];
 556         }
 557
 558         /**
 559          * Whether the module is a ResourceLoaderFileModule (including subclasses).
 560          *
 561          * @param string $name Module name
 562          * @return bool
 563          */
 564         protected function isFileModule( $name ) {
 565                 if ( !isset( $this->moduleInfos[$name] ) ) {
 566                         return false;
 567                 }
 568                 $info = $this->moduleInfos[$name];
 569                 if ( isset( $info['object'] ) ) {
 570                         return false;
 571                 }
 572                 return (
 573                         // The implied default for 'class' is ResourceLoaderFileModule
 574                         !isset( $info['class'] ) ||
 575                         // Explicit default
 576                         $info['class'] === ResourceLoaderFileModule::class ||
 577                         is_subclass_of( $info['class'], ResourceLoaderFileModule::class )
 578                 );
 579         }
 580
 581         /**
 582          * Get the list of sources.
 583          *
 584          * @return array Like [ id => load.php url, ... ]
 585          */
 586         public function getSources() {
 587                 return $this->sources;
 588         }
 589
 590         /**
 591          * Get the URL to the load.php endpoint for the given
 592          * ResourceLoader source
 593          *
 594          * @since 1.24
 595          * @param string $source
 596          * @throws MWException On an invalid $source name
 597          * @return string
 598          */
 599         public function getLoadScript( $source ) {
 600                 if ( !isset( $this->sources[$source] ) ) {
 601                         throw new MWException( "The $source source was never registered in ResourceLoader." );
 602                 }
 603                 return $this->sources[$source];
 604         }
 605
 606         /**
 607          * @since 1.26
 608          * @param string $value
 609          * @return string Hash
 610          */
 611         public static function makeHash( $value ) {
 612                 $hash = hash( 'fnv132', $value );
 613                 return Wikimedia\base_convert( $hash, 16, 36, 7 );
 614         }
 615
 616         /**
 617          * Add an error to the 'errors' array and log it.
 618          *
 619          * @private For internal use by ResourceLoader and ResourceLoaderStartUpModule.
 620          * @since 1.29
 621          * @param Exception $e
 622          * @param string $msg
 623          * @param array $context
 624          */
 625         public function outputErrorAndLog( Exception $e, $msg, array $context = [] ) {
 626                 MWExceptionHandler::logException( $e );
 627                 $this->logger->warning(
 628                         $msg,
 629                         $context + [ 'exception' => $e ]
 630                 );
 631                 $this->errors[] = self::formatExceptionNoComment( $e );
 632         }
 633
 634         /**
 635          * Helper method to get and combine versions of multiple modules.
 636          *
 637          * @since 1.26
 638          * @param ResourceLoaderContext $context
 639          * @param string[] $moduleNames List of known module names
 640          * @return string Hash
 641          */
 642         public function getCombinedVersion( ResourceLoaderContext $context, array $moduleNames ) {
 643                 if ( !$moduleNames ) {
 644                         return '';
 645                 }
 646                 $hashes = array_map( function ( $module ) use ( $context ) {
 647                         try {
 648                                 return $this->getModule( $module )->getVersionHash( $context );
 649                         } catch ( Exception $e ) {
 650                                 // If modules fail to compute a version, don't fail the request (T152266)
 651                                 // and still compute versions of other modules.
 652                                 $this->outputErrorAndLog( $e,
 653                                         'Calculating version for "{module}" failed: {exception}',
 654                                         [
 655                                                 'module' => $module,
 656                                         ]
 657                                 );
 658                                 return '';
 659                         }
 660                 }, $moduleNames );
 661                 return self::makeHash( implode( '', $hashes ) );
 662         }
 663
 664         /**
 665          * Get the expected value of the 'version' query parameter.
 666          *
 667          * This is used by respond() to set a short Cache-Control header for requests with
 668          * information newer than the current server has. This avoids pollution of edge caches.
 669          * Typically during deployment. (T117587)
 670          *
 671          * This MUST match return value of `mw.loader#getCombinedVersion()` client-side.
 672          *
 673          * @since 1.28
 674          * @param ResourceLoaderContext $context
 675          * @return string Hash
 676          */
 677         public function makeVersionQuery( ResourceLoaderContext $context ) {
 678                 // As of MediaWiki 1.28, the server and client use the same algorithm for combining
 679                 // version hashes. There is no technical reason for this to be same, and for years the
 680                 // implementations differed. If getCombinedVersion in PHP (used for StartupModule and
 681                 // E-Tag headers) differs in the future from getCombinedVersion in JS (used for 'version'
 682                 // query parameter), then this method must continue to match the JS one.
 683                 $moduleNames = [];
 684                 foreach ( $context->getModules() as $name ) {
 685                         if ( !$this->getModule( $name ) ) {
 686                                 // If a versioned request contains a missing module, the version is a mismatch
 687                                 // as the client considered a module (and version) we don't have.
 688                                 return '';
 689                         }
 690                         $moduleNames[] = $name;
 691                 }
 692                 return $this->getCombinedVersion( $context, $moduleNames );
 693         }
 694
 695         /**
 696          * Output a response to a load request, including the content-type header.
 697          *
 698          * @param ResourceLoaderContext $context Context in which a response should be formed
 699          */
 700         public function respond( ResourceLoaderContext $context ) {
 701                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 702                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 703                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 704                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 705                 // the whole thing in our own output buffer to be sure the active buffer
 706                 // doesn't use ob_gzhandler.
 707                 // See https://bugs.php.net/bug.php?id=36514
 708                 ob_start();
 709
 710                 $this->measureResponseTime( RequestContext::getMain()->getTiming() );
 711
 712                 // Find out which modules are missing and instantiate the others
 713                 $modules = [];
 714                 $missing = [];
 715                 foreach ( $context->getModules() as $name ) {
 716                         $module = $this->getModule( $name );
 717                         if ( $module ) {
 718                                 // Do not allow private modules to be loaded from the web.
 719                                 // This is a security issue, see T36907.
 720                                 if ( $module->getGroup() === 'private' ) {
 721                                         $this->logger->debug( "Request for private module '$name' denied" );
 722                                         $this->errors[] = "Cannot show private module \"$name\"";
 723                                         continue;
 724                                 }
 725                                 $modules[$name] = $module;
 726                         } else {
 727                                 $missing[] = $name;
 728                         }
 729                 }
 730
 731                 try {
 732                         // Preload for getCombinedVersion() and for batch makeModuleResponse()
 733                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 734                 } catch ( Exception $e ) {
 735                         $this->outputErrorAndLog( $e, 'Preloading module info failed: {exception}' );
 736                 }
 737
 738                 // Combine versions to propagate cache invalidation
 739                 $versionHash = '';
 740                 try {
 741                         $versionHash = $this->getCombinedVersion( $context, array_keys( $modules ) );
 742                 } catch ( Exception $e ) {
 743                         $this->outputErrorAndLog( $e, 'Calculating version hash failed: {exception}' );
 744                 }
 745
 746                 // See RFC 2616 § 3.11 Entity Tags
 747                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.11
 748                 $etag = 'W/"' . $versionHash . '"';
 749
 750                 // Try the client-side cache first
 751                 if ( $this->tryRespondNotModified( $context, $etag ) ) {
 752                         return; // output handled (buffers cleared)
 753                 }
 754
 755                 // Use file cache if enabled and available...
 756                 if ( $this->config->get( 'UseFileCache' ) ) {
 757                         $fileCache = ResourceFileCache::newFromContext( $context );
 758                         if ( $this->tryRespondFromFileCache( $fileCache, $context, $etag ) ) {
 759                                 return; // output handled
 760                         }
 761                 }
 762
 763                 // Generate a response
 764                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 765
 766                 // Capture any PHP warnings from the output buffer and append them to the
 767                 // error list if we're in debug mode.
 768                 if ( $context->getDebug() ) {
 769                         $warnings = ob_get_contents();
 770                         if ( strlen( $warnings ) ) {
 771                                 $this->errors[] = $warnings;
 772                         }
 773                 }
 774
 775                 // Save response to file cache unless there are errors
 776                 if ( isset( $fileCache ) && !$this->errors && $missing === [] ) {
 777                         // Cache single modules and images...and other requests if there are enough hits
 778                         if ( ResourceFileCache::useFileCache( $context ) ) {
 779                                 if ( $fileCache->isCacheWorthy() ) {
 780                                         $fileCache->saveText( $response );
 781                                 } else {
 782                                         $fileCache->incrMissesRecent( $context->getRequest() );
 783                                 }
 784                         }
 785                 }
 786
 787                 $this->sendResponseHeaders( $context, $etag, (bool)$this->errors, $this->extraHeaders );
 788
 789                 // Remove the output buffer and output the response
 790                 ob_end_clean();
 791
 792                 if ( $context->getImageObj() && $this->errors ) {
 793                         // We can't show both the error messages and the response when it's an image.
 794                         $response = implode( "\n\n", $this->errors );
 795                 } elseif ( $this->errors ) {
 796                         $errorText = implode( "\n\n", $this->errors );
 797                         $errorResponse = self::makeComment( $errorText );
 798                         if ( $context->shouldIncludeScripts() ) {
 799                                 $errorResponse .= 'if (window.console && console.error) {'
 800                                         . Xml::encodeJsCall( 'console.error', [ $errorText ] )
 801                                         . "}\n";
 802                         }
 803
 804                         // Prepend error info to the response
 805                         $response = $errorResponse . $response;
 806                 }
 807
 808                 $this->errors = [];
 809                 echo $response;
 810         }
 811
 812         protected function measureResponseTime( Timing $timing ) {
 813                 DeferredUpdates::addCallableUpdate( function () use ( $timing ) {
 814                         $measure = $timing->measure( 'responseTime', 'requestStart', 'requestShutdown' );
 815                         if ( $measure !== false ) {
 816                                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
 817                                 $stats->timing( 'resourceloader.responseTime', $measure['duration'] * 1000 );
 818                         }
 819                 } );
 820         }
 821
 822         /**
 823          * Send main response headers to the client.
 824          *
 825          * Deals with Content-Type, CORS (for stylesheets), and caching.
 826          *
 827          * @param ResourceLoaderContext $context
 828          * @param string $etag ETag header value
 829          * @param bool $errors Whether there are errors in the response
 830          * @param string[] $extra Array of extra HTTP response headers
 831          * @return void
 832          */
 833         protected function sendResponseHeaders(
 834                 ResourceLoaderContext $context, $etag, $errors, array $extra = []
 835         ) {
 836                 \MediaWiki\HeaderCallback::warnIfHeadersSent();
 837                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 838                 // Use a short cache expiry so that updates propagate to clients quickly, if:
 839                 // - No version specified (shared resources, e.g. stylesheets)
 840                 // - There were errors (recover quickly)
 841                 // - Version mismatch (T117587, T47877)
 842                 if ( is_null( $context->getVersion() )
 843                         || $errors
 844                         || $context->getVersion() !== $this->makeVersionQuery( $context )
 845                 ) {
 846                         $maxage = $rlMaxage['unversioned']['client'];
 847                         $smaxage = $rlMaxage['unversioned']['server'];
 848                 // If a version was specified we can use a longer expiry time since changing
 849                 // version numbers causes cache misses
 850                 } else {
 851                         $maxage = $rlMaxage['versioned']['client'];
 852                         $smaxage = $rlMaxage['versioned']['server'];
 853                 }
 854                 if ( $context->getImageObj() ) {
 855                         // Output different headers if we're outputting textual errors.
 856                         if ( $errors ) {
 857                                 header( 'Content-Type: text/plain; charset=utf-8' );
 858                         } else {
 859                                 $context->getImageObj()->sendResponseHeaders( $context );
 860                         }
 861                 } elseif ( $context->getOnly() === 'styles' ) {
 862                         header( 'Content-Type: text/css; charset=utf-8' );
 863                         header( 'Access-Control-Allow-Origin: *' );
 864                 } else {
 865                         header( 'Content-Type: text/javascript; charset=utf-8' );
 866                 }
 867                 // See RFC 2616 § 14.19 ETag
 868                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.19
 869                 header( 'ETag: ' . $etag );
 870                 if ( $context->getDebug() ) {
 871                         // Do not cache debug responses
 872                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 873                         header( 'Pragma: no-cache' );
 874                 } else {
 875                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 876                         $exp = min( $maxage, $smaxage );
 877                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 878                 }
 879                 foreach ( $extra as $header ) {
 880                         header( $header );
 881                 }
 882         }
 883
 884         /**
 885          * Respond with HTTP 304 Not Modified if appropiate.
 886          *
 887          * If there's an If-None-Match header, respond with a 304 appropriately
 888          * and clear out the output buffer. If the client cache is too old then do nothing.
 889          *
 890          * @param ResourceLoaderContext $context
 891          * @param string $etag ETag header value
 892          * @return bool True if HTTP 304 was sent and output handled
 893          */
 894         protected function tryRespondNotModified( ResourceLoaderContext $context, $etag ) {
 895                 // See RFC 2616 § 14.26 If-None-Match
 896                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
 897                 $clientKeys = $context->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST );
 898                 // Never send 304s in debug mode
 899                 if ( $clientKeys !== false && !$context->getDebug() && in_array( $etag, $clientKeys ) ) {
 900                         // There's another bug in ob_gzhandler (see also the comment at
 901                         // the top of this function) that causes it to gzip even empty
 902                         // responses, meaning it's impossible to produce a truly empty
 903                         // response (because the gzip header is always there). This is
 904                         // a problem because 304 responses have to be completely empty
 905                         // per the HTTP spec, and Firefox behaves buggily when they're not.
 906                         // See also https://bugs.php.net/bug.php?id=51579
 907                         // To work around this, we tear down all output buffering before
 908                         // sending the 304.
 909                         wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 910
 911                         HttpStatus::header( 304 );
 912
 913                         $this->sendResponseHeaders( $context, $etag, false );
 914                         return true;
 915                 }
 916                 return false;
 917         }
 918
 919         /**
 920          * Send out code for a response from file cache if possible.
 921          *
 922          * @param ResourceFileCache $fileCache Cache object for this request URL
 923          * @param ResourceLoaderContext $context Context in which to generate a response
 924          * @param string $etag ETag header value
 925          * @return bool If this found a cache file and handled the response
 926          */
 927         protected function tryRespondFromFileCache(
 928                 ResourceFileCache $fileCache,
 929                 ResourceLoaderContext $context,
 930                 $etag
 931         ) {
 932                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 933                 // Buffer output to catch warnings.
 934                 ob_start();
 935                 // Get the maximum age the cache can be
 936                 $maxage = is_null( $context->getVersion() )
 937                         ? $rlMaxage['unversioned']['server']
 938                         : $rlMaxage['versioned']['server'];
 939                 // Minimum timestamp the cache file must have
 940                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 941                 if ( !$good ) {
 942                         try { // RL always hits the DB on file cache miss...
 943                                 wfGetDB( DB_REPLICA );
 944                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 945                                 $good = $fileCache->isCacheGood(); // cache existence check
 946                         }
 947                 }
 948                 if ( $good ) {
 949                         $ts = $fileCache->cacheTimestamp();
 950                         // Send content type and cache headers
 951                         $this->sendResponseHeaders( $context, $etag, false );
 952                         $response = $fileCache->fetchText();
 953                         // Capture any PHP warnings from the output buffer and append them to the
 954                         // response in a comment if we're in debug mode.
 955                         if ( $context->getDebug() ) {
 956                                 $warnings = ob_get_contents();
 957                                 if ( strlen( $warnings ) ) {
 958                                         $response = self::makeComment( $warnings ) . $response;
 959                                 }
 960                         }
 961                         // Remove the output buffer and output the response
 962                         ob_end_clean();
 963                         echo $response . "\n/* Cached {$ts} */";
 964                         return true; // cache hit
 965                 }
 966                 // Clear buffer
 967                 ob_end_clean();
 968
 969                 return false; // cache miss
 970         }
 971
 972         /**
 973          * Generate a CSS or JS comment block.
 974          *
 975          * Only use this for public data, not error message details.
 976          *
 977          * @param string $text
 978          * @return string
 979          */
 980         public static function makeComment( $text ) {
 981                 $encText = str_replace( '*/', '* /', $text );
 982                 return "/*\n$encText\n*/\n";
 983         }
 984
 985         /**
 986          * Handle exception display.
 987          *
 988          * @param Exception $e Exception to be shown to the user
 989          * @return string Sanitized text in a CSS/JS comment that can be returned to the user
 990          */
 991         public static function formatException( $e ) {
 992                 return self::makeComment( self::formatExceptionNoComment( $e ) );
 993         }
 994
 995         /**
 996          * Handle exception display.
 997          *
 998          * @since 1.25
 999          * @param Exception $e Exception to be shown to the user
1000          * @return string Sanitized text that can be returned to the user
1001          */
1002         protected static function formatExceptionNoComment( $e ) {
1003                 global $wgShowExceptionDetails;
1004
1005                 if ( !$wgShowExceptionDetails ) {
1006                         return MWExceptionHandler::getPublicLogMessage( $e );
1007                 }
1008
1009                 return MWExceptionHandler::getLogMessage( $e ) .
1010                         "\nBacktrace:\n" .
1011                         MWExceptionHandler::getRedactedTraceAsString( $e );
1012         }
1013
1014         /**
1015          * Generate code for a response.
1016          *
1017          * Calling this method also populates the `errors` and `headers` members,
1018          * later used by respond().
1019          *
1020          * @param ResourceLoaderContext $context Context in which to generate a response
1021          * @param ResourceLoaderModule[] $modules List of module objects keyed by module name
1022          * @param string[] $missing List of requested module names that are unregistered (optional)
1023          * @return string Response data
1024          */
1025         public function makeModuleResponse( ResourceLoaderContext $context,
1026                 array $modules, array $missing = []
1027         ) {
1028                 $out = '';
1029                 $states = [];
1030
1031                 if ( $modules === [] && $missing === [] ) {
1032                         return <<<MESSAGE
1033 /* This file is the Web entry point for MediaWiki's ResourceLoader:
1034    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
1035    no modules were requested. Max made me put this here. */
1036 MESSAGE;
1037                 }
1038
1039                 $image = $context->getImageObj();
1040                 if ( $image ) {
1041                         $data = $image->getImageData( $context );
1042                         if ( $data === false ) {
1043                                 $data = '';
1044                                 $this->errors[] = 'Image generation failed';
1045                         }
1046                         return $data;
1047                 }
1048
1049                 foreach ( $missing as $name ) {
1050                         $states[$name] = 'missing';
1051                 }
1052
1053                 // Generate output
1054                 $isRaw = false;
1055
1056                 $filter = $context->getOnly() === 'styles' ? 'minify-css' : 'minify-js';
1057
1058                 foreach ( $modules as $name => $module ) {
1059                         try {
1060                                 $content = $module->getModuleContent( $context );
1061                                 $implementKey = $name . '@' . $module->getVersionHash( $context );
1062                                 $strContent = '';
1063
1064                                 if ( isset( $content['headers'] ) ) {
1065                                         $this->extraHeaders = array_merge( $this->extraHeaders, $content['headers'] );
1066                                 }
1067
1068                                 // Append output
1069                                 switch ( $context->getOnly() ) {
1070                                         case 'scripts':
1071                                                 $scripts = $content['scripts'];
1072                                                 if ( is_string( $scripts ) ) {
1073                                                         // Load scripts raw...
1074                                                         $strContent = $scripts;
1075                                                 } elseif ( is_array( $scripts ) ) {
1076                                                         // ...except when $scripts is an array of URLs or an associative array
1077                                                         $strContent = self::makeLoaderImplementScript( $implementKey, $scripts, [], [], [] );
1078                                                 }
1079                                                 break;
1080                                         case 'styles':
1081                                                 $styles = $content['styles'];
1082                                                 // We no longer separate into media, they are all combined now with
1083                                                 // custom media type groups into @media .. {} sections as part of the css string.
1084                                                 // Module returns either an empty array or a numerical array with css strings.
1085                                                 $strContent = isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
1086                                                 break;
1087                                         default:
1088                                                 $scripts = $content['scripts'] ?? '';
1089                                                 if ( is_string( $scripts ) ) {
1090                                                         if ( $name === 'site' || $name === 'user' ) {
1091                                                                 // Legacy scripts that run in the global scope without a closure.
1092                                                                 // mw.loader.implement will use globalEval if scripts is a string.
1093                                                                 // Minify manually here, because general response minification is
1094                                                                 // not effective due it being a string literal, not a function.
1095                                                                 if ( !$context->getDebug() ) {
1096                                                                         $scripts = self::filter( 'minify-js', $scripts ); // T107377
1097                                                                 }
1098                                                         } else {
1099                                                                 $scripts = new XmlJsCode( $scripts );
1100                                                         }
1101                                                 }
1102                                                 $strContent = self::makeLoaderImplementScript(
1103                                                         $implementKey,
1104                                                         $scripts,
1105                                                         $content['styles'] ?? [],
1106                                                         isset( $content['messagesBlob'] ) ? new XmlJsCode( $content['messagesBlob'] ) : [],
1107                                                         $content['templates'] ?? []
1108                                                 );
1109                                                 break;
1110                                 }
1111
1112                                 if ( !$context->getDebug() ) {
1113                                         $strContent = self::filter( $filter, $strContent );
1114                                 } else {
1115                                         // In debug mode, separate each response by a new line.
1116                                         // For example, between 'mw.loader.implement();' statements.
1117                                         $strContent = $this->ensureNewline( $strContent );
1118                                 }
1119
1120                                 if ( $context->getOnly() === 'scripts' ) {
1121                                         // Use a linebreak between module scripts (T162719)
1122                                         $out .= $this->ensureNewline( $strContent );
1123                                 } else {
1124                                         $out .= $strContent;
1125                                 }
1126
1127                         } catch ( Exception $e ) {
1128                                 $this->outputErrorAndLog( $e, 'Generating module package failed: {exception}' );
1129
1130                                 // Respond to client with error-state instead of module implementation
1131                                 $states[$name] = 'error';
1132                                 unset( $modules[$name] );
1133                         }
1134                         $isRaw |= $module->isRaw();
1135                 }
1136
1137                 // Update module states
1138                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
1139                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
1140                                 // Set the state of modules loaded as only scripts to ready as
1141                                 // they don't have an mw.loader.implement wrapper that sets the state
1142                                 foreach ( $modules as $name => $module ) {
1143                                         $states[$name] = 'ready';
1144                                 }
1145                         }
1146
1147                         // Set the state of modules we didn't respond to with mw.loader.implement
1148                         if ( count( $states ) ) {
1149                                 $stateScript = self::makeLoaderStateScript( $states );
1150                                 if ( !$context->getDebug() ) {
1151                                         $stateScript = self::filter( 'minify-js', $stateScript );
1152                                 }
1153                                 // Use a linebreak between module script and state script (T162719)
1154                                 $out = $this->ensureNewline( $out ) . $stateScript;
1155                         }
1156                 } elseif ( $states ) {
1157                         $this->errors[] = 'Problematic modules: '
1158                                 . self::encodeJsonForScript( $states );
1159                 }
1160
1161                 return $out;
1162         }
1163
1164         /**
1165          * Ensure the string is either empty or ends in a line break
1166          * @param string $str
1167          * @return string
1168          */
1169         private function ensureNewline( $str ) {
1170                 $end = substr( $str, -1 );
1171                 if ( $end === false || $end === '' || $end === "\n" ) {
1172                         return $str;
1173                 }
1174                 return $str . "\n";
1175         }
1176
1177         /**
1178          * Get names of modules that use a certain message.
1179          *
1180          * @param string $messageKey
1181          * @return array List of module names
1182          */
1183         public function getModulesByMessage( $messageKey ) {
1184                 $moduleNames = [];
1185                 foreach ( $this->getModuleNames() as $moduleName ) {
1186                         $module = $this->getModule( $moduleName );
1187                         if ( in_array( $messageKey, $module->getMessages() ) ) {
1188                                 $moduleNames[] = $moduleName;
1189                         }
1190                 }
1191                 return $moduleNames;
1192         }
1193
1194         /**
1195          * Return JS code that calls mw.loader.implement with given module properties.
1196          *
1197          * @param string $name Module name or implement key (format "`[name]@[version]`")
1198          * @param XmlJsCode|array|string $scripts Code as XmlJsCode (to be wrapped in a closure),
1199          *  list of URLs to JavaScript files, string of JavaScript for `$.globalEval`, or array with
1200          *  'files' and 'main' properties (see ResourceLoaderModule::getScript())
1201          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1202          *   to CSS files keyed by media type
1203          * @param mixed $messages List of messages associated with this module. May either be an
1204          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1205          *   the same data, wrapped in an XmlJsCode object.
1206          * @param array $templates Keys are name of templates and values are the source of
1207          *   the template.
1208          * @throws MWException
1209          * @return string JavaScript code
1210          */
1211         protected static function makeLoaderImplementScript(
1212                 $name, $scripts, $styles, $messages, $templates
1213         ) {
1214                 if ( $scripts instanceof XmlJsCode ) {
1215                         if ( $scripts->value === '' ) {
1216                                 $scripts = null;
1217                         } elseif ( self::inDebugMode() ) {
1218                                 $scripts = new XmlJsCode( "function ( $, jQuery, require, module ) {\n{$scripts->value}\n}" );
1219                         } else {
1220                                 $scripts = new XmlJsCode( 'function($,jQuery,require,module){' . $scripts->value . '}' );
1221                         }
1222                 } elseif ( is_array( $scripts ) && isset( $scripts['files'] ) ) {
1223                         $files = $scripts['files'];
1224                         foreach ( $files as $path => &$file ) {
1225                                 // $file is changed (by reference) from a descriptor array to the content of the file
1226                                 // All of these essentially do $file = $file['content'];, some just have wrapping around it
1227                                 if ( $file['type'] === 'script' ) {
1228                                         // Multi-file modules only get two parameters ($ and jQuery are being phased out)
1229                                         if ( self::inDebugMode() ) {
1230                                                 $file = new XmlJsCode( "function ( require, module ) {\n{$file['content']}\n}" );
1231                                         } else {
1232                                                 $file = new XmlJsCode( 'function(require,module){' . $file['content'] . '}' );
1233                                         }
1234                                 } else {
1235                                         $file = $file['content'];
1236                                 }
1237                         }
1238                         $scripts = XmlJsCode::encodeObject( [
1239                                 'main' => $scripts['main'],
1240                                 'files' => XmlJsCode::encodeObject( $files, self::inDebugMode() )
1241                         ], self::inDebugMode() );
1242                 } elseif ( !is_string( $scripts ) && !is_array( $scripts ) ) {
1243                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1244                 }
1245
1246                 // mw.loader.implement requires 'styles', 'messages' and 'templates' to be objects (not
1247                 // arrays). json_encode considers empty arrays to be numerical and outputs "[]" instead
1248                 // of "{}". Force them to objects.
1249                 $module = [
1250                         $name,
1251                         $scripts,
1252                         (object)$styles,
1253                         (object)$messages,
1254                         (object)$templates
1255                 ];
1256                 self::trimArray( $module );
1257
1258                 return Xml::encodeJsCall( 'mw.loader.implement', $module, self::inDebugMode() );
1259         }
1260
1261         /**
1262          * Returns JS code which, when called, will register a given list of messages.
1263          *
1264          * @param mixed $messages Either an associative array mapping message key to value, or a
1265          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1266          * @return string JavaScript code
1267          */
1268         public static function makeMessageSetScript( $messages ) {
1269                 return Xml::encodeJsCall(
1270                         'mw.messages.set',
1271                         [ (object)$messages ],
1272                         self::inDebugMode()
1273                 );
1274         }
1275
1276         /**
1277          * Combines an associative array mapping media type to CSS into a
1278          * single stylesheet with "@media" blocks.
1279          *
1280          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1281          * @return array
1282          */
1283         public static function makeCombinedStyles( array $stylePairs ) {
1284                 $out = [];
1285                 foreach ( $stylePairs as $media => $styles ) {
1286                         // ResourceLoaderFileModule::getStyle can return the styles
1287                         // as a string or an array of strings. This is to allow separation in
1288                         // the front-end.
1289                         $styles = (array)$styles;
1290                         foreach ( $styles as $style ) {
1291                                 $style = trim( $style );
1292                                 // Don't output an empty "@media print { }" block (T42498)
1293                                 if ( $style !== '' ) {
1294                                         // Transform the media type based on request params and config
1295                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1296                                         $media = OutputPage::transformCssMedia( $media );
1297
1298                                         if ( $media === '' || $media == 'all' ) {
1299                                                 $out[] = $style;
1300                                         } elseif ( is_string( $media ) ) {
1301                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1302                                         }
1303                                         // else: skip
1304                                 }
1305                         }
1306                 }
1307                 return $out;
1308         }
1309
1310         /**
1311          * Wrapper around json_encode that avoids needless escapes,
1312          * and pretty-prints in debug mode.
1313          *
1314          * @internal
1315          * @since 1.32
1316          * @param bool|string|array $data
1317          * @return string JSON
1318          */
1319         public static function encodeJsonForScript( $data ) {
1320                 // Keep output as small as possible by disabling needless escape modes
1321                 // that PHP uses by default.
1322                 // However, while most module scripts are only served on HTTP responses
1323                 // for JavaScript, some modules can also be embedded in the HTML as inline
1324                 // scripts. This, and the fact that we sometimes need to export strings
1325                 // containing user-generated content and labels that may genuinely contain
1326                 // a sequences like "</script>", we need to encode either '/' or '<'.
1327                 // By default PHP escapes '/'. Let's escape '<' instead which is less common
1328                 // and allows URLs to mostly remain readable.
1329                 $jsonFlags = JSON_UNESCAPED_SLASHES |
1330                         JSON_UNESCAPED_UNICODE |
1331                         JSON_HEX_TAG |
1332                         JSON_HEX_AMP;
1333                 if ( self::inDebugMode() ) {
1334                         $jsonFlags |= JSON_PRETTY_PRINT;
1335                 }
1336                 return json_encode( $data, $jsonFlags );
1337         }
1338
1339         /**
1340          * Returns a JS call to mw.loader.state, which sets the state of one
1341          * ore more modules to a given value. Has two calling conventions:
1342          *
1343          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1344          *         Set the state of a single module called $name to $state
1345          *
1346          *    - ResourceLoader::makeLoaderStateScript( [ $name => $state, ... ] ):
1347          *         Set the state of modules with the given names to the given states
1348          *
1349          * @param array|string $states
1350          * @param string|null $state
1351          * @return string JavaScript code
1352          */
1353         public static function makeLoaderStateScript( $states, $state = null ) {
1354                 if ( !is_array( $states ) ) {
1355                         $states = [ $states => $state ];
1356                 }
1357                 return Xml::encodeJsCall(
1358                         'mw.loader.state',
1359                         [ $states ],
1360                         self::inDebugMode()
1361                 );
1362         }
1363
1364         private static function isEmptyObject( stdClass $obj ) {
1365                 foreach ( $obj as $key => $value ) {
1366                         return false;
1367                 }
1368                 return true;
1369         }
1370
1371         /**
1372          * Remove empty values from the end of an array.
1373          *
1374          * Values considered empty:
1375          *
1376          * - null
1377          * - []
1378          * - new XmlJsCode( '{}' )
1379          * - new stdClass() // (object) []
1380          *
1381          * @param array $array
1382          */
1383         private static function trimArray( array &$array ) {
1384                 $i = count( $array );
1385                 while ( $i-- ) {
1386                         if ( $array[$i] === null
1387                                 || $array[$i] === []
1388                                 || ( $array[$i] instanceof XmlJsCode && $array[$i]->value === '{}' )
1389                                 || ( $array[$i] instanceof stdClass && self::isEmptyObject( $array[$i] ) )
1390                         ) {
1391                                 unset( $array[$i] );
1392                         } else {
1393                                 break;
1394                         }
1395                 }
1396         }
1397
1398         /**
1399          * Returns JS code which calls mw.loader.register with the given
1400          * parameter.
1401          *
1402          * @par Example
1403          * @code
1404          *
1405          *     ResourceLoader::makeLoaderRegisterScript( [
1406          *        [ $name1, $version1, $dependencies1, $group1, $source1, $skip1 ],
1407          *        [ $name2, $version2, $dependencies1, $group2, $source2, $skip2 ],
1408          *        ...
1409          *     ] ):
1410          * @endcode
1411          *
1412          * @internal
1413          * @since 1.32
1414          * @param array $modules Array of module registration arrays, each containing
1415          *  - string: module name
1416          *  - string: module version
1417          *  - array|null: List of dependencies (optional)
1418          *  - string|null: Module group (optional)
1419          *  - string|null: Name of foreign module source, or 'local' (optional)
1420          *  - string|null: Script body of a skip function (optional)
1421          * @return string JavaScript code
1422          */
1423         public static function makeLoaderRegisterScript( array $modules ) {
1424                 // Optimisation: Transform dependency names into indexes when possible
1425                 // to produce smaller output. They are expanded by mw.loader.register on
1426                 // the other end using resolveIndexedDependencies().
1427                 $index = [];
1428                 foreach ( $modules as $i => &$module ) {
1429                         // Build module name index
1430                         $index[$module[0]] = $i;
1431                 }
1432                 foreach ( $modules as &$module ) {
1433                         if ( isset( $module[2] ) ) {
1434                                 foreach ( $module[2] as &$dependency ) {
1435                                         if ( isset( $index[$dependency] ) ) {
1436                                                 // Replace module name in dependency list with index
1437                                                 $dependency = $index[$dependency];
1438                                         }
1439                                 }
1440                         }
1441                 }
1442
1443                 array_walk( $modules, [ self::class, 'trimArray' ] );
1444
1445                 return Xml::encodeJsCall(
1446                         'mw.loader.register',
1447                         [ $modules ],
1448                         self::inDebugMode()
1449                 );
1450         }
1451
1452         /**
1453          * Returns JS code which calls mw.loader.addSource() with the given
1454          * parameters. Has two calling conventions:
1455          *
1456          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1457          *       Register a single source
1458          *
1459          *   - ResourceLoader::makeLoaderSourcesScript( [ $id1 => $loadUrl, $id2 => $loadUrl, ... ] );
1460          *       Register sources with the given IDs and properties.
1461          *
1462          * @param string|array $sources Source ID
1463          * @param string|null $loadUrl load.php url
1464          * @return string JavaScript code
1465          */
1466         public static function makeLoaderSourcesScript( $sources, $loadUrl = null ) {
1467                 if ( !is_array( $sources ) ) {
1468                         $sources = [ $sources => $loadUrl ];
1469                 }
1470                 return Xml::encodeJsCall(
1471                         'mw.loader.addSource',
1472                         [ $sources ],
1473                         self::inDebugMode()
1474                 );
1475         }
1476
1477         /**
1478          * Wraps JavaScript code to run after the startup module.
1479          *
1480          * @param string $script JavaScript code
1481          * @return string JavaScript code
1482          */
1483         public static function makeLoaderConditionalScript( $script ) {
1484                 // Adds a function to lazy-created RLQ
1485                 return '(RLQ=window.RLQ||[]).push(function(){' .
1486                         trim( $script ) . '});';
1487         }
1488
1489         /**
1490          * Wraps JavaScript code to run after a required module.
1491          *
1492          * @since 1.32
1493          * @param string|string[] $modules Module name(s)
1494          * @param string $script JavaScript code
1495          * @return string JavaScript code
1496          */
1497         public static function makeInlineCodeWithModule( $modules, $script ) {
1498                 // Adds an array to lazy-created RLQ
1499                 return '(RLQ=window.RLQ||[]).push(['
1500                         . self::encodeJsonForScript( $modules ) . ','
1501                         . 'function(){' . trim( $script ) . '}'
1502                         . ']);';
1503         }
1504
1505         /**
1506          * Returns an HTML script tag that runs given JS code after startup and base modules.
1507          *
1508          * The code will be wrapped in a closure, and it will be executed by ResourceLoader's
1509          * startup module if the client has adequate support for MediaWiki JavaScript code.
1510          *
1511          * @param string $script JavaScript code
1512          * @param string|null $nonce [optional] Content-Security-Policy nonce
1513          *  (from OutputPage::getCSPNonce)
1514          * @return string|WrappedString HTML
1515          */
1516         public static function makeInlineScript( $script, $nonce = null ) {
1517                 $js = self::makeLoaderConditionalScript( $script );
1518                 $escNonce = '';
1519                 if ( $nonce === null ) {
1520                         wfWarn( __METHOD__ . " did not get nonce. Will break CSP" );
1521                 } elseif ( $nonce !== false ) {
1522                         // If it was false, CSP is disabled, so no nonce attribute.
1523                         // Nonce should be only base64 characters, so should be safe,
1524                         // but better to be safely escaped than sorry.
1525                         $escNonce = ' nonce="' . htmlspecialchars( $nonce ) . '"';
1526                 }
1527
1528                 return new WrappedString(
1529                         Html::inlineScript( $js, $nonce ),
1530                         "<script$escNonce>(RLQ=window.RLQ||[]).push(function(){",
1531                         '});</script>'
1532                 );
1533         }
1534
1535         /**
1536          * Returns JS code which will set the MediaWiki configuration array to
1537          * the given value.
1538          *
1539          * @param array $configuration List of configuration values keyed by variable name
1540          * @return string JavaScript code
1541          * @throws Exception
1542          */
1543         public static function makeConfigSetScript( array $configuration ) {
1544                 $js = Xml::encodeJsCall(
1545                         'mw.config.set',
1546                         [ $configuration ],
1547                         self::inDebugMode()
1548                 );
1549                 if ( $js === false ) {
1550                         $e = new Exception(
1551                                 'JSON serialization of config data failed. ' .
1552                                 'This usually means the config data is not valid UTF-8.'
1553                         );
1554                         MWExceptionHandler::logException( $e );
1555                         $js = Xml::encodeJsCall( 'mw.log.error', [ $e->__toString() ] );
1556                 }
1557                 return $js;
1558         }
1559
1560         /**
1561          * Convert an array of module names to a packed query string.
1562          *
1563          * For example, `[ 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' ]`
1564          * becomes `'foo.bar,baz|bar.baz,quux'`.
1565          *
1566          * This process is reversed by ResourceLoader::expandModuleNames().
1567          * See also mw.loader#buildModulesString() which is a port of this, used
1568          * on the client-side.
1569          *
1570          * @param array $modules List of module names (strings)
1571          * @return string Packed query string
1572          */
1573         public static function makePackedModulesString( $modules ) {
1574                 $moduleMap = []; // [ prefix => [ suffixes ] ]
1575                 foreach ( $modules as $module ) {
1576                         $pos = strrpos( $module, '.' );
1577                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1578                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1579                         $moduleMap[$prefix][] = $suffix;
1580                 }
1581
1582                 $arr = [];
1583                 foreach ( $moduleMap as $prefix => $suffixes ) {
1584                         $p = $prefix === '' ? '' : $prefix . '.';
1585                         $arr[] = $p . implode( ',', $suffixes );
1586                 }
1587                 return implode( '|', $arr );
1588         }
1589
1590         /**
1591          * Expand a string of the form `jquery.foo,bar|jquery.ui.baz,quux` to
1592          * an array of module names like `[ 'jquery.foo', 'jquery.bar',
1593          * 'jquery.ui.baz', 'jquery.ui.quux' ]`.
1594          *
1595          * This process is reversed by ResourceLoader::makePackedModulesString().
1596          *
1597          * @since 1.33
1598          * @param string $modules Packed module name list
1599          * @return array Array of module names
1600          */
1601         public static function expandModuleNames( $modules ) {
1602                 $retval = [];
1603                 $exploded = explode( '|', $modules );
1604                 foreach ( $exploded as $group ) {
1605                         if ( strpos( $group, ',' ) === false ) {
1606                                 // This is not a set of modules in foo.bar,baz notation
1607                                 // but a single module
1608                                 $retval[] = $group;
1609                         } else {
1610                                 // This is a set of modules in foo.bar,baz notation
1611                                 $pos = strrpos( $group, '.' );
1612                                 if ( $pos === false ) {
1613                                         // Prefixless modules, i.e. without dots
1614                                         $retval = array_merge( $retval, explode( ',', $group ) );
1615                                 } else {
1616                                         // We have a prefix and a bunch of suffixes
1617                                         $prefix = substr( $group, 0, $pos ); // 'foo'
1618                                         $suffixes = explode( ',', substr( $group, $pos + 1 ) ); // [ 'bar', 'baz' ]
1619                                         foreach ( $suffixes as $suffix ) {
1620                                                 $retval[] = "$prefix.$suffix";
1621                                         }
1622                                 }
1623                         }
1624                 }
1625                 return $retval;
1626         }
1627
1628         /**
1629          * Determine whether debug mode was requested
1630          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1631          * @return bool
1632          */
1633         public static function inDebugMode() {
1634                 if ( self::$debugMode === null ) {
1635                         global $wgRequest, $wgResourceLoaderDebug;
1636                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1637                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1638                         );
1639                 }
1640                 return self::$debugMode;
1641         }
1642
1643         /**
1644          * Reset static members used for caching.
1645          *
1646          * Global state and $wgRequest are evil, but we're using it right
1647          * now and sometimes we need to be able to force ResourceLoader to
1648          * re-evaluate the context because it has changed (e.g. in the test suite).
1649          *
1650          * @internal For use by unit tests
1651          * @codeCoverageIgnore
1652          */
1653         public static function clearCache() {
1654                 self::$debugMode = null;
1655         }
1656
1657         /**
1658          * Build a load.php URL
1659          *
1660          * @since 1.24
1661          * @param string $source Name of the ResourceLoader source
1662          * @param ResourceLoaderContext $context
1663          * @param array $extraQuery
1664          * @return string URL to load.php. May be protocol-relative if $wgLoadScript is, too.
1665          */
1666         public function createLoaderURL( $source, ResourceLoaderContext $context,
1667                 $extraQuery = []
1668         ) {
1669                 $query = self::createLoaderQuery( $context, $extraQuery );
1670                 $script = $this->getLoadScript( $source );
1671
1672                 return wfAppendQuery( $script, $query );
1673         }
1674
1675         /**
1676          * Helper for createLoaderURL()
1677          *
1678          * @since 1.24
1679          * @see makeLoaderQuery
1680          * @param ResourceLoaderContext $context
1681          * @param array $extraQuery
1682          * @return array
1683          */
1684         protected static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = [] ) {
1685                 return self::makeLoaderQuery(
1686                         $context->getModules(),
1687                         $context->getLanguage(),
1688                         $context->getSkin(),
1689                         $context->getUser(),
1690                         $context->getVersion(),
1691                         $context->getDebug(),
1692                         $context->getOnly(),
1693                         $context->getRequest()->getBool( 'printable' ),
1694                         $context->getRequest()->getBool( 'handheld' ),
1695                         $extraQuery
1696                 );
1697         }
1698
1699         /**
1700          * Build a query array (array representation of query string) for load.php. Helper
1701          * function for createLoaderURL().
1702          *
1703          * @param array $modules
1704          * @param string $lang
1705          * @param string $skin
1706          * @param string|null $user
1707          * @param string|null $version
1708          * @param bool $debug
1709          * @param string|null $only
1710          * @param bool $printable
1711          * @param bool $handheld
1712          * @param array $extraQuery
1713          *
1714          * @return array
1715          */
1716         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1717                 $version = null, $debug = false, $only = null, $printable = false,
1718                 $handheld = false, $extraQuery = []
1719         ) {
1720                 $query = [
1721                         'modules' => self::makePackedModulesString( $modules ),
1722                         'lang' => $lang,
1723                         'skin' => $skin,
1724                 ];
1725                 if ( $debug === true ) {
1726                         $query['debug'] = 'true';
1727                 }
1728                 if ( $user !== null ) {
1729                         $query['user'] = $user;
1730                 }
1731                 if ( $version !== null ) {
1732                         $query['version'] = $version;
1733                 }
1734                 if ( $only !== null ) {
1735                         $query['only'] = $only;
1736                 }
1737                 if ( $printable ) {
1738                         $query['printable'] = 1;
1739                 }
1740                 if ( $handheld ) {
1741                         $query['handheld'] = 1;
1742                 }
1743                 $query += $extraQuery;
1744
1745                 // Make queries uniform in order
1746                 ksort( $query );
1747                 return $query;
1748         }
1749
1750         /**
1751          * Check a module name for validity.
1752          *
1753          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1754          * at most 255 bytes.
1755          *
1756          * @param string $moduleName Module name to check
1757          * @return bool Whether $moduleName is a valid module name
1758          */
1759         public static function isValidModuleName( $moduleName ) {
1760                 return strcspn( $moduleName, '!,|', 0, 255 ) === strlen( $moduleName );
1761         }
1762
1763         /**
1764          * Returns LESS compiler set up for use with MediaWiki
1765          *
1766          * @since 1.27
1767          * @param array $vars Associative array of variables that should be used
1768          *  for compilation. Since 1.32, this method no longer automatically includes
1769          *  global LESS vars from ResourceLoader::getLessVars (T191937).
1770          * @throws MWException
1771          * @return Less_Parser
1772          */
1773         public function getLessCompiler( $vars = [] ) {
1774                 global $IP;
1775                 // When called from the installer, it is possible that a required PHP extension
1776                 // is missing (at least for now; see T49564). If this is the case, throw an
1777                 // exception (caught by the installer) to prevent a fatal error later on.
1778                 if ( !class_exists( 'Less_Parser' ) ) {
1779                         throw new MWException( 'MediaWiki requires the less.php parser' );
1780                 }
1781
1782                 $parser = new Less_Parser;
1783                 $parser->ModifyVars( $vars );
1784                 $parser->SetImportDirs( [
1785                         "$IP/resources/src/mediawiki.less/" => '',
1786                 ] );
1787                 $parser->SetOption( 'relativeUrls', false );
1788
1789                 return $parser;
1790         }
1791
1792         /**
1793          * Get global LESS variables.
1794          *
1795          * @since 1.27
1796          * @deprecated since 1.32 Use ResourceLoderModule::getLessVars() instead.
1797          * @return array Map of variable names to string CSS values.
1798          */
1799         public function getLessVars() {
1800                 return [];
1801         }
1802 }