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