includes/resourceloader/ResourceLoader.php

   1 <?php
   2 /**
   3  * Base class for resource loading system.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @author Roan Kattouw
  22  * @author Trevor Parscal
  23  */
  24
  25 use MediaWiki\MediaWikiServices;
  26 use Psr\Log\LoggerAwareInterface;
  27 use Psr\Log\LoggerInterface;
  28 use Psr\Log\NullLogger;
  29 use WrappedString\WrappedString;
  30 use Wikimedia\Rdbms\DBConnectionError;
  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         protected static $filterCacheVersion = 7;
  41
  42         /** @var bool */
  43         protected static $debugMode = null;
  44
  45         /** @var array */
  46         private $lessVars = null;
  47
  48         /**
  49          * Module name/ResourceLoaderModule object pairs
  50          * @var array
  51          */
  52         protected $modules = [];
  53
  54         /**
  55          * Associative array mapping module name to info associative array
  56          * @var array
  57          */
  58         protected $moduleInfos = [];
  59
  60         /** @var Config $config */
  61         protected $config;
  62
  63         /**
  64          * Associative array mapping framework ids to a list of names of test suite modules
  65          * like [ 'qunit' => [ 'mediawiki.tests.qunit.suites', 'ext.foo.tests', ... ], ... ]
  66          * @var array
  67          */
  68         protected $testModuleNames = [];
  69
  70         /**
  71          * E.g. [ 'source-id' => 'http://.../load.php' ]
  72          * @var array
  73          */
  74         protected $sources = [];
  75
  76         /**
  77          * Errors accumulated during current respond() call.
  78          * @var array
  79          */
  80         protected $errors = [];
  81
  82         /**
  83          * List of extra HTTP response headers provided by loaded modules.
  84          *
  85          * Populated by makeModuleResponse().
  86          *
  87          * @var array
  88          */
  89         protected $extraHeaders = [];
  90
  91         /**
  92          * @var MessageBlobStore
  93          */
  94         protected $blobStore;
  95
  96         /**
  97          * @var LoggerInterface
  98          */
  99         private $logger;
 100
 101         /** @var string JavaScript / CSS pragma to disable minification. **/
 102         const FILTER_NOMIN = '/*@nomin*/';
 103
 104         /**
 105          * Load information stored in the database about modules.
 106          *
 107          * This method grabs modules dependencies from the database and updates modules
 108          * objects.
 109          *
 110          * This is not inside the module code because it is much faster to
 111          * request all of the information at once than it is to have each module
 112          * requests its own information. This sacrifice of modularity yields a substantial
 113          * performance improvement.
 114          *
 115          * @param array $moduleNames List of module names to preload information for
 116          * @param ResourceLoaderContext $context Context to load the information within
 117          */
 118         public function preloadModuleInfo( array $moduleNames, ResourceLoaderContext $context ) {
 119                 if ( !$moduleNames ) {
 120                         // Or else Database*::select() will explode, plus it's cheaper!
 121                         return;
 122                 }
 123                 $dbr = wfGetDB( DB_REPLICA );
 124                 $skin = $context->getSkin();
 125                 $lang = $context->getLanguage();
 126
 127                 // Batched version of ResourceLoaderModule::getFileDependencies
 128                 $vary = "$skin|$lang";
 129                 $res = $dbr->select( 'module_deps', [ 'md_module', 'md_deps' ], [
 130                                 'md_module' => $moduleNames,
 131                                 'md_skin' => $vary,
 132                         ], __METHOD__
 133                 );
 134
 135                 // Prime in-object cache for file dependencies
 136                 $modulesWithDeps = [];
 137                 foreach ( $res as $row ) {
 138                         $module = $this->getModule( $row->md_module );
 139                         if ( $module ) {
 140                                 $module->setFileDependencies( $context, ResourceLoaderModule::expandRelativePaths(
 141                                         FormatJson::decode( $row->md_deps, true )
 142                                 ) );
 143                                 $modulesWithDeps[] = $row->md_module;
 144                         }
 145                 }
 146                 // Register the absence of a dependency row too
 147                 foreach ( array_diff( $moduleNames, $modulesWithDeps ) as $name ) {
 148                         $module = $this->getModule( $name );
 149                         if ( $module ) {
 150                                 $this->getModule( $name )->setFileDependencies( $context, [] );
 151                         }
 152                 }
 153
 154                 // Batched version of ResourceLoaderWikiModule::getTitleInfo
 155                 ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $moduleNames );
 156
 157                 // Prime in-object cache for message blobs for modules with messages
 158                 $modules = [];
 159                 foreach ( $moduleNames as $name ) {
 160                         $module = $this->getModule( $name );
 161                         if ( $module && $module->getMessages() ) {
 162                                 $modules[$name] = $module;
 163                         }
 164                 }
 165                 $store = $this->getMessageBlobStore();
 166                 $blobs = $store->getBlobs( $modules, $lang );
 167                 foreach ( $blobs as $name => $blob ) {
 168                         $modules[$name]->setMessageBlob( $blob, $lang );
 169                 }
 170         }
 171
 172         /**
 173          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 174          *
 175          * Available filters are:
 176          *
 177          *    - minify-js \see JavaScriptMinifier::minify
 178          *    - minify-css \see CSSMin::minify
 179          *
 180          * If $data is empty, only contains whitespace or the filter was unknown,
 181          * $data is returned unmodified.
 182          *
 183          * @param string $filter Name of filter to run
 184          * @param string $data Text to filter, such as JavaScript or CSS text
 185          * @param array $options Keys:
 186          *  - (bool) cache: Whether to allow caching this data. Default: true.
 187          * @return string Filtered data, or a comment containing an error message
 188          */
 189         public static function filter( $filter, $data, array $options = [] ) {
 190                 if ( strpos( $data, self::FILTER_NOMIN ) !== false ) {
 191                         return $data;
 192                 }
 193
 194                 if ( isset( $options['cache'] ) && $options['cache'] === false ) {
 195                         return self::applyFilter( $filter, $data );
 196                 }
 197
 198                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
 199                 $cache = ObjectCache::getLocalServerInstance( CACHE_ANYTHING );
 200
 201                 $key = $cache->makeGlobalKey(
 202                         'resourceloader',
 203                         'filter',
 204                         $filter,
 205                         self::$filterCacheVersion, md5( $data )
 206                 );
 207
 208                 $result = $cache->get( $key );
 209                 if ( $result === false ) {
 210                         $stats->increment( "resourceloader_cache.$filter.miss" );
 211                         $result = self::applyFilter( $filter, $data );
 212                         $cache->set( $key, $result, 24 * 3600 );
 213                 } else {
 214                         $stats->increment( "resourceloader_cache.$filter.hit" );
 215                 }
 216                 if ( $result === null ) {
 217                         // Cached failure
 218                         $result = $data;
 219                 }
 220
 221                 return $result;
 222         }
 223
 224         private static function applyFilter( $filter, $data ) {
 225                 $data = trim( $data );
 226                 if ( $data ) {
 227                         try {
 228                                 $data = ( $filter === 'minify-css' )
 229                                         ? CSSMin::minify( $data )
 230                                         : JavaScriptMinifier::minify( $data );
 231                         } catch ( Exception $e ) {
 232                                 MWExceptionHandler::logException( $e );
 233                                 return null;
 234                         }
 235                 }
 236                 return $data;
 237         }
 238
 239         /**
 240          * Register core modules and runs registration hooks.
 241          * @param Config $config [optional]
 242          * @param LoggerInterface $logger [optional]
 243          */
 244         public function __construct( Config $config = null, LoggerInterface $logger = null ) {
 245                 global $IP;
 246
 247                 $this->logger = $logger ?: new NullLogger();
 248
 249                 if ( !$config ) {
 250                         $this->logger->debug( __METHOD__ . ' was called without providing a Config instance' );
 251                         $config = MediaWikiServices::getInstance()->getMainConfig();
 252                 }
 253                 $this->config = $config;
 254
 255                 // Add 'local' source first
 256                 $this->addSource( 'local', $config->get( 'LoadScript' ) );
 257
 258                 // Add other sources
 259                 $this->addSource( $config->get( 'ResourceLoaderSources' ) );
 260
 261                 // Register core modules
 262                 $this->register( include "$IP/resources/Resources.php" );
 263                 // Register extension modules
 264                 $this->register( $config->get( 'ResourceModules' ) );
 265
 266                 // Avoid PHP 7.1 warning from passing $this by reference
 267                 $rl = $this;
 268                 Hooks::run( 'ResourceLoaderRegisterModules', [ &$rl ] );
 269
 270                 if ( $config->get( 'EnableJavaScriptTest' ) === true ) {
 271                         $this->registerTestModules();
 272                 }
 273
 274                 $this->setMessageBlobStore( new MessageBlobStore( $this, $this->logger ) );
 275         }
 276
 277         /**
 278          * @return Config
 279          */
 280         public function getConfig() {
 281                 return $this->config;
 282         }
 283
 284         /**
 285          * @since 1.26
 286          * @param LoggerInterface $logger
 287          */
 288         public function setLogger( LoggerInterface $logger ) {
 289                 $this->logger = $logger;
 290         }
 291
 292         /**
 293          * @since 1.27
 294          * @return LoggerInterface
 295          */
 296         public function getLogger() {
 297                 return $this->logger;
 298         }
 299
 300         /**
 301          * @since 1.26
 302          * @return MessageBlobStore
 303          */
 304         public function getMessageBlobStore() {
 305                 return $this->blobStore;
 306         }
 307
 308         /**
 309          * @since 1.25
 310          * @param MessageBlobStore $blobStore
 311          */
 312         public function setMessageBlobStore( MessageBlobStore $blobStore ) {
 313                 $this->blobStore = $blobStore;
 314         }
 315
 316         /**
 317          * Register a module with the ResourceLoader system.
 318          *
 319          * @param mixed $name Name of module as a string or List of name/object pairs as an array
 320          * @param array $info Module info array. For backwards compatibility with 1.17alpha,
 321          *   this may also be a ResourceLoaderModule object. Optional when using
 322          *   multiple-registration calling style.
 323          * @throws MWException If a duplicate module registration is attempted
 324          * @throws MWException If a module name contains illegal characters (pipes or commas)
 325          * @throws MWException If something other than a ResourceLoaderModule is being registered
 326          * @return bool False if there were any errors, in which case one or more modules were
 327          *   not registered
 328          */
 329         public function register( $name, $info = null ) {
 330                 $moduleSkinStyles = $this->config->get( 'ResourceModuleSkinStyles' );
 331
 332                 // Allow multiple modules to be registered in one call
 333                 $registrations = is_array( $name ) ? $name : [ $name => $info ];
 334                 foreach ( $registrations as $name => $info ) {
 335                         // Warn on duplicate registrations
 336                         if ( isset( $this->moduleInfos[$name] ) ) {
 337                                 // A module has already been registered by this name
 338                                 $this->logger->warning(
 339                                         'ResourceLoader duplicate registration warning. ' .
 340                                         'Another module has already been registered as ' . $name
 341                                 );
 342                         }
 343
 344                         // Check $name for validity
 345                         if ( !self::isValidModuleName( $name ) ) {
 346                                 throw new MWException( "ResourceLoader module name '$name' is invalid, "
 347                                         . "see ResourceLoader::isValidModuleName()" );
 348                         }
 349
 350                         // Attach module
 351                         if ( $info instanceof ResourceLoaderModule ) {
 352                                 $this->moduleInfos[$name] = [ 'object' => $info ];
 353                                 $info->setName( $name );
 354                                 $this->modules[$name] = $info;
 355                         } elseif ( is_array( $info ) ) {
 356                                 // New calling convention
 357                                 $this->moduleInfos[$name] = $info;
 358                         } else {
 359                                 throw new MWException(
 360                                         'ResourceLoader module info type error for module \'' . $name .
 361                                         '\': expected ResourceLoaderModule or array (got: ' . gettype( $info ) . ')'
 362                                 );
 363                         }
 364
 365                         // Last-minute changes
 366
 367                         // Apply custom skin-defined styles to existing modules.
 368                         if ( $this->isFileModule( $name ) ) {
 369                                 foreach ( $moduleSkinStyles as $skinName => $skinStyles ) {
 370                                         // If this module already defines skinStyles for this skin, ignore $wgResourceModuleSkinStyles.
 371                                         if ( isset( $this->moduleInfos[$name]['skinStyles'][$skinName] ) ) {
 372                                                 continue;
 373                                         }
 374
 375                                         // If $name is preceded with a '+', the defined style files will be added to 'default'
 376                                         // skinStyles, otherwise 'default' will be ignored as it normally would be.
 377                                         if ( isset( $skinStyles[$name] ) ) {
 378                                                 $paths = (array)$skinStyles[$name];
 379                                                 $styleFiles = [];
 380                                         } elseif ( isset( $skinStyles['+' . $name] ) ) {
 381                                                 $paths = (array)$skinStyles['+' . $name];
 382                                                 $styleFiles = isset( $this->moduleInfos[$name]['skinStyles']['default'] ) ?
 383                                                         (array)$this->moduleInfos[$name]['skinStyles']['default'] :
 384                                                         [];
 385                                         } else {
 386                                                 continue;
 387                                         }
 388
 389                                         // Add new file paths, remapping them to refer to our directories and not use settings
 390                                         // from the module we're modifying, which come from the base definition.
 391                                         list( $localBasePath, $remoteBasePath ) =
 392                                                 ResourceLoaderFileModule::extractBasePaths( $skinStyles );
 393
 394                                         foreach ( $paths as $path ) {
 395                                                 $styleFiles[] = new ResourceLoaderFilePath( $path, $localBasePath, $remoteBasePath );
 396                                         }
 397
 398                                         $this->moduleInfos[$name]['skinStyles'][$skinName] = $styleFiles;
 399                                 }
 400                         }
 401                 }
 402         }
 403
 404         public function registerTestModules() {
 405                 global $IP;
 406
 407                 if ( $this->config->get( 'EnableJavaScriptTest' ) !== true ) {
 408                         throw new MWException( 'Attempt to register JavaScript test modules '
 409                                 . 'but <code>$wgEnableJavaScriptTest</code> is false. '
 410                                 . 'Edit your <code>LocalSettings.php</code> to enable it.' );
 411                 }
 412
 413                 // Get core test suites
 414                 $testModules = [];
 415                 $testModules['qunit'] = [];
 416                 // Get other test suites (e.g. from extensions)
 417                 // Avoid PHP 7.1 warning from passing $this by reference
 418                 $rl = $this;
 419                 Hooks::run( 'ResourceLoaderTestModules', [ &$testModules, &$rl ] );
 420
 421                 // Add the testrunner (which configures QUnit) to the dependencies.
 422                 // Since it must be ready before any of the test suites are executed.
 423                 foreach ( $testModules['qunit'] as &$module ) {
 424                         // Make sure all test modules are top-loading so that when QUnit starts
 425                         // on document-ready, it will run once and finish. If some tests arrive
 426                         // later (possibly after QUnit has already finished) they will be ignored.
 427                         $module['position'] = 'top';
 428                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 429                 }
 430
 431                 $testModules['qunit'] =
 432                         ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules['qunit'];
 433
 434                 foreach ( $testModules as $id => $names ) {
 435                         // Register test modules
 436                         $this->register( $testModules[$id] );
 437
 438                         // Keep track of their names so that they can be loaded together
 439                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 440                 }
 441         }
 442
 443         /**
 444          * Add a foreign source of modules.
 445          *
 446          * Source IDs are typically the same as the Wiki ID or database name (e.g. lowercase a-z).
 447          *
 448          * @param array|string $id Source ID (string), or [ id1 => loadUrl, id2 => loadUrl, ... ]
 449          * @param string|array $loadUrl load.php url (string), or array with loadUrl key for
 450          *  backwards-compatibility.
 451          * @throws MWException
 452          */
 453         public function addSource( $id, $loadUrl = null ) {
 454                 // Allow multiple sources to be registered in one call
 455                 if ( is_array( $id ) ) {
 456                         foreach ( $id as $key => $value ) {
 457                                 $this->addSource( $key, $value );
 458                         }
 459                         return;
 460                 }
 461
 462                 // Disallow duplicates
 463                 if ( isset( $this->sources[$id] ) ) {
 464                         throw new MWException(
 465                                 'ResourceLoader duplicate source addition error. ' .
 466                                 'Another source has already been registered as ' . $id
 467                         );
 468                 }
 469
 470                 // Pre 1.24 backwards-compatibility
 471                 if ( is_array( $loadUrl ) ) {
 472                         if ( !isset( $loadUrl['loadScript'] ) ) {
 473                                 throw new MWException(
 474                                         __METHOD__ . ' was passed an array with no "loadScript" key.'
 475                                 );
 476                         }
 477
 478                         $loadUrl = $loadUrl['loadScript'];
 479                 }
 480
 481                 $this->sources[$id] = $loadUrl;
 482         }
 483
 484         /**
 485          * Get a list of module names.
 486          *
 487          * @return array List of module names
 488          */
 489         public function getModuleNames() {
 490                 return array_keys( $this->moduleInfos );
 491         }
 492
 493         /**
 494          * Get a list of test module names for one (or all) frameworks.
 495          *
 496          * If the given framework id is unknkown, or if the in-object variable is not an array,
 497          * then it will return an empty array.
 498          *
 499          * @param string $framework Get only the test module names for one
 500          *   particular framework (optional)
 501          * @return array
 502          */
 503         public function getTestModuleNames( $framework = 'all' ) {
 504                 /** @todo api siteinfo prop testmodulenames modulenames */
 505                 if ( $framework == 'all' ) {
 506                         return $this->testModuleNames;
 507                 } elseif ( isset( $this->testModuleNames[$framework] )
 508                         && is_array( $this->testModuleNames[$framework] )
 509                 ) {
 510                         return $this->testModuleNames[$framework];
 511                 } else {
 512                         return [];
 513                 }
 514         }
 515
 516         /**
 517          * Check whether a ResourceLoader module is registered
 518          *
 519          * @since 1.25
 520          * @param string $name
 521          * @return bool
 522          */
 523         public function isModuleRegistered( $name ) {
 524                 return isset( $this->moduleInfos[$name] );
 525         }
 526
 527         /**
 528          * Get the ResourceLoaderModule object for a given module name.
 529          *
 530          * If an array of module parameters exists but a ResourceLoaderModule object has not
 531          * yet been instantiated, this method will instantiate and cache that object such that
 532          * subsequent calls simply return the same object.
 533          *
 534          * @param string $name Module name
 535          * @return ResourceLoaderModule|null If module has been registered, return a
 536          *  ResourceLoaderModule instance. Otherwise, return null.
 537          */
 538         public function getModule( $name ) {
 539                 if ( !isset( $this->modules[$name] ) ) {
 540                         if ( !isset( $this->moduleInfos[$name] ) ) {
 541                                 // No such module
 542                                 return null;
 543                         }
 544                         // Construct the requested object
 545                         $info = $this->moduleInfos[$name];
 546                         /** @var ResourceLoaderModule $object */
 547                         if ( isset( $info['object'] ) ) {
 548                                 // Object given in info array
 549                                 $object = $info['object'];
 550                         } elseif ( isset( $info['factory'] ) ) {
 551                                 $object = call_user_func( $info['factory'], $info );
 552                                 $object->setConfig( $this->getConfig() );
 553                                 $object->setLogger( $this->logger );
 554                         } else {
 555                                 if ( !isset( $info['class'] ) ) {
 556                                         $class = 'ResourceLoaderFileModule';
 557                                 } else {
 558                                         $class = $info['class'];
 559                                 }
 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          * Return whether the definition of a module corresponds to a simple ResourceLoaderFileModule
 574          * or one of its subclasses.
 575          *
 576          * @param string $name Module name
 577          * @return bool
 578          */
 579         protected function isFileModule( $name ) {
 580                 if ( !isset( $this->moduleInfos[$name] ) ) {
 581                         return false;
 582                 }
 583                 $info = $this->moduleInfos[$name];
 584                 if ( isset( $info['object'] ) ) {
 585                         return false;
 586                 }
 587                 if (
 588                         isset( $info['class'] ) &&
 589                         $info['class'] !== 'ResourceLoaderFileModule' &&
 590                         !is_subclass_of( $info['class'], 'ResourceLoaderFileModule' )
 591                 ) {
 592                         return false;
 593                 }
 594                 return true;
 595         }
 596
 597         /**
 598          * Get the list of sources.
 599          *
 600          * @return array Like [ id => load.php url, ... ]
 601          */
 602         public function getSources() {
 603                 return $this->sources;
 604         }
 605
 606         /**
 607          * Get the URL to the load.php endpoint for the given
 608          * ResourceLoader source
 609          *
 610          * @since 1.24
 611          * @param string $source
 612          * @throws MWException On an invalid $source name
 613          * @return string
 614          */
 615         public function getLoadScript( $source ) {
 616                 if ( !isset( $this->sources[$source] ) ) {
 617                         throw new MWException( "The $source source was never registered in ResourceLoader." );
 618                 }
 619                 return $this->sources[$source];
 620         }
 621
 622         /**
 623          * @since 1.26
 624          * @param string $value
 625          * @return string Hash
 626          */
 627         public static function makeHash( $value ) {
 628                 $hash = hash( 'fnv132', $value );
 629                 return Wikimedia\base_convert( $hash, 16, 36, 7 );
 630         }
 631
 632         /**
 633          * Add an error to the 'errors' array and log it.
 634          *
 635          * Should only be called from within respond().
 636          *
 637          * @since 1.29
 638          * @param Exception $e
 639          * @param string $msg
 640          * @param array $context
 641          */
 642         protected function outputErrorAndLog( Exception $e, $msg, array $context = [] ) {
 643                 MWExceptionHandler::logException( $e );
 644                 $this->logger->warning(
 645                         $msg,
 646                         $context + [ 'exception' => $e ]
 647                 );
 648                 $this->errors[] = self::formatExceptionNoComment( $e );
 649         }
 650
 651         /**
 652          * Helper method to get and combine versions of multiple modules.
 653          *
 654          * @since 1.26
 655          * @param ResourceLoaderContext $context
 656          * @param string[] $moduleNames List of known module names
 657          * @return string Hash
 658          */
 659         public function getCombinedVersion( ResourceLoaderContext $context, array $moduleNames ) {
 660                 if ( !$moduleNames ) {
 661                         return '';
 662                 }
 663                 $hashes = array_map( function ( $module ) use ( $context ) {
 664                         try {
 665                                 return $this->getModule( $module )->getVersionHash( $context );
 666                         } catch ( Exception $e ) {
 667                                 // If modules fail to compute a version, do still consider the versions
 668                                 // of other modules - don't set an empty string E-Tag for the whole request.
 669                                 // See also T152266 and StartupModule::getModuleRegistrations().
 670                                 $this->outputErrorAndLog( $e,
 671                                         'Calculating version for "{module}" failed: {exception}',
 672                                         [
 673                                                 'module' => $module,
 674                                         ]
 675                                 );
 676                                 return '';
 677                         }
 678                 }, $moduleNames );
 679                 return self::makeHash( implode( '', $hashes ) );
 680         }
 681
 682         /**
 683          * Get the expected value of the 'version' query parameter.
 684          *
 685          * This is used by respond() to set a short Cache-Control header for requests with
 686          * information newer than the current server has. This avoids pollution of edge caches.
 687          * Typically during deployment. (T117587)
 688          *
 689          * This MUST match return value of `mw.loader#getCombinedVersion()` client-side.
 690          *
 691          * @since 1.28
 692          * @param ResourceLoaderContext $context
 693          * @param string[] $modules List of module names
 694          * @return string Hash
 695          */
 696         public function makeVersionQuery( ResourceLoaderContext $context ) {
 697                 // As of MediaWiki 1.28, the server and client use the same algorithm for combining
 698                 // version hashes. There is no technical reason for this to be same, and for years the
 699                 // implementations differed. If getCombinedVersion in PHP (used for StartupModule and
 700                 // E-Tag headers) differs in the future from getCombinedVersion in JS (used for 'version'
 701                 // query parameter), then this method must continue to match the JS one.
 702                 $moduleNames = [];
 703                 foreach ( $context->getModules() as $name ) {
 704                         if ( !$this->getModule( $name ) ) {
 705                                 // If a versioned request contains a missing module, the version is a mismatch
 706                                 // as the client considered a module (and version) we don't have.
 707                                 return '';
 708                         }
 709                         $moduleNames[] = $name;
 710                 }
 711                 return $this->getCombinedVersion( $context, $moduleNames );
 712         }
 713
 714         /**
 715          * Output a response to a load request, including the content-type header.
 716          *
 717          * @param ResourceLoaderContext $context Context in which a response should be formed
 718          */
 719         public function respond( ResourceLoaderContext $context ) {
 720                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 721                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 722                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 723                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 724                 // the whole thing in our own output buffer to be sure the active buffer
 725                 // doesn't use ob_gzhandler.
 726                 // See https://bugs.php.net/bug.php?id=36514
 727                 ob_start();
 728
 729                 $this->measureResponseTime( RequestContext::getMain()->getTiming() );
 730
 731                 // Find out which modules are missing and instantiate the others
 732                 $modules = [];
 733                 $missing = [];
 734                 foreach ( $context->getModules() as $name ) {
 735                         $module = $this->getModule( $name );
 736                         if ( $module ) {
 737                                 // Do not allow private modules to be loaded from the web.
 738                                 // This is a security issue, see T36907.
 739                                 if ( $module->getGroup() === 'private' ) {
 740                                         $this->logger->debug( "Request for private module '$name' denied" );
 741                                         $this->errors[] = "Cannot show private module \"$name\"";
 742                                         continue;
 743                                 }
 744                                 $modules[$name] = $module;
 745                         } else {
 746                                 $missing[] = $name;
 747                         }
 748                 }
 749
 750                 try {
 751                         // Preload for getCombinedVersion() and for batch makeModuleResponse()
 752                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 753                 } catch ( Exception $e ) {
 754                         $this->outputErrorAndLog( $e, 'Preloading module info failed: {exception}' );
 755                 }
 756
 757                 // Combine versions to propagate cache invalidation
 758                 $versionHash = '';
 759                 try {
 760                         $versionHash = $this->getCombinedVersion( $context, array_keys( $modules ) );
 761                 } catch ( Exception $e ) {
 762                         $this->outputErrorAndLog( $e, 'Calculating version hash failed: {exception}' );
 763                 }
 764
 765                 // See RFC 2616 § 3.11 Entity Tags
 766                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.11
 767                 $etag = 'W/"' . $versionHash . '"';
 768
 769                 // Try the client-side cache first
 770                 if ( $this->tryRespondNotModified( $context, $etag ) ) {
 771                         return; // output handled (buffers cleared)
 772                 }
 773
 774                 // Use file cache if enabled and available...
 775                 if ( $this->config->get( 'UseFileCache' ) ) {
 776                         $fileCache = ResourceFileCache::newFromContext( $context );
 777                         if ( $this->tryRespondFromFileCache( $fileCache, $context, $etag ) ) {
 778                                 return; // output handled
 779                         }
 780                 }
 781
 782                 // Generate a response
 783                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 784
 785                 // Capture any PHP warnings from the output buffer and append them to the
 786                 // error list if we're in debug mode.
 787                 if ( $context->getDebug() ) {
 788                         $warnings = ob_get_contents();
 789                         if ( strlen( $warnings ) ) {
 790                                 $this->errors[] = $warnings;
 791                         }
 792                 }
 793
 794                 // Save response to file cache unless there are errors
 795                 if ( isset( $fileCache ) && !$this->errors && !count( $missing ) ) {
 796                         // Cache single modules and images...and other requests if there are enough hits
 797                         if ( ResourceFileCache::useFileCache( $context ) ) {
 798                                 if ( $fileCache->isCacheWorthy() ) {
 799                                         $fileCache->saveText( $response );
 800                                 } else {
 801                                         $fileCache->incrMissesRecent( $context->getRequest() );
 802                                 }
 803                         }
 804                 }
 805
 806                 $this->sendResponseHeaders( $context, $etag, (bool)$this->errors, $this->extraHeaders );
 807
 808                 // Remove the output buffer and output the response
 809                 ob_end_clean();
 810
 811                 if ( $context->getImageObj() && $this->errors ) {
 812                         // We can't show both the error messages and the response when it's an image.
 813                         $response = implode( "\n\n", $this->errors );
 814                 } elseif ( $this->errors ) {
 815                         $errorText = implode( "\n\n", $this->errors );
 816                         $errorResponse = self::makeComment( $errorText );
 817                         if ( $context->shouldIncludeScripts() ) {
 818                                 $errorResponse .= 'if (window.console && console.error) {'
 819                                         . Xml::encodeJsCall( 'console.error', [ $errorText ] )
 820                                         . "}\n";
 821                         }
 822
 823                         // Prepend error info to the response
 824                         $response = $errorResponse . $response;
 825                 }
 826
 827                 $this->errors = [];
 828                 echo $response;
 829         }
 830
 831         protected function measureResponseTime( Timing $timing ) {
 832                 DeferredUpdates::addCallableUpdate( function () use ( $timing ) {
 833                         $measure = $timing->measure( 'responseTime', 'requestStart', 'requestShutdown' );
 834                         if ( $measure !== false ) {
 835                                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
 836                                 $stats->timing( 'resourceloader.responseTime', $measure['duration'] * 1000 );
 837                         }
 838                 } );
 839         }
 840
 841         /**
 842          * Send main response headers to the client.
 843          *
 844          * Deals with Content-Type, CORS (for stylesheets), and caching.
 845          *
 846          * @param ResourceLoaderContext $context
 847          * @param string $etag ETag header value
 848          * @param bool $errors Whether there are errors in the response
 849          * @param string[] $extra Array of extra HTTP response headers
 850          * @return void
 851          */
 852         protected function sendResponseHeaders(
 853                 ResourceLoaderContext $context, $etag, $errors, array $extra = []
 854         ) {
 855                 \MediaWiki\HeaderCallback::warnIfHeadersSent();
 856                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 857                 // Use a short cache expiry so that updates propagate to clients quickly, if:
 858                 // - No version specified (shared resources, e.g. stylesheets)
 859                 // - There were errors (recover quickly)
 860                 // - Version mismatch (T117587, T47877)
 861                 if ( is_null( $context->getVersion() )
 862                         || $errors
 863                         || $context->getVersion() !== $this->makeVersionQuery( $context )
 864                 ) {
 865                         $maxage = $rlMaxage['unversioned']['client'];
 866                         $smaxage = $rlMaxage['unversioned']['server'];
 867                 // If a version was specified we can use a longer expiry time since changing
 868                 // version numbers causes cache misses
 869                 } else {
 870                         $maxage = $rlMaxage['versioned']['client'];
 871                         $smaxage = $rlMaxage['versioned']['server'];
 872                 }
 873                 if ( $context->getImageObj() ) {
 874                         // Output different headers if we're outputting textual errors.
 875                         if ( $errors ) {
 876                                 header( 'Content-Type: text/plain; charset=utf-8' );
 877                         } else {
 878                                 $context->getImageObj()->sendResponseHeaders( $context );
 879                         }
 880                 } elseif ( $context->getOnly() === 'styles' ) {
 881                         header( 'Content-Type: text/css; charset=utf-8' );
 882                         header( 'Access-Control-Allow-Origin: *' );
 883                 } else {
 884                         header( 'Content-Type: text/javascript; charset=utf-8' );
 885                 }
 886                 // See RFC 2616 § 14.19 ETag
 887                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.19
 888                 header( 'ETag: ' . $etag );
 889                 if ( $context->getDebug() ) {
 890                         // Do not cache debug responses
 891                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 892                         header( 'Pragma: no-cache' );
 893                 } else {
 894                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 895                         $exp = min( $maxage, $smaxage );
 896                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 897                 }
 898                 foreach ( $extra as $header ) {
 899                         header( $header );
 900                 }
 901         }
 902
 903         /**
 904          * Respond with HTTP 304 Not Modified if appropiate.
 905          *
 906          * If there's an If-None-Match header, respond with a 304 appropriately
 907          * and clear out the output buffer. If the client cache is too old then do nothing.
 908          *
 909          * @param ResourceLoaderContext $context
 910          * @param string $etag ETag header value
 911          * @return bool True if HTTP 304 was sent and output handled
 912          */
 913         protected function tryRespondNotModified( ResourceLoaderContext $context, $etag ) {
 914                 // See RFC 2616 § 14.26 If-None-Match
 915                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
 916                 $clientKeys = $context->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST );
 917                 // Never send 304s in debug mode
 918                 if ( $clientKeys !== false && !$context->getDebug() && in_array( $etag, $clientKeys ) ) {
 919                         // There's another bug in ob_gzhandler (see also the comment at
 920                         // the top of this function) that causes it to gzip even empty
 921                         // responses, meaning it's impossible to produce a truly empty
 922                         // response (because the gzip header is always there). This is
 923                         // a problem because 304 responses have to be completely empty
 924                         // per the HTTP spec, and Firefox behaves buggily when they're not.
 925                         // See also https://bugs.php.net/bug.php?id=51579
 926                         // To work around this, we tear down all output buffering before
 927                         // sending the 304.
 928                         wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 929
 930                         HttpStatus::header( 304 );
 931
 932                         $this->sendResponseHeaders( $context, $etag, false );
 933                         return true;
 934                 }
 935                 return false;
 936         }
 937
 938         /**
 939          * Send out code for a response from file cache if possible.
 940          *
 941          * @param ResourceFileCache $fileCache Cache object for this request URL
 942          * @param ResourceLoaderContext $context Context in which to generate a response
 943          * @param string $etag ETag header value
 944          * @return bool If this found a cache file and handled the response
 945          */
 946         protected function tryRespondFromFileCache(
 947                 ResourceFileCache $fileCache,
 948                 ResourceLoaderContext $context,
 949                 $etag
 950         ) {
 951                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 952                 // Buffer output to catch warnings.
 953                 ob_start();
 954                 // Get the maximum age the cache can be
 955                 $maxage = is_null( $context->getVersion() )
 956                         ? $rlMaxage['unversioned']['server']
 957                         : $rlMaxage['versioned']['server'];
 958                 // Minimum timestamp the cache file must have
 959                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 960                 if ( !$good ) {
 961                         try { // RL always hits the DB on file cache miss...
 962                                 wfGetDB( DB_REPLICA );
 963                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 964                                 $good = $fileCache->isCacheGood(); // cache existence check
 965                         }
 966                 }
 967                 if ( $good ) {
 968                         $ts = $fileCache->cacheTimestamp();
 969                         // Send content type and cache headers
 970                         $this->sendResponseHeaders( $context, $etag, false );
 971                         $response = $fileCache->fetchText();
 972                         // Capture any PHP warnings from the output buffer and append them to the
 973                         // response in a comment if we're in debug mode.
 974                         if ( $context->getDebug() ) {
 975                                 $warnings = ob_get_contents();
 976                                 if ( strlen( $warnings ) ) {
 977                                         $response = self::makeComment( $warnings ) . $response;
 978                                 }
 979                         }
 980                         // Remove the output buffer and output the response
 981                         ob_end_clean();
 982                         echo $response . "\n/* Cached {$ts} */";
 983                         return true; // cache hit
 984                 }
 985                 // Clear buffer
 986                 ob_end_clean();
 987
 988                 return false; // cache miss
 989         }
 990
 991         /**
 992          * Generate a CSS or JS comment block.
 993          *
 994          * Only use this for public data, not error message details.
 995          *
 996          * @param string $text
 997          * @return string
 998          */
 999         public static function makeComment( $text ) {
1000                 $encText = str_replace( '*/', '* /', $text );
1001                 return "/*\n$encText\n*/\n";
1002         }
1003
1004         /**
1005          * Handle exception display.
1006          *
1007          * @param Exception $e Exception to be shown to the user
1008          * @return string Sanitized text in a CSS/JS comment that can be returned to the user
1009          */
1010         public static function formatException( $e ) {
1011                 return self::makeComment( self::formatExceptionNoComment( $e ) );
1012         }
1013
1014         /**
1015          * Handle exception display.
1016          *
1017          * @since 1.25
1018          * @param Exception $e Exception to be shown to the user
1019          * @return string Sanitized text that can be returned to the user
1020          */
1021         protected static function formatExceptionNoComment( $e ) {
1022                 global $wgShowExceptionDetails;
1023
1024                 if ( !$wgShowExceptionDetails ) {
1025                         return MWExceptionHandler::getPublicLogMessage( $e );
1026                 }
1027
1028                 return MWExceptionHandler::getLogMessage( $e ) .
1029                         "\nBacktrace:\n" .
1030                         MWExceptionHandler::getRedactedTraceAsString( $e );
1031         }
1032
1033         /**
1034          * Generate code for a response.
1035          *
1036          * Calling this method also populates the `errors` and `headers` members,
1037          * later used by respond().
1038          *
1039          * @param ResourceLoaderContext $context Context in which to generate a response
1040          * @param ResourceLoaderModule[] $modules List of module objects keyed by module name
1041          * @param string[] $missing List of requested module names that are unregistered (optional)
1042          * @return string Response data
1043          */
1044         public function makeModuleResponse( ResourceLoaderContext $context,
1045                 array $modules, array $missing = []
1046         ) {
1047                 $out = '';
1048                 $states = [];
1049
1050                 if ( !count( $modules ) && !count( $missing ) ) {
1051                         return <<<MESSAGE
1052 /* This file is the Web entry point for MediaWiki's ResourceLoader:
1053    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
1054    no modules were requested. Max made me put this here. */
1055 MESSAGE;
1056                 }
1057
1058                 $image = $context->getImageObj();
1059                 if ( $image ) {
1060                         $data = $image->getImageData( $context );
1061                         if ( $data === false ) {
1062                                 $data = '';
1063                                 $this->errors[] = 'Image generation failed';
1064                         }
1065                         return $data;
1066                 }
1067
1068                 foreach ( $missing as $name ) {
1069                         $states[$name] = 'missing';
1070                 }
1071
1072                 // Generate output
1073                 $isRaw = false;
1074
1075                 $filter = $context->getOnly() === 'styles' ? 'minify-css' : 'minify-js';
1076
1077                 foreach ( $modules as $name => $module ) {
1078                         try {
1079                                 $content = $module->getModuleContent( $context );
1080                                 $implementKey = $name . '@' . $module->getVersionHash( $context );
1081                                 $strContent = '';
1082
1083                                 if ( isset( $content['headers'] ) ) {
1084                                         $this->extraHeaders = array_merge( $this->extraHeaders, $content['headers'] );
1085                                 }
1086
1087                                 // Append output
1088                                 switch ( $context->getOnly() ) {
1089                                         case 'scripts':
1090                                                 $scripts = $content['scripts'];
1091                                                 if ( is_string( $scripts ) ) {
1092                                                         // Load scripts raw...
1093                                                         $strContent = $scripts;
1094                                                 } elseif ( is_array( $scripts ) ) {
1095                                                         // ...except when $scripts is an array of URLs
1096                                                         $strContent = self::makeLoaderImplementScript( $implementKey, $scripts, [], [], [] );
1097                                                 }
1098                                                 break;
1099                                         case 'styles':
1100                                                 $styles = $content['styles'];
1101                                                 // We no longer seperate into media, they are all combined now with
1102                                                 // custom media type groups into @media .. {} sections as part of the css string.
1103                                                 // Module returns either an empty array or a numerical array with css strings.
1104                                                 $strContent = isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
1105                                                 break;
1106                                         default:
1107                                                 $scripts = isset( $content['scripts'] ) ? $content['scripts'] : '';
1108                                                 if ( is_string( $scripts ) ) {
1109                                                         if ( $name === 'site' || $name === 'user' ) {
1110                                                                 // Legacy scripts that run in the global scope without a closure.
1111                                                                 // mw.loader.implement will use globalEval if scripts is a string.
1112                                                                 // Minify manually here, because general response minification is
1113                                                                 // not effective due it being a string literal, not a function.
1114                                                                 if ( !self::inDebugMode() ) {
1115                                                                         $scripts = self::filter( 'minify-js', $scripts ); // T107377
1116                                                                 }
1117                                                         } else {
1118                                                                 $scripts = new XmlJsCode( $scripts );
1119                                                         }
1120                                                 }
1121                                                 $strContent = self::makeLoaderImplementScript(
1122                                                         $implementKey,
1123                                                         $scripts,
1124                                                         isset( $content['styles'] ) ? $content['styles'] : [],
1125                                                         isset( $content['messagesBlob'] ) ? new XmlJsCode( $content['messagesBlob'] ) : [],
1126                                                         isset( $content['templates'] ) ? $content['templates'] : []
1127                                                 );
1128                                                 break;
1129                                 }
1130
1131                                 if ( !$context->getDebug() ) {
1132                                         $strContent = self::filter( $filter, $strContent );
1133                                 }
1134
1135                                 if ( $context->getOnly() === 'scripts' ) {
1136                                         // Use a linebreak between module scripts (T162719)
1137                                         $out .= $this->ensureNewline( $strContent );
1138                                 } else {
1139                                         $out .= $strContent;
1140                                 }
1141
1142                         } catch ( Exception $e ) {
1143                                 $this->outputErrorAndLog( $e, 'Generating module package failed: {exception}' );
1144
1145                                 // Respond to client with error-state instead of module implementation
1146                                 $states[$name] = 'error';
1147                                 unset( $modules[$name] );
1148                         }
1149                         $isRaw |= $module->isRaw();
1150                 }
1151
1152                 // Update module states
1153                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
1154                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
1155                                 // Set the state of modules loaded as only scripts to ready as
1156                                 // they don't have an mw.loader.implement wrapper that sets the state
1157                                 foreach ( $modules as $name => $module ) {
1158                                         $states[$name] = 'ready';
1159                                 }
1160                         }
1161
1162                         // Set the state of modules we didn't respond to with mw.loader.implement
1163                         if ( count( $states ) ) {
1164                                 $stateScript = self::makeLoaderStateScript( $states );
1165                                 if ( !$context->getDebug() ) {
1166                                         $stateScript = self::filter( 'minify-js', $stateScript );
1167                                 }
1168                                 // Use a linebreak between module script and state script (T162719)
1169                                 $out = $this->ensureNewline( $out ) . $stateScript;
1170                         }
1171                 } else {
1172                         if ( count( $states ) ) {
1173                                 $this->errors[] = 'Problematic modules: ' .
1174                                         FormatJson::encode( $states, self::inDebugMode() );
1175                         }
1176                 }
1177
1178                 return $out;
1179         }
1180
1181         /**
1182          * Ensure the string is either empty or ends in a line break
1183          * @param string $str
1184          * @return string
1185          */
1186         private function ensureNewline( $str ) {
1187                 $end = substr( $str, -1 );
1188                 if ( $end === false || $end === "\n" ) {
1189                         return $str;
1190                 }
1191                 return $str . "\n";
1192         }
1193
1194         /**
1195          * Get names of modules that use a certain message.
1196          *
1197          * @param string $messageKey
1198          * @return array List of module names
1199          */
1200         public function getModulesByMessage( $messageKey ) {
1201                 $moduleNames = [];
1202                 foreach ( $this->getModuleNames() as $moduleName ) {
1203                         $module = $this->getModule( $moduleName );
1204                         if ( in_array( $messageKey, $module->getMessages() ) ) {
1205                                 $moduleNames[] = $moduleName;
1206                         }
1207                 }
1208                 return $moduleNames;
1209         }
1210
1211         /**
1212          * Return JS code that calls mw.loader.implement with given module properties.
1213          *
1214          * @param string $name Module name or implement key (format "`[name]@[version]`")
1215          * @param XmlJsCode|array|string $scripts Code as XmlJsCode (to be wrapped in a closure),
1216          *  list of URLs to JavaScript files, or a string of JavaScript for `$.globalEval`.
1217          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1218          *   to CSS files keyed by media type
1219          * @param mixed $messages List of messages associated with this module. May either be an
1220          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1221          *   the same data, wrapped in an XmlJsCode object.
1222          * @param array $templates Keys are name of templates and values are the source of
1223          *   the template.
1224          * @throws MWException
1225          * @return string JavaScript code
1226          */
1227         protected static function makeLoaderImplementScript(
1228                 $name, $scripts, $styles, $messages, $templates
1229         ) {
1230                 if ( $scripts instanceof XmlJsCode ) {
1231                         $scripts = new XmlJsCode( "function ( $, jQuery, require, module ) {\n{$scripts->value}\n}" );
1232                 } elseif ( !is_string( $scripts ) && !is_array( $scripts ) ) {
1233                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1234                 }
1235                 // mw.loader.implement requires 'styles', 'messages' and 'templates' to be objects (not
1236                 // arrays). json_encode considers empty arrays to be numerical and outputs "[]" instead
1237                 // of "{}". Force them to objects.
1238                 $module = [
1239                         $name,
1240                         $scripts,
1241                         (object)$styles,
1242                         (object)$messages,
1243                         (object)$templates,
1244                 ];
1245                 self::trimArray( $module );
1246
1247                 return Xml::encodeJsCall( 'mw.loader.implement', $module, self::inDebugMode() );
1248         }
1249
1250         /**
1251          * Returns JS code which, when called, will register a given list of messages.
1252          *
1253          * @param mixed $messages Either an associative array mapping message key to value, or a
1254          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1255          * @return string JavaScript code
1256          */
1257         public static function makeMessageSetScript( $messages ) {
1258                 return Xml::encodeJsCall(
1259                         'mw.messages.set',
1260                         [ (object)$messages ],
1261                         self::inDebugMode()
1262                 );
1263         }
1264
1265         /**
1266          * Combines an associative array mapping media type to CSS into a
1267          * single stylesheet with "@media" blocks.
1268          *
1269          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1270          * @return array
1271          */
1272         public static function makeCombinedStyles( array $stylePairs ) {
1273                 $out = [];
1274                 foreach ( $stylePairs as $media => $styles ) {
1275                         // ResourceLoaderFileModule::getStyle can return the styles
1276                         // as a string or an array of strings. This is to allow separation in
1277                         // the front-end.
1278                         $styles = (array)$styles;
1279                         foreach ( $styles as $style ) {
1280                                 $style = trim( $style );
1281                                 // Don't output an empty "@media print { }" block (T42498)
1282                                 if ( $style !== '' ) {
1283                                         // Transform the media type based on request params and config
1284                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1285                                         $media = OutputPage::transformCssMedia( $media );
1286
1287                                         if ( $media === '' || $media == 'all' ) {
1288                                                 $out[] = $style;
1289                                         } elseif ( is_string( $media ) ) {
1290                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1291                                         }
1292                                         // else: skip
1293                                 }
1294                         }
1295                 }
1296                 return $out;
1297         }
1298
1299         /**
1300          * Returns a JS call to mw.loader.state, which sets the state of a
1301          * module or modules to a given value. Has two calling conventions:
1302          *
1303          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1304          *         Set the state of a single module called $name to $state
1305          *
1306          *    - ResourceLoader::makeLoaderStateScript( [ $name => $state, ... ] ):
1307          *         Set the state of modules with the given names to the given states
1308          *
1309          * @param string $name
1310          * @param string $state
1311          * @return string JavaScript code
1312          */
1313         public static function makeLoaderStateScript( $name, $state = null ) {
1314                 if ( is_array( $name ) ) {
1315                         return Xml::encodeJsCall(
1316                                 'mw.loader.state',
1317                                 [ $name ],
1318                                 self::inDebugMode()
1319                         );
1320                 } else {
1321                         return Xml::encodeJsCall(
1322                                 'mw.loader.state',
1323                                 [ $name, $state ],
1324                                 self::inDebugMode()
1325                         );
1326                 }
1327         }
1328
1329         /**
1330          * Returns JS code which calls the script given by $script. The script will
1331          * be called with local variables name, version, dependencies and group,
1332          * which will have values corresponding to $name, $version, $dependencies
1333          * and $group as supplied.
1334          *
1335          * @param string $name Module name
1336          * @param string $version Module version hash
1337          * @param array $dependencies List of module names on which this module depends
1338          * @param string $group Group which the module is in.
1339          * @param string $source Source of the module, or 'local' if not foreign.
1340          * @param string $script JavaScript code
1341          * @return string JavaScript code
1342          */
1343         public static function makeCustomLoaderScript( $name, $version, $dependencies,
1344                 $group, $source, $script
1345         ) {
1346                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1347                 return Xml::encodeJsCall(
1348                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1349                         [ $name, $version, $dependencies, $group, $source ],
1350                         self::inDebugMode()
1351                 );
1352         }
1353
1354         private static function isEmptyObject( stdClass $obj ) {
1355                 foreach ( $obj as $key => $value ) {
1356                         return false;
1357                 }
1358                 return true;
1359         }
1360
1361         /**
1362          * Remove empty values from the end of an array.
1363          *
1364          * Values considered empty:
1365          *
1366          * - null
1367          * - []
1368          * - new XmlJsCode( '{}' )
1369          * - new stdClass() // (object) []
1370          *
1371          * @param Array $array
1372          */
1373         private static function trimArray( array &$array ) {
1374                 $i = count( $array );
1375                 while ( $i-- ) {
1376                         if ( $array[$i] === null
1377                                 || $array[$i] === []
1378                                 || ( $array[$i] instanceof XmlJsCode && $array[$i]->value === '{}' )
1379                                 || ( $array[$i] instanceof stdClass && self::isEmptyObject( $array[$i] ) )
1380                         ) {
1381                                 unset( $array[$i] );
1382                         } else {
1383                                 break;
1384                         }
1385                 }
1386         }
1387
1388         /**
1389          * Returns JS code which calls mw.loader.register with the given
1390          * parameters. Has three calling conventions:
1391          *
1392          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version,
1393          *        $dependencies, $group, $source, $skip
1394          *     ):
1395          *        Register a single module.
1396          *
1397          *   - ResourceLoader::makeLoaderRegisterScript( [ $name1, $name2 ] ):
1398          *        Register modules with the given names.
1399          *
1400          *   - ResourceLoader::makeLoaderRegisterScript( [
1401          *        [ $name1, $version1, $dependencies1, $group1, $source1, $skip1 ],
1402          *        [ $name2, $version2, $dependencies1, $group2, $source2, $skip2 ],
1403          *        ...
1404          *     ] ):
1405          *        Registers modules with the given names and parameters.
1406          *
1407          * @param string $name Module name
1408          * @param string $version Module version hash
1409          * @param array $dependencies List of module names on which this module depends
1410          * @param string $group Group which the module is in
1411          * @param string $source Source of the module, or 'local' if not foreign
1412          * @param string $skip Script body of the skip function
1413          * @return string JavaScript code
1414          */
1415         public static function makeLoaderRegisterScript( $name, $version = null,
1416                 $dependencies = null, $group = null, $source = null, $skip = null
1417         ) {
1418                 if ( is_array( $name ) ) {
1419                         // Build module name index
1420                         $index = [];
1421                         foreach ( $name as $i => &$module ) {
1422                                 $index[$module[0]] = $i;
1423                         }
1424
1425                         // Transform dependency names into indexes when possible, they will be resolved by
1426                         // mw.loader.register on the other end
1427                         foreach ( $name as &$module ) {
1428                                 if ( isset( $module[2] ) ) {
1429                                         foreach ( $module[2] as &$dependency ) {
1430                                                 if ( isset( $index[$dependency] ) ) {
1431                                                         $dependency = $index[$dependency];
1432                                                 }
1433                                         }
1434                                 }
1435                         }
1436
1437                         array_walk( $name, [ 'self', 'trimArray' ] );
1438
1439                         return Xml::encodeJsCall(
1440                                 'mw.loader.register',
1441                                 [ $name ],
1442                                 self::inDebugMode()
1443                         );
1444                 } else {
1445                         $registration = [ $name, $version, $dependencies, $group, $source, $skip ];
1446                         self::trimArray( $registration );
1447                         return Xml::encodeJsCall(
1448                                 'mw.loader.register',
1449                                 $registration,
1450                                 self::inDebugMode()
1451                         );
1452                 }
1453         }
1454
1455         /**
1456          * Returns JS code which calls mw.loader.addSource() with the given
1457          * parameters. Has two calling conventions:
1458          *
1459          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1460          *       Register a single source
1461          *
1462          *   - ResourceLoader::makeLoaderSourcesScript( [ $id1 => $loadUrl, $id2 => $loadUrl, ... ] );
1463          *       Register sources with the given IDs and properties.
1464          *
1465          * @param string $id Source ID
1466          * @param string $loadUrl load.php url
1467          * @return string JavaScript code
1468          */
1469         public static function makeLoaderSourcesScript( $id, $loadUrl = null ) {
1470                 if ( is_array( $id ) ) {
1471                         return Xml::encodeJsCall(
1472                                 'mw.loader.addSource',
1473                                 [ $id ],
1474                                 self::inDebugMode()
1475                         );
1476                 } else {
1477                         return Xml::encodeJsCall(
1478                                 'mw.loader.addSource',
1479                                 [ $id, $loadUrl ],
1480                                 self::inDebugMode()
1481                         );
1482                 }
1483         }
1484
1485         /**
1486          * Returns JS code which runs given JS code if the client-side framework is
1487          * present.
1488          *
1489          * @deprecated since 1.25; use makeInlineScript instead
1490          * @param string $script JavaScript code
1491          * @return string JavaScript code
1492          */
1493         public static function makeLoaderConditionalScript( $script ) {
1494                 return '(window.RLQ=window.RLQ||[]).push(function(){' .
1495                         trim( $script ) . '});';
1496         }
1497
1498         /**
1499          * Construct an inline script tag with given JS code.
1500          *
1501          * The code will be wrapped in a closure, and it will be executed by ResourceLoader
1502          * only if the client has adequate support for MediaWiki JavaScript code.
1503          *
1504          * @param string $script JavaScript code
1505          * @return WrappedString HTML
1506          */
1507         public static function makeInlineScript( $script ) {
1508                 $js = self::makeLoaderConditionalScript( $script );
1509                 return new WrappedString(
1510                         Html::inlineScript( $js ),
1511                         '<script>(window.RLQ=window.RLQ||[]).push(function(){',
1512                         '});</script>'
1513                 );
1514         }
1515
1516         /**
1517          * Returns JS code which will set the MediaWiki configuration array to
1518          * the given value.
1519          *
1520          * @param array $configuration List of configuration values keyed by variable name
1521          * @return string JavaScript code
1522          */
1523         public static function makeConfigSetScript( array $configuration ) {
1524                 return Xml::encodeJsCall(
1525                         'mw.config.set',
1526                         [ $configuration ],
1527                         self::inDebugMode()
1528                 );
1529         }
1530
1531         /**
1532          * Convert an array of module names to a packed query string.
1533          *
1534          * For example, [ 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' ]
1535          * becomes 'foo.bar,baz|bar.baz,quux'
1536          * @param array $modules List of module names (strings)
1537          * @return string Packed query string
1538          */
1539         public static function makePackedModulesString( $modules ) {
1540                 $groups = []; // [ prefix => [ suffixes ] ]
1541                 foreach ( $modules as $module ) {
1542                         $pos = strrpos( $module, '.' );
1543                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1544                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1545                         $groups[$prefix][] = $suffix;
1546                 }
1547
1548                 $arr = [];
1549                 foreach ( $groups as $prefix => $suffixes ) {
1550                         $p = $prefix === '' ? '' : $prefix . '.';
1551                         $arr[] = $p . implode( ',', $suffixes );
1552                 }
1553                 $str = implode( '|', $arr );
1554                 return $str;
1555         }
1556
1557         /**
1558          * Determine whether debug mode was requested
1559          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1560          * @return bool
1561          */
1562         public static function inDebugMode() {
1563                 if ( self::$debugMode === null ) {
1564                         global $wgRequest, $wgResourceLoaderDebug;
1565                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1566                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1567                         );
1568                 }
1569                 return self::$debugMode;
1570         }
1571
1572         /**
1573          * Reset static members used for caching.
1574          *
1575          * Global state and $wgRequest are evil, but we're using it right
1576          * now and sometimes we need to be able to force ResourceLoader to
1577          * re-evaluate the context because it has changed (e.g. in the test suite).
1578          */
1579         public static function clearCache() {
1580                 self::$debugMode = null;
1581         }
1582
1583         /**
1584          * Build a load.php URL
1585          *
1586          * @since 1.24
1587          * @param string $source Name of the ResourceLoader source
1588          * @param ResourceLoaderContext $context
1589          * @param array $extraQuery
1590          * @return string URL to load.php. May be protocol-relative if $wgLoadScript is, too.
1591          */
1592         public function createLoaderURL( $source, ResourceLoaderContext $context,
1593                 $extraQuery = []
1594         ) {
1595                 $query = self::createLoaderQuery( $context, $extraQuery );
1596                 $script = $this->getLoadScript( $source );
1597
1598                 return wfAppendQuery( $script, $query );
1599         }
1600
1601         /**
1602          * Helper for createLoaderURL()
1603          *
1604          * @since 1.24
1605          * @see makeLoaderQuery
1606          * @param ResourceLoaderContext $context
1607          * @param array $extraQuery
1608          * @return array
1609          */
1610         protected static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = [] ) {
1611                 return self::makeLoaderQuery(
1612                         $context->getModules(),
1613                         $context->getLanguage(),
1614                         $context->getSkin(),
1615                         $context->getUser(),
1616                         $context->getVersion(),
1617                         $context->getDebug(),
1618                         $context->getOnly(),
1619                         $context->getRequest()->getBool( 'printable' ),
1620                         $context->getRequest()->getBool( 'handheld' ),
1621                         $extraQuery
1622                 );
1623         }
1624
1625         /**
1626          * Build a query array (array representation of query string) for load.php. Helper
1627          * function for createLoaderURL().
1628          *
1629          * @param array $modules
1630          * @param string $lang
1631          * @param string $skin
1632          * @param string $user
1633          * @param string $version
1634          * @param bool $debug
1635          * @param string $only
1636          * @param bool $printable
1637          * @param bool $handheld
1638          * @param array $extraQuery
1639          *
1640          * @return array
1641          */
1642         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1643                 $version = null, $debug = false, $only = null, $printable = false,
1644                 $handheld = false, $extraQuery = []
1645         ) {
1646                 $query = [
1647                         'modules' => self::makePackedModulesString( $modules ),
1648                         'lang' => $lang,
1649                         'skin' => $skin,
1650                         'debug' => $debug ? 'true' : 'false',
1651                 ];
1652                 if ( $user !== null ) {
1653                         $query['user'] = $user;
1654                 }
1655                 if ( $version !== null ) {
1656                         $query['version'] = $version;
1657                 }
1658                 if ( $only !== null ) {
1659                         $query['only'] = $only;
1660                 }
1661                 if ( $printable ) {
1662                         $query['printable'] = 1;
1663                 }
1664                 if ( $handheld ) {
1665                         $query['handheld'] = 1;
1666                 }
1667                 $query += $extraQuery;
1668
1669                 // Make queries uniform in order
1670                 ksort( $query );
1671                 return $query;
1672         }
1673
1674         /**
1675          * Check a module name for validity.
1676          *
1677          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1678          * at most 255 bytes.
1679          *
1680          * @param string $moduleName Module name to check
1681          * @return bool Whether $moduleName is a valid module name
1682          */
1683         public static function isValidModuleName( $moduleName ) {
1684                 return strcspn( $moduleName, '!,|', 0, 255 ) === strlen( $moduleName );
1685         }
1686
1687         /**
1688          * Returns LESS compiler set up for use with MediaWiki
1689          *
1690          * @since 1.27
1691          * @param array $extraVars Associative array of extra (i.e., other than the
1692          *   globally-configured ones) that should be used for compilation.
1693          * @throws MWException
1694          * @return Less_Parser
1695          */
1696         public function getLessCompiler( $extraVars = [] ) {
1697                 // When called from the installer, it is possible that a required PHP extension
1698                 // is missing (at least for now; see T49564). If this is the case, throw an
1699                 // exception (caught by the installer) to prevent a fatal error later on.
1700                 if ( !class_exists( 'Less_Parser' ) ) {
1701                         throw new MWException( 'MediaWiki requires the less.php parser' );
1702                 }
1703
1704                 $parser = new Less_Parser;
1705                 $parser->ModifyVars( array_merge( $this->getLessVars(), $extraVars ) );
1706                 $parser->SetImportDirs(
1707                         array_fill_keys( $this->config->get( 'ResourceLoaderLESSImportPaths' ), '' )
1708                 );
1709                 $parser->SetOption( 'relativeUrls', false );
1710
1711                 return $parser;
1712         }
1713
1714         /**
1715          * Get global LESS variables.
1716          *
1717          * @since 1.27
1718          * @return array Map of variable names to string CSS values.
1719          */
1720         public function getLessVars() {
1721                 if ( !$this->lessVars ) {
1722                         $lessVars = $this->config->get( 'ResourceLoaderLESSVars' );
1723                         Hooks::run( 'ResourceLoaderGetLessVars', [ &$lessVars ] );
1724                         $this->lessVars = $lessVars;
1725                 }
1726                 return $this->lessVars;
1727         }
1728 }