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          * @return string Hash
 694          */
 695         public function makeVersionQuery( ResourceLoaderContext $context ) {
 696                 // As of MediaWiki 1.28, the server and client use the same algorithm for combining
 697                 // version hashes. There is no technical reason for this to be same, and for years the
 698                 // implementations differed. If getCombinedVersion in PHP (used for StartupModule and
 699                 // E-Tag headers) differs in the future from getCombinedVersion in JS (used for 'version'
 700                 // query parameter), then this method must continue to match the JS one.
 701                 $moduleNames = [];
 702                 foreach ( $context->getModules() as $name ) {
 703                         if ( !$this->getModule( $name ) ) {
 704                                 // If a versioned request contains a missing module, the version is a mismatch
 705                                 // as the client considered a module (and version) we don't have.
 706                                 return '';
 707                         }
 708                         $moduleNames[] = $name;
 709                 }
 710                 return $this->getCombinedVersion( $context, $moduleNames );
 711         }
 712
 713         /**
 714          * Output a response to a load request, including the content-type header.
 715          *
 716          * @param ResourceLoaderContext $context Context in which a response should be formed
 717          */
 718         public function respond( ResourceLoaderContext $context ) {
 719                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 720                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 721                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 722                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 723                 // the whole thing in our own output buffer to be sure the active buffer
 724                 // doesn't use ob_gzhandler.
 725                 // See https://bugs.php.net/bug.php?id=36514
 726                 ob_start();
 727
 728                 $this->measureResponseTime( RequestContext::getMain()->getTiming() );
 729
 730                 // Find out which modules are missing and instantiate the others
 731                 $modules = [];
 732                 $missing = [];
 733                 foreach ( $context->getModules() as $name ) {
 734                         $module = $this->getModule( $name );
 735                         if ( $module ) {
 736                                 // Do not allow private modules to be loaded from the web.
 737                                 // This is a security issue, see T36907.
 738                                 if ( $module->getGroup() === 'private' ) {
 739                                         $this->logger->debug( "Request for private module '$name' denied" );
 740                                         $this->errors[] = "Cannot show private module \"$name\"";
 741                                         continue;
 742                                 }
 743                                 $modules[$name] = $module;
 744                         } else {
 745                                 $missing[] = $name;
 746                         }
 747                 }
 748
 749                 try {
 750                         // Preload for getCombinedVersion() and for batch makeModuleResponse()
 751                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 752                 } catch ( Exception $e ) {
 753                         $this->outputErrorAndLog( $e, 'Preloading module info failed: {exception}' );
 754                 }
 755
 756                 // Combine versions to propagate cache invalidation
 757                 $versionHash = '';
 758                 try {
 759                         $versionHash = $this->getCombinedVersion( $context, array_keys( $modules ) );
 760                 } catch ( Exception $e ) {
 761                         $this->outputErrorAndLog( $e, 'Calculating version hash failed: {exception}' );
 762                 }
 763
 764                 // See RFC 2616 § 3.11 Entity Tags
 765                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.11
 766                 $etag = 'W/"' . $versionHash . '"';
 767
 768                 // Try the client-side cache first
 769                 if ( $this->tryRespondNotModified( $context, $etag ) ) {
 770                         return; // output handled (buffers cleared)
 771                 }
 772
 773                 // Use file cache if enabled and available...
 774                 if ( $this->config->get( 'UseFileCache' ) ) {
 775                         $fileCache = ResourceFileCache::newFromContext( $context );
 776                         if ( $this->tryRespondFromFileCache( $fileCache, $context, $etag ) ) {
 777                                 return; // output handled
 778                         }
 779                 }
 780
 781                 // Generate a response
 782                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 783
 784                 // Capture any PHP warnings from the output buffer and append them to the
 785                 // error list if we're in debug mode.
 786                 if ( $context->getDebug() ) {
 787                         $warnings = ob_get_contents();
 788                         if ( strlen( $warnings ) ) {
 789                                 $this->errors[] = $warnings;
 790                         }
 791                 }
 792
 793                 // Save response to file cache unless there are errors
 794                 if ( isset( $fileCache ) && !$this->errors && !count( $missing ) ) {
 795                         // Cache single modules and images...and other requests if there are enough hits
 796                         if ( ResourceFileCache::useFileCache( $context ) ) {
 797                                 if ( $fileCache->isCacheWorthy() ) {
 798                                         $fileCache->saveText( $response );
 799                                 } else {
 800                                         $fileCache->incrMissesRecent( $context->getRequest() );
 801                                 }
 802                         }
 803                 }
 804
 805                 $this->sendResponseHeaders( $context, $etag, (bool)$this->errors, $this->extraHeaders );
 806
 807                 // Remove the output buffer and output the response
 808                 ob_end_clean();
 809
 810                 if ( $context->getImageObj() && $this->errors ) {
 811                         // We can't show both the error messages and the response when it's an image.
 812                         $response = implode( "\n\n", $this->errors );
 813                 } elseif ( $this->errors ) {
 814                         $errorText = implode( "\n\n", $this->errors );
 815                         $errorResponse = self::makeComment( $errorText );
 816                         if ( $context->shouldIncludeScripts() ) {
 817                                 $errorResponse .= 'if (window.console && console.error) {'
 818                                         . Xml::encodeJsCall( 'console.error', [ $errorText ] )
 819                                         . "}\n";
 820                         }
 821
 822                         // Prepend error info to the response
 823                         $response = $errorResponse . $response;
 824                 }
 825
 826                 $this->errors = [];
 827                 echo $response;
 828         }
 829
 830         protected function measureResponseTime( Timing $timing ) {
 831                 DeferredUpdates::addCallableUpdate( function () use ( $timing ) {
 832                         $measure = $timing->measure( 'responseTime', 'requestStart', 'requestShutdown' );
 833                         if ( $measure !== false ) {
 834                                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
 835                                 $stats->timing( 'resourceloader.responseTime', $measure['duration'] * 1000 );
 836                         }
 837                 } );
 838         }
 839
 840         /**
 841          * Send main response headers to the client.
 842          *
 843          * Deals with Content-Type, CORS (for stylesheets), and caching.
 844          *
 845          * @param ResourceLoaderContext $context
 846          * @param string $etag ETag header value
 847          * @param bool $errors Whether there are errors in the response
 848          * @param string[] $extra Array of extra HTTP response headers
 849          * @return void
 850          */
 851         protected function sendResponseHeaders(
 852                 ResourceLoaderContext $context, $etag, $errors, array $extra = []
 853         ) {
 854                 \MediaWiki\HeaderCallback::warnIfHeadersSent();
 855                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 856                 // Use a short cache expiry so that updates propagate to clients quickly, if:
 857                 // - No version specified (shared resources, e.g. stylesheets)
 858                 // - There were errors (recover quickly)
 859                 // - Version mismatch (T117587, T47877)
 860                 if ( is_null( $context->getVersion() )
 861                         || $errors
 862                         || $context->getVersion() !== $this->makeVersionQuery( $context )
 863                 ) {
 864                         $maxage = $rlMaxage['unversioned']['client'];
 865                         $smaxage = $rlMaxage['unversioned']['server'];
 866                 // If a version was specified we can use a longer expiry time since changing
 867                 // version numbers causes cache misses
 868                 } else {
 869                         $maxage = $rlMaxage['versioned']['client'];
 870                         $smaxage = $rlMaxage['versioned']['server'];
 871                 }
 872                 if ( $context->getImageObj() ) {
 873                         // Output different headers if we're outputting textual errors.
 874                         if ( $errors ) {
 875                                 header( 'Content-Type: text/plain; charset=utf-8' );
 876                         } else {
 877                                 $context->getImageObj()->sendResponseHeaders( $context );
 878                         }
 879                 } elseif ( $context->getOnly() === 'styles' ) {
 880                         header( 'Content-Type: text/css; charset=utf-8' );
 881                         header( 'Access-Control-Allow-Origin: *' );
 882                 } else {
 883                         header( 'Content-Type: text/javascript; charset=utf-8' );
 884                 }
 885                 // See RFC 2616 § 14.19 ETag
 886                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.19
 887                 header( 'ETag: ' . $etag );
 888                 if ( $context->getDebug() ) {
 889                         // Do not cache debug responses
 890                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 891                         header( 'Pragma: no-cache' );
 892                 } else {
 893                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 894                         $exp = min( $maxage, $smaxage );
 895                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 896                 }
 897                 foreach ( $extra as $header ) {
 898                         header( $header );
 899                 }
 900         }
 901
 902         /**
 903          * Respond with HTTP 304 Not Modified if appropiate.
 904          *
 905          * If there's an If-None-Match header, respond with a 304 appropriately
 906          * and clear out the output buffer. If the client cache is too old then do nothing.
 907          *
 908          * @param ResourceLoaderContext $context
 909          * @param string $etag ETag header value
 910          * @return bool True if HTTP 304 was sent and output handled
 911          */
 912         protected function tryRespondNotModified( ResourceLoaderContext $context, $etag ) {
 913                 // See RFC 2616 § 14.26 If-None-Match
 914                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
 915                 $clientKeys = $context->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST );
 916                 // Never send 304s in debug mode
 917                 if ( $clientKeys !== false && !$context->getDebug() && in_array( $etag, $clientKeys ) ) {
 918                         // There's another bug in ob_gzhandler (see also the comment at
 919                         // the top of this function) that causes it to gzip even empty
 920                         // responses, meaning it's impossible to produce a truly empty
 921                         // response (because the gzip header is always there). This is
 922                         // a problem because 304 responses have to be completely empty
 923                         // per the HTTP spec, and Firefox behaves buggily when they're not.
 924                         // See also https://bugs.php.net/bug.php?id=51579
 925                         // To work around this, we tear down all output buffering before
 926                         // sending the 304.
 927                         wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 928
 929                         HttpStatus::header( 304 );
 930
 931                         $this->sendResponseHeaders( $context, $etag, false );
 932                         return true;
 933                 }
 934                 return false;
 935         }
 936
 937         /**
 938          * Send out code for a response from file cache if possible.
 939          *
 940          * @param ResourceFileCache $fileCache Cache object for this request URL
 941          * @param ResourceLoaderContext $context Context in which to generate a response
 942          * @param string $etag ETag header value
 943          * @return bool If this found a cache file and handled the response
 944          */
 945         protected function tryRespondFromFileCache(
 946                 ResourceFileCache $fileCache,
 947                 ResourceLoaderContext $context,
 948                 $etag
 949         ) {
 950                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 951                 // Buffer output to catch warnings.
 952                 ob_start();
 953                 // Get the maximum age the cache can be
 954                 $maxage = is_null( $context->getVersion() )
 955                         ? $rlMaxage['unversioned']['server']
 956                         : $rlMaxage['versioned']['server'];
 957                 // Minimum timestamp the cache file must have
 958                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 959                 if ( !$good ) {
 960                         try { // RL always hits the DB on file cache miss...
 961                                 wfGetDB( DB_REPLICA );
 962                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 963                                 $good = $fileCache->isCacheGood(); // cache existence check
 964                         }
 965                 }
 966                 if ( $good ) {
 967                         $ts = $fileCache->cacheTimestamp();
 968                         // Send content type and cache headers
 969                         $this->sendResponseHeaders( $context, $etag, false );
 970                         $response = $fileCache->fetchText();
 971                         // Capture any PHP warnings from the output buffer and append them to the
 972                         // response in a comment if we're in debug mode.
 973                         if ( $context->getDebug() ) {
 974                                 $warnings = ob_get_contents();
 975                                 if ( strlen( $warnings ) ) {
 976                                         $response = self::makeComment( $warnings ) . $response;
 977                                 }
 978                         }
 979                         // Remove the output buffer and output the response
 980                         ob_end_clean();
 981                         echo $response . "\n/* Cached {$ts} */";
 982                         return true; // cache hit
 983                 }
 984                 // Clear buffer
 985                 ob_end_clean();
 986
 987                 return false; // cache miss
 988         }
 989
 990         /**
 991          * Generate a CSS or JS comment block.
 992          *
 993          * Only use this for public data, not error message details.
 994          *
 995          * @param string $text
 996          * @return string
 997          */
 998         public static function makeComment( $text ) {
 999                 $encText = str_replace( '*/', '* /', $text );
1000                 return "/*\n$encText\n*/\n";
1001         }
1002
1003         /**
1004          * Handle exception display.
1005          *
1006          * @param Exception $e Exception to be shown to the user
1007          * @return string Sanitized text in a CSS/JS comment that can be returned to the user
1008          */
1009         public static function formatException( $e ) {
1010                 return self::makeComment( self::formatExceptionNoComment( $e ) );
1011         }
1012
1013         /**
1014          * Handle exception display.
1015          *
1016          * @since 1.25
1017          * @param Exception $e Exception to be shown to the user
1018          * @return string Sanitized text that can be returned to the user
1019          */
1020         protected static function formatExceptionNoComment( $e ) {
1021                 global $wgShowExceptionDetails;
1022
1023                 if ( !$wgShowExceptionDetails ) {
1024                         return MWExceptionHandler::getPublicLogMessage( $e );
1025                 }
1026
1027                 return MWExceptionHandler::getLogMessage( $e ) .
1028                         "\nBacktrace:\n" .
1029                         MWExceptionHandler::getRedactedTraceAsString( $e );
1030         }
1031
1032         /**
1033          * Generate code for a response.
1034          *
1035          * Calling this method also populates the `errors` and `headers` members,
1036          * later used by respond().
1037          *
1038          * @param ResourceLoaderContext $context Context in which to generate a response
1039          * @param ResourceLoaderModule[] $modules List of module objects keyed by module name
1040          * @param string[] $missing List of requested module names that are unregistered (optional)
1041          * @return string Response data
1042          */
1043         public function makeModuleResponse( ResourceLoaderContext $context,
1044                 array $modules, array $missing = []
1045         ) {
1046                 $out = '';
1047                 $states = [];
1048
1049                 if ( !count( $modules ) && !count( $missing ) ) {
1050                         return <<<MESSAGE
1051 /* This file is the Web entry point for MediaWiki's ResourceLoader:
1052    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
1053    no modules were requested. Max made me put this here. */
1054 MESSAGE;
1055                 }
1056
1057                 $image = $context->getImageObj();
1058                 if ( $image ) {
1059                         $data = $image->getImageData( $context );
1060                         if ( $data === false ) {
1061                                 $data = '';
1062                                 $this->errors[] = 'Image generation failed';
1063                         }
1064                         return $data;
1065                 }
1066
1067                 foreach ( $missing as $name ) {
1068                         $states[$name] = 'missing';
1069                 }
1070
1071                 // Generate output
1072                 $isRaw = false;
1073
1074                 $filter = $context->getOnly() === 'styles' ? 'minify-css' : 'minify-js';
1075
1076                 foreach ( $modules as $name => $module ) {
1077                         try {
1078                                 $content = $module->getModuleContent( $context );
1079                                 $implementKey = $name . '@' . $module->getVersionHash( $context );
1080                                 $strContent = '';
1081
1082                                 if ( isset( $content['headers'] ) ) {
1083                                         $this->extraHeaders = array_merge( $this->extraHeaders, $content['headers'] );
1084                                 }
1085
1086                                 // Append output
1087                                 switch ( $context->getOnly() ) {
1088                                         case 'scripts':
1089                                                 $scripts = $content['scripts'];
1090                                                 if ( is_string( $scripts ) ) {
1091                                                         // Load scripts raw...
1092                                                         $strContent = $scripts;
1093                                                 } elseif ( is_array( $scripts ) ) {
1094                                                         // ...except when $scripts is an array of URLs
1095                                                         $strContent = self::makeLoaderImplementScript( $implementKey, $scripts, [], [], [] );
1096                                                 }
1097                                                 break;
1098                                         case 'styles':
1099                                                 $styles = $content['styles'];
1100                                                 // We no longer seperate into media, they are all combined now with
1101                                                 // custom media type groups into @media .. {} sections as part of the css string.
1102                                                 // Module returns either an empty array or a numerical array with css strings.
1103                                                 $strContent = isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
1104                                                 break;
1105                                         default:
1106                                                 $scripts = isset( $content['scripts'] ) ? $content['scripts'] : '';
1107                                                 if ( is_string( $scripts ) ) {
1108                                                         if ( $name === 'site' || $name === 'user' ) {
1109                                                                 // Legacy scripts that run in the global scope without a closure.
1110                                                                 // mw.loader.implement will use globalEval if scripts is a string.
1111                                                                 // Minify manually here, because general response minification is
1112                                                                 // not effective due it being a string literal, not a function.
1113                                                                 if ( !self::inDebugMode() ) {
1114                                                                         $scripts = self::filter( 'minify-js', $scripts ); // T107377
1115                                                                 }
1116                                                         } else {
1117                                                                 $scripts = new XmlJsCode( $scripts );
1118                                                         }
1119                                                 }
1120                                                 $strContent = self::makeLoaderImplementScript(
1121                                                         $implementKey,
1122                                                         $scripts,
1123                                                         isset( $content['styles'] ) ? $content['styles'] : [],
1124                                                         isset( $content['messagesBlob'] ) ? new XmlJsCode( $content['messagesBlob'] ) : [],
1125                                                         isset( $content['templates'] ) ? $content['templates'] : []
1126                                                 );
1127                                                 break;
1128                                 }
1129
1130                                 if ( !$context->getDebug() ) {
1131                                         $strContent = self::filter( $filter, $strContent );
1132                                 }
1133
1134                                 if ( $context->getOnly() === 'scripts' ) {
1135                                         // Use a linebreak between module scripts (T162719)
1136                                         $out .= $this->ensureNewline( $strContent );
1137                                 } else {
1138                                         $out .= $strContent;
1139                                 }
1140
1141                         } catch ( Exception $e ) {
1142                                 $this->outputErrorAndLog( $e, 'Generating module package failed: {exception}' );
1143
1144                                 // Respond to client with error-state instead of module implementation
1145                                 $states[$name] = 'error';
1146                                 unset( $modules[$name] );
1147                         }
1148                         $isRaw |= $module->isRaw();
1149                 }
1150
1151                 // Update module states
1152                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
1153                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
1154                                 // Set the state of modules loaded as only scripts to ready as
1155                                 // they don't have an mw.loader.implement wrapper that sets the state
1156                                 foreach ( $modules as $name => $module ) {
1157                                         $states[$name] = 'ready';
1158                                 }
1159                         }
1160
1161                         // Set the state of modules we didn't respond to with mw.loader.implement
1162                         if ( count( $states ) ) {
1163                                 $stateScript = self::makeLoaderStateScript( $states );
1164                                 if ( !$context->getDebug() ) {
1165                                         $stateScript = self::filter( 'minify-js', $stateScript );
1166                                 }
1167                                 // Use a linebreak between module script and state script (T162719)
1168                                 $out = $this->ensureNewline( $out ) . $stateScript;
1169                         }
1170                 } else {
1171                         if ( count( $states ) ) {
1172                                 $this->errors[] = 'Problematic modules: ' .
1173                                         FormatJson::encode( $states, self::inDebugMode() );
1174                         }
1175                 }
1176
1177                 return $out;
1178         }
1179
1180         /**
1181          * Ensure the string is either empty or ends in a line break
1182          * @param string $str
1183          * @return string
1184          */
1185         private function ensureNewline( $str ) {
1186                 $end = substr( $str, -1 );
1187                 if ( $end === false || $end === "\n" ) {
1188                         return $str;
1189                 }
1190                 return $str . "\n";
1191         }
1192
1193         /**
1194          * Get names of modules that use a certain message.
1195          *
1196          * @param string $messageKey
1197          * @return array List of module names
1198          */
1199         public function getModulesByMessage( $messageKey ) {
1200                 $moduleNames = [];
1201                 foreach ( $this->getModuleNames() as $moduleName ) {
1202                         $module = $this->getModule( $moduleName );
1203                         if ( in_array( $messageKey, $module->getMessages() ) ) {
1204                                 $moduleNames[] = $moduleName;
1205                         }
1206                 }
1207                 return $moduleNames;
1208         }
1209
1210         /**
1211          * Return JS code that calls mw.loader.implement with given module properties.
1212          *
1213          * @param string $name Module name or implement key (format "`[name]@[version]`")
1214          * @param XmlJsCode|array|string $scripts Code as XmlJsCode (to be wrapped in a closure),
1215          *  list of URLs to JavaScript files, or a string of JavaScript for `$.globalEval`.
1216          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1217          *   to CSS files keyed by media type
1218          * @param mixed $messages List of messages associated with this module. May either be an
1219          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1220          *   the same data, wrapped in an XmlJsCode object.
1221          * @param array $templates Keys are name of templates and values are the source of
1222          *   the template.
1223          * @throws MWException
1224          * @return string JavaScript code
1225          */
1226         protected static function makeLoaderImplementScript(
1227                 $name, $scripts, $styles, $messages, $templates
1228         ) {
1229                 if ( $scripts instanceof XmlJsCode ) {
1230                         $scripts = new XmlJsCode( "function ( $, jQuery, require, module ) {\n{$scripts->value}\n}" );
1231                 } elseif ( !is_string( $scripts ) && !is_array( $scripts ) ) {
1232                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1233                 }
1234                 // mw.loader.implement requires 'styles', 'messages' and 'templates' to be objects (not
1235                 // arrays). json_encode considers empty arrays to be numerical and outputs "[]" instead
1236                 // of "{}". Force them to objects.
1237                 $module = [
1238                         $name,
1239                         $scripts,
1240                         (object)$styles,
1241                         (object)$messages,
1242                         (object)$templates,
1243                 ];
1244                 self::trimArray( $module );
1245
1246                 return Xml::encodeJsCall( 'mw.loader.implement', $module, self::inDebugMode() );
1247         }
1248
1249         /**
1250          * Returns JS code which, when called, will register a given list of messages.
1251          *
1252          * @param mixed $messages Either an associative array mapping message key to value, or a
1253          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1254          * @return string JavaScript code
1255          */
1256         public static function makeMessageSetScript( $messages ) {
1257                 return Xml::encodeJsCall(
1258                         'mw.messages.set',
1259                         [ (object)$messages ],
1260                         self::inDebugMode()
1261                 );
1262         }
1263
1264         /**
1265          * Combines an associative array mapping media type to CSS into a
1266          * single stylesheet with "@media" blocks.
1267          *
1268          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1269          * @return array
1270          */
1271         public static function makeCombinedStyles( array $stylePairs ) {
1272                 $out = [];
1273                 foreach ( $stylePairs as $media => $styles ) {
1274                         // ResourceLoaderFileModule::getStyle can return the styles
1275                         // as a string or an array of strings. This is to allow separation in
1276                         // the front-end.
1277                         $styles = (array)$styles;
1278                         foreach ( $styles as $style ) {
1279                                 $style = trim( $style );
1280                                 // Don't output an empty "@media print { }" block (T42498)
1281                                 if ( $style !== '' ) {
1282                                         // Transform the media type based on request params and config
1283                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1284                                         $media = OutputPage::transformCssMedia( $media );
1285
1286                                         if ( $media === '' || $media == 'all' ) {
1287                                                 $out[] = $style;
1288                                         } elseif ( is_string( $media ) ) {
1289                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1290                                         }
1291                                         // else: skip
1292                                 }
1293                         }
1294                 }
1295                 return $out;
1296         }
1297
1298         /**
1299          * Returns a JS call to mw.loader.state, which sets the state of a
1300          * module or modules to a given value. Has two calling conventions:
1301          *
1302          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1303          *         Set the state of a single module called $name to $state
1304          *
1305          *    - ResourceLoader::makeLoaderStateScript( [ $name => $state, ... ] ):
1306          *         Set the state of modules with the given names to the given states
1307          *
1308          * @param string $name
1309          * @param string $state
1310          * @return string JavaScript code
1311          */
1312         public static function makeLoaderStateScript( $name, $state = null ) {
1313                 if ( is_array( $name ) ) {
1314                         return Xml::encodeJsCall(
1315                                 'mw.loader.state',
1316                                 [ $name ],
1317                                 self::inDebugMode()
1318                         );
1319                 } else {
1320                         return Xml::encodeJsCall(
1321                                 'mw.loader.state',
1322                                 [ $name, $state ],
1323                                 self::inDebugMode()
1324                         );
1325                 }
1326         }
1327
1328         /**
1329          * Returns JS code which calls the script given by $script. The script will
1330          * be called with local variables name, version, dependencies and group,
1331          * which will have values corresponding to $name, $version, $dependencies
1332          * and $group as supplied.
1333          *
1334          * @param string $name Module name
1335          * @param string $version Module version hash
1336          * @param array $dependencies List of module names on which this module depends
1337          * @param string $group Group which the module is in.
1338          * @param string $source Source of the module, or 'local' if not foreign.
1339          * @param string $script JavaScript code
1340          * @return string JavaScript code
1341          */
1342         public static function makeCustomLoaderScript( $name, $version, $dependencies,
1343                 $group, $source, $script
1344         ) {
1345                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1346                 return Xml::encodeJsCall(
1347                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1348                         [ $name, $version, $dependencies, $group, $source ],
1349                         self::inDebugMode()
1350                 );
1351         }
1352
1353         private static function isEmptyObject( stdClass $obj ) {
1354                 foreach ( $obj as $key => $value ) {
1355                         return false;
1356                 }
1357                 return true;
1358         }
1359
1360         /**
1361          * Remove empty values from the end of an array.
1362          *
1363          * Values considered empty:
1364          *
1365          * - null
1366          * - []
1367          * - new XmlJsCode( '{}' )
1368          * - new stdClass() // (object) []
1369          *
1370          * @param Array $array
1371          */
1372         private static function trimArray( array &$array ) {
1373                 $i = count( $array );
1374                 while ( $i-- ) {
1375                         if ( $array[$i] === null
1376                                 || $array[$i] === []
1377                                 || ( $array[$i] instanceof XmlJsCode && $array[$i]->value === '{}' )
1378                                 || ( $array[$i] instanceof stdClass && self::isEmptyObject( $array[$i] ) )
1379                         ) {
1380                                 unset( $array[$i] );
1381                         } else {
1382                                 break;
1383                         }
1384                 }
1385         }
1386
1387         /**
1388          * Returns JS code which calls mw.loader.register with the given
1389          * parameters. Has three calling conventions:
1390          *
1391          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version,
1392          *        $dependencies, $group, $source, $skip
1393          *     ):
1394          *        Register a single module.
1395          *
1396          *   - ResourceLoader::makeLoaderRegisterScript( [ $name1, $name2 ] ):
1397          *        Register modules with the given names.
1398          *
1399          *   - ResourceLoader::makeLoaderRegisterScript( [
1400          *        [ $name1, $version1, $dependencies1, $group1, $source1, $skip1 ],
1401          *        [ $name2, $version2, $dependencies1, $group2, $source2, $skip2 ],
1402          *        ...
1403          *     ] ):
1404          *        Registers modules with the given names and parameters.
1405          *
1406          * @param string $name Module name
1407          * @param string $version Module version hash
1408          * @param array $dependencies List of module names on which this module depends
1409          * @param string $group Group which the module is in
1410          * @param string $source Source of the module, or 'local' if not foreign
1411          * @param string $skip Script body of the skip function
1412          * @return string JavaScript code
1413          */
1414         public static function makeLoaderRegisterScript( $name, $version = null,
1415                 $dependencies = null, $group = null, $source = null, $skip = null
1416         ) {
1417                 if ( is_array( $name ) ) {
1418                         // Build module name index
1419                         $index = [];
1420                         foreach ( $name as $i => &$module ) {
1421                                 $index[$module[0]] = $i;
1422                         }
1423
1424                         // Transform dependency names into indexes when possible, they will be resolved by
1425                         // mw.loader.register on the other end
1426                         foreach ( $name as &$module ) {
1427                                 if ( isset( $module[2] ) ) {
1428                                         foreach ( $module[2] as &$dependency ) {
1429                                                 if ( isset( $index[$dependency] ) ) {
1430                                                         $dependency = $index[$dependency];
1431                                                 }
1432                                         }
1433                                 }
1434                         }
1435
1436                         array_walk( $name, [ 'self', 'trimArray' ] );
1437
1438                         return Xml::encodeJsCall(
1439                                 'mw.loader.register',
1440                                 [ $name ],
1441                                 self::inDebugMode()
1442                         );
1443                 } else {
1444                         $registration = [ $name, $version, $dependencies, $group, $source, $skip ];
1445                         self::trimArray( $registration );
1446                         return Xml::encodeJsCall(
1447                                 'mw.loader.register',
1448                                 $registration,
1449                                 self::inDebugMode()
1450                         );
1451                 }
1452         }
1453
1454         /**
1455          * Returns JS code which calls mw.loader.addSource() with the given
1456          * parameters. Has two calling conventions:
1457          *
1458          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1459          *       Register a single source
1460          *
1461          *   - ResourceLoader::makeLoaderSourcesScript( [ $id1 => $loadUrl, $id2 => $loadUrl, ... ] );
1462          *       Register sources with the given IDs and properties.
1463          *
1464          * @param string $id Source ID
1465          * @param string $loadUrl load.php url
1466          * @return string JavaScript code
1467          */
1468         public static function makeLoaderSourcesScript( $id, $loadUrl = null ) {
1469                 if ( is_array( $id ) ) {
1470                         return Xml::encodeJsCall(
1471                                 'mw.loader.addSource',
1472                                 [ $id ],
1473                                 self::inDebugMode()
1474                         );
1475                 } else {
1476                         return Xml::encodeJsCall(
1477                                 'mw.loader.addSource',
1478                                 [ $id, $loadUrl ],
1479                                 self::inDebugMode()
1480                         );
1481                 }
1482         }
1483
1484         /**
1485          * Returns JS code which runs given JS code if the client-side framework is
1486          * present.
1487          *
1488          * @deprecated since 1.25; use makeInlineScript instead
1489          * @param string $script JavaScript code
1490          * @return string JavaScript code
1491          */
1492         public static function makeLoaderConditionalScript( $script ) {
1493                 return '(window.RLQ=window.RLQ||[]).push(function(){' .
1494                         trim( $script ) . '});';
1495         }
1496
1497         /**
1498          * Construct an inline script tag with given JS code.
1499          *
1500          * The code will be wrapped in a closure, and it will be executed by ResourceLoader
1501          * only if the client has adequate support for MediaWiki JavaScript code.
1502          *
1503          * @param string $script JavaScript code
1504          * @return WrappedString HTML
1505          */
1506         public static function makeInlineScript( $script ) {
1507                 $js = self::makeLoaderConditionalScript( $script );
1508                 return new WrappedString(
1509                         Html::inlineScript( $js ),
1510                         '<script>(window.RLQ=window.RLQ||[]).push(function(){',
1511                         '});</script>'
1512                 );
1513         }
1514
1515         /**
1516          * Returns JS code which will set the MediaWiki configuration array to
1517          * the given value.
1518          *
1519          * @param array $configuration List of configuration values keyed by variable name
1520          * @return string JavaScript code
1521          */
1522         public static function makeConfigSetScript( array $configuration ) {
1523                 return Xml::encodeJsCall(
1524                         'mw.config.set',
1525                         [ $configuration ],
1526                         self::inDebugMode()
1527                 );
1528         }
1529
1530         /**
1531          * Convert an array of module names to a packed query string.
1532          *
1533          * For example, [ 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' ]
1534          * becomes 'foo.bar,baz|bar.baz,quux'
1535          * @param array $modules List of module names (strings)
1536          * @return string Packed query string
1537          */
1538         public static function makePackedModulesString( $modules ) {
1539                 $groups = []; // [ prefix => [ suffixes ] ]
1540                 foreach ( $modules as $module ) {
1541                         $pos = strrpos( $module, '.' );
1542                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1543                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1544                         $groups[$prefix][] = $suffix;
1545                 }
1546
1547                 $arr = [];
1548                 foreach ( $groups as $prefix => $suffixes ) {
1549                         $p = $prefix === '' ? '' : $prefix . '.';
1550                         $arr[] = $p . implode( ',', $suffixes );
1551                 }
1552                 $str = implode( '|', $arr );
1553                 return $str;
1554         }
1555
1556         /**
1557          * Determine whether debug mode was requested
1558          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1559          * @return bool
1560          */
1561         public static function inDebugMode() {
1562                 if ( self::$debugMode === null ) {
1563                         global $wgRequest, $wgResourceLoaderDebug;
1564                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1565                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1566                         );
1567                 }
1568                 return self::$debugMode;
1569         }
1570
1571         /**
1572          * Reset static members used for caching.
1573          *
1574          * Global state and $wgRequest are evil, but we're using it right
1575          * now and sometimes we need to be able to force ResourceLoader to
1576          * re-evaluate the context because it has changed (e.g. in the test suite).
1577          */
1578         public static function clearCache() {
1579                 self::$debugMode = null;
1580         }
1581
1582         /**
1583          * Build a load.php URL
1584          *
1585          * @since 1.24
1586          * @param string $source Name of the ResourceLoader source
1587          * @param ResourceLoaderContext $context
1588          * @param array $extraQuery
1589          * @return string URL to load.php. May be protocol-relative if $wgLoadScript is, too.
1590          */
1591         public function createLoaderURL( $source, ResourceLoaderContext $context,
1592                 $extraQuery = []
1593         ) {
1594                 $query = self::createLoaderQuery( $context, $extraQuery );
1595                 $script = $this->getLoadScript( $source );
1596
1597                 return wfAppendQuery( $script, $query );
1598         }
1599
1600         /**
1601          * Helper for createLoaderURL()
1602          *
1603          * @since 1.24
1604          * @see makeLoaderQuery
1605          * @param ResourceLoaderContext $context
1606          * @param array $extraQuery
1607          * @return array
1608          */
1609         protected static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = [] ) {
1610                 return self::makeLoaderQuery(
1611                         $context->getModules(),
1612                         $context->getLanguage(),
1613                         $context->getSkin(),
1614                         $context->getUser(),
1615                         $context->getVersion(),
1616                         $context->getDebug(),
1617                         $context->getOnly(),
1618                         $context->getRequest()->getBool( 'printable' ),
1619                         $context->getRequest()->getBool( 'handheld' ),
1620                         $extraQuery
1621                 );
1622         }
1623
1624         /**
1625          * Build a query array (array representation of query string) for load.php. Helper
1626          * function for createLoaderURL().
1627          *
1628          * @param array $modules
1629          * @param string $lang
1630          * @param string $skin
1631          * @param string $user
1632          * @param string $version
1633          * @param bool $debug
1634          * @param string $only
1635          * @param bool $printable
1636          * @param bool $handheld
1637          * @param array $extraQuery
1638          *
1639          * @return array
1640          */
1641         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1642                 $version = null, $debug = false, $only = null, $printable = false,
1643                 $handheld = false, $extraQuery = []
1644         ) {
1645                 $query = [
1646                         'modules' => self::makePackedModulesString( $modules ),
1647                         'lang' => $lang,
1648                         'skin' => $skin,
1649                         'debug' => $debug ? 'true' : 'false',
1650                 ];
1651                 if ( $user !== null ) {
1652                         $query['user'] = $user;
1653                 }
1654                 if ( $version !== null ) {
1655                         $query['version'] = $version;
1656                 }
1657                 if ( $only !== null ) {
1658                         $query['only'] = $only;
1659                 }
1660                 if ( $printable ) {
1661                         $query['printable'] = 1;
1662                 }
1663                 if ( $handheld ) {
1664                         $query['handheld'] = 1;
1665                 }
1666                 $query += $extraQuery;
1667
1668                 // Make queries uniform in order
1669                 ksort( $query );
1670                 return $query;
1671         }
1672
1673         /**
1674          * Check a module name for validity.
1675          *
1676          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1677          * at most 255 bytes.
1678          *
1679          * @param string $moduleName Module name to check
1680          * @return bool Whether $moduleName is a valid module name
1681          */
1682         public static function isValidModuleName( $moduleName ) {
1683                 return strcspn( $moduleName, '!,|', 0, 255 ) === strlen( $moduleName );
1684         }
1685
1686         /**
1687          * Returns LESS compiler set up for use with MediaWiki
1688          *
1689          * @since 1.27
1690          * @param array $extraVars Associative array of extra (i.e., other than the
1691          *   globally-configured ones) that should be used for compilation.
1692          * @throws MWException
1693          * @return Less_Parser
1694          */
1695         public function getLessCompiler( $extraVars = [] ) {
1696                 // When called from the installer, it is possible that a required PHP extension
1697                 // is missing (at least for now; see T49564). If this is the case, throw an
1698                 // exception (caught by the installer) to prevent a fatal error later on.
1699                 if ( !class_exists( 'Less_Parser' ) ) {
1700                         throw new MWException( 'MediaWiki requires the less.php parser' );
1701                 }
1702
1703                 $parser = new Less_Parser;
1704                 $parser->ModifyVars( array_merge( $this->getLessVars(), $extraVars ) );
1705                 $parser->SetImportDirs(
1706                         array_fill_keys( $this->config->get( 'ResourceLoaderLESSImportPaths' ), '' )
1707                 );
1708                 $parser->SetOption( 'relativeUrls', false );
1709
1710                 return $parser;
1711         }
1712
1713         /**
1714          * Get global LESS variables.
1715          *
1716          * @since 1.27
1717          * @return array Map of variable names to string CSS values.
1718          */
1719         public function getLessVars() {
1720                 if ( !$this->lessVars ) {
1721                         $lessVars = $this->config->get( 'ResourceLoaderLESSVars' );
1722                         Hooks::run( 'ResourceLoaderGetLessVars', [ &$lessVars ] );
1723                         $this->lessVars = $lessVars;
1724                 }
1725                 return $this->lessVars;
1726         }
1727 }