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          * @var MessageBlobStore
  84          */
  85         protected $blobStore;
  86
  87         /**
  88          * @var LoggerInterface
  89          */
  90         private $logger;
  91
  92         /** @var string JavaScript / CSS pragma to disable minification. **/
  93         const FILTER_NOMIN = '/*@nomin*/';
  94
  95         /**
  96          * Load information stored in the database about modules.
  97          *
  98          * This method grabs modules dependencies from the database and updates modules
  99          * objects.
 100          *
 101          * This is not inside the module code because it is much faster to
 102          * request all of the information at once than it is to have each module
 103          * requests its own information. This sacrifice of modularity yields a substantial
 104          * performance improvement.
 105          *
 106          * @param array $moduleNames List of module names to preload information for
 107          * @param ResourceLoaderContext $context Context to load the information within
 108          */
 109         public function preloadModuleInfo( array $moduleNames, ResourceLoaderContext $context ) {
 110                 if ( !$moduleNames ) {
 111                         // Or else Database*::select() will explode, plus it's cheaper!
 112                         return;
 113                 }
 114                 $dbr = wfGetDB( DB_REPLICA );
 115                 $skin = $context->getSkin();
 116                 $lang = $context->getLanguage();
 117
 118                 // Batched version of ResourceLoaderModule::getFileDependencies
 119                 $vary = "$skin|$lang";
 120                 $res = $dbr->select( 'module_deps', [ 'md_module', 'md_deps' ], [
 121                                 'md_module' => $moduleNames,
 122                                 'md_skin' => $vary,
 123                         ], __METHOD__
 124                 );
 125
 126                 // Prime in-object cache for file dependencies
 127                 $modulesWithDeps = [];
 128                 foreach ( $res as $row ) {
 129                         $module = $this->getModule( $row->md_module );
 130                         if ( $module ) {
 131                                 $module->setFileDependencies( $context, ResourceLoaderModule::expandRelativePaths(
 132                                         FormatJson::decode( $row->md_deps, true )
 133                                 ) );
 134                                 $modulesWithDeps[] = $row->md_module;
 135                         }
 136                 }
 137                 // Register the absence of a dependency row too
 138                 foreach ( array_diff( $moduleNames, $modulesWithDeps ) as $name ) {
 139                         $module = $this->getModule( $name );
 140                         if ( $module ) {
 141                                 $this->getModule( $name )->setFileDependencies( $context, [] );
 142                         }
 143                 }
 144
 145                 // Batched version of ResourceLoaderWikiModule::getTitleInfo
 146                 ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $moduleNames );
 147
 148                 // Prime in-object cache for message blobs for modules with messages
 149                 $modules = [];
 150                 foreach ( $moduleNames as $name ) {
 151                         $module = $this->getModule( $name );
 152                         if ( $module && $module->getMessages() ) {
 153                                 $modules[$name] = $module;
 154                         }
 155                 }
 156                 $store = $this->getMessageBlobStore();
 157                 $blobs = $store->getBlobs( $modules, $lang );
 158                 foreach ( $blobs as $name => $blob ) {
 159                         $modules[$name]->setMessageBlob( $blob, $lang );
 160                 }
 161         }
 162
 163         /**
 164          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 165          *
 166          * Available filters are:
 167          *
 168          *    - minify-js \see JavaScriptMinifier::minify
 169          *    - minify-css \see CSSMin::minify
 170          *
 171          * If $data is empty, only contains whitespace or the filter was unknown,
 172          * $data is returned unmodified.
 173          *
 174          * @param string $filter Name of filter to run
 175          * @param string $data Text to filter, such as JavaScript or CSS text
 176          * @param array $options Keys:
 177          *  - (bool) cache: Whether to allow caching this data. Default: true.
 178          * @return string Filtered data, or a comment containing an error message
 179          */
 180         public static function filter( $filter, $data, array $options = [] ) {
 181                 if ( strpos( $data, ResourceLoader::FILTER_NOMIN ) !== false ) {
 182                         return $data;
 183                 }
 184
 185                 if ( isset( $options['cache'] ) && $options['cache'] === false ) {
 186                         return self::applyFilter( $filter, $data );
 187                 }
 188
 189                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
 190                 $cache = ObjectCache::getLocalServerInstance( CACHE_ANYTHING );
 191
 192                 $key = $cache->makeGlobalKey(
 193                         'resourceloader',
 194                         'filter',
 195                         $filter,
 196                         self::$filterCacheVersion, md5( $data )
 197                 );
 198
 199                 $result = $cache->get( $key );
 200                 if ( $result === false ) {
 201                         $stats->increment( "resourceloader_cache.$filter.miss" );
 202                         $result = self::applyFilter( $filter, $data );
 203                         $cache->set( $key, $result, 24 * 3600 );
 204                 } else {
 205                         $stats->increment( "resourceloader_cache.$filter.hit" );
 206                 }
 207                 if ( $result === null ) {
 208                         // Cached failure
 209                         $result = $data;
 210                 }
 211
 212                 return $result;
 213         }
 214
 215         private static function applyFilter( $filter, $data ) {
 216                 $data = trim( $data );
 217                 if ( $data ) {
 218                         try {
 219                                 $data = ( $filter === 'minify-css' )
 220                                         ? CSSMin::minify( $data )
 221                                         : JavaScriptMinifier::minify( $data );
 222                         } catch ( Exception $e ) {
 223                                 MWExceptionHandler::logException( $e );
 224                                 return null;
 225                         }
 226                 }
 227                 return $data;
 228         }
 229
 230         /* Methods */
 231
 232         /**
 233          * Register core modules and runs registration hooks.
 234          * @param Config $config [optional]
 235          * @param LoggerInterface $logger [optional]
 236          */
 237         public function __construct( Config $config = null, LoggerInterface $logger = null ) {
 238                 global $IP;
 239
 240                 $this->logger = $logger ?: new NullLogger();
 241
 242                 if ( !$config ) {
 243                         $this->logger->debug( __METHOD__ . ' was called without providing a Config instance' );
 244                         $config = MediaWikiServices::getInstance()->getMainConfig();
 245                 }
 246                 $this->config = $config;
 247
 248                 // Add 'local' source first
 249                 $this->addSource( 'local', $config->get( 'LoadScript' ) );
 250
 251                 // Add other sources
 252                 $this->addSource( $config->get( 'ResourceLoaderSources' ) );
 253
 254                 // Register core modules
 255                 $this->register( include "$IP/resources/Resources.php" );
 256                 $this->register( include "$IP/resources/ResourcesOOUI.php" );
 257                 // Register extension modules
 258                 $this->register( $config->get( 'ResourceModules' ) );
 259
 260                 // Avoid PHP 7.1 warning from passing $this by reference
 261                 $rl = $this;
 262                 Hooks::run( 'ResourceLoaderRegisterModules', [ &$rl ] );
 263
 264                 if ( $config->get( 'EnableJavaScriptTest' ) === true ) {
 265                         $this->registerTestModules();
 266                 }
 267
 268                 $this->setMessageBlobStore( new MessageBlobStore( $this, $this->logger ) );
 269         }
 270
 271         /**
 272          * @return Config
 273          */
 274         public function getConfig() {
 275                 return $this->config;
 276         }
 277
 278         /**
 279          * @since 1.26
 280          * @param LoggerInterface $logger
 281          */
 282         public function setLogger( LoggerInterface $logger ) {
 283                 $this->logger = $logger;
 284         }
 285
 286         /**
 287          * @since 1.27
 288          * @return LoggerInterface
 289          */
 290         public function getLogger() {
 291                 return $this->logger;
 292         }
 293
 294         /**
 295          * @since 1.26
 296          * @return MessageBlobStore
 297          */
 298         public function getMessageBlobStore() {
 299                 return $this->blobStore;
 300         }
 301
 302         /**
 303          * @since 1.25
 304          * @param MessageBlobStore $blobStore
 305          */
 306         public function setMessageBlobStore( MessageBlobStore $blobStore ) {
 307                 $this->blobStore = $blobStore;
 308         }
 309
 310         /**
 311          * Register a module with the ResourceLoader system.
 312          *
 313          * @param mixed $name Name of module as a string or List of name/object pairs as an array
 314          * @param array $info Module info array. For backwards compatibility with 1.17alpha,
 315          *   this may also be a ResourceLoaderModule object. Optional when using
 316          *   multiple-registration calling style.
 317          * @throws MWException If a duplicate module registration is attempted
 318          * @throws MWException If a module name contains illegal characters (pipes or commas)
 319          * @throws MWException If something other than a ResourceLoaderModule is being registered
 320          * @return bool False if there were any errors, in which case one or more modules were
 321          *   not registered
 322          */
 323         public function register( $name, $info = null ) {
 324                 $moduleSkinStyles = $this->config->get( 'ResourceModuleSkinStyles' );
 325
 326                 // Allow multiple modules to be registered in one call
 327                 $registrations = is_array( $name ) ? $name : [ $name => $info ];
 328                 foreach ( $registrations as $name => $info ) {
 329                         // Warn on duplicate registrations
 330                         if ( isset( $this->moduleInfos[$name] ) ) {
 331                                 // A module has already been registered by this name
 332                                 $this->logger->warning(
 333                                         'ResourceLoader duplicate registration warning. ' .
 334                                         'Another module has already been registered as ' . $name
 335                                 );
 336                         }
 337
 338                         // Check $name for validity
 339                         if ( !self::isValidModuleName( $name ) ) {
 340                                 throw new MWException( "ResourceLoader module name '$name' is invalid, "
 341                                         . "see ResourceLoader::isValidModuleName()" );
 342                         }
 343
 344                         // Attach module
 345                         if ( $info instanceof ResourceLoaderModule ) {
 346                                 $this->moduleInfos[$name] = [ 'object' => $info ];
 347                                 $info->setName( $name );
 348                                 $this->modules[$name] = $info;
 349                         } elseif ( is_array( $info ) ) {
 350                                 // New calling convention
 351                                 $this->moduleInfos[$name] = $info;
 352                         } else {
 353                                 throw new MWException(
 354                                         'ResourceLoader module info type error for module \'' . $name .
 355                                         '\': expected ResourceLoaderModule or array (got: ' . gettype( $info ) . ')'
 356                                 );
 357                         }
 358
 359                         // Last-minute changes
 360
 361                         // Apply custom skin-defined styles to existing modules.
 362                         if ( $this->isFileModule( $name ) ) {
 363                                 foreach ( $moduleSkinStyles as $skinName => $skinStyles ) {
 364                                         // If this module already defines skinStyles for this skin, ignore $wgResourceModuleSkinStyles.
 365                                         if ( isset( $this->moduleInfos[$name]['skinStyles'][$skinName] ) ) {
 366                                                 continue;
 367                                         }
 368
 369                                         // If $name is preceded with a '+', the defined style files will be added to 'default'
 370                                         // skinStyles, otherwise 'default' will be ignored as it normally would be.
 371                                         if ( isset( $skinStyles[$name] ) ) {
 372                                                 $paths = (array)$skinStyles[$name];
 373                                                 $styleFiles = [];
 374                                         } elseif ( isset( $skinStyles['+' . $name] ) ) {
 375                                                 $paths = (array)$skinStyles['+' . $name];
 376                                                 $styleFiles = isset( $this->moduleInfos[$name]['skinStyles']['default'] ) ?
 377                                                         (array)$this->moduleInfos[$name]['skinStyles']['default'] :
 378                                                         [];
 379                                         } else {
 380                                                 continue;
 381                                         }
 382
 383                                         // Add new file paths, remapping them to refer to our directories and not use settings
 384                                         // from the module we're modifying, which come from the base definition.
 385                                         list( $localBasePath, $remoteBasePath ) =
 386                                                 ResourceLoaderFileModule::extractBasePaths( $skinStyles );
 387
 388                                         foreach ( $paths as $path ) {
 389                                                 $styleFiles[] = new ResourceLoaderFilePath( $path, $localBasePath, $remoteBasePath );
 390                                         }
 391
 392                                         $this->moduleInfos[$name]['skinStyles'][$skinName] = $styleFiles;
 393                                 }
 394                         }
 395                 }
 396         }
 397
 398         public function registerTestModules() {
 399                 global $IP;
 400
 401                 if ( $this->config->get( 'EnableJavaScriptTest' ) !== true ) {
 402                         throw new MWException( 'Attempt to register JavaScript test modules '
 403                                 . 'but <code>$wgEnableJavaScriptTest</code> is false. '
 404                                 . 'Edit your <code>LocalSettings.php</code> to enable it.' );
 405                 }
 406
 407                 // Get core test suites
 408                 $testModules = [];
 409                 $testModules['qunit'] = [];
 410                 // Get other test suites (e.g. from extensions)
 411                 // Avoid PHP 7.1 warning from passing $this by reference
 412                 $rl = $this;
 413                 Hooks::run( 'ResourceLoaderTestModules', [ &$testModules, &$rl ] );
 414
 415                 // Add the testrunner (which configures QUnit) to the dependencies.
 416                 // Since it must be ready before any of the test suites are executed.
 417                 foreach ( $testModules['qunit'] as &$module ) {
 418                         // Make sure all test modules are top-loading so that when QUnit starts
 419                         // on document-ready, it will run once and finish. If some tests arrive
 420                         // later (possibly after QUnit has already finished) they will be ignored.
 421                         $module['position'] = 'top';
 422                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 423                 }
 424
 425                 $testModules['qunit'] =
 426                         ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules['qunit'];
 427
 428                 foreach ( $testModules as $id => $names ) {
 429                         // Register test modules
 430                         $this->register( $testModules[$id] );
 431
 432                         // Keep track of their names so that they can be loaded together
 433                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 434                 }
 435         }
 436
 437         /**
 438          * Add a foreign source of modules.
 439          *
 440          * Source IDs are typically the same as the Wiki ID or database name (e.g. lowercase a-z).
 441          *
 442          * @param array|string $id Source ID (string), or [ id1 => loadUrl, id2 => loadUrl, ... ]
 443          * @param string|array $loadUrl load.php url (string), or array with loadUrl key for
 444          *  backwards-compatibility.
 445          * @throws MWException
 446          */
 447         public function addSource( $id, $loadUrl = null ) {
 448                 // Allow multiple sources to be registered in one call
 449                 if ( is_array( $id ) ) {
 450                         foreach ( $id as $key => $value ) {
 451                                 $this->addSource( $key, $value );
 452                         }
 453                         return;
 454                 }
 455
 456                 // Disallow duplicates
 457                 if ( isset( $this->sources[$id] ) ) {
 458                         throw new MWException(
 459                                 'ResourceLoader duplicate source addition error. ' .
 460                                 'Another source has already been registered as ' . $id
 461                         );
 462                 }
 463
 464                 // Pre 1.24 backwards-compatibility
 465                 if ( is_array( $loadUrl ) ) {
 466                         if ( !isset( $loadUrl['loadScript'] ) ) {
 467                                 throw new MWException(
 468                                         __METHOD__ . ' was passed an array with no "loadScript" key.'
 469                                 );
 470                         }
 471
 472                         $loadUrl = $loadUrl['loadScript'];
 473                 }
 474
 475                 $this->sources[$id] = $loadUrl;
 476         }
 477
 478         /**
 479          * Get a list of module names.
 480          *
 481          * @return array List of module names
 482          */
 483         public function getModuleNames() {
 484                 return array_keys( $this->moduleInfos );
 485         }
 486
 487         /**
 488          * Get a list of test module names for one (or all) frameworks.
 489          *
 490          * If the given framework id is unknkown, or if the in-object variable is not an array,
 491          * then it will return an empty array.
 492          *
 493          * @param string $framework Get only the test module names for one
 494          *   particular framework (optional)
 495          * @return array
 496          */
 497         public function getTestModuleNames( $framework = 'all' ) {
 498                 /** @todo api siteinfo prop testmodulenames modulenames */
 499                 if ( $framework == 'all' ) {
 500                         return $this->testModuleNames;
 501                 } elseif ( isset( $this->testModuleNames[$framework] )
 502                         && is_array( $this->testModuleNames[$framework] )
 503                 ) {
 504                         return $this->testModuleNames[$framework];
 505                 } else {
 506                         return [];
 507                 }
 508         }
 509
 510         /**
 511          * Check whether a ResourceLoader module is registered
 512          *
 513          * @since 1.25
 514          * @param string $name
 515          * @return bool
 516          */
 517         public function isModuleRegistered( $name ) {
 518                 return isset( $this->moduleInfos[$name] );
 519         }
 520
 521         /**
 522          * Get the ResourceLoaderModule object for a given module name.
 523          *
 524          * If an array of module parameters exists but a ResourceLoaderModule object has not
 525          * yet been instantiated, this method will instantiate and cache that object such that
 526          * subsequent calls simply return the same object.
 527          *
 528          * @param string $name Module name
 529          * @return ResourceLoaderModule|null If module has been registered, return a
 530          *  ResourceLoaderModule instance. Otherwise, return null.
 531          */
 532         public function getModule( $name ) {
 533                 if ( !isset( $this->modules[$name] ) ) {
 534                         if ( !isset( $this->moduleInfos[$name] ) ) {
 535                                 // No such module
 536                                 return null;
 537                         }
 538                         // Construct the requested object
 539                         $info = $this->moduleInfos[$name];
 540                         /** @var ResourceLoaderModule $object */
 541                         if ( isset( $info['object'] ) ) {
 542                                 // Object given in info array
 543                                 $object = $info['object'];
 544                         } elseif ( isset( $info['factory'] ) ) {
 545                                 $object = call_user_func( $info['factory'], $info );
 546                                 $object->setConfig( $this->getConfig() );
 547                                 $object->setLogger( $this->logger );
 548                         } else {
 549                                 if ( !isset( $info['class'] ) ) {
 550                                         $class = 'ResourceLoaderFileModule';
 551                                 } else {
 552                                         $class = $info['class'];
 553                                 }
 554                                 /** @var ResourceLoaderModule $object */
 555                                 $object = new $class( $info );
 556                                 $object->setConfig( $this->getConfig() );
 557                                 $object->setLogger( $this->logger );
 558                         }
 559                         $object->setName( $name );
 560                         $this->modules[$name] = $object;
 561                 }
 562
 563                 return $this->modules[$name];
 564         }
 565
 566         /**
 567          * Return whether the definition of a module corresponds to a simple ResourceLoaderFileModule.
 568          *
 569          * @param string $name Module name
 570          * @return bool
 571          */
 572         protected function isFileModule( $name ) {
 573                 if ( !isset( $this->moduleInfos[$name] ) ) {
 574                         return false;
 575                 }
 576                 $info = $this->moduleInfos[$name];
 577                 if ( isset( $info['object'] ) || isset( $info['class'] ) ) {
 578                         return false;
 579                 }
 580                 return true;
 581         }
 582
 583         /**
 584          * Get the list of sources.
 585          *
 586          * @return array Like [ id => load.php url, ... ]
 587          */
 588         public function getSources() {
 589                 return $this->sources;
 590         }
 591
 592         /**
 593          * Get the URL to the load.php endpoint for the given
 594          * ResourceLoader source
 595          *
 596          * @since 1.24
 597          * @param string $source
 598          * @throws MWException On an invalid $source name
 599          * @return string
 600          */
 601         public function getLoadScript( $source ) {
 602                 if ( !isset( $this->sources[$source] ) ) {
 603                         throw new MWException( "The $source source was never registered in ResourceLoader." );
 604                 }
 605                 return $this->sources[$source];
 606         }
 607
 608         /**
 609          * @since 1.26
 610          * @param string $value
 611          * @return string Hash
 612          */
 613         public static function makeHash( $value ) {
 614                 $hash = hash( 'fnv132', $value );
 615                 return Wikimedia\base_convert( $hash, 16, 36, 7 );
 616         }
 617
 618         /**
 619          * Add an error to the 'errors' array and log it.
 620          *
 621          * Should only be called from within respond().
 622          *
 623          * @since 1.29
 624          * @param Exception $e
 625          * @param string $msg
 626          * @param array $context
 627          */
 628         protected function outputErrorAndLog( Exception $e, $msg, array $context = [] ) {
 629                 MWExceptionHandler::logException( $e );
 630                 $this->logger->warning(
 631                         $msg,
 632                         $context + [ 'exception' => $e ]
 633                 );
 634                 $this->errors[] = self::formatExceptionNoComment( $e );
 635         }
 636
 637         /**
 638          * Helper method to get and combine versions of multiple modules.
 639          *
 640          * @since 1.26
 641          * @param ResourceLoaderContext $context
 642          * @param string[] $modules List of known module names
 643          * @return string Hash
 644          */
 645         public function getCombinedVersion( ResourceLoaderContext $context, array $moduleNames ) {
 646                 if ( !$moduleNames ) {
 647                         return '';
 648                 }
 649                 $hashes = array_map( function ( $module ) use ( $context ) {
 650                         try {
 651                                 return $this->getModule( $module )->getVersionHash( $context );
 652                         } catch ( Exception $e ) {
 653                                 // If modules fail to compute a version, do still consider the versions
 654                                 // of other modules - don't set an empty string E-Tag for the whole request.
 655                                 // See also T152266 and StartupModule::getModuleRegistrations().
 656                                 $this->outputErrorAndLog( $e,
 657                                         'Calculating version for "{module}" failed: {exception}',
 658                                         [
 659                                                 'module' => $module,
 660                                         ]
 661                                 );
 662                                 return '';
 663                         }
 664                 }, $moduleNames );
 665                 return self::makeHash( implode( '', $hashes ) );
 666         }
 667
 668         /**
 669          * Get the expected value of the 'version' query parameter.
 670          *
 671          * This is used by respond() to set a short Cache-Control header for requests with
 672          * information newer than the current server has. This avoids pollution of edge caches.
 673          * Typically during deployment. (T117587)
 674          *
 675          * This MUST match return value of `mw.loader#getCombinedVersion()` client-side.
 676          *
 677          * @since 1.28
 678          * @param ResourceLoaderContext $context
 679          * @param string[] $modules List of module names
 680          * @return string Hash
 681          */
 682         public function makeVersionQuery( ResourceLoaderContext $context ) {
 683                 // As of MediaWiki 1.28, the server and client use the same algorithm for combining
 684                 // version hashes. There is no technical reason for this to be same, and for years the
 685                 // implementations differed. If getCombinedVersion in PHP (used for StartupModule and
 686                 // E-Tag headers) differs in the future from getCombinedVersion in JS (used for 'version'
 687                 // query parameter), then this method must continue to match the JS one.
 688                 $moduleNames = [];
 689                 foreach ( $context->getModules() as $name ) {
 690                         if ( !$this->getModule( $name ) ) {
 691                                 // If a versioned request contains a missing module, the version is a mismatch
 692                                 // as the client considered a module (and version) we don't have.
 693                                 return '';
 694                         }
 695                         $moduleNames[] = $name;
 696                 }
 697                 return $this->getCombinedVersion( $context, $moduleNames );
 698         }
 699
 700         /**
 701          * Output a response to a load request, including the content-type header.
 702          *
 703          * @param ResourceLoaderContext $context Context in which a response should be formed
 704          */
 705         public function respond( ResourceLoaderContext $context ) {
 706                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 707                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 708                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 709                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 710                 // the whole thing in our own output buffer to be sure the active buffer
 711                 // doesn't use ob_gzhandler.
 712                 // See https://bugs.php.net/bug.php?id=36514
 713                 ob_start();
 714
 715                 // Find out which modules are missing and instantiate the others
 716                 $modules = [];
 717                 $missing = [];
 718                 foreach ( $context->getModules() as $name ) {
 719                         $module = $this->getModule( $name );
 720                         if ( $module ) {
 721                                 // Do not allow private modules to be loaded from the web.
 722                                 // This is a security issue, see T36907.
 723                                 if ( $module->getGroup() === 'private' ) {
 724                                         $this->logger->debug( "Request for private module '$name' denied" );
 725                                         $this->errors[] = "Cannot show private module \"$name\"";
 726                                         continue;
 727                                 }
 728                                 $modules[$name] = $module;
 729                         } else {
 730                                 $missing[] = $name;
 731                         }
 732                 }
 733
 734                 try {
 735                         // Preload for getCombinedVersion() and for batch makeModuleResponse()
 736                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 737                 } catch ( Exception $e ) {
 738                         $this->outputErrorAndLog( $e, 'Preloading module info failed: {exception}' );
 739                 }
 740
 741                 // Combine versions to propagate cache invalidation
 742                 $versionHash = '';
 743                 try {
 744                         $versionHash = $this->getCombinedVersion( $context, array_keys( $modules ) );
 745                 } catch ( Exception $e ) {
 746                         $this->outputErrorAndLog( $e, 'Calculating version hash failed: {exception}' );
 747                 }
 748
 749                 // See RFC 2616 § 3.11 Entity Tags
 750                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.11
 751                 $etag = 'W/"' . $versionHash . '"';
 752
 753                 // Try the client-side cache first
 754                 if ( $this->tryRespondNotModified( $context, $etag ) ) {
 755                         return; // output handled (buffers cleared)
 756                 }
 757
 758                 // Use file cache if enabled and available...
 759                 if ( $this->config->get( 'UseFileCache' ) ) {
 760                         $fileCache = ResourceFileCache::newFromContext( $context );
 761                         if ( $this->tryRespondFromFileCache( $fileCache, $context, $etag ) ) {
 762                                 return; // output handled
 763                         }
 764                 }
 765
 766                 // Generate a response
 767                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 768
 769                 // Capture any PHP warnings from the output buffer and append them to the
 770                 // error list if we're in debug mode.
 771                 if ( $context->getDebug() ) {
 772                         $warnings = ob_get_contents();
 773                         if ( strlen( $warnings ) ) {
 774                                 $this->errors[] = $warnings;
 775                         }
 776                 }
 777
 778                 // Save response to file cache unless there are errors
 779                 if ( isset( $fileCache ) && !$this->errors && !count( $missing ) ) {
 780                         // Cache single modules and images...and other requests if there are enough hits
 781                         if ( ResourceFileCache::useFileCache( $context ) ) {
 782                                 if ( $fileCache->isCacheWorthy() ) {
 783                                         $fileCache->saveText( $response );
 784                                 } else {
 785                                         $fileCache->incrMissesRecent( $context->getRequest() );
 786                                 }
 787                         }
 788                 }
 789
 790                 $this->sendResponseHeaders( $context, $etag, (bool)$this->errors );
 791
 792                 // Remove the output buffer and output the response
 793                 ob_end_clean();
 794
 795                 if ( $context->getImageObj() && $this->errors ) {
 796                         // We can't show both the error messages and the response when it's an image.
 797                         $response = implode( "\n\n", $this->errors );
 798                 } elseif ( $this->errors ) {
 799                         $errorText = implode( "\n\n", $this->errors );
 800                         $errorResponse = self::makeComment( $errorText );
 801                         if ( $context->shouldIncludeScripts() ) {
 802                                 $errorResponse .= 'if (window.console && console.error) {'
 803                                         . Xml::encodeJsCall( 'console.error', [ $errorText ] )
 804                                         . "}\n";
 805                         }
 806
 807                         // Prepend error info to the response
 808                         $response = $errorResponse . $response;
 809                 }
 810
 811                 $this->errors = [];
 812                 echo $response;
 813         }
 814
 815         /**
 816          * Send main response headers to the client.
 817          *
 818          * Deals with Content-Type, CORS (for stylesheets), and caching.
 819          *
 820          * @param ResourceLoaderContext $context
 821          * @param string $etag ETag header value
 822          * @param bool $errors Whether there are errors in the response
 823          * @return void
 824          */
 825         protected function sendResponseHeaders( ResourceLoaderContext $context, $etag, $errors ) {
 826                 \MediaWiki\HeaderCallback::warnIfHeadersSent();
 827                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 828                 // Use a short cache expiry so that updates propagate to clients quickly, if:
 829                 // - No version specified (shared resources, e.g. stylesheets)
 830                 // - There were errors (recover quickly)
 831                 // - Version mismatch (T117587, T47877)
 832                 if ( is_null( $context->getVersion() )
 833                         || $errors
 834                         || $context->getVersion() !== $this->makeVersionQuery( $context )
 835                 ) {
 836                         $maxage = $rlMaxage['unversioned']['client'];
 837                         $smaxage = $rlMaxage['unversioned']['server'];
 838                 // If a version was specified we can use a longer expiry time since changing
 839                 // version numbers causes cache misses
 840                 } else {
 841                         $maxage = $rlMaxage['versioned']['client'];
 842                         $smaxage = $rlMaxage['versioned']['server'];
 843                 }
 844                 if ( $context->getImageObj() ) {
 845                         // Output different headers if we're outputting textual errors.
 846                         if ( $errors ) {
 847                                 header( 'Content-Type: text/plain; charset=utf-8' );
 848                         } else {
 849                                 $context->getImageObj()->sendResponseHeaders( $context );
 850                         }
 851                 } elseif ( $context->getOnly() === 'styles' ) {
 852                         header( 'Content-Type: text/css; charset=utf-8' );
 853                         header( 'Access-Control-Allow-Origin: *' );
 854                 } else {
 855                         header( 'Content-Type: text/javascript; charset=utf-8' );
 856                 }
 857                 // See RFC 2616 § 14.19 ETag
 858                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.19
 859                 header( 'ETag: ' . $etag );
 860                 if ( $context->getDebug() ) {
 861                         // Do not cache debug responses
 862                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 863                         header( 'Pragma: no-cache' );
 864                 } else {
 865                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 866                         $exp = min( $maxage, $smaxage );
 867                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 868                 }
 869         }
 870
 871         /**
 872          * Respond with HTTP 304 Not Modified if appropiate.
 873          *
 874          * If there's an If-None-Match header, respond with a 304 appropriately
 875          * and clear out the output buffer. If the client cache is too old then do nothing.
 876          *
 877          * @param ResourceLoaderContext $context
 878          * @param string $etag ETag header value
 879          * @return bool True if HTTP 304 was sent and output handled
 880          */
 881         protected function tryRespondNotModified( ResourceLoaderContext $context, $etag ) {
 882                 // See RFC 2616 § 14.26 If-None-Match
 883                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
 884                 $clientKeys = $context->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST );
 885                 // Never send 304s in debug mode
 886                 if ( $clientKeys !== false && !$context->getDebug() && in_array( $etag, $clientKeys ) ) {
 887                         // There's another bug in ob_gzhandler (see also the comment at
 888                         // the top of this function) that causes it to gzip even empty
 889                         // responses, meaning it's impossible to produce a truly empty
 890                         // response (because the gzip header is always there). This is
 891                         // a problem because 304 responses have to be completely empty
 892                         // per the HTTP spec, and Firefox behaves buggily when they're not.
 893                         // See also https://bugs.php.net/bug.php?id=51579
 894                         // To work around this, we tear down all output buffering before
 895                         // sending the 304.
 896                         wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 897
 898                         HttpStatus::header( 304 );
 899
 900                         $this->sendResponseHeaders( $context, $etag, false );
 901                         return true;
 902                 }
 903                 return false;
 904         }
 905
 906         /**
 907          * Send out code for a response from file cache if possible.
 908          *
 909          * @param ResourceFileCache $fileCache Cache object for this request URL
 910          * @param ResourceLoaderContext $context Context in which to generate a response
 911          * @param string $etag ETag header value
 912          * @return bool If this found a cache file and handled the response
 913          */
 914         protected function tryRespondFromFileCache(
 915                 ResourceFileCache $fileCache,
 916                 ResourceLoaderContext $context,
 917                 $etag
 918         ) {
 919                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 920                 // Buffer output to catch warnings.
 921                 ob_start();
 922                 // Get the maximum age the cache can be
 923                 $maxage = is_null( $context->getVersion() )
 924                         ? $rlMaxage['unversioned']['server']
 925                         : $rlMaxage['versioned']['server'];
 926                 // Minimum timestamp the cache file must have
 927                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 928                 if ( !$good ) {
 929                         try { // RL always hits the DB on file cache miss...
 930                                 wfGetDB( DB_REPLICA );
 931                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 932                                 $good = $fileCache->isCacheGood(); // cache existence check
 933                         }
 934                 }
 935                 if ( $good ) {
 936                         $ts = $fileCache->cacheTimestamp();
 937                         // Send content type and cache headers
 938                         $this->sendResponseHeaders( $context, $etag, false );
 939                         $response = $fileCache->fetchText();
 940                         // Capture any PHP warnings from the output buffer and append them to the
 941                         // response in a comment if we're in debug mode.
 942                         if ( $context->getDebug() ) {
 943                                 $warnings = ob_get_contents();
 944                                 if ( strlen( $warnings ) ) {
 945                                         $response = self::makeComment( $warnings ) . $response;
 946                                 }
 947                         }
 948                         // Remove the output buffer and output the response
 949                         ob_end_clean();
 950                         echo $response . "\n/* Cached {$ts} */";
 951                         return true; // cache hit
 952                 }
 953                 // Clear buffer
 954                 ob_end_clean();
 955
 956                 return false; // cache miss
 957         }
 958
 959         /**
 960          * Generate a CSS or JS comment block.
 961          *
 962          * Only use this for public data, not error message details.
 963          *
 964          * @param string $text
 965          * @return string
 966          */
 967         public static function makeComment( $text ) {
 968                 $encText = str_replace( '*/', '* /', $text );
 969                 return "/*\n$encText\n*/\n";
 970         }
 971
 972         /**
 973          * Handle exception display.
 974          *
 975          * @param Exception $e Exception to be shown to the user
 976          * @return string Sanitized text in a CSS/JS comment that can be returned to the user
 977          */
 978         public static function formatException( $e ) {
 979                 return self::makeComment( self::formatExceptionNoComment( $e ) );
 980         }
 981
 982         /**
 983          * Handle exception display.
 984          *
 985          * @since 1.25
 986          * @param Exception $e Exception to be shown to the user
 987          * @return string Sanitized text that can be returned to the user
 988          */
 989         protected static function formatExceptionNoComment( $e ) {
 990                 global $wgShowExceptionDetails;
 991
 992                 if ( !$wgShowExceptionDetails ) {
 993                         return MWExceptionHandler::getPublicLogMessage( $e );
 994                 }
 995
 996                 return MWExceptionHandler::getLogMessage( $e ) .
 997                         "\nBacktrace:\n" .
 998                         MWExceptionHandler::getRedactedTraceAsString( $e );
 999         }
1000
1001         /**
1002          * Generate code for a response.
1003          *
1004          * @param ResourceLoaderContext $context Context in which to generate a response
1005          * @param ResourceLoaderModule[] $modules List of module objects keyed by module name
1006          * @param string[] $missing List of requested module names that are unregistered (optional)
1007          * @return string Response data
1008          */
1009         public function makeModuleResponse( ResourceLoaderContext $context,
1010                 array $modules, array $missing = []
1011         ) {
1012                 $out = '';
1013                 $states = [];
1014
1015                 if ( !count( $modules ) && !count( $missing ) ) {
1016                         return <<<MESSAGE
1017 /* This file is the Web entry point for MediaWiki's ResourceLoader:
1018    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
1019    no modules were requested. Max made me put this here. */
1020 MESSAGE;
1021                 }
1022
1023                 $image = $context->getImageObj();
1024                 if ( $image ) {
1025                         $data = $image->getImageData( $context );
1026                         if ( $data === false ) {
1027                                 $data = '';
1028                                 $this->errors[] = 'Image generation failed';
1029                         }
1030                         return $data;
1031                 }
1032
1033                 foreach ( $missing as $name ) {
1034                         $states[$name] = 'missing';
1035                 }
1036
1037                 // Generate output
1038                 $isRaw = false;
1039
1040                 $filter = $context->getOnly() === 'styles' ? 'minify-css' : 'minify-js';
1041
1042                 foreach ( $modules as $name => $module ) {
1043                         try {
1044                                 $content = $module->getModuleContent( $context );
1045                                 $implementKey = $name . '@' . $module->getVersionHash( $context );
1046                                 $strContent = '';
1047
1048                                 // Append output
1049                                 switch ( $context->getOnly() ) {
1050                                         case 'scripts':
1051                                                 $scripts = $content['scripts'];
1052                                                 if ( is_string( $scripts ) ) {
1053                                                         // Load scripts raw...
1054                                                         $strContent = $scripts;
1055                                                 } elseif ( is_array( $scripts ) ) {
1056                                                         // ...except when $scripts is an array of URLs
1057                                                         $strContent = self::makeLoaderImplementScript( $implementKey, $scripts, [], [], [] );
1058                                                 }
1059                                                 break;
1060                                         case 'styles':
1061                                                 $styles = $content['styles'];
1062                                                 // We no longer seperate into media, they are all combined now with
1063                                                 // custom media type groups into @media .. {} sections as part of the css string.
1064                                                 // Module returns either an empty array or a numerical array with css strings.
1065                                                 $strContent = isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
1066                                                 break;
1067                                         default:
1068                                                 $scripts = isset( $content['scripts'] ) ? $content['scripts'] : '';
1069                                                 if ( is_string( $scripts ) ) {
1070                                                         if ( $name === 'site' || $name === 'user' ) {
1071                                                                 // Legacy scripts that run in the global scope without a closure.
1072                                                                 // mw.loader.implement will use globalEval if scripts is a string.
1073                                                                 // Minify manually here, because general response minification is
1074                                                                 // not effective due it being a string literal, not a function.
1075                                                                 if ( !ResourceLoader::inDebugMode() ) {
1076                                                                         $scripts = self::filter( 'minify-js', $scripts ); // T107377
1077                                                                 }
1078                                                         } else {
1079                                                                 $scripts = new XmlJsCode( $scripts );
1080                                                         }
1081                                                 }
1082                                                 $strContent = self::makeLoaderImplementScript(
1083                                                         $implementKey,
1084                                                         $scripts,
1085                                                         isset( $content['styles'] ) ? $content['styles'] : [],
1086                                                         isset( $content['messagesBlob'] ) ? new XmlJsCode( $content['messagesBlob'] ) : [],
1087                                                         isset( $content['templates'] ) ? $content['templates'] : []
1088                                                 );
1089                                                 break;
1090                                 }
1091
1092                                 if ( !$context->getDebug() ) {
1093                                         $strContent = self::filter( $filter, $strContent );
1094                                 }
1095
1096                                 $out .= $strContent;
1097
1098                         } catch ( Exception $e ) {
1099                                 $this->outputErrorAndLog( $e, 'Generating module package failed: {exception}' );
1100
1101                                 // Respond to client with error-state instead of module implementation
1102                                 $states[$name] = 'error';
1103                                 unset( $modules[$name] );
1104                         }
1105                         $isRaw |= $module->isRaw();
1106                 }
1107
1108                 // Update module states
1109                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
1110                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
1111                                 // Set the state of modules loaded as only scripts to ready as
1112                                 // they don't have an mw.loader.implement wrapper that sets the state
1113                                 foreach ( $modules as $name => $module ) {
1114                                         $states[$name] = 'ready';
1115                                 }
1116                         }
1117
1118                         // Set the state of modules we didn't respond to with mw.loader.implement
1119                         if ( count( $states ) ) {
1120                                 $stateScript = self::makeLoaderStateScript( $states );
1121                                 if ( !$context->getDebug() ) {
1122                                         $stateScript = self::filter( 'minify-js', $stateScript );
1123                                 }
1124                                 $out .= $stateScript;
1125                         }
1126                 } else {
1127                         if ( count( $states ) ) {
1128                                 $this->errors[] = 'Problematic modules: ' .
1129                                         FormatJson::encode( $states, ResourceLoader::inDebugMode() );
1130                         }
1131                 }
1132
1133                 return $out;
1134         }
1135
1136         /**
1137          * Get names of modules that use a certain message.
1138          *
1139          * @param string $messageKey
1140          * @return array List of module names
1141          */
1142         public function getModulesByMessage( $messageKey ) {
1143                 $moduleNames = [];
1144                 foreach ( $this->getModuleNames() as $moduleName ) {
1145                         $module = $this->getModule( $moduleName );
1146                         if ( in_array( $messageKey, $module->getMessages() ) ) {
1147                                 $moduleNames[] = $moduleName;
1148                         }
1149                 }
1150                 return $moduleNames;
1151         }
1152
1153         /* Static Methods */
1154
1155         /**
1156          * Return JS code that calls mw.loader.implement with given module properties.
1157          *
1158          * @param string $name Module name or implement key (format "`[name]@[version]`")
1159          * @param XmlJsCode|array|string $scripts Code as XmlJsCode (to be wrapped in a closure),
1160          *  list of URLs to JavaScript files, or a string of JavaScript for `$.globalEval`.
1161          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1162          *   to CSS files keyed by media type
1163          * @param mixed $messages List of messages associated with this module. May either be an
1164          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1165          *   the same data, wrapped in an XmlJsCode object.
1166          * @param array $templates Keys are name of templates and values are the source of
1167          *   the template.
1168          * @throws MWException
1169          * @return string
1170          */
1171         protected static function makeLoaderImplementScript(
1172                 $name, $scripts, $styles, $messages, $templates
1173         ) {
1174                 if ( $scripts instanceof XmlJsCode ) {
1175                         $scripts = new XmlJsCode( "function ( $, jQuery, require, module ) {\n{$scripts->value}\n}" );
1176                 } elseif ( !is_string( $scripts ) && !is_array( $scripts ) ) {
1177                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1178                 }
1179                 // mw.loader.implement requires 'styles', 'messages' and 'templates' to be objects (not
1180                 // arrays). json_encode considers empty arrays to be numerical and outputs "[]" instead
1181                 // of "{}". Force them to objects.
1182                 $module = [
1183                         $name,
1184                         $scripts,
1185                         (object)$styles,
1186                         (object)$messages,
1187                         (object)$templates,
1188                 ];
1189                 self::trimArray( $module );
1190
1191                 return Xml::encodeJsCall( 'mw.loader.implement', $module, ResourceLoader::inDebugMode() );
1192         }
1193
1194         /**
1195          * Returns JS code which, when called, will register a given list of messages.
1196          *
1197          * @param mixed $messages Either an associative array mapping message key to value, or a
1198          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1199          * @return string
1200          */
1201         public static function makeMessageSetScript( $messages ) {
1202                 return Xml::encodeJsCall(
1203                         'mw.messages.set',
1204                         [ (object)$messages ],
1205                         ResourceLoader::inDebugMode()
1206                 );
1207         }
1208
1209         /**
1210          * Combines an associative array mapping media type to CSS into a
1211          * single stylesheet with "@media" blocks.
1212          *
1213          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1214          * @return array
1215          */
1216         public static function makeCombinedStyles( array $stylePairs ) {
1217                 $out = [];
1218                 foreach ( $stylePairs as $media => $styles ) {
1219                         // ResourceLoaderFileModule::getStyle can return the styles
1220                         // as a string or an array of strings. This is to allow separation in
1221                         // the front-end.
1222                         $styles = (array)$styles;
1223                         foreach ( $styles as $style ) {
1224                                 $style = trim( $style );
1225                                 // Don't output an empty "@media print { }" block (T42498)
1226                                 if ( $style !== '' ) {
1227                                         // Transform the media type based on request params and config
1228                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1229                                         $media = OutputPage::transformCssMedia( $media );
1230
1231                                         if ( $media === '' || $media == 'all' ) {
1232                                                 $out[] = $style;
1233                                         } elseif ( is_string( $media ) ) {
1234                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1235                                         }
1236                                         // else: skip
1237                                 }
1238                         }
1239                 }
1240                 return $out;
1241         }
1242
1243         /**
1244          * Returns a JS call to mw.loader.state, which sets the state of a
1245          * module or modules to a given value. Has two calling conventions:
1246          *
1247          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1248          *         Set the state of a single module called $name to $state
1249          *
1250          *    - ResourceLoader::makeLoaderStateScript( [ $name => $state, ... ] ):
1251          *         Set the state of modules with the given names to the given states
1252          *
1253          * @param string $name
1254          * @param string $state
1255          * @return string
1256          */
1257         public static function makeLoaderStateScript( $name, $state = null ) {
1258                 if ( is_array( $name ) ) {
1259                         return Xml::encodeJsCall(
1260                                 'mw.loader.state',
1261                                 [ $name ],
1262                                 ResourceLoader::inDebugMode()
1263                         );
1264                 } else {
1265                         return Xml::encodeJsCall(
1266                                 'mw.loader.state',
1267                                 [ $name, $state ],
1268                                 ResourceLoader::inDebugMode()
1269                         );
1270                 }
1271         }
1272
1273         /**
1274          * Returns JS code which calls the script given by $script. The script will
1275          * be called with local variables name, version, dependencies and group,
1276          * which will have values corresponding to $name, $version, $dependencies
1277          * and $group as supplied.
1278          *
1279          * @param string $name Module name
1280          * @param string $version Module version hash
1281          * @param array $dependencies List of module names on which this module depends
1282          * @param string $group Group which the module is in.
1283          * @param string $source Source of the module, or 'local' if not foreign.
1284          * @param string $script JavaScript code
1285          * @return string
1286          */
1287         public static function makeCustomLoaderScript( $name, $version, $dependencies,
1288                 $group, $source, $script
1289         ) {
1290                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1291                 return Xml::encodeJsCall(
1292                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1293                         [ $name, $version, $dependencies, $group, $source ],
1294                         ResourceLoader::inDebugMode()
1295                 );
1296         }
1297
1298         private static function isEmptyObject( stdClass $obj ) {
1299                 foreach ( $obj as $key => $value ) {
1300                         return false;
1301                 }
1302                 return true;
1303         }
1304
1305         /**
1306          * Remove empty values from the end of an array.
1307          *
1308          * Values considered empty:
1309          *
1310          * - null
1311          * - []
1312          * - new XmlJsCode( '{}' )
1313          * - new stdClass() // (object) []
1314          *
1315          * @param Array $array
1316          */
1317         private static function trimArray( array &$array ) {
1318                 $i = count( $array );
1319                 while ( $i-- ) {
1320                         if ( $array[$i] === null
1321                                 || $array[$i] === []
1322                                 || ( $array[$i] instanceof XmlJsCode && $array[$i]->value === '{}' )
1323                                 || ( $array[$i] instanceof stdClass && self::isEmptyObject( $array[$i] ) )
1324                         ) {
1325                                 unset( $array[$i] );
1326                         } else {
1327                                 break;
1328                         }
1329                 }
1330         }
1331
1332         /**
1333          * Returns JS code which calls mw.loader.register with the given
1334          * parameters. Has three calling conventions:
1335          *
1336          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version,
1337          *        $dependencies, $group, $source, $skip
1338          *     ):
1339          *        Register a single module.
1340          *
1341          *   - ResourceLoader::makeLoaderRegisterScript( [ $name1, $name2 ] ):
1342          *        Register modules with the given names.
1343          *
1344          *   - ResourceLoader::makeLoaderRegisterScript( [
1345          *        [ $name1, $version1, $dependencies1, $group1, $source1, $skip1 ],
1346          *        [ $name2, $version2, $dependencies1, $group2, $source2, $skip2 ],
1347          *        ...
1348          *     ] ):
1349          *        Registers modules with the given names and parameters.
1350          *
1351          * @param string $name Module name
1352          * @param string $version Module version hash
1353          * @param array $dependencies List of module names on which this module depends
1354          * @param string $group Group which the module is in
1355          * @param string $source Source of the module, or 'local' if not foreign
1356          * @param string $skip Script body of the skip function
1357          * @return string
1358          */
1359         public static function makeLoaderRegisterScript( $name, $version = null,
1360                 $dependencies = null, $group = null, $source = null, $skip = null
1361         ) {
1362                 if ( is_array( $name ) ) {
1363                         // Build module name index
1364                         $index = [];
1365                         foreach ( $name as $i => &$module ) {
1366                                 $index[$module[0]] = $i;
1367                         }
1368
1369                         // Transform dependency names into indexes when possible, they will be resolved by
1370                         // mw.loader.register on the other end
1371                         foreach ( $name as &$module ) {
1372                                 if ( isset( $module[2] ) ) {
1373                                         foreach ( $module[2] as &$dependency ) {
1374                                                 if ( isset( $index[$dependency] ) ) {
1375                                                         $dependency = $index[$dependency];
1376                                                 }
1377                                         }
1378                                 }
1379                         }
1380
1381                         array_walk( $name, [ 'self', 'trimArray' ] );
1382
1383                         return Xml::encodeJsCall(
1384                                 'mw.loader.register',
1385                                 [ $name ],
1386                                 ResourceLoader::inDebugMode()
1387                         );
1388                 } else {
1389                         $registration = [ $name, $version, $dependencies, $group, $source, $skip ];
1390                         self::trimArray( $registration );
1391                         return Xml::encodeJsCall(
1392                                 'mw.loader.register',
1393                                 $registration,
1394                                 ResourceLoader::inDebugMode()
1395                         );
1396                 }
1397         }
1398
1399         /**
1400          * Returns JS code which calls mw.loader.addSource() with the given
1401          * parameters. Has two calling conventions:
1402          *
1403          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1404          *       Register a single source
1405          *
1406          *   - ResourceLoader::makeLoaderSourcesScript( [ $id1 => $loadUrl, $id2 => $loadUrl, ... ] );
1407          *       Register sources with the given IDs and properties.
1408          *
1409          * @param string $id Source ID
1410          * @param string $loadUrl load.php url
1411          * @return string
1412          */
1413         public static function makeLoaderSourcesScript( $id, $loadUrl = null ) {
1414                 if ( is_array( $id ) ) {
1415                         return Xml::encodeJsCall(
1416                                 'mw.loader.addSource',
1417                                 [ $id ],
1418                                 ResourceLoader::inDebugMode()
1419                         );
1420                 } else {
1421                         return Xml::encodeJsCall(
1422                                 'mw.loader.addSource',
1423                                 [ $id, $loadUrl ],
1424                                 ResourceLoader::inDebugMode()
1425                         );
1426                 }
1427         }
1428
1429         /**
1430          * Returns JS code which runs given JS code if the client-side framework is
1431          * present.
1432          *
1433          * @deprecated since 1.25; use makeInlineScript instead
1434          * @param string $script JavaScript code
1435          * @return string
1436          */
1437         public static function makeLoaderConditionalScript( $script ) {
1438                 return '(window.RLQ=window.RLQ||[]).push(function(){' .
1439                         trim( $script ) . '});';
1440         }
1441
1442         /**
1443          * Construct an inline script tag with given JS code.
1444          *
1445          * The code will be wrapped in a closure, and it will be executed by ResourceLoader
1446          * only if the client has adequate support for MediaWiki JavaScript code.
1447          *
1448          * @param string $script JavaScript code
1449          * @return WrappedString HTML
1450          */
1451         public static function makeInlineScript( $script ) {
1452                 $js = self::makeLoaderConditionalScript( $script );
1453                 return new WrappedString(
1454                         Html::inlineScript( $js ),
1455                         '<script>(window.RLQ=window.RLQ||[]).push(function(){',
1456                         '});</script>'
1457                 );
1458         }
1459
1460         /**
1461          * Returns JS code which will set the MediaWiki configuration array to
1462          * the given value.
1463          *
1464          * @param array $configuration List of configuration values keyed by variable name
1465          * @return string
1466          */
1467         public static function makeConfigSetScript( array $configuration ) {
1468                 return Xml::encodeJsCall(
1469                         'mw.config.set',
1470                         [ $configuration ],
1471                         ResourceLoader::inDebugMode()
1472                 );
1473         }
1474
1475         /**
1476          * Convert an array of module names to a packed query string.
1477          *
1478          * For example, [ 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' ]
1479          * becomes 'foo.bar,baz|bar.baz,quux'
1480          * @param array $modules List of module names (strings)
1481          * @return string Packed query string
1482          */
1483         public static function makePackedModulesString( $modules ) {
1484                 $groups = []; // [ prefix => [ suffixes ] ]
1485                 foreach ( $modules as $module ) {
1486                         $pos = strrpos( $module, '.' );
1487                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1488                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1489                         $groups[$prefix][] = $suffix;
1490                 }
1491
1492                 $arr = [];
1493                 foreach ( $groups as $prefix => $suffixes ) {
1494                         $p = $prefix === '' ? '' : $prefix . '.';
1495                         $arr[] = $p . implode( ',', $suffixes );
1496                 }
1497                 $str = implode( '|', $arr );
1498                 return $str;
1499         }
1500
1501         /**
1502          * Determine whether debug mode was requested
1503          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1504          * @return bool
1505          */
1506         public static function inDebugMode() {
1507                 if ( self::$debugMode === null ) {
1508                         global $wgRequest, $wgResourceLoaderDebug;
1509                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1510                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1511                         );
1512                 }
1513                 return self::$debugMode;
1514         }
1515
1516         /**
1517          * Reset static members used for caching.
1518          *
1519          * Global state and $wgRequest are evil, but we're using it right
1520          * now and sometimes we need to be able to force ResourceLoader to
1521          * re-evaluate the context because it has changed (e.g. in the test suite).
1522          */
1523         public static function clearCache() {
1524                 self::$debugMode = null;
1525         }
1526
1527         /**
1528          * Build a load.php URL
1529          *
1530          * @since 1.24
1531          * @param string $source Name of the ResourceLoader source
1532          * @param ResourceLoaderContext $context
1533          * @param array $extraQuery
1534          * @return string URL to load.php. May be protocol-relative if $wgLoadScript is, too.
1535          */
1536         public function createLoaderURL( $source, ResourceLoaderContext $context,
1537                 $extraQuery = []
1538         ) {
1539                 $query = self::createLoaderQuery( $context, $extraQuery );
1540                 $script = $this->getLoadScript( $source );
1541
1542                 return wfAppendQuery( $script, $query );
1543         }
1544
1545         /**
1546          * Helper for createLoaderURL()
1547          *
1548          * @since 1.24
1549          * @see makeLoaderQuery
1550          * @param ResourceLoaderContext $context
1551          * @param array $extraQuery
1552          * @return array
1553          */
1554         protected static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = [] ) {
1555                 return self::makeLoaderQuery(
1556                         $context->getModules(),
1557                         $context->getLanguage(),
1558                         $context->getSkin(),
1559                         $context->getUser(),
1560                         $context->getVersion(),
1561                         $context->getDebug(),
1562                         $context->getOnly(),
1563                         $context->getRequest()->getBool( 'printable' ),
1564                         $context->getRequest()->getBool( 'handheld' ),
1565                         $extraQuery
1566                 );
1567         }
1568
1569         /**
1570          * Build a query array (array representation of query string) for load.php. Helper
1571          * function for createLoaderURL().
1572          *
1573          * @param array $modules
1574          * @param string $lang
1575          * @param string $skin
1576          * @param string $user
1577          * @param string $version
1578          * @param bool $debug
1579          * @param string $only
1580          * @param bool $printable
1581          * @param bool $handheld
1582          * @param array $extraQuery
1583          *
1584          * @return array
1585          */
1586         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1587                 $version = null, $debug = false, $only = null, $printable = false,
1588                 $handheld = false, $extraQuery = []
1589         ) {
1590                 $query = [
1591                         'modules' => self::makePackedModulesString( $modules ),
1592                         'lang' => $lang,
1593                         'skin' => $skin,
1594                         'debug' => $debug ? 'true' : 'false',
1595                 ];
1596                 if ( $user !== null ) {
1597                         $query['user'] = $user;
1598                 }
1599                 if ( $version !== null ) {
1600                         $query['version'] = $version;
1601                 }
1602                 if ( $only !== null ) {
1603                         $query['only'] = $only;
1604                 }
1605                 if ( $printable ) {
1606                         $query['printable'] = 1;
1607                 }
1608                 if ( $handheld ) {
1609                         $query['handheld'] = 1;
1610                 }
1611                 $query += $extraQuery;
1612
1613                 // Make queries uniform in order
1614                 ksort( $query );
1615                 return $query;
1616         }
1617
1618         /**
1619          * Check a module name for validity.
1620          *
1621          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1622          * at most 255 bytes.
1623          *
1624          * @param string $moduleName Module name to check
1625          * @return bool Whether $moduleName is a valid module name
1626          */
1627         public static function isValidModuleName( $moduleName ) {
1628                 return strcspn( $moduleName, '!,|', 0, 255 ) === strlen( $moduleName );
1629         }
1630
1631         /**
1632          * Returns LESS compiler set up for use with MediaWiki
1633          *
1634          * @since 1.27
1635          * @param array $extraVars Associative array of extra (i.e., other than the
1636          *   globally-configured ones) that should be used for compilation.
1637          * @throws MWException
1638          * @return Less_Parser
1639          */
1640         public function getLessCompiler( $extraVars = [] ) {
1641                 // When called from the installer, it is possible that a required PHP extension
1642                 // is missing (at least for now; see T49564). If this is the case, throw an
1643                 // exception (caught by the installer) to prevent a fatal error later on.
1644                 if ( !class_exists( 'Less_Parser' ) ) {
1645                         throw new MWException( 'MediaWiki requires the less.php parser' );
1646                 }
1647
1648                 $parser = new Less_Parser;
1649                 $parser->ModifyVars( array_merge( $this->getLessVars(), $extraVars ) );
1650                 $parser->SetImportDirs(
1651                         array_fill_keys( $this->config->get( 'ResourceLoaderLESSImportPaths' ), '' )
1652                 );
1653                 $parser->SetOption( 'relativeUrls', false );
1654
1655                 return $parser;
1656         }
1657
1658         /**
1659          * Get global LESS variables.
1660          *
1661          * @since 1.27
1662          * @return array Map of variable names to string CSS values.
1663          */
1664         public function getLessVars() {
1665                 if ( !$this->lessVars ) {
1666                         $lessVars = $this->config->get( 'ResourceLoaderLESSVars' );
1667                         Hooks::run( 'ResourceLoaderGetLessVars', [ &$lessVars ] );
1668                         $this->lessVars = $lessVars;
1669                 }
1670                 return $this->lessVars;
1671         }
1672 }