includes/resourceloader/ResourceLoader.php

   1 <?php
   2 /**
   3  * Base class for resource loading system.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @author Roan Kattouw
  22  * @author Trevor Parscal
  23  */
  24
  25 use MediaWiki\MediaWikiServices;
  26 use Psr\Log\LoggerAwareInterface;
  27 use Psr\Log\LoggerInterface;
  28 use Psr\Log\NullLogger;
  29 use Wikimedia\Rdbms\DBConnectionError;
  30 use Wikimedia\WrappedString;
  31
  32 /**
  33  * Dynamic JavaScript and CSS resource loading system.
  34  *
  35  * Most of the documentation is on the MediaWiki documentation wiki starting at:
  36  *    https://www.mediawiki.org/wiki/ResourceLoader
  37  */
  38 class ResourceLoader implements LoggerAwareInterface {
  39         /** @var int */
  40         protected static $filterCacheVersion = 8;
  41
  42         /** @var bool */
  43         protected static $debugMode = null;
  44
  45         /**
  46          * Module name/ResourceLoaderModule object pairs
  47          * @var array
  48          */
  49         protected $modules = [];
  50
  51         /**
  52          * Associative array mapping module name to info associative array
  53          * @var array
  54          */
  55         protected $moduleInfos = [];
  56
  57         /** @var Config $config */
  58         protected $config;
  59
  60         /**
  61          * Associative array mapping framework ids to a list of names of test suite modules
  62          * like [ 'qunit' => [ 'mediawiki.tests.qunit.suites', 'ext.foo.tests', ... ], ... ]
  63          * @var array
  64          */
  65         protected $testModuleNames = [];
  66
  67         /**
  68          * E.g. [ 'source-id' => 'http://.../load.php' ]
  69          * @var array
  70          */
  71         protected $sources = [];
  72
  73         /**
  74          * Errors accumulated during current respond() call.
  75          * @var array
  76          */
  77         protected $errors = [];
  78
  79         /**
  80          * List of extra HTTP response headers provided by loaded modules.
  81          *
  82          * Populated by makeModuleResponse().
  83          *
  84          * @var array
  85          */
  86         protected $extraHeaders = [];
  87
  88         /**
  89          * @var MessageBlobStore
  90          */
  91         protected $blobStore;
  92
  93         /**
  94          * @var LoggerInterface
  95          */
  96         private $logger;
  97
  98         /** @var string JavaScript / CSS pragma to disable minification. **/
  99         const FILTER_NOMIN = '/*@nomin*/';
 100
 101         /**
 102          * Load information stored in the database about modules.
 103          *
 104          * This method grabs modules dependencies from the database and updates modules
 105          * objects.
 106          *
 107          * This is not inside the module code because it is much faster to
 108          * request all of the information at once than it is to have each module
 109          * requests its own information. This sacrifice of modularity yields a substantial
 110          * performance improvement.
 111          *
 112          * @param array $moduleNames List of module names to preload information for
 113          * @param ResourceLoaderContext $context Context to load the information within
 114          */
 115         public function preloadModuleInfo( array $moduleNames, ResourceLoaderContext $context ) {
 116                 if ( !$moduleNames ) {
 117                         // Or else Database*::select() will explode, plus it's cheaper!
 118                         return;
 119                 }
 120                 $dbr = wfGetDB( DB_REPLICA );
 121                 $skin = $context->getSkin();
 122                 $lang = $context->getLanguage();
 123
 124                 // Batched version of ResourceLoaderModule::getFileDependencies
 125                 $vary = "$skin|$lang";
 126                 $res = $dbr->select( 'module_deps', [ 'md_module', 'md_deps' ], [
 127                                 'md_module' => $moduleNames,
 128                                 'md_skin' => $vary,
 129                         ], __METHOD__
 130                 );
 131
 132                 // Prime in-object cache for file dependencies
 133                 $modulesWithDeps = [];
 134                 foreach ( $res as $row ) {
 135                         $module = $this->getModule( $row->md_module );
 136                         if ( $module ) {
 137                                 $module->setFileDependencies( $context, ResourceLoaderModule::expandRelativePaths(
 138                                         json_decode( $row->md_deps, true )
 139                                 ) );
 140                                 $modulesWithDeps[] = $row->md_module;
 141                         }
 142                 }
 143                 // Register the absence of a dependency row too
 144                 foreach ( array_diff( $moduleNames, $modulesWithDeps ) as $name ) {
 145                         $module = $this->getModule( $name );
 146                         if ( $module ) {
 147                                 $this->getModule( $name )->setFileDependencies( $context, [] );
 148                         }
 149                 }
 150
 151                 // Batched version of ResourceLoaderWikiModule::getTitleInfo
 152                 ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $moduleNames );
 153
 154                 // Prime in-object cache for message blobs for modules with messages
 155                 $modules = [];
 156                 foreach ( $moduleNames as $name ) {
 157                         $module = $this->getModule( $name );
 158                         if ( $module && $module->getMessages() ) {
 159                                 $modules[$name] = $module;
 160                         }
 161                 }
 162                 $store = $this->getMessageBlobStore();
 163                 $blobs = $store->getBlobs( $modules, $lang );
 164                 foreach ( $blobs as $name => $blob ) {
 165                         $modules[$name]->setMessageBlob( $blob, $lang );
 166                 }
 167         }
 168
 169         /**
 170          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 171          *
 172          * Available filters are:
 173          *
 174          *    - minify-js \see JavaScriptMinifier::minify
 175          *    - minify-css \see CSSMin::minify
 176          *
 177          * If $data is empty, only contains whitespace or the filter was unknown,
 178          * $data is returned unmodified.
 179          *
 180          * @param string $filter Name of filter to run
 181          * @param string $data Text to filter, such as JavaScript or CSS text
 182          * @param array $options Keys:
 183          *  - (bool) cache: Whether to allow caching this data. Default: true.
 184          * @return string Filtered data, or a comment containing an error message
 185          */
 186         public static function filter( $filter, $data, array $options = [] ) {
 187                 if ( strpos( $data, self::FILTER_NOMIN ) !== false ) {
 188                         return $data;
 189                 }
 190
 191                 if ( isset( $options['cache'] ) && $options['cache'] === false ) {
 192                         return self::applyFilter( $filter, $data );
 193                 }
 194
 195                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
 196                 $cache = ObjectCache::getLocalServerInstance( CACHE_ANYTHING );
 197
 198                 $key = $cache->makeGlobalKey(
 199                         'resourceloader',
 200                         'filter',
 201                         $filter,
 202                         self::$filterCacheVersion, md5( $data )
 203                 );
 204
 205                 $result = $cache->get( $key );
 206                 if ( $result === false ) {
 207                         $stats->increment( "resourceloader_cache.$filter.miss" );
 208                         $result = self::applyFilter( $filter, $data );
 209                         $cache->set( $key, $result, 24 * 3600 );
 210                 } else {
 211                         $stats->increment( "resourceloader_cache.$filter.hit" );
 212                 }
 213                 if ( $result === null ) {
 214                         // Cached failure
 215                         $result = $data;
 216                 }
 217
 218                 return $result;
 219         }
 220
 221         private static function applyFilter( $filter, $data ) {
 222                 $data = trim( $data );
 223                 if ( $data ) {
 224                         try {
 225                                 $data = ( $filter === 'minify-css' )
 226                                         ? CSSMin::minify( $data )
 227                                         : JavaScriptMinifier::minify( $data );
 228                         } catch ( Exception $e ) {
 229                                 MWExceptionHandler::logException( $e );
 230                                 return null;
 231                         }
 232                 }
 233                 return $data;
 234         }
 235
 236         /**
 237          * Register core modules and runs registration hooks.
 238          * @param Config|null $config [optional]
 239          * @param LoggerInterface|null $logger [optional]
 240          */
 241         public function __construct( Config $config = null, LoggerInterface $logger = null ) {
 242                 global $IP;
 243
 244                 $this->logger = $logger ?: new NullLogger();
 245
 246                 if ( !$config ) {
 247                         $this->logger->debug( __METHOD__ . ' was called without providing a Config instance' );
 248                         $config = MediaWikiServices::getInstance()->getMainConfig();
 249                 }
 250                 $this->config = $config;
 251
 252                 // Add 'local' source first
 253                 $this->addSource( 'local', $config->get( 'LoadScript' ) );
 254
 255                 // Add other sources
 256                 $this->addSource( $config->get( 'ResourceLoaderSources' ) );
 257
 258                 // Register core modules
 259                 $this->register( include "$IP/resources/Resources.php" );
 260                 // Register extension modules
 261                 $this->register( $config->get( 'ResourceModules' ) );
 262
 263                 // Avoid PHP 7.1 warning from passing $this by reference
 264                 $rl = $this;
 265                 Hooks::run( 'ResourceLoaderRegisterModules', [ &$rl ] );
 266
 267                 if ( $config->get( 'EnableJavaScriptTest' ) === true ) {
 268                         $this->registerTestModules();
 269                 }
 270
 271                 $this->setMessageBlobStore( new MessageBlobStore( $this, $this->logger ) );
 272         }
 273
 274         /**
 275          * @return Config
 276          */
 277         public function getConfig() {
 278                 return $this->config;
 279         }
 280
 281         /**
 282          * @since 1.26
 283          * @param LoggerInterface $logger
 284          */
 285         public function setLogger( LoggerInterface $logger ) {
 286                 $this->logger = $logger;
 287         }
 288
 289         /**
 290          * @since 1.27
 291          * @return LoggerInterface
 292          */
 293         public function getLogger() {
 294                 return $this->logger;
 295         }
 296
 297         /**
 298          * @since 1.26
 299          * @return MessageBlobStore
 300          */
 301         public function getMessageBlobStore() {
 302                 return $this->blobStore;
 303         }
 304
 305         /**
 306          * @since 1.25
 307          * @param MessageBlobStore $blobStore
 308          */
 309         public function setMessageBlobStore( MessageBlobStore $blobStore ) {
 310                 $this->blobStore = $blobStore;
 311         }
 312
 313         /**
 314          * Register a module with the ResourceLoader system.
 315          *
 316          * @param mixed $name Name of module as a string or List of name/object pairs as an array
 317          * @param array|null $info Module info array. For backwards compatibility with 1.17alpha,
 318          *   this may also be a ResourceLoaderModule object. Optional when using
 319          *   multiple-registration calling style.
 320          * @throws MWException If a duplicate module registration is attempted
 321          * @throws MWException If a module name contains illegal characters (pipes or commas)
 322          * @throws MWException If something other than a ResourceLoaderModule is being registered
 323          * @return bool False if there were any errors, in which case one or more modules were
 324          *   not registered
 325          */
 326         public function register( $name, $info = null ) {
 327                 $moduleSkinStyles = $this->config->get( 'ResourceModuleSkinStyles' );
 328
 329                 // Allow multiple modules to be registered in one call
 330                 $registrations = is_array( $name ) ? $name : [ $name => $info ];
 331                 foreach ( $registrations as $name => $info ) {
 332                         // Warn on duplicate registrations
 333                         if ( isset( $this->moduleInfos[$name] ) ) {
 334                                 // A module has already been registered by this name
 335                                 $this->logger->warning(
 336                                         'ResourceLoader duplicate registration warning. ' .
 337                                         'Another module has already been registered as ' . $name
 338                                 );
 339                         }
 340
 341                         // Check $name for validity
 342                         if ( !self::isValidModuleName( $name ) ) {
 343                                 throw new MWException( "ResourceLoader module name '$name' is invalid, "
 344                                         . "see ResourceLoader::isValidModuleName()" );
 345                         }
 346
 347                         // Attach module
 348                         if ( $info instanceof ResourceLoaderModule ) {
 349                                 $this->moduleInfos[$name] = [ 'object' => $info ];
 350                                 $info->setName( $name );
 351                                 $this->modules[$name] = $info;
 352                         } elseif ( is_array( $info ) ) {
 353                                 // New calling convention
 354                                 $this->moduleInfos[$name] = $info;
 355                         } else {
 356                                 throw new MWException(
 357                                         'ResourceLoader module info type error for module \'' . $name .
 358                                         '\': expected ResourceLoaderModule or array (got: ' . gettype( $info ) . ')'
 359                                 );
 360                         }
 361
 362                         // Last-minute changes
 363
 364                         // Apply custom skin-defined styles to existing modules.
 365                         if ( $this->isFileModule( $name ) ) {
 366                                 foreach ( $moduleSkinStyles as $skinName => $skinStyles ) {
 367                                         // If this module already defines skinStyles for this skin, ignore $wgResourceModuleSkinStyles.
 368                                         if ( isset( $this->moduleInfos[$name]['skinStyles'][$skinName] ) ) {
 369                                                 continue;
 370                                         }
 371
 372                                         // If $name is preceded with a '+', the defined style files will be added to 'default'
 373                                         // skinStyles, otherwise 'default' will be ignored as it normally would be.
 374                                         if ( isset( $skinStyles[$name] ) ) {
 375                                                 $paths = (array)$skinStyles[$name];
 376                                                 $styleFiles = [];
 377                                         } elseif ( isset( $skinStyles['+' . $name] ) ) {
 378                                                 $paths = (array)$skinStyles['+' . $name];
 379                                                 $styleFiles = isset( $this->moduleInfos[$name]['skinStyles']['default'] ) ?
 380                                                         (array)$this->moduleInfos[$name]['skinStyles']['default'] :
 381                                                         [];
 382                                         } else {
 383                                                 continue;
 384                                         }
 385
 386                                         // Add new file paths, remapping them to refer to our directories and not use settings
 387                                         // from the module we're modifying, which come from the base definition.
 388                                         list( $localBasePath, $remoteBasePath ) =
 389                                                 ResourceLoaderFileModule::extractBasePaths( $skinStyles );
 390
 391                                         foreach ( $paths as $path ) {
 392                                                 $styleFiles[] = new ResourceLoaderFilePath( $path, $localBasePath, $remoteBasePath );
 393                                         }
 394
 395                                         $this->moduleInfos[$name]['skinStyles'][$skinName] = $styleFiles;
 396                                 }
 397                         }
 398                 }
 399         }
 400
 401         public function registerTestModules() {
 402                 global $IP;
 403
 404                 if ( $this->config->get( 'EnableJavaScriptTest' ) !== true ) {
 405                         throw new MWException( 'Attempt to register JavaScript test modules '
 406                                 . 'but <code>$wgEnableJavaScriptTest</code> is false. '
 407                                 . 'Edit your <code>LocalSettings.php</code> to enable it.' );
 408                 }
 409
 410                 // Get core test suites
 411                 $testModules = [];
 412                 $testModules['qunit'] = [];
 413                 // Get other test suites (e.g. from extensions)
 414                 // Avoid PHP 7.1 warning from passing $this by reference
 415                 $rl = $this;
 416                 Hooks::run( 'ResourceLoaderTestModules', [ &$testModules, &$rl ] );
 417
 418                 // Add the testrunner (which configures QUnit) to the dependencies.
 419                 // Since it must be ready before any of the test suites are executed.
 420                 foreach ( $testModules['qunit'] as &$module ) {
 421                         // Make sure all test modules are top-loading so that when QUnit starts
 422                         // on document-ready, it will run once and finish. If some tests arrive
 423                         // later (possibly after QUnit has already finished) they will be ignored.
 424                         $module['position'] = 'top';
 425                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 426                 }
 427
 428                 $testModules['qunit'] =
 429                         ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules['qunit'];
 430
 431                 foreach ( $testModules as $id => $names ) {
 432                         // Register test modules
 433                         $this->register( $testModules[$id] );
 434
 435                         // Keep track of their names so that they can be loaded together
 436                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 437                 }
 438         }
 439
 440         /**
 441          * Add a foreign source of modules.
 442          *
 443          * Source IDs are typically the same as the Wiki ID or database name (e.g. lowercase a-z).
 444          *
 445          * @param array|string $id Source ID (string), or [ id1 => loadUrl, id2 => loadUrl, ... ]
 446          * @param string|array|null $loadUrl load.php url (string), or array with loadUrl key for
 447          *  backwards-compatibility.
 448          * @throws MWException
 449          */
 450         public function addSource( $id, $loadUrl = null ) {
 451                 // Allow multiple sources to be registered in one call
 452                 if ( is_array( $id ) ) {
 453                         foreach ( $id as $key => $value ) {
 454                                 $this->addSource( $key, $value );
 455                         }
 456                         return;
 457                 }
 458
 459                 // Disallow duplicates
 460                 if ( isset( $this->sources[$id] ) ) {
 461                         throw new MWException(
 462                                 'ResourceLoader duplicate source addition error. ' .
 463                                 'Another source has already been registered as ' . $id
 464                         );
 465                 }
 466
 467                 // Pre 1.24 backwards-compatibility
 468                 if ( is_array( $loadUrl ) ) {
 469                         if ( !isset( $loadUrl['loadScript'] ) ) {
 470                                 throw new MWException(
 471                                         __METHOD__ . ' was passed an array with no "loadScript" key.'
 472                                 );
 473                         }
 474
 475                         $loadUrl = $loadUrl['loadScript'];
 476                 }
 477
 478                 $this->sources[$id] = $loadUrl;
 479         }
 480
 481         /**
 482          * Get a list of module names.
 483          *
 484          * @return array List of module names
 485          */
 486         public function getModuleNames() {
 487                 return array_keys( $this->moduleInfos );
 488         }
 489
 490         /**
 491          * Get a list of test module names for one (or all) frameworks.
 492          *
 493          * If the given framework id is unknkown, or if the in-object variable is not an array,
 494          * then it will return an empty array.
 495          *
 496          * @param string $framework Get only the test module names for one
 497          *   particular framework (optional)
 498          * @return array
 499          */
 500         public function getTestModuleNames( $framework = 'all' ) {
 501                 /** @todo api siteinfo prop testmodulenames modulenames */
 502                 if ( $framework == 'all' ) {
 503                         return $this->testModuleNames;
 504                 } elseif ( isset( $this->testModuleNames[$framework] )
 505                         && is_array( $this->testModuleNames[$framework] )
 506                 ) {
 507                         return $this->testModuleNames[$framework];
 508                 } else {
 509                         return [];
 510                 }
 511         }
 512
 513         /**
 514          * Check whether a ResourceLoader module is registered
 515          *
 516          * @since 1.25
 517          * @param string $name
 518          * @return bool
 519          */
 520         public function isModuleRegistered( $name ) {
 521                 return isset( $this->moduleInfos[$name] );
 522         }
 523
 524         /**
 525          * Get the ResourceLoaderModule object for a given module name.
 526          *
 527          * If an array of module parameters exists but a ResourceLoaderModule object has not
 528          * yet been instantiated, this method will instantiate and cache that object such that
 529          * subsequent calls simply return the same object.
 530          *
 531          * @param string $name Module name
 532          * @return ResourceLoaderModule|null If module has been registered, return a
 533          *  ResourceLoaderModule instance. Otherwise, return null.
 534          */
 535         public function getModule( $name ) {
 536                 if ( !isset( $this->modules[$name] ) ) {
 537                         if ( !isset( $this->moduleInfos[$name] ) ) {
 538                                 // No such module
 539                                 return null;
 540                         }
 541                         // Construct the requested object
 542                         $info = $this->moduleInfos[$name];
 543                         /** @var ResourceLoaderModule $object */
 544                         if ( isset( $info['object'] ) ) {
 545                                 // Object given in info array
 546                                 $object = $info['object'];
 547                         } elseif ( isset( $info['factory'] ) ) {
 548                                 $object = call_user_func( $info['factory'], $info );
 549                                 $object->setConfig( $this->getConfig() );
 550                                 $object->setLogger( $this->logger );
 551                         } else {
 552                                 if ( !isset( $info['class'] ) ) {
 553                                         $class = ResourceLoaderFileModule::class;
 554                                 } else {
 555                                         $class = $info['class'];
 556                                 }
 557                                 /** @var ResourceLoaderModule $object */
 558                                 $object = new $class( $info );
 559                                 $object->setConfig( $this->getConfig() );
 560                                 $object->setLogger( $this->logger );
 561                         }
 562                         $object->setName( $name );
 563                         $this->modules[$name] = $object;
 564                 }
 565
 566                 return $this->modules[$name];
 567         }
 568
 569         /**
 570          * Whether the module is a ResourceLoaderFileModule (including subclasses).
 571          *
 572          * @param string $name Module name
 573          * @return bool
 574          */
 575         protected function isFileModule( $name ) {
 576                 if ( !isset( $this->moduleInfos[$name] ) ) {
 577                         return false;
 578                 }
 579                 $info = $this->moduleInfos[$name];
 580                 if ( isset( $info['object'] ) ) {
 581                         return false;
 582                 }
 583                 return (
 584                         // The implied default for 'class' is ResourceLoaderFileModule
 585                         !isset( $info['class'] ) ||
 586                         // Explicit default
 587                         $info['class'] === ResourceLoaderFileModule::class ||
 588                         is_subclass_of( $info['class'], ResourceLoaderFileModule::class )
 589                 );
 590         }
 591
 592         /**
 593          * Get the list of sources.
 594          *
 595          * @return array Like [ id => load.php url, ... ]
 596          */
 597         public function getSources() {
 598                 return $this->sources;
 599         }
 600
 601         /**
 602          * Get the URL to the load.php endpoint for the given
 603          * ResourceLoader source
 604          *
 605          * @since 1.24
 606          * @param string $source
 607          * @throws MWException On an invalid $source name
 608          * @return string
 609          */
 610         public function getLoadScript( $source ) {
 611                 if ( !isset( $this->sources[$source] ) ) {
 612                         throw new MWException( "The $source source was never registered in ResourceLoader." );
 613                 }
 614                 return $this->sources[$source];
 615         }
 616
 617         /**
 618          * @since 1.26
 619          * @param string $value
 620          * @return string Hash
 621          */
 622         public static function makeHash( $value ) {
 623                 $hash = hash( 'fnv132', $value );
 624                 return Wikimedia\base_convert( $hash, 16, 36, 7 );
 625         }
 626
 627         /**
 628          * Add an error to the 'errors' array and log it.
 629          *
 630          * Should only be called from within respond().
 631          *
 632          * @since 1.29
 633          * @param Exception $e
 634          * @param string $msg
 635          * @param array $context
 636          */
 637         protected function outputErrorAndLog( Exception $e, $msg, array $context = [] ) {
 638                 MWExceptionHandler::logException( $e );
 639                 $this->logger->warning(
 640                         $msg,
 641                         $context + [ 'exception' => $e ]
 642                 );
 643                 $this->errors[] = self::formatExceptionNoComment( $e );
 644         }
 645
 646         /**
 647          * Helper method to get and combine versions of multiple modules.
 648          *
 649          * @since 1.26
 650          * @param ResourceLoaderContext $context
 651          * @param string[] $moduleNames List of known module names
 652          * @return string Hash
 653          */
 654         public function getCombinedVersion( ResourceLoaderContext $context, array $moduleNames ) {
 655                 if ( !$moduleNames ) {
 656                         return '';
 657                 }
 658                 $hashes = array_map( function ( $module ) use ( $context ) {
 659                         try {
 660                                 return $this->getModule( $module )->getVersionHash( $context );
 661                         } catch ( Exception $e ) {
 662                                 // If modules fail to compute a version, do still consider the versions
 663                                 // of other modules - don't set an empty string E-Tag for the whole request.
 664                                 // See also T152266 and StartupModule::getModuleRegistrations().
 665                                 $this->outputErrorAndLog( $e,
 666                                         'Calculating version for "{module}" failed: {exception}',
 667                                         [
 668                                                 'module' => $module,
 669                                         ]
 670                                 );
 671                                 return '';
 672                         }
 673                 }, $moduleNames );
 674                 return self::makeHash( implode( '', $hashes ) );
 675         }
 676
 677         /**
 678          * Get the expected value of the 'version' query parameter.
 679          *
 680          * This is used by respond() to set a short Cache-Control header for requests with
 681          * information newer than the current server has. This avoids pollution of edge caches.
 682          * Typically during deployment. (T117587)
 683          *
 684          * This MUST match return value of `mw.loader#getCombinedVersion()` client-side.
 685          *
 686          * @since 1.28
 687          * @param ResourceLoaderContext $context
 688          * @return string Hash
 689          */
 690         public function makeVersionQuery( ResourceLoaderContext $context ) {
 691                 // As of MediaWiki 1.28, the server and client use the same algorithm for combining
 692                 // version hashes. There is no technical reason for this to be same, and for years the
 693                 // implementations differed. If getCombinedVersion in PHP (used for StartupModule and
 694                 // E-Tag headers) differs in the future from getCombinedVersion in JS (used for 'version'
 695                 // query parameter), then this method must continue to match the JS one.
 696                 $moduleNames = [];
 697                 foreach ( $context->getModules() as $name ) {
 698                         if ( !$this->getModule( $name ) ) {
 699                                 // If a versioned request contains a missing module, the version is a mismatch
 700                                 // as the client considered a module (and version) we don't have.
 701                                 return '';
 702                         }
 703                         $moduleNames[] = $name;
 704                 }
 705                 return $this->getCombinedVersion( $context, $moduleNames );
 706         }
 707
 708         /**
 709          * Output a response to a load request, including the content-type header.
 710          *
 711          * @param ResourceLoaderContext $context Context in which a response should be formed
 712          */
 713         public function respond( ResourceLoaderContext $context ) {
 714                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 715                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 716                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 717                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 718                 // the whole thing in our own output buffer to be sure the active buffer
 719                 // doesn't use ob_gzhandler.
 720                 // See https://bugs.php.net/bug.php?id=36514
 721                 ob_start();
 722
 723                 $this->measureResponseTime( RequestContext::getMain()->getTiming() );
 724
 725                 // Find out which modules are missing and instantiate the others
 726                 $modules = [];
 727                 $missing = [];
 728                 foreach ( $context->getModules() as $name ) {
 729                         $module = $this->getModule( $name );
 730                         if ( $module ) {
 731                                 // Do not allow private modules to be loaded from the web.
 732                                 // This is a security issue, see T36907.
 733                                 if ( $module->getGroup() === 'private' ) {
 734                                         $this->logger->debug( "Request for private module '$name' denied" );
 735                                         $this->errors[] = "Cannot show private module \"$name\"";
 736                                         continue;
 737                                 }
 738                                 $modules[$name] = $module;
 739                         } else {
 740                                 $missing[] = $name;
 741                         }
 742                 }
 743
 744                 try {
 745                         // Preload for getCombinedVersion() and for batch makeModuleResponse()
 746                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 747                 } catch ( Exception $e ) {
 748                         $this->outputErrorAndLog( $e, 'Preloading module info failed: {exception}' );
 749                 }
 750
 751                 // Combine versions to propagate cache invalidation
 752                 $versionHash = '';
 753                 try {
 754                         $versionHash = $this->getCombinedVersion( $context, array_keys( $modules ) );
 755                 } catch ( Exception $e ) {
 756                         $this->outputErrorAndLog( $e, 'Calculating version hash failed: {exception}' );
 757                 }
 758
 759                 // See RFC 2616 § 3.11 Entity Tags
 760                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.11
 761                 $etag = 'W/"' . $versionHash . '"';
 762
 763                 // Try the client-side cache first
 764                 if ( $this->tryRespondNotModified( $context, $etag ) ) {
 765                         return; // output handled (buffers cleared)
 766                 }
 767
 768                 // Use file cache if enabled and available...
 769                 if ( $this->config->get( 'UseFileCache' ) ) {
 770                         $fileCache = ResourceFileCache::newFromContext( $context );
 771                         if ( $this->tryRespondFromFileCache( $fileCache, $context, $etag ) ) {
 772                                 return; // output handled
 773                         }
 774                 }
 775
 776                 // Generate a response
 777                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 778
 779                 // Capture any PHP warnings from the output buffer and append them to the
 780                 // error list if we're in debug mode.
 781                 if ( $context->getDebug() ) {
 782                         $warnings = ob_get_contents();
 783                         if ( strlen( $warnings ) ) {
 784                                 $this->errors[] = $warnings;
 785                         }
 786                 }
 787
 788                 // Save response to file cache unless there are errors
 789                 if ( isset( $fileCache ) && !$this->errors && !count( $missing ) ) {
 790                         // Cache single modules and images...and other requests if there are enough hits
 791                         if ( ResourceFileCache::useFileCache( $context ) ) {
 792                                 if ( $fileCache->isCacheWorthy() ) {
 793                                         $fileCache->saveText( $response );
 794                                 } else {
 795                                         $fileCache->incrMissesRecent( $context->getRequest() );
 796                                 }
 797                         }
 798                 }
 799
 800                 $this->sendResponseHeaders( $context, $etag, (bool)$this->errors, $this->extraHeaders );
 801
 802                 // Remove the output buffer and output the response
 803                 ob_end_clean();
 804
 805                 if ( $context->getImageObj() && $this->errors ) {
 806                         // We can't show both the error messages and the response when it's an image.
 807                         $response = implode( "\n\n", $this->errors );
 808                 } elseif ( $this->errors ) {
 809                         $errorText = implode( "\n\n", $this->errors );
 810                         $errorResponse = self::makeComment( $errorText );
 811                         if ( $context->shouldIncludeScripts() ) {
 812                                 $errorResponse .= 'if (window.console && console.error) {'
 813                                         . Xml::encodeJsCall( 'console.error', [ $errorText ] )
 814                                         . "}\n";
 815                         }
 816
 817                         // Prepend error info to the response
 818                         $response = $errorResponse . $response;
 819                 }
 820
 821                 $this->errors = [];
 822                 echo $response;
 823         }
 824
 825         protected function measureResponseTime( Timing $timing ) {
 826                 DeferredUpdates::addCallableUpdate( function () use ( $timing ) {
 827                         $measure = $timing->measure( 'responseTime', 'requestStart', 'requestShutdown' );
 828                         if ( $measure !== false ) {
 829                                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
 830                                 $stats->timing( 'resourceloader.responseTime', $measure['duration'] * 1000 );
 831                         }
 832                 } );
 833         }
 834
 835         /**
 836          * Send main response headers to the client.
 837          *
 838          * Deals with Content-Type, CORS (for stylesheets), and caching.
 839          *
 840          * @param ResourceLoaderContext $context
 841          * @param string $etag ETag header value
 842          * @param bool $errors Whether there are errors in the response
 843          * @param string[] $extra Array of extra HTTP response headers
 844          * @return void
 845          */
 846         protected function sendResponseHeaders(
 847                 ResourceLoaderContext $context, $etag, $errors, array $extra = []
 848         ) {
 849                 \MediaWiki\HeaderCallback::warnIfHeadersSent();
 850                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 851                 // Use a short cache expiry so that updates propagate to clients quickly, if:
 852                 // - No version specified (shared resources, e.g. stylesheets)
 853                 // - There were errors (recover quickly)
 854                 // - Version mismatch (T117587, T47877)
 855                 if ( is_null( $context->getVersion() )
 856                         || $errors
 857                         || $context->getVersion() !== $this->makeVersionQuery( $context )
 858                 ) {
 859                         $maxage = $rlMaxage['unversioned']['client'];
 860                         $smaxage = $rlMaxage['unversioned']['server'];
 861                 // If a version was specified we can use a longer expiry time since changing
 862                 // version numbers causes cache misses
 863                 } else {
 864                         $maxage = $rlMaxage['versioned']['client'];
 865                         $smaxage = $rlMaxage['versioned']['server'];
 866                 }
 867                 if ( $context->getImageObj() ) {
 868                         // Output different headers if we're outputting textual errors.
 869                         if ( $errors ) {
 870                                 header( 'Content-Type: text/plain; charset=utf-8' );
 871                         } else {
 872                                 $context->getImageObj()->sendResponseHeaders( $context );
 873                         }
 874                 } elseif ( $context->getOnly() === 'styles' ) {
 875                         header( 'Content-Type: text/css; charset=utf-8' );
 876                         header( 'Access-Control-Allow-Origin: *' );
 877                 } else {
 878                         header( 'Content-Type: text/javascript; charset=utf-8' );
 879                 }
 880                 // See RFC 2616 § 14.19 ETag
 881                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.19
 882                 header( 'ETag: ' . $etag );
 883                 if ( $context->getDebug() ) {
 884                         // Do not cache debug responses
 885                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 886                         header( 'Pragma: no-cache' );
 887                 } else {
 888                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 889                         $exp = min( $maxage, $smaxage );
 890                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 891                 }
 892                 foreach ( $extra as $header ) {
 893                         header( $header );
 894                 }
 895         }
 896
 897         /**
 898          * Respond with HTTP 304 Not Modified if appropiate.
 899          *
 900          * If there's an If-None-Match header, respond with a 304 appropriately
 901          * and clear out the output buffer. If the client cache is too old then do nothing.
 902          *
 903          * @param ResourceLoaderContext $context
 904          * @param string $etag ETag header value
 905          * @return bool True if HTTP 304 was sent and output handled
 906          */
 907         protected function tryRespondNotModified( ResourceLoaderContext $context, $etag ) {
 908                 // See RFC 2616 § 14.26 If-None-Match
 909                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
 910                 $clientKeys = $context->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST );
 911                 // Never send 304s in debug mode
 912                 if ( $clientKeys !== false && !$context->getDebug() && in_array( $etag, $clientKeys ) ) {
 913                         // There's another bug in ob_gzhandler (see also the comment at
 914                         // the top of this function) that causes it to gzip even empty
 915                         // responses, meaning it's impossible to produce a truly empty
 916                         // response (because the gzip header is always there). This is
 917                         // a problem because 304 responses have to be completely empty
 918                         // per the HTTP spec, and Firefox behaves buggily when they're not.
 919                         // See also https://bugs.php.net/bug.php?id=51579
 920                         // To work around this, we tear down all output buffering before
 921                         // sending the 304.
 922                         wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 923
 924                         HttpStatus::header( 304 );
 925
 926                         $this->sendResponseHeaders( $context, $etag, false );
 927                         return true;
 928                 }
 929                 return false;
 930         }
 931
 932         /**
 933          * Send out code for a response from file cache if possible.
 934          *
 935          * @param ResourceFileCache $fileCache Cache object for this request URL
 936          * @param ResourceLoaderContext $context Context in which to generate a response
 937          * @param string $etag ETag header value
 938          * @return bool If this found a cache file and handled the response
 939          */
 940         protected function tryRespondFromFileCache(
 941                 ResourceFileCache $fileCache,
 942                 ResourceLoaderContext $context,
 943                 $etag
 944         ) {
 945                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 946                 // Buffer output to catch warnings.
 947                 ob_start();
 948                 // Get the maximum age the cache can be
 949                 $maxage = is_null( $context->getVersion() )
 950                         ? $rlMaxage['unversioned']['server']
 951                         : $rlMaxage['versioned']['server'];
 952                 // Minimum timestamp the cache file must have
 953                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 954                 if ( !$good ) {
 955                         try { // RL always hits the DB on file cache miss...
 956                                 wfGetDB( DB_REPLICA );
 957                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 958                                 $good = $fileCache->isCacheGood(); // cache existence check
 959                         }
 960                 }
 961                 if ( $good ) {
 962                         $ts = $fileCache->cacheTimestamp();
 963                         // Send content type and cache headers
 964                         $this->sendResponseHeaders( $context, $etag, false );
 965                         $response = $fileCache->fetchText();
 966                         // Capture any PHP warnings from the output buffer and append them to the
 967                         // response in a comment if we're in debug mode.
 968                         if ( $context->getDebug() ) {
 969                                 $warnings = ob_get_contents();
 970                                 if ( strlen( $warnings ) ) {
 971                                         $response = self::makeComment( $warnings ) . $response;
 972                                 }
 973                         }
 974                         // Remove the output buffer and output the response
 975                         ob_end_clean();
 976                         echo $response . "\n/* Cached {$ts} */";
 977                         return true; // cache hit
 978                 }
 979                 // Clear buffer
 980                 ob_end_clean();
 981
 982                 return false; // cache miss
 983         }
 984
 985         /**
 986          * Generate a CSS or JS comment block.
 987          *
 988          * Only use this for public data, not error message details.
 989          *
 990          * @param string $text
 991          * @return string
 992          */
 993         public static function makeComment( $text ) {
 994                 $encText = str_replace( '*/', '* /', $text );
 995                 return "/*\n$encText\n*/\n";
 996         }
 997
 998         /**
 999          * Handle exception display.
1000          *
1001          * @param Exception $e Exception to be shown to the user
1002          * @return string Sanitized text in a CSS/JS comment that can be returned to the user
1003          */
1004         public static function formatException( $e ) {
1005                 return self::makeComment( self::formatExceptionNoComment( $e ) );
1006         }
1007
1008         /**
1009          * Handle exception display.
1010          *
1011          * @since 1.25
1012          * @param Exception $e Exception to be shown to the user
1013          * @return string Sanitized text that can be returned to the user
1014          */
1015         protected static function formatExceptionNoComment( $e ) {
1016                 global $wgShowExceptionDetails;
1017
1018                 if ( !$wgShowExceptionDetails ) {
1019                         return MWExceptionHandler::getPublicLogMessage( $e );
1020                 }
1021
1022                 return MWExceptionHandler::getLogMessage( $e ) .
1023                         "\nBacktrace:\n" .
1024                         MWExceptionHandler::getRedactedTraceAsString( $e );
1025         }
1026
1027         /**
1028          * Generate code for a response.
1029          *
1030          * Calling this method also populates the `errors` and `headers` members,
1031          * later used by respond().
1032          *
1033          * @param ResourceLoaderContext $context Context in which to generate a response
1034          * @param ResourceLoaderModule[] $modules List of module objects keyed by module name
1035          * @param string[] $missing List of requested module names that are unregistered (optional)
1036          * @return string Response data
1037          */
1038         public function makeModuleResponse( ResourceLoaderContext $context,
1039                 array $modules, array $missing = []
1040         ) {
1041                 $out = '';
1042                 $states = [];
1043
1044                 if ( !count( $modules ) && !count( $missing ) ) {
1045                         return <<<MESSAGE
1046 /* This file is the Web entry point for MediaWiki's ResourceLoader:
1047    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
1048    no modules were requested. Max made me put this here. */
1049 MESSAGE;
1050                 }
1051
1052                 $image = $context->getImageObj();
1053                 if ( $image ) {
1054                         $data = $image->getImageData( $context );
1055                         if ( $data === false ) {
1056                                 $data = '';
1057                                 $this->errors[] = 'Image generation failed';
1058                         }
1059                         return $data;
1060                 }
1061
1062                 foreach ( $missing as $name ) {
1063                         $states[$name] = 'missing';
1064                 }
1065
1066                 // Generate output
1067                 $isRaw = false;
1068
1069                 $filter = $context->getOnly() === 'styles' ? 'minify-css' : 'minify-js';
1070
1071                 foreach ( $modules as $name => $module ) {
1072                         try {
1073                                 $content = $module->getModuleContent( $context );
1074                                 $implementKey = $name . '@' . $module->getVersionHash( $context );
1075                                 $strContent = '';
1076
1077                                 if ( isset( $content['headers'] ) ) {
1078                                         $this->extraHeaders = array_merge( $this->extraHeaders, $content['headers'] );
1079                                 }
1080
1081                                 // Append output
1082                                 switch ( $context->getOnly() ) {
1083                                         case 'scripts':
1084                                                 $scripts = $content['scripts'];
1085                                                 if ( is_string( $scripts ) ) {
1086                                                         // Load scripts raw...
1087                                                         $strContent = $scripts;
1088                                                 } elseif ( is_array( $scripts ) ) {
1089                                                         // ...except when $scripts is an array of URLs
1090                                                         $strContent = self::makeLoaderImplementScript( $implementKey, $scripts, [], [], [] );
1091                                                 }
1092                                                 break;
1093                                         case 'styles':
1094                                                 $styles = $content['styles'];
1095                                                 // We no longer separate into media, they are all combined now with
1096                                                 // custom media type groups into @media .. {} sections as part of the css string.
1097                                                 // Module returns either an empty array or a numerical array with css strings.
1098                                                 $strContent = isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
1099                                                 break;
1100                                         default:
1101                                                 $scripts = $content['scripts'] ?? '';
1102                                                 if ( is_string( $scripts ) ) {
1103                                                         if ( $name === 'site' || $name === 'user' ) {
1104                                                                 // Legacy scripts that run in the global scope without a closure.
1105                                                                 // mw.loader.implement will use globalEval if scripts is a string.
1106                                                                 // Minify manually here, because general response minification is
1107                                                                 // not effective due it being a string literal, not a function.
1108                                                                 if ( !self::inDebugMode() ) {
1109                                                                         $scripts = self::filter( 'minify-js', $scripts ); // T107377
1110                                                                 }
1111                                                         } else {
1112                                                                 $scripts = new XmlJsCode( $scripts );
1113                                                         }
1114                                                 }
1115                                                 $strContent = self::makeLoaderImplementScript(
1116                                                         $implementKey,
1117                                                         $scripts,
1118                                                         $content['styles'] ?? [],
1119                                                         isset( $content['messagesBlob'] ) ? new XmlJsCode( $content['messagesBlob'] ) : [],
1120                                                         $content['templates'] ?? []
1121                                                 );
1122                                                 break;
1123                                 }
1124
1125                                 if ( !$context->getDebug() ) {
1126                                         $strContent = self::filter( $filter, $strContent );
1127                                 }
1128
1129                                 if ( $context->getOnly() === 'scripts' ) {
1130                                         // Use a linebreak between module scripts (T162719)
1131                                         $out .= $this->ensureNewline( $strContent );
1132                                 } else {
1133                                         $out .= $strContent;
1134                                 }
1135
1136                         } catch ( Exception $e ) {
1137                                 $this->outputErrorAndLog( $e, 'Generating module package failed: {exception}' );
1138
1139                                 // Respond to client with error-state instead of module implementation
1140                                 $states[$name] = 'error';
1141                                 unset( $modules[$name] );
1142                         }
1143                         $isRaw |= $module->isRaw();
1144                 }
1145
1146                 // Update module states
1147                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
1148                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
1149                                 // Set the state of modules loaded as only scripts to ready as
1150                                 // they don't have an mw.loader.implement wrapper that sets the state
1151                                 foreach ( $modules as $name => $module ) {
1152                                         $states[$name] = 'ready';
1153                                 }
1154                         }
1155
1156                         // Set the state of modules we didn't respond to with mw.loader.implement
1157                         if ( count( $states ) ) {
1158                                 $stateScript = self::makeLoaderStateScript( $states );
1159                                 if ( !$context->getDebug() ) {
1160                                         $stateScript = self::filter( 'minify-js', $stateScript );
1161                                 }
1162                                 // Use a linebreak between module script and state script (T162719)
1163                                 $out = $this->ensureNewline( $out ) . $stateScript;
1164                         }
1165                 } else {
1166                         if ( $states ) {
1167                                 // Keep default escaping of slashes (e.g. "</script>") for ResourceLoaderClientHtml.
1168                                 $this->errors[] = 'Problematic modules: ' . json_encode( $states, JSON_PRETTY_PRINT );
1169                         }
1170                 }
1171
1172                 return $out;
1173         }
1174
1175         /**
1176          * Ensure the string is either empty or ends in a line break
1177          * @param string $str
1178          * @return string
1179          */
1180         private function ensureNewline( $str ) {
1181                 $end = substr( $str, -1 );
1182                 if ( $end === false || $end === "\n" ) {
1183                         return $str;
1184                 }
1185                 return $str . "\n";
1186         }
1187
1188         /**
1189          * Get names of modules that use a certain message.
1190          *
1191          * @param string $messageKey
1192          * @return array List of module names
1193          */
1194         public function getModulesByMessage( $messageKey ) {
1195                 $moduleNames = [];
1196                 foreach ( $this->getModuleNames() as $moduleName ) {
1197                         $module = $this->getModule( $moduleName );
1198                         if ( in_array( $messageKey, $module->getMessages() ) ) {
1199                                 $moduleNames[] = $moduleName;
1200                         }
1201                 }
1202                 return $moduleNames;
1203         }
1204
1205         /**
1206          * Return JS code that calls mw.loader.implement with given module properties.
1207          *
1208          * @param string $name Module name or implement key (format "`[name]@[version]`")
1209          * @param XmlJsCode|array|string $scripts Code as XmlJsCode (to be wrapped in a closure),
1210          *  list of URLs to JavaScript files, or a string of JavaScript for `$.globalEval`.
1211          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1212          *   to CSS files keyed by media type
1213          * @param mixed $messages List of messages associated with this module. May either be an
1214          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1215          *   the same data, wrapped in an XmlJsCode object.
1216          * @param array $templates Keys are name of templates and values are the source of
1217          *   the template.
1218          * @throws MWException
1219          * @return string JavaScript code
1220          */
1221         protected static function makeLoaderImplementScript(
1222                 $name, $scripts, $styles, $messages, $templates
1223         ) {
1224                 if ( $scripts instanceof XmlJsCode ) {
1225                         if ( self::inDebugMode() ) {
1226                                 $scripts = new XmlJsCode( "function ( $, jQuery, require, module ) {\n{$scripts->value}\n}" );
1227                         } else {
1228                                 $scripts = new XmlJsCode( 'function($,jQuery,require,module){'. $scripts->value . '}' );
1229                         }
1230                 } elseif ( !is_string( $scripts ) && !is_array( $scripts ) ) {
1231                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1232                 }
1233                 // mw.loader.implement requires 'styles', 'messages' and 'templates' to be objects (not
1234                 // arrays). json_encode considers empty arrays to be numerical and outputs "[]" instead
1235                 // of "{}". Force them to objects.
1236                 $module = [
1237                         $name,
1238                         $scripts,
1239                         (object)$styles,
1240                         (object)$messages,
1241                         (object)$templates,
1242                 ];
1243                 self::trimArray( $module );
1244
1245                 return Xml::encodeJsCall( 'mw.loader.implement', $module, self::inDebugMode() );
1246         }
1247
1248         /**
1249          * Returns JS code which, when called, will register a given list of messages.
1250          *
1251          * @param mixed $messages Either an associative array mapping message key to value, or a
1252          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1253          * @return string JavaScript code
1254          */
1255         public static function makeMessageSetScript( $messages ) {
1256                 return Xml::encodeJsCall(
1257                         'mw.messages.set',
1258                         [ (object)$messages ],
1259                         self::inDebugMode()
1260                 );
1261         }
1262
1263         /**
1264          * Combines an associative array mapping media type to CSS into a
1265          * single stylesheet with "@media" blocks.
1266          *
1267          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1268          * @return array
1269          */
1270         public static function makeCombinedStyles( array $stylePairs ) {
1271                 $out = [];
1272                 foreach ( $stylePairs as $media => $styles ) {
1273                         // ResourceLoaderFileModule::getStyle can return the styles
1274                         // as a string or an array of strings. This is to allow separation in
1275                         // the front-end.
1276                         $styles = (array)$styles;
1277                         foreach ( $styles as $style ) {
1278                                 $style = trim( $style );
1279                                 // Don't output an empty "@media print { }" block (T42498)
1280                                 if ( $style !== '' ) {
1281                                         // Transform the media type based on request params and config
1282                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1283                                         $media = OutputPage::transformCssMedia( $media );
1284
1285                                         if ( $media === '' || $media == 'all' ) {
1286                                                 $out[] = $style;
1287                                         } elseif ( is_string( $media ) ) {
1288                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1289                                         }
1290                                         // else: skip
1291                                 }
1292                         }
1293                 }
1294                 return $out;
1295         }
1296
1297         /**
1298          * Returns a JS call to mw.loader.state, which sets the state of one
1299          * ore more modules to a given value. Has two calling conventions:
1300          *
1301          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1302          *         Set the state of a single module called $name to $state
1303          *
1304          *    - ResourceLoader::makeLoaderStateScript( [ $name => $state, ... ] ):
1305          *         Set the state of modules with the given names to the given states
1306          *
1307          * @param array|string $states
1308          * @param string|null $state
1309          * @return string JavaScript code
1310          */
1311         public static function makeLoaderStateScript( $states, $state = null ) {
1312                 if ( !is_array( $states ) ) {
1313                         $states = [ $states => $state ];
1314                 }
1315                 return Xml::encodeJsCall(
1316                         'mw.loader.state',
1317                         [ $states ],
1318                         self::inDebugMode()
1319                 );
1320         }
1321
1322         /**
1323          * Returns JS code which calls the script given by $script. The script will
1324          * be called with local variables name, version, dependencies and group,
1325          * which will have values corresponding to $name, $version, $dependencies
1326          * and $group as supplied.
1327          *
1328          * @param string $name Module name
1329          * @param string $version Module version hash
1330          * @param array $dependencies List of module names on which this module depends
1331          * @param string $group Group which the module is in.
1332          * @param string $source Source of the module, or 'local' if not foreign.
1333          * @param string $script JavaScript code
1334          * @return string JavaScript code
1335          */
1336         public static function makeCustomLoaderScript( $name, $version, $dependencies,
1337                 $group, $source, $script
1338         ) {
1339                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1340                 return Xml::encodeJsCall(
1341                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1342                         [ $name, $version, $dependencies, $group, $source ],
1343                         self::inDebugMode()
1344                 );
1345         }
1346
1347         private static function isEmptyObject( stdClass $obj ) {
1348                 foreach ( $obj as $key => $value ) {
1349                         return false;
1350                 }
1351                 return true;
1352         }
1353
1354         /**
1355          * Remove empty values from the end of an array.
1356          *
1357          * Values considered empty:
1358          *
1359          * - null
1360          * - []
1361          * - new XmlJsCode( '{}' )
1362          * - new stdClass() // (object) []
1363          *
1364          * @param Array $array
1365          */
1366         private static function trimArray( array &$array ) {
1367                 $i = count( $array );
1368                 while ( $i-- ) {
1369                         if ( $array[$i] === null
1370                                 || $array[$i] === []
1371                                 || ( $array[$i] instanceof XmlJsCode && $array[$i]->value === '{}' )
1372                                 || ( $array[$i] instanceof stdClass && self::isEmptyObject( $array[$i] ) )
1373                         ) {
1374                                 unset( $array[$i] );
1375                         } else {
1376                                 break;
1377                         }
1378                 }
1379         }
1380
1381         /**
1382          * Returns JS code which calls mw.loader.register with the given
1383          * parameters. Has three calling conventions:
1384          *
1385          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version,
1386          *        $dependencies, $group, $source, $skip
1387          *     ):
1388          *        Register a single module.
1389          *
1390          *   - ResourceLoader::makeLoaderRegisterScript( [ $name1, $name2 ] ):
1391          *        Register modules with the given names.
1392          *
1393          *   - ResourceLoader::makeLoaderRegisterScript( [
1394          *        [ $name1, $version1, $dependencies1, $group1, $source1, $skip1 ],
1395          *        [ $name2, $version2, $dependencies1, $group2, $source2, $skip2 ],
1396          *        ...
1397          *     ] ):
1398          *        Registers modules with the given names and parameters.
1399          *
1400          * @param string $name Module name
1401          * @param string|null $version Module version hash
1402          * @param array|null $dependencies List of module names on which this module depends
1403          * @param string|null $group Group which the module is in
1404          * @param string|null $source Source of the module, or 'local' if not foreign
1405          * @param string|null $skip Script body of the skip function
1406          * @return string JavaScript code
1407          */
1408         public static function makeLoaderRegisterScript( $name, $version = null,
1409                 $dependencies = null, $group = null, $source = null, $skip = null
1410         ) {
1411                 if ( is_array( $name ) ) {
1412                         // Build module name index
1413                         $index = [];
1414                         foreach ( $name as $i => &$module ) {
1415                                 $index[$module[0]] = $i;
1416                         }
1417
1418                         // Transform dependency names into indexes when possible, they will be resolved by
1419                         // mw.loader.register on the other end
1420                         foreach ( $name as &$module ) {
1421                                 if ( isset( $module[2] ) ) {
1422                                         foreach ( $module[2] as &$dependency ) {
1423                                                 if ( isset( $index[$dependency] ) ) {
1424                                                         $dependency = $index[$dependency];
1425                                                 }
1426                                         }
1427                                 }
1428                         }
1429
1430                         array_walk( $name, [ 'self', 'trimArray' ] );
1431
1432                         return Xml::encodeJsCall(
1433                                 'mw.loader.register',
1434                                 [ $name ],
1435                                 self::inDebugMode()
1436                         );
1437                 } else {
1438                         $registration = [ $name, $version, $dependencies, $group, $source, $skip ];
1439                         self::trimArray( $registration );
1440                         return Xml::encodeJsCall(
1441                                 'mw.loader.register',
1442                                 $registration,
1443                                 self::inDebugMode()
1444                         );
1445                 }
1446         }
1447
1448         /**
1449          * Returns JS code which calls mw.loader.addSource() with the given
1450          * parameters. Has two calling conventions:
1451          *
1452          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1453          *       Register a single source
1454          *
1455          *   - ResourceLoader::makeLoaderSourcesScript( [ $id1 => $loadUrl, $id2 => $loadUrl, ... ] );
1456          *       Register sources with the given IDs and properties.
1457          *
1458          * @param string $id Source ID
1459          * @param string|null $loadUrl load.php url
1460          * @return string JavaScript code
1461          */
1462         public static function makeLoaderSourcesScript( $id, $loadUrl = null ) {
1463                 if ( is_array( $id ) ) {
1464                         return Xml::encodeJsCall(
1465                                 'mw.loader.addSource',
1466                                 [ $id ],
1467                                 self::inDebugMode()
1468                         );
1469                 } else {
1470                         return Xml::encodeJsCall(
1471                                 'mw.loader.addSource',
1472                                 [ $id, $loadUrl ],
1473                                 self::inDebugMode()
1474                         );
1475                 }
1476         }
1477
1478         /**
1479          * Wraps JavaScript code to run after the startup module.
1480          *
1481          * @param string $script JavaScript code
1482          * @return string JavaScript code
1483          */
1484         public static function makeLoaderConditionalScript( $script ) {
1485                 // Adds a function to lazy-created RLQ
1486                 return '(window.RLQ=window.RLQ||[]).push(function(){' .
1487                         trim( $script ) . '});';
1488         }
1489
1490         /**
1491          * Wraps JavaScript code to run after a required module.
1492          *
1493          * @since 1.32
1494          * @param string|string[] $modules Module name(s)
1495          * @param string $script JavaScript code
1496          * @return string JavaScript code
1497          */
1498         public static function makeInlineCodeWithModule( $modules, $script ) {
1499                 // Adds an array to lazy-created RLQ
1500                 return '(window.RLQ=window.RLQ||[]).push(['
1501                         . json_encode( $modules ) . ','
1502                         . 'function(){' . trim( $script ) . '}'
1503                         . ']);';
1504         }
1505
1506         /**
1507          * Returns an HTML script tag that runs given JS code after startup and base modules.
1508          *
1509          * The code will be wrapped in a closure, and it will be executed by ResourceLoader's
1510          * startup module if the client has adequate support for MediaWiki JavaScript code.
1511          *
1512          * @param string $script JavaScript code
1513          * @param string|null $nonce [optional] Content-Security-Policy nonce
1514          *  (from OutputPage::getCSPNonce)
1515          * @return string|WrappedString HTML
1516          */
1517         public static function makeInlineScript( $script, $nonce = null ) {
1518                 $js = self::makeLoaderConditionalScript( $script );
1519                 $escNonce = '';
1520                 if ( $nonce === null ) {
1521                         wfWarn( __METHOD__ . " did not get nonce. Will break CSP" );
1522                 } elseif ( $nonce !== false ) {
1523                         // If it was false, CSP is disabled, so no nonce attribute.
1524                         // Nonce should be only base64 characters, so should be safe,
1525                         // but better to be safely escaped than sorry.
1526                         $escNonce = ' nonce="' . htmlspecialchars( $nonce ) . '"';
1527                 }
1528
1529                 return new WrappedString(
1530                         Html::inlineScript( $js, $nonce ),
1531                         "<script$escNonce>(window.RLQ=window.RLQ||[]).push(function(){",
1532                         '});</script>'
1533                 );
1534         }
1535
1536         /**
1537          * Returns JS code which will set the MediaWiki configuration array to
1538          * the given value.
1539          *
1540          * @param array $configuration List of configuration values keyed by variable name
1541          * @return string JavaScript code
1542          */
1543         public static function makeConfigSetScript( array $configuration ) {
1544                 return Xml::encodeJsCall(
1545                         'mw.config.set',
1546                         [ $configuration ],
1547                         self::inDebugMode()
1548                 );
1549         }
1550
1551         /**
1552          * Convert an array of module names to a packed query string.
1553          *
1554          * For example, `[ 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' ]`
1555          * becomes `'foo.bar,baz|bar.baz,quux'`.
1556          *
1557          * This process is reversed by ResourceLoaderContext::expandModuleNames().
1558          * See also mw.loader#buildModulesString() which is a port of this, used
1559          * on the client-side.
1560          *
1561          * @param array $modules List of module names (strings)
1562          * @return string Packed query string
1563          */
1564         public static function makePackedModulesString( $modules ) {
1565                 $moduleMap = []; // [ prefix => [ suffixes ] ]
1566                 foreach ( $modules as $module ) {
1567                         $pos = strrpos( $module, '.' );
1568                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1569                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1570                         $moduleMap[$prefix][] = $suffix;
1571                 }
1572
1573                 $arr = [];
1574                 foreach ( $moduleMap as $prefix => $suffixes ) {
1575                         $p = $prefix === '' ? '' : $prefix . '.';
1576                         $arr[] = $p . implode( ',', $suffixes );
1577                 }
1578                 return implode( '|', $arr );
1579         }
1580
1581         /**
1582          * Determine whether debug mode was requested
1583          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1584          * @return bool
1585          */
1586         public static function inDebugMode() {
1587                 if ( self::$debugMode === null ) {
1588                         global $wgRequest, $wgResourceLoaderDebug;
1589                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1590                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1591                         );
1592                 }
1593                 return self::$debugMode;
1594         }
1595
1596         /**
1597          * Reset static members used for caching.
1598          *
1599          * Global state and $wgRequest are evil, but we're using it right
1600          * now and sometimes we need to be able to force ResourceLoader to
1601          * re-evaluate the context because it has changed (e.g. in the test suite).
1602          */
1603         public static function clearCache() {
1604                 self::$debugMode = null;
1605         }
1606
1607         /**
1608          * Build a load.php URL
1609          *
1610          * @since 1.24
1611          * @param string $source Name of the ResourceLoader source
1612          * @param ResourceLoaderContext $context
1613          * @param array $extraQuery
1614          * @return string URL to load.php. May be protocol-relative if $wgLoadScript is, too.
1615          */
1616         public function createLoaderURL( $source, ResourceLoaderContext $context,
1617                 $extraQuery = []
1618         ) {
1619                 $query = self::createLoaderQuery( $context, $extraQuery );
1620                 $script = $this->getLoadScript( $source );
1621
1622                 return wfAppendQuery( $script, $query );
1623         }
1624
1625         /**
1626          * Helper for createLoaderURL()
1627          *
1628          * @since 1.24
1629          * @see makeLoaderQuery
1630          * @param ResourceLoaderContext $context
1631          * @param array $extraQuery
1632          * @return array
1633          */
1634         protected static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = [] ) {
1635                 return self::makeLoaderQuery(
1636                         $context->getModules(),
1637                         $context->getLanguage(),
1638                         $context->getSkin(),
1639                         $context->getUser(),
1640                         $context->getVersion(),
1641                         $context->getDebug(),
1642                         $context->getOnly(),
1643                         $context->getRequest()->getBool( 'printable' ),
1644                         $context->getRequest()->getBool( 'handheld' ),
1645                         $extraQuery
1646                 );
1647         }
1648
1649         /**
1650          * Build a query array (array representation of query string) for load.php. Helper
1651          * function for createLoaderURL().
1652          *
1653          * @param array $modules
1654          * @param string $lang
1655          * @param string $skin
1656          * @param string|null $user
1657          * @param string|null $version
1658          * @param bool $debug
1659          * @param string|null $only
1660          * @param bool $printable
1661          * @param bool $handheld
1662          * @param array $extraQuery
1663          *
1664          * @return array
1665          */
1666         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1667                 $version = null, $debug = false, $only = null, $printable = false,
1668                 $handheld = false, $extraQuery = []
1669         ) {
1670                 $query = [
1671                         'modules' => self::makePackedModulesString( $modules ),
1672                         'lang' => $lang,
1673                         'skin' => $skin,
1674                         'debug' => $debug ? 'true' : 'false',
1675                 ];
1676                 if ( $user !== null ) {
1677                         $query['user'] = $user;
1678                 }
1679                 if ( $version !== null ) {
1680                         $query['version'] = $version;
1681                 }
1682                 if ( $only !== null ) {
1683                         $query['only'] = $only;
1684                 }
1685                 if ( $printable ) {
1686                         $query['printable'] = 1;
1687                 }
1688                 if ( $handheld ) {
1689                         $query['handheld'] = 1;
1690                 }
1691                 $query += $extraQuery;
1692
1693                 // Make queries uniform in order
1694                 ksort( $query );
1695                 return $query;
1696         }
1697
1698         /**
1699          * Check a module name for validity.
1700          *
1701          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1702          * at most 255 bytes.
1703          *
1704          * @param string $moduleName Module name to check
1705          * @return bool Whether $moduleName is a valid module name
1706          */
1707         public static function isValidModuleName( $moduleName ) {
1708                 return strcspn( $moduleName, '!,|', 0, 255 ) === strlen( $moduleName );
1709         }
1710
1711         /**
1712          * Returns LESS compiler set up for use with MediaWiki
1713          *
1714          * @since 1.27
1715          * @param array $vars Associative array of variables that should be used
1716          *  for compilation. Since 1.32, this method no longer automatically includes
1717          *  global LESS vars from ResourceLoader::getLessVars (T191937).
1718          * @throws MWException
1719          * @return Less_Parser
1720          */
1721         public function getLessCompiler( $vars = [] ) {
1722                 global $IP;
1723                 // When called from the installer, it is possible that a required PHP extension
1724                 // is missing (at least for now; see T49564). If this is the case, throw an
1725                 // exception (caught by the installer) to prevent a fatal error later on.
1726                 if ( !class_exists( 'Less_Parser' ) ) {
1727                         throw new MWException( 'MediaWiki requires the less.php parser' );
1728                 }
1729
1730                 $parser = new Less_Parser;
1731                 $parser->ModifyVars( $vars );
1732                 $parser->SetImportDirs( [
1733                         "$IP/resources/src/mediawiki.less/" => '',
1734                 ] );
1735                 $parser->SetOption( 'relativeUrls', false );
1736
1737                 return $parser;
1738         }
1739
1740         /**
1741          * Get global LESS variables.
1742          *
1743          * @since 1.27
1744          * @deprecated since 1.32 Use ResourceLoderModule::getLessVars() instead.
1745          * @return array Map of variable names to string CSS values.
1746          */
1747         public function getLessVars() {
1748                 return [];
1749         }
1750 }