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
  31 /**
  32  * Dynamic JavaScript and CSS resource loading system.
  33  *
  34  * Most of the documentation is on the MediaWiki documentation wiki starting at:
  35  *    https://www.mediawiki.org/wiki/ResourceLoader
  36  */
  37 class ResourceLoader implements LoggerAwareInterface {
  38         /** @var int */
  39         protected static $filterCacheVersion = 7;
  40
  41         /** @var bool */
  42         protected static $debugMode = null;
  43
  44         /** @var array */
  45         private $lessVars = null;
  46
  47         /**
  48          * Module name/ResourceLoaderModule object pairs
  49          * @var array
  50          */
  51         protected $modules = [];
  52
  53         /**
  54          * Associative array mapping module name to info associative array
  55          * @var array
  56          */
  57         protected $moduleInfos = [];
  58
  59         /** @var Config $config */
  60         protected $config;
  61
  62         /**
  63          * Associative array mapping framework ids to a list of names of test suite modules
  64          * like [ 'qunit' => [ 'mediawiki.tests.qunit.suites', 'ext.foo.tests', ... ], ... ]
  65          * @var array
  66          */
  67         protected $testModuleNames = [];
  68
  69         /**
  70          * E.g. [ 'source-id' => 'http://.../load.php' ]
  71          * @var array
  72          */
  73         protected $sources = [];
  74
  75         /**
  76          * Errors accumulated during current respond() call.
  77          * @var array
  78          */
  79         protected $errors = [];
  80
  81         /**
  82          * @var MessageBlobStore
  83          */
  84         protected $blobStore;
  85
  86         /**
  87          * @var LoggerInterface
  88          */
  89         private $logger;
  90
  91         /** @var string JavaScript / CSS pragma to disable minification. **/
  92         const FILTER_NOMIN = '/*@nomin*/';
  93
  94         /**
  95          * Load information stored in the database about modules.
  96          *
  97          * This method grabs modules dependencies from the database and updates modules
  98          * objects.
  99          *
 100          * This is not inside the module code because it is much faster to
 101          * request all of the information at once than it is to have each module
 102          * requests its own information. This sacrifice of modularity yields a substantial
 103          * performance improvement.
 104          *
 105          * @param array $moduleNames List of module names to preload information for
 106          * @param ResourceLoaderContext $context Context to load the information within
 107          */
 108         public function preloadModuleInfo( array $moduleNames, ResourceLoaderContext $context ) {
 109                 if ( !$moduleNames ) {
 110                         // Or else Database*::select() will explode, plus it's cheaper!
 111                         return;
 112                 }
 113                 $dbr = wfGetDB( DB_REPLICA );
 114                 $skin = $context->getSkin();
 115                 $lang = $context->getLanguage();
 116
 117                 // Batched version of ResourceLoaderModule::getFileDependencies
 118                 $vary = "$skin|$lang";
 119                 $res = $dbr->select( 'module_deps', [ 'md_module', 'md_deps' ], [
 120                                 'md_module' => $moduleNames,
 121                                 'md_skin' => $vary,
 122                         ], __METHOD__
 123                 );
 124
 125                 // Prime in-object cache for file dependencies
 126                 $modulesWithDeps = [];
 127                 foreach ( $res as $row ) {
 128                         $module = $this->getModule( $row->md_module );
 129                         if ( $module ) {
 130                                 $module->setFileDependencies( $context, ResourceLoaderModule::expandRelativePaths(
 131                                         FormatJson::decode( $row->md_deps, true )
 132                                 ) );
 133                                 $modulesWithDeps[] = $row->md_module;
 134                         }
 135                 }
 136                 // Register the absence of a dependency row too
 137                 foreach ( array_diff( $moduleNames, $modulesWithDeps ) as $name ) {
 138                         $module = $this->getModule( $name );
 139                         if ( $module ) {
 140                                 $this->getModule( $name )->setFileDependencies( $context, [] );
 141                         }
 142                 }
 143
 144                 // Batched version of ResourceLoaderWikiModule::getTitleInfo
 145                 ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $moduleNames );
 146
 147                 // Prime in-object cache for message blobs for modules with messages
 148                 $modules = [];
 149                 foreach ( $moduleNames as $name ) {
 150                         $module = $this->getModule( $name );
 151                         if ( $module && $module->getMessages() ) {
 152                                 $modules[$name] = $module;
 153                         }
 154                 }
 155                 $store = $this->getMessageBlobStore();
 156                 $blobs = $store->getBlobs( $modules, $lang );
 157                 foreach ( $blobs as $name => $blob ) {
 158                         $modules[$name]->setMessageBlob( $blob, $lang );
 159                 }
 160         }
 161
 162         /**
 163          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 164          *
 165          * Available filters are:
 166          *
 167          *    - minify-js \see JavaScriptMinifier::minify
 168          *    - minify-css \see CSSMin::minify
 169          *
 170          * If $data is empty, only contains whitespace or the filter was unknown,
 171          * $data is returned unmodified.
 172          *
 173          * @param string $filter Name of filter to run
 174          * @param string $data Text to filter, such as JavaScript or CSS text
 175          * @param array $options Keys:
 176          *  - (bool) cache: Whether to allow caching this data. Default: true.
 177          * @return string Filtered data, or a comment containing an error message
 178          */
 179         public static function filter( $filter, $data, array $options = [] ) {
 180                 if ( strpos( $data, ResourceLoader::FILTER_NOMIN ) !== false ) {
 181                         return $data;
 182                 }
 183
 184                 if ( isset( $options['cache'] ) && $options['cache'] === false ) {
 185                         return self::applyFilter( $filter, $data );
 186                 }
 187
 188                 $stats = RequestContext::getMain()->getStats();
 189                 $cache = ObjectCache::getLocalServerInstance( CACHE_ANYTHING );
 190
 191                 $key = $cache->makeGlobalKey(
 192                         'resourceloader',
 193                         'filter',
 194                         $filter,
 195                         self::$filterCacheVersion, md5( $data )
 196                 );
 197
 198                 $result = $cache->get( $key );
 199                 if ( $result === false ) {
 200                         $stats->increment( "resourceloader_cache.$filter.miss" );
 201                         $result = self::applyFilter( $filter, $data );
 202                         $cache->set( $key, $result, 24 * 3600 );
 203                 } else {
 204                         $stats->increment( "resourceloader_cache.$filter.hit" );
 205                 }
 206                 if ( $result === null ) {
 207                         // Cached failure
 208                         $result = $data;
 209                 }
 210
 211                 return $result;
 212         }
 213
 214         private static function applyFilter( $filter, $data ) {
 215                 $data = trim( $data );
 216                 if ( $data ) {
 217                         try {
 218                                 $data = ( $filter === 'minify-css' )
 219                                         ? CSSMin::minify( $data )
 220                                         : JavaScriptMinifier::minify( $data );
 221                         } catch ( Exception $e ) {
 222                                 MWExceptionHandler::logException( $e );
 223                                 return null;
 224                         }
 225                 }
 226                 return $data;
 227         }
 228
 229         /* Methods */
 230
 231         /**
 232          * Register core modules and runs registration hooks.
 233          * @param Config $config [optional]
 234          * @param LoggerInterface $logger [optional]
 235          */
 236         public function __construct( Config $config = null, LoggerInterface $logger = null ) {
 237                 global $IP;
 238
 239                 $this->logger = $logger ?: new NullLogger();
 240
 241                 if ( !$config ) {
 242                         $this->logger->debug( __METHOD__ . ' was called without providing a Config instance' );
 243                         $config = MediaWikiServices::getInstance()->getMainConfig();
 244                 }
 245                 $this->config = $config;
 246
 247                 // Add 'local' source first
 248                 $this->addSource( 'local', $config->get( 'LoadScript' ) );
 249
 250                 // Add other sources
 251                 $this->addSource( $config->get( 'ResourceLoaderSources' ) );
 252
 253                 // Register core modules
 254                 $this->register( include "$IP/resources/Resources.php" );
 255                 $this->register( include "$IP/resources/ResourcesOOUI.php" );
 256                 // Register extension modules
 257                 $this->register( $config->get( 'ResourceModules' ) );
 258                 Hooks::run( 'ResourceLoaderRegisterModules', [ &$this ] );
 259
 260                 if ( $config->get( 'EnableJavaScriptTest' ) === true ) {
 261                         $this->registerTestModules();
 262                 }
 263
 264                 $this->setMessageBlobStore( new MessageBlobStore( $this, $this->logger ) );
 265         }
 266
 267         /**
 268          * @return Config
 269          */
 270         public function getConfig() {
 271                 return $this->config;
 272         }
 273
 274         /**
 275          * @since 1.26
 276          * @param LoggerInterface $logger
 277          */
 278         public function setLogger( LoggerInterface $logger ) {
 279                 $this->logger = $logger;
 280         }
 281
 282         /**
 283          * @since 1.27
 284          * @return LoggerInterface
 285          */
 286         public function getLogger() {
 287                 return $this->logger;
 288         }
 289
 290         /**
 291          * @since 1.26
 292          * @return MessageBlobStore
 293          */
 294         public function getMessageBlobStore() {
 295                 return $this->blobStore;
 296         }
 297
 298         /**
 299          * @since 1.25
 300          * @param MessageBlobStore $blobStore
 301          */
 302         public function setMessageBlobStore( MessageBlobStore $blobStore ) {
 303                 $this->blobStore = $blobStore;
 304         }
 305
 306         /**
 307          * Register a module with the ResourceLoader system.
 308          *
 309          * @param mixed $name Name of module as a string or List of name/object pairs as an array
 310          * @param array $info Module info array. For backwards compatibility with 1.17alpha,
 311          *   this may also be a ResourceLoaderModule object. Optional when using
 312          *   multiple-registration calling style.
 313          * @throws MWException If a duplicate module registration is attempted
 314          * @throws MWException If a module name contains illegal characters (pipes or commas)
 315          * @throws MWException If something other than a ResourceLoaderModule is being registered
 316          * @return bool False if there were any errors, in which case one or more modules were
 317          *   not registered
 318          */
 319         public function register( $name, $info = null ) {
 320                 $moduleSkinStyles = $this->config->get( 'ResourceModuleSkinStyles' );
 321
 322                 // Allow multiple modules to be registered in one call
 323                 $registrations = is_array( $name ) ? $name : [ $name => $info ];
 324                 foreach ( $registrations as $name => $info ) {
 325                         // Warn on duplicate registrations
 326                         if ( isset( $this->moduleInfos[$name] ) ) {
 327                                 // A module has already been registered by this name
 328                                 $this->logger->warning(
 329                                         'ResourceLoader duplicate registration warning. ' .
 330                                         'Another module has already been registered as ' . $name
 331                                 );
 332                         }
 333
 334                         // Check $name for validity
 335                         if ( !self::isValidModuleName( $name ) ) {
 336                                 throw new MWException( "ResourceLoader module name '$name' is invalid, "
 337                                         . "see ResourceLoader::isValidModuleName()" );
 338                         }
 339
 340                         // Attach module
 341                         if ( $info instanceof ResourceLoaderModule ) {
 342                                 $this->moduleInfos[$name] = [ 'object' => $info ];
 343                                 $info->setName( $name );
 344                                 $this->modules[$name] = $info;
 345                         } elseif ( is_array( $info ) ) {
 346                                 // New calling convention
 347                                 $this->moduleInfos[$name] = $info;
 348                         } else {
 349                                 throw new MWException(
 350                                         'ResourceLoader module info type error for module \'' . $name .
 351                                         '\': expected ResourceLoaderModule or array (got: ' . gettype( $info ) . ')'
 352                                 );
 353                         }
 354
 355                         // Last-minute changes
 356
 357                         // Apply custom skin-defined styles to existing modules.
 358                         if ( $this->isFileModule( $name ) ) {
 359                                 foreach ( $moduleSkinStyles as $skinName => $skinStyles ) {
 360                                         // If this module already defines skinStyles for this skin, ignore $wgResourceModuleSkinStyles.
 361                                         if ( isset( $this->moduleInfos[$name]['skinStyles'][$skinName] ) ) {
 362                                                 continue;
 363                                         }
 364
 365                                         // If $name is preceded with a '+', the defined style files will be added to 'default'
 366                                         // skinStyles, otherwise 'default' will be ignored as it normally would be.
 367                                         if ( isset( $skinStyles[$name] ) ) {
 368                                                 $paths = (array)$skinStyles[$name];
 369                                                 $styleFiles = [];
 370                                         } elseif ( isset( $skinStyles['+' . $name] ) ) {
 371                                                 $paths = (array)$skinStyles['+' . $name];
 372                                                 $styleFiles = isset( $this->moduleInfos[$name]['skinStyles']['default'] ) ?
 373                                                         (array)$this->moduleInfos[$name]['skinStyles']['default'] :
 374                                                         [];
 375                                         } else {
 376                                                 continue;
 377                                         }
 378
 379                                         // Add new file paths, remapping them to refer to our directories and not use settings
 380                                         // from the module we're modifying, which come from the base definition.
 381                                         list( $localBasePath, $remoteBasePath ) =
 382                                                 ResourceLoaderFileModule::extractBasePaths( $skinStyles );
 383
 384                                         foreach ( $paths as $path ) {
 385                                                 $styleFiles[] = new ResourceLoaderFilePath( $path, $localBasePath, $remoteBasePath );
 386                                         }
 387
 388                                         $this->moduleInfos[$name]['skinStyles'][$skinName] = $styleFiles;
 389                                 }
 390                         }
 391                 }
 392         }
 393
 394         public function registerTestModules() {
 395                 global $IP;
 396
 397                 if ( $this->config->get( 'EnableJavaScriptTest' ) !== true ) {
 398                         throw new MWException( 'Attempt to register JavaScript test modules '
 399                                 . 'but <code>$wgEnableJavaScriptTest</code> is false. '
 400                                 . 'Edit your <code>LocalSettings.php</code> to enable it.' );
 401                 }
 402
 403                 // Get core test suites
 404                 $testModules = [];
 405                 $testModules['qunit'] = [];
 406                 // Get other test suites (e.g. from extensions)
 407                 Hooks::run( 'ResourceLoaderTestModules', [ &$testModules, &$this ] );
 408
 409                 // Add the testrunner (which configures QUnit) to the dependencies.
 410                 // Since it must be ready before any of the test suites are executed.
 411                 foreach ( $testModules['qunit'] as &$module ) {
 412                         // Make sure all test modules are top-loading so that when QUnit starts
 413                         // on document-ready, it will run once and finish. If some tests arrive
 414                         // later (possibly after QUnit has already finished) they will be ignored.
 415                         $module['position'] = 'top';
 416                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 417                 }
 418
 419                 $testModules['qunit'] =
 420                         ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules['qunit'];
 421
 422                 foreach ( $testModules as $id => $names ) {
 423                         // Register test modules
 424                         $this->register( $testModules[$id] );
 425
 426                         // Keep track of their names so that they can be loaded together
 427                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 428                 }
 429         }
 430
 431         /**
 432          * Add a foreign source of modules.
 433          *
 434          * Source IDs are typically the same as the Wiki ID or database name (e.g. lowercase a-z).
 435          *
 436          * @param array|string $id Source ID (string), or [ id1 => loadUrl, id2 => loadUrl, ... ]
 437          * @param string|array $loadUrl load.php url (string), or array with loadUrl key for
 438          *  backwards-compatibility.
 439          * @throws MWException
 440          */
 441         public function addSource( $id, $loadUrl = null ) {
 442                 // Allow multiple sources to be registered in one call
 443                 if ( is_array( $id ) ) {
 444                         foreach ( $id as $key => $value ) {
 445                                 $this->addSource( $key, $value );
 446                         }
 447                         return;
 448                 }
 449
 450                 // Disallow duplicates
 451                 if ( isset( $this->sources[$id] ) ) {
 452                         throw new MWException(
 453                                 'ResourceLoader duplicate source addition error. ' .
 454                                 'Another source has already been registered as ' . $id
 455                         );
 456                 }
 457
 458                 // Pre 1.24 backwards-compatibility
 459                 if ( is_array( $loadUrl ) ) {
 460                         if ( !isset( $loadUrl['loadScript'] ) ) {
 461                                 throw new MWException(
 462                                         __METHOD__ . ' was passed an array with no "loadScript" key.'
 463                                 );
 464                         }
 465
 466                         $loadUrl = $loadUrl['loadScript'];
 467                 }
 468
 469                 $this->sources[$id] = $loadUrl;
 470         }
 471
 472         /**
 473          * Get a list of module names.
 474          *
 475          * @return array List of module names
 476          */
 477         public function getModuleNames() {
 478                 return array_keys( $this->moduleInfos );
 479         }
 480
 481         /**
 482          * Get a list of test module names for one (or all) frameworks.
 483          *
 484          * If the given framework id is unknkown, or if the in-object variable is not an array,
 485          * then it will return an empty array.
 486          *
 487          * @param string $framework Get only the test module names for one
 488          *   particular framework (optional)
 489          * @return array
 490          */
 491         public function getTestModuleNames( $framework = 'all' ) {
 492                 /** @todo api siteinfo prop testmodulenames modulenames */
 493                 if ( $framework == 'all' ) {
 494                         return $this->testModuleNames;
 495                 } elseif ( isset( $this->testModuleNames[$framework] )
 496                         && is_array( $this->testModuleNames[$framework] )
 497                 ) {
 498                         return $this->testModuleNames[$framework];
 499                 } else {
 500                         return [];
 501                 }
 502         }
 503
 504         /**
 505          * Check whether a ResourceLoader module is registered
 506          *
 507          * @since 1.25
 508          * @param string $name
 509          * @return bool
 510          */
 511         public function isModuleRegistered( $name ) {
 512                 return isset( $this->moduleInfos[$name] );
 513         }
 514
 515         /**
 516          * Get the ResourceLoaderModule object for a given module name.
 517          *
 518          * If an array of module parameters exists but a ResourceLoaderModule object has not
 519          * yet been instantiated, this method will instantiate and cache that object such that
 520          * subsequent calls simply return the same object.
 521          *
 522          * @param string $name Module name
 523          * @return ResourceLoaderModule|null If module has been registered, return a
 524          *  ResourceLoaderModule instance. Otherwise, return null.
 525          */
 526         public function getModule( $name ) {
 527                 if ( !isset( $this->modules[$name] ) ) {
 528                         if ( !isset( $this->moduleInfos[$name] ) ) {
 529                                 // No such module
 530                                 return null;
 531                         }
 532                         // Construct the requested object
 533                         $info = $this->moduleInfos[$name];
 534                         /** @var ResourceLoaderModule $object */
 535                         if ( isset( $info['object'] ) ) {
 536                                 // Object given in info array
 537                                 $object = $info['object'];
 538                         } else {
 539                                 if ( !isset( $info['class'] ) ) {
 540                                         $class = 'ResourceLoaderFileModule';
 541                                 } else {
 542                                         $class = $info['class'];
 543                                 }
 544                                 /** @var ResourceLoaderModule $object */
 545                                 $object = new $class( $info );
 546                                 $object->setConfig( $this->getConfig() );
 547                                 $object->setLogger( $this->logger );
 548                         }
 549                         $object->setName( $name );
 550                         $this->modules[$name] = $object;
 551                 }
 552
 553                 return $this->modules[$name];
 554         }
 555
 556         /**
 557          * Return whether the definition of a module corresponds to a simple ResourceLoaderFileModule.
 558          *
 559          * @param string $name Module name
 560          * @return bool
 561          */
 562         protected function isFileModule( $name ) {
 563                 if ( !isset( $this->moduleInfos[$name] ) ) {
 564                         return false;
 565                 }
 566                 $info = $this->moduleInfos[$name];
 567                 if ( isset( $info['object'] ) || isset( $info['class'] ) ) {
 568                         return false;
 569                 }
 570                 return true;
 571         }
 572
 573         /**
 574          * Get the list of sources.
 575          *
 576          * @return array Like [ id => load.php url, ... ]
 577          */
 578         public function getSources() {
 579                 return $this->sources;
 580         }
 581
 582         /**
 583          * Get the URL to the load.php endpoint for the given
 584          * ResourceLoader source
 585          *
 586          * @since 1.24
 587          * @param string $source
 588          * @throws MWException On an invalid $source name
 589          * @return string
 590          */
 591         public function getLoadScript( $source ) {
 592                 if ( !isset( $this->sources[$source] ) ) {
 593                         throw new MWException( "The $source source was never registered in ResourceLoader." );
 594                 }
 595                 return $this->sources[$source];
 596         }
 597
 598         /**
 599          * @since 1.26
 600          * @param string $value
 601          * @return string Hash
 602          */
 603         public static function makeHash( $value ) {
 604                 $hash = hash( 'fnv132', $value );
 605                 return Wikimedia\base_convert( $hash, 16, 36, 7 );
 606         }
 607
 608         /**
 609          * Add an error to the 'errors' array and log it.
 610          *
 611          * Should only be called from within respond().
 612          *
 613          * @since 1.29
 614          * @param Exception $e
 615          * @param string $msg
 616          * @param array $context
 617          */
 618         protected function outputErrorAndLog( Exception $e, $msg, array $context = [] ) {
 619                 MWExceptionHandler::logException( $e );
 620                 $this->logger->warning(
 621                         $msg,
 622                         $context + [ 'exception' => $e ]
 623                 );
 624                 $this->errors[] = self::formatExceptionNoComment( $e );
 625         }
 626
 627         /**
 628          * Helper method to get and combine versions of multiple modules.
 629          *
 630          * @since 1.26
 631          * @param ResourceLoaderContext $context
 632          * @param string[] $modules List of known module names
 633          * @return string Hash
 634          */
 635         public function getCombinedVersion( ResourceLoaderContext $context, array $moduleNames ) {
 636                 if ( !$moduleNames ) {
 637                         return '';
 638                 }
 639                 $hashes = array_map( function ( $module ) use ( $context ) {
 640                         try {
 641                                 return $this->getModule( $module )->getVersionHash( $context );
 642                         } catch ( Exception $e ) {
 643                                 // If modules fail to compute a version, do still consider the versions
 644                                 // of other modules - don't set an empty string E-Tag for the whole request.
 645                                 // See also T152266 and StartupModule::getModuleRegistrations().
 646                                 $this->outputErrorAndLog( $e,
 647                                         'Calculating version for "{module}" failed: {exception}',
 648                                         [
 649                                                 'module' => $module,
 650                                         ]
 651                                 );
 652                                 return '';
 653                         }
 654                 }, $moduleNames );
 655                 return self::makeHash( implode( '', $hashes ) );
 656         }
 657
 658         /**
 659          * Get the expected value of the 'version' query parameter.
 660          *
 661          * This is used by respond() to set a short Cache-Control header for requests with
 662          * information newer than the current server has. This avoids pollution of edge caches.
 663          * Typically during deployment. (T117587)
 664          *
 665          * This MUST match return value of `mw.loader#getCombinedVersion()` client-side.
 666          *
 667          * @since 1.28
 668          * @param ResourceLoaderContext $context
 669          * @param string[] $modules List of module names
 670          * @return string Hash
 671          */
 672         public function makeVersionQuery( ResourceLoaderContext $context ) {
 673                 // As of MediaWiki 1.28, the server and client use the same algorithm for combining
 674                 // version hashes. There is no technical reason for this to be same, and for years the
 675                 // implementations differed. If getCombinedVersion in PHP (used for StartupModule and
 676                 // E-Tag headers) differs in the future from getCombinedVersion in JS (used for 'version'
 677                 // query parameter), then this method must continue to match the JS one.
 678                 $moduleNames = [];
 679                 foreach ( $context->getModules() as $name ) {
 680                         if ( !$this->getModule( $name ) ) {
 681                                 // If a versioned request contains a missing module, the version is a mismatch
 682                                 // as the client considered a module (and version) we don't have.
 683                                 return '';
 684                         }
 685                         $moduleNames[] = $name;
 686                 }
 687                 return $this->getCombinedVersion( $context, $moduleNames );
 688         }
 689
 690         /**
 691          * Output a response to a load request, including the content-type header.
 692          *
 693          * @param ResourceLoaderContext $context Context in which a response should be formed
 694          */
 695         public function respond( ResourceLoaderContext $context ) {
 696                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 697                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 698                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 699                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 700                 // the whole thing in our own output buffer to be sure the active buffer
 701                 // doesn't use ob_gzhandler.
 702                 // See https://bugs.php.net/bug.php?id=36514
 703                 ob_start();
 704
 705                 // Find out which modules are missing and instantiate the others
 706                 $modules = [];
 707                 $missing = [];
 708                 foreach ( $context->getModules() as $name ) {
 709                         $module = $this->getModule( $name );
 710                         if ( $module ) {
 711                                 // Do not allow private modules to be loaded from the web.
 712                                 // This is a security issue, see bug 34907.
 713                                 if ( $module->getGroup() === 'private' ) {
 714                                         $this->logger->debug( "Request for private module '$name' denied" );
 715                                         $this->errors[] = "Cannot show private module \"$name\"";
 716                                         continue;
 717                                 }
 718                                 $modules[$name] = $module;
 719                         } else {
 720                                 $missing[] = $name;
 721                         }
 722                 }
 723
 724                 try {
 725                         // Preload for getCombinedVersion() and for batch makeModuleResponse()
 726                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 727                 } catch ( Exception $e ) {
 728                         $this->outputErrorAndLog( $e, 'Preloading module info failed: {exception}' );
 729                 }
 730
 731                 // Combine versions to propagate cache invalidation
 732                 $versionHash = '';
 733                 try {
 734                         $versionHash = $this->getCombinedVersion( $context, array_keys( $modules ) );
 735                 } catch ( Exception $e ) {
 736                         $this->outputErrorAndLog( $e, 'Calculating version hash failed: {exception}' );
 737                 }
 738
 739                 // See RFC 2616 § 3.11 Entity Tags
 740                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.11
 741                 $etag = 'W/"' . $versionHash . '"';
 742
 743                 // Try the client-side cache first
 744                 if ( $this->tryRespondNotModified( $context, $etag ) ) {
 745                         return; // output handled (buffers cleared)
 746                 }
 747
 748                 // Use file cache if enabled and available...
 749                 if ( $this->config->get( 'UseFileCache' ) ) {
 750                         $fileCache = ResourceFileCache::newFromContext( $context );
 751                         if ( $this->tryRespondFromFileCache( $fileCache, $context, $etag ) ) {
 752                                 return; // output handled
 753                         }
 754                 }
 755
 756                 // Generate a response
 757                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 758
 759                 // Capture any PHP warnings from the output buffer and append them to the
 760                 // error list if we're in debug mode.
 761                 if ( $context->getDebug() ) {
 762                         $warnings = ob_get_contents();
 763                         if ( strlen( $warnings ) ) {
 764                                 $this->errors[] = $warnings;
 765                         }
 766                 }
 767
 768                 // Save response to file cache unless there are errors
 769                 if ( isset( $fileCache ) && !$this->errors && !count( $missing ) ) {
 770                         // Cache single modules and images...and other requests if there are enough hits
 771                         if ( ResourceFileCache::useFileCache( $context ) ) {
 772                                 if ( $fileCache->isCacheWorthy() ) {
 773                                         $fileCache->saveText( $response );
 774                                 } else {
 775                                         $fileCache->incrMissesRecent( $context->getRequest() );
 776                                 }
 777                         }
 778                 }
 779
 780                 $this->sendResponseHeaders( $context, $etag, (bool)$this->errors );
 781
 782                 // Remove the output buffer and output the response
 783                 ob_end_clean();
 784
 785                 if ( $context->getImageObj() && $this->errors ) {
 786                         // We can't show both the error messages and the response when it's an image.
 787                         $response = implode( "\n\n", $this->errors );
 788                 } elseif ( $this->errors ) {
 789                         $errorText = implode( "\n\n", $this->errors );
 790                         $errorResponse = self::makeComment( $errorText );
 791                         if ( $context->shouldIncludeScripts() ) {
 792                                 $errorResponse .= 'if (window.console && console.error) {'
 793                                         . Xml::encodeJsCall( 'console.error', [ $errorText ] )
 794                                         . "}\n";
 795                         }
 796
 797                         // Prepend error info to the response
 798                         $response = $errorResponse . $response;
 799                 }
 800
 801                 $this->errors = [];
 802                 echo $response;
 803         }
 804
 805         /**
 806          * Send main response headers to the client.
 807          *
 808          * Deals with Content-Type, CORS (for stylesheets), and caching.
 809          *
 810          * @param ResourceLoaderContext $context
 811          * @param string $etag ETag header value
 812          * @param bool $errors Whether there are errors in the response
 813          * @return void
 814          */
 815         protected function sendResponseHeaders( ResourceLoaderContext $context, $etag, $errors ) {
 816                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 817                 // Use a short cache expiry so that updates propagate to clients quickly, if:
 818                 // - No version specified (shared resources, e.g. stylesheets)
 819                 // - There were errors (recover quickly)
 820                 // - Version mismatch (T117587, T47877)
 821                 if ( is_null( $context->getVersion() )
 822                         || $errors
 823                         || $context->getVersion() !== $this->makeVersionQuery( $context )
 824                 ) {
 825                         $maxage = $rlMaxage['unversioned']['client'];
 826                         $smaxage = $rlMaxage['unversioned']['server'];
 827                 // If a version was specified we can use a longer expiry time since changing
 828                 // version numbers causes cache misses
 829                 } else {
 830                         $maxage = $rlMaxage['versioned']['client'];
 831                         $smaxage = $rlMaxage['versioned']['server'];
 832                 }
 833                 if ( $context->getImageObj() ) {
 834                         // Output different headers if we're outputting textual errors.
 835                         if ( $errors ) {
 836                                 header( 'Content-Type: text/plain; charset=utf-8' );
 837                         } else {
 838                                 $context->getImageObj()->sendResponseHeaders( $context );
 839                         }
 840                 } elseif ( $context->getOnly() === 'styles' ) {
 841                         header( 'Content-Type: text/css; charset=utf-8' );
 842                         header( 'Access-Control-Allow-Origin: *' );
 843                 } else {
 844                         header( 'Content-Type: text/javascript; charset=utf-8' );
 845                 }
 846                 // See RFC 2616 § 14.19 ETag
 847                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.19
 848                 header( 'ETag: ' . $etag );
 849                 if ( $context->getDebug() ) {
 850                         // Do not cache debug responses
 851                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 852                         header( 'Pragma: no-cache' );
 853                 } else {
 854                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 855                         $exp = min( $maxage, $smaxage );
 856                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 857                 }
 858         }
 859
 860         /**
 861          * Respond with HTTP 304 Not Modified if appropiate.
 862          *
 863          * If there's an If-None-Match header, respond with a 304 appropriately
 864          * and clear out the output buffer. If the client cache is too old then do nothing.
 865          *
 866          * @param ResourceLoaderContext $context
 867          * @param string $etag ETag header value
 868          * @return bool True if HTTP 304 was sent and output handled
 869          */
 870         protected function tryRespondNotModified( ResourceLoaderContext $context, $etag ) {
 871                 // See RFC 2616 § 14.26 If-None-Match
 872                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
 873                 $clientKeys = $context->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST );
 874                 // Never send 304s in debug mode
 875                 if ( $clientKeys !== false && !$context->getDebug() && in_array( $etag, $clientKeys ) ) {
 876                         // There's another bug in ob_gzhandler (see also the comment at
 877                         // the top of this function) that causes it to gzip even empty
 878                         // responses, meaning it's impossible to produce a truly empty
 879                         // response (because the gzip header is always there). This is
 880                         // a problem because 304 responses have to be completely empty
 881                         // per the HTTP spec, and Firefox behaves buggily when they're not.
 882                         // See also https://bugs.php.net/bug.php?id=51579
 883                         // To work around this, we tear down all output buffering before
 884                         // sending the 304.
 885                         wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 886
 887                         HttpStatus::header( 304 );
 888
 889                         $this->sendResponseHeaders( $context, $etag, false );
 890                         return true;
 891                 }
 892                 return false;
 893         }
 894
 895         /**
 896          * Send out code for a response from file cache if possible.
 897          *
 898          * @param ResourceFileCache $fileCache Cache object for this request URL
 899          * @param ResourceLoaderContext $context Context in which to generate a response
 900          * @param string $etag ETag header value
 901          * @return bool If this found a cache file and handled the response
 902          */
 903         protected function tryRespondFromFileCache(
 904                 ResourceFileCache $fileCache,
 905                 ResourceLoaderContext $context,
 906                 $etag
 907         ) {
 908                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 909                 // Buffer output to catch warnings.
 910                 ob_start();
 911                 // Get the maximum age the cache can be
 912                 $maxage = is_null( $context->getVersion() )
 913                         ? $rlMaxage['unversioned']['server']
 914                         : $rlMaxage['versioned']['server'];
 915                 // Minimum timestamp the cache file must have
 916                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 917                 if ( !$good ) {
 918                         try { // RL always hits the DB on file cache miss...
 919                                 wfGetDB( DB_REPLICA );
 920                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 921                                 $good = $fileCache->isCacheGood(); // cache existence check
 922                         }
 923                 }
 924                 if ( $good ) {
 925                         $ts = $fileCache->cacheTimestamp();
 926                         // Send content type and cache headers
 927                         $this->sendResponseHeaders( $context, $etag, false );
 928                         $response = $fileCache->fetchText();
 929                         // Capture any PHP warnings from the output buffer and append them to the
 930                         // response in a comment if we're in debug mode.
 931                         if ( $context->getDebug() ) {
 932                                 $warnings = ob_get_contents();
 933                                 if ( strlen( $warnings ) ) {
 934                                         $response = self::makeComment( $warnings ) . $response;
 935                                 }
 936                         }
 937                         // Remove the output buffer and output the response
 938                         ob_end_clean();
 939                         echo $response . "\n/* Cached {$ts} */";
 940                         return true; // cache hit
 941                 }
 942                 // Clear buffer
 943                 ob_end_clean();
 944
 945                 return false; // cache miss
 946         }
 947
 948         /**
 949          * Generate a CSS or JS comment block.
 950          *
 951          * Only use this for public data, not error message details.
 952          *
 953          * @param string $text
 954          * @return string
 955          */
 956         public static function makeComment( $text ) {
 957                 $encText = str_replace( '*/', '* /', $text );
 958                 return "/*\n$encText\n*/\n";
 959         }
 960
 961         /**
 962          * Handle exception display.
 963          *
 964          * @param Exception $e Exception to be shown to the user
 965          * @return string Sanitized text in a CSS/JS comment that can be returned to the user
 966          */
 967         public static function formatException( $e ) {
 968                 return self::makeComment( self::formatExceptionNoComment( $e ) );
 969         }
 970
 971         /**
 972          * Handle exception display.
 973          *
 974          * @since 1.25
 975          * @param Exception $e Exception to be shown to the user
 976          * @return string Sanitized text that can be returned to the user
 977          */
 978         protected static function formatExceptionNoComment( $e ) {
 979                 global $wgShowExceptionDetails;
 980
 981                 if ( !$wgShowExceptionDetails ) {
 982                         return MWExceptionHandler::getPublicLogMessage( $e );
 983                 }
 984
 985                 return MWExceptionHandler::getLogMessage( $e ) .
 986                         "\nBacktrace:\n" .
 987                         MWExceptionHandler::getRedactedTraceAsString( $e );
 988         }
 989
 990         /**
 991          * Generate code for a response.
 992          *
 993          * @param ResourceLoaderContext $context Context in which to generate a response
 994          * @param ResourceLoaderModule[] $modules List of module objects keyed by module name
 995          * @param string[] $missing List of requested module names that are unregistered (optional)
 996          * @return string Response data
 997          */
 998         public function makeModuleResponse( ResourceLoaderContext $context,
 999                 array $modules, array $missing = []
1000         ) {
1001                 $out = '';
1002                 $states = [];
1003
1004                 if ( !count( $modules ) && !count( $missing ) ) {
1005                         return <<<MESSAGE
1006 /* This file is the Web entry point for MediaWiki's ResourceLoader:
1007    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
1008    no modules were requested. Max made me put this here. */
1009 MESSAGE;
1010                 }
1011
1012                 $image = $context->getImageObj();
1013                 if ( $image ) {
1014                         $data = $image->getImageData( $context );
1015                         if ( $data === false ) {
1016                                 $data = '';
1017                                 $this->errors[] = 'Image generation failed';
1018                         }
1019                         return $data;
1020                 }
1021
1022                 foreach ( $missing as $name ) {
1023                         $states[$name] = 'missing';
1024                 }
1025
1026                 // Generate output
1027                 $isRaw = false;
1028
1029                 $filter = $context->getOnly() === 'styles' ? 'minify-css' : 'minify-js';
1030
1031                 foreach ( $modules as $name => $module ) {
1032                         try {
1033                                 $content = $module->getModuleContent( $context );
1034                                 $implementKey = $name . '@' . $module->getVersionHash( $context );
1035                                 $strContent = '';
1036
1037                                 // Append output
1038                                 switch ( $context->getOnly() ) {
1039                                         case 'scripts':
1040                                                 $scripts = $content['scripts'];
1041                                                 if ( is_string( $scripts ) ) {
1042                                                         // Load scripts raw...
1043                                                         $strContent = $scripts;
1044                                                 } elseif ( is_array( $scripts ) ) {
1045                                                         // ...except when $scripts is an array of URLs
1046                                                         $strContent = self::makeLoaderImplementScript( $implementKey, $scripts, [], [], [] );
1047                                                 }
1048                                                 break;
1049                                         case 'styles':
1050                                                 $styles = $content['styles'];
1051                                                 // We no longer seperate into media, they are all combined now with
1052                                                 // custom media type groups into @media .. {} sections as part of the css string.
1053                                                 // Module returns either an empty array or a numerical array with css strings.
1054                                                 $strContent = isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
1055                                                 break;
1056                                         default:
1057                                                 $scripts = isset( $content['scripts'] ) ? $content['scripts'] : '';
1058                                                 if ( is_string( $scripts ) ) {
1059                                                         if ( $name === 'site' || $name === 'user' ) {
1060                                                                 // Legacy scripts that run in the global scope without a closure.
1061                                                                 // mw.loader.implement will use globalEval if scripts is a string.
1062                                                                 // Minify manually here, because general response minification is
1063                                                                 // not effective due it being a string literal, not a function.
1064                                                                 if ( !ResourceLoader::inDebugMode() ) {
1065                                                                         $scripts = self::filter( 'minify-js', $scripts ); // T107377
1066                                                                 }
1067                                                         } else {
1068                                                                 $scripts = new XmlJsCode( $scripts );
1069                                                         }
1070                                                 }
1071                                                 $strContent = self::makeLoaderImplementScript(
1072                                                         $implementKey,
1073                                                         $scripts,
1074                                                         isset( $content['styles'] ) ? $content['styles'] : [],
1075                                                         isset( $content['messagesBlob'] ) ? new XmlJsCode( $content['messagesBlob'] ) : [],
1076                                                         isset( $content['templates'] ) ? $content['templates'] : []
1077                                                 );
1078                                                 break;
1079                                 }
1080
1081                                 if ( !$context->getDebug() ) {
1082                                         $strContent = self::filter( $filter, $strContent );
1083                                 }
1084
1085                                 $out .= $strContent;
1086
1087                         } catch ( Exception $e ) {
1088                                 $this->outputErrorAndLog( $e, 'Generating module package failed: {exception}' );
1089
1090                                 // Respond to client with error-state instead of module implementation
1091                                 $states[$name] = 'error';
1092                                 unset( $modules[$name] );
1093                         }
1094                         $isRaw |= $module->isRaw();
1095                 }
1096
1097                 // Update module states
1098                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
1099                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
1100                                 // Set the state of modules loaded as only scripts to ready as
1101                                 // they don't have an mw.loader.implement wrapper that sets the state
1102                                 foreach ( $modules as $name => $module ) {
1103                                         $states[$name] = 'ready';
1104                                 }
1105                         }
1106
1107                         // Set the state of modules we didn't respond to with mw.loader.implement
1108                         if ( count( $states ) ) {
1109                                 $stateScript = self::makeLoaderStateScript( $states );
1110                                 if ( !$context->getDebug() ) {
1111                                         $stateScript = self::filter( 'minify-js', $stateScript );
1112                                 }
1113                                 $out .= $stateScript;
1114                         }
1115                 } else {
1116                         if ( count( $states ) ) {
1117                                 $this->errors[] = 'Problematic modules: ' .
1118                                         FormatJson::encode( $states, ResourceLoader::inDebugMode() );
1119                         }
1120                 }
1121
1122                 return $out;
1123         }
1124
1125         /**
1126          * Get names of modules that use a certain message.
1127          *
1128          * @param string $messageKey
1129          * @return array List of module names
1130          */
1131         public function getModulesByMessage( $messageKey ) {
1132                 $moduleNames = [];
1133                 foreach ( $this->getModuleNames() as $moduleName ) {
1134                         $module = $this->getModule( $moduleName );
1135                         if ( in_array( $messageKey, $module->getMessages() ) ) {
1136                                 $moduleNames[] = $moduleName;
1137                         }
1138                 }
1139                 return $moduleNames;
1140         }
1141
1142         /* Static Methods */
1143
1144         /**
1145          * Return JS code that calls mw.loader.implement with given module properties.
1146          *
1147          * @param string $name Module name or implement key (format "`[name]@[version]`")
1148          * @param XmlJsCode|array|string $scripts Code as XmlJsCode (to be wrapped in a closure),
1149          *  list of URLs to JavaScript files, or a string of JavaScript for `$.globalEval`.
1150          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1151          *   to CSS files keyed by media type
1152          * @param mixed $messages List of messages associated with this module. May either be an
1153          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1154          *   the same data, wrapped in an XmlJsCode object.
1155          * @param array $templates Keys are name of templates and values are the source of
1156          *   the template.
1157          * @throws MWException
1158          * @return string
1159          */
1160         protected static function makeLoaderImplementScript(
1161                 $name, $scripts, $styles, $messages, $templates
1162         ) {
1163                 if ( $scripts instanceof XmlJsCode ) {
1164                         $scripts = new XmlJsCode( "function ( $, jQuery, require, module ) {\n{$scripts->value}\n}" );
1165                 } elseif ( !is_string( $scripts ) && !is_array( $scripts ) ) {
1166                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1167                 }
1168                 // mw.loader.implement requires 'styles', 'messages' and 'templates' to be objects (not
1169                 // arrays). json_encode considers empty arrays to be numerical and outputs "[]" instead
1170                 // of "{}". Force them to objects.
1171                 $module = [
1172                         $name,
1173                         $scripts,
1174                         (object)$styles,
1175                         (object)$messages,
1176                         (object)$templates,
1177                 ];
1178                 self::trimArray( $module );
1179
1180                 return Xml::encodeJsCall( 'mw.loader.implement', $module, ResourceLoader::inDebugMode() );
1181         }
1182
1183         /**
1184          * Returns JS code which, when called, will register a given list of messages.
1185          *
1186          * @param mixed $messages Either an associative array mapping message key to value, or a
1187          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1188          * @return string
1189          */
1190         public static function makeMessageSetScript( $messages ) {
1191                 return Xml::encodeJsCall(
1192                         'mw.messages.set',
1193                         [ (object)$messages ],
1194                         ResourceLoader::inDebugMode()
1195                 );
1196         }
1197
1198         /**
1199          * Combines an associative array mapping media type to CSS into a
1200          * single stylesheet with "@media" blocks.
1201          *
1202          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1203          * @return array
1204          */
1205         public static function makeCombinedStyles( array $stylePairs ) {
1206                 $out = [];
1207                 foreach ( $stylePairs as $media => $styles ) {
1208                         // ResourceLoaderFileModule::getStyle can return the styles
1209                         // as a string or an array of strings. This is to allow separation in
1210                         // the front-end.
1211                         $styles = (array)$styles;
1212                         foreach ( $styles as $style ) {
1213                                 $style = trim( $style );
1214                                 // Don't output an empty "@media print { }" block (bug 40498)
1215                                 if ( $style !== '' ) {
1216                                         // Transform the media type based on request params and config
1217                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1218                                         $media = OutputPage::transformCssMedia( $media );
1219
1220                                         if ( $media === '' || $media == 'all' ) {
1221                                                 $out[] = $style;
1222                                         } elseif ( is_string( $media ) ) {
1223                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1224                                         }
1225                                         // else: skip
1226                                 }
1227                         }
1228                 }
1229                 return $out;
1230         }
1231
1232         /**
1233          * Returns a JS call to mw.loader.state, which sets the state of a
1234          * module or modules to a given value. Has two calling conventions:
1235          *
1236          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1237          *         Set the state of a single module called $name to $state
1238          *
1239          *    - ResourceLoader::makeLoaderStateScript( [ $name => $state, ... ] ):
1240          *         Set the state of modules with the given names to the given states
1241          *
1242          * @param string $name
1243          * @param string $state
1244          * @return string
1245          */
1246         public static function makeLoaderStateScript( $name, $state = null ) {
1247                 if ( is_array( $name ) ) {
1248                         return Xml::encodeJsCall(
1249                                 'mw.loader.state',
1250                                 [ $name ],
1251                                 ResourceLoader::inDebugMode()
1252                         );
1253                 } else {
1254                         return Xml::encodeJsCall(
1255                                 'mw.loader.state',
1256                                 [ $name, $state ],
1257                                 ResourceLoader::inDebugMode()
1258                         );
1259                 }
1260         }
1261
1262         /**
1263          * Returns JS code which calls the script given by $script. The script will
1264          * be called with local variables name, version, dependencies and group,
1265          * which will have values corresponding to $name, $version, $dependencies
1266          * and $group as supplied.
1267          *
1268          * @param string $name Module name
1269          * @param string $version Module version hash
1270          * @param array $dependencies List of module names on which this module depends
1271          * @param string $group Group which the module is in.
1272          * @param string $source Source of the module, or 'local' if not foreign.
1273          * @param string $script JavaScript code
1274          * @return string
1275          */
1276         public static function makeCustomLoaderScript( $name, $version, $dependencies,
1277                 $group, $source, $script
1278         ) {
1279                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1280                 return Xml::encodeJsCall(
1281                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1282                         [ $name, $version, $dependencies, $group, $source ],
1283                         ResourceLoader::inDebugMode()
1284                 );
1285         }
1286
1287         private static function isEmptyObject( stdClass $obj ) {
1288                 foreach ( $obj as $key => $value ) {
1289                         return false;
1290                 }
1291                 return true;
1292         }
1293
1294         /**
1295          * Remove empty values from the end of an array.
1296          *
1297          * Values considered empty:
1298          *
1299          * - null
1300          * - []
1301          * - new XmlJsCode( '{}' )
1302          * - new stdClass() // (object) []
1303          *
1304          * @param Array $array
1305          */
1306         private static function trimArray( array &$array ) {
1307                 $i = count( $array );
1308                 while ( $i-- ) {
1309                         if ( $array[$i] === null
1310                                 || $array[$i] === []
1311                                 || ( $array[$i] instanceof XmlJsCode && $array[$i]->value === '{}' )
1312                                 || ( $array[$i] instanceof stdClass && self::isEmptyObject( $array[$i] ) )
1313                         ) {
1314                                 unset( $array[$i] );
1315                         } else {
1316                                 break;
1317                         }
1318                 }
1319         }
1320
1321         /**
1322          * Returns JS code which calls mw.loader.register with the given
1323          * parameters. Has three calling conventions:
1324          *
1325          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version,
1326          *        $dependencies, $group, $source, $skip
1327          *     ):
1328          *        Register a single module.
1329          *
1330          *   - ResourceLoader::makeLoaderRegisterScript( [ $name1, $name2 ] ):
1331          *        Register modules with the given names.
1332          *
1333          *   - ResourceLoader::makeLoaderRegisterScript( [
1334          *        [ $name1, $version1, $dependencies1, $group1, $source1, $skip1 ],
1335          *        [ $name2, $version2, $dependencies1, $group2, $source2, $skip2 ],
1336          *        ...
1337          *     ] ):
1338          *        Registers modules with the given names and parameters.
1339          *
1340          * @param string $name Module name
1341          * @param string $version Module version hash
1342          * @param array $dependencies List of module names on which this module depends
1343          * @param string $group Group which the module is in
1344          * @param string $source Source of the module, or 'local' if not foreign
1345          * @param string $skip Script body of the skip function
1346          * @return string
1347          */
1348         public static function makeLoaderRegisterScript( $name, $version = null,
1349                 $dependencies = null, $group = null, $source = null, $skip = null
1350         ) {
1351                 if ( is_array( $name ) ) {
1352                         // Build module name index
1353                         $index = [];
1354                         foreach ( $name as $i => &$module ) {
1355                                 $index[$module[0]] = $i;
1356                         }
1357
1358                         // Transform dependency names into indexes when possible, they will be resolved by
1359                         // mw.loader.register on the other end
1360                         foreach ( $name as &$module ) {
1361                                 if ( isset( $module[2] ) ) {
1362                                         foreach ( $module[2] as &$dependency ) {
1363                                                 if ( isset( $index[$dependency] ) ) {
1364                                                         $dependency = $index[$dependency];
1365                                                 }
1366                                         }
1367                                 }
1368                         }
1369
1370                         array_walk( $name, [ 'self', 'trimArray' ] );
1371
1372                         return Xml::encodeJsCall(
1373                                 'mw.loader.register',
1374                                 [ $name ],
1375                                 ResourceLoader::inDebugMode()
1376                         );
1377                 } else {
1378                         $registration = [ $name, $version, $dependencies, $group, $source, $skip ];
1379                         self::trimArray( $registration );
1380                         return Xml::encodeJsCall(
1381                                 'mw.loader.register',
1382                                 $registration,
1383                                 ResourceLoader::inDebugMode()
1384                         );
1385                 }
1386         }
1387
1388         /**
1389          * Returns JS code which calls mw.loader.addSource() with the given
1390          * parameters. Has two calling conventions:
1391          *
1392          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1393          *       Register a single source
1394          *
1395          *   - ResourceLoader::makeLoaderSourcesScript( [ $id1 => $loadUrl, $id2 => $loadUrl, ... ] );
1396          *       Register sources with the given IDs and properties.
1397          *
1398          * @param string $id Source ID
1399          * @param string $loadUrl load.php url
1400          * @return string
1401          */
1402         public static function makeLoaderSourcesScript( $id, $loadUrl = null ) {
1403                 if ( is_array( $id ) ) {
1404                         return Xml::encodeJsCall(
1405                                 'mw.loader.addSource',
1406                                 [ $id ],
1407                                 ResourceLoader::inDebugMode()
1408                         );
1409                 } else {
1410                         return Xml::encodeJsCall(
1411                                 'mw.loader.addSource',
1412                                 [ $id, $loadUrl ],
1413                                 ResourceLoader::inDebugMode()
1414                         );
1415                 }
1416         }
1417
1418         /**
1419          * Returns JS code which runs given JS code if the client-side framework is
1420          * present.
1421          *
1422          * @deprecated since 1.25; use makeInlineScript instead
1423          * @param string $script JavaScript code
1424          * @return string
1425          */
1426         public static function makeLoaderConditionalScript( $script ) {
1427                 return '(window.RLQ=window.RLQ||[]).push(function(){' .
1428                         trim( $script ) . '});';
1429         }
1430
1431         /**
1432          * Construct an inline script tag with given JS code.
1433          *
1434          * The code will be wrapped in a closure, and it will be executed by ResourceLoader
1435          * only if the client has adequate support for MediaWiki JavaScript code.
1436          *
1437          * @param string $script JavaScript code
1438          * @return WrappedString HTML
1439          */
1440         public static function makeInlineScript( $script ) {
1441                 $js = self::makeLoaderConditionalScript( $script );
1442                 return new WrappedString(
1443                         Html::inlineScript( $js ),
1444                         '<script>(window.RLQ=window.RLQ||[]).push(function(){',
1445                         '});</script>'
1446                 );
1447         }
1448
1449         /**
1450          * Returns JS code which will set the MediaWiki configuration array to
1451          * the given value.
1452          *
1453          * @param array $configuration List of configuration values keyed by variable name
1454          * @return string
1455          */
1456         public static function makeConfigSetScript( array $configuration ) {
1457                 return Xml::encodeJsCall(
1458                         'mw.config.set',
1459                         [ $configuration ],
1460                         ResourceLoader::inDebugMode()
1461                 );
1462         }
1463
1464         /**
1465          * Convert an array of module names to a packed query string.
1466          *
1467          * For example, [ 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' ]
1468          * becomes 'foo.bar,baz|bar.baz,quux'
1469          * @param array $modules List of module names (strings)
1470          * @return string Packed query string
1471          */
1472         public static function makePackedModulesString( $modules ) {
1473                 $groups = []; // [ prefix => [ suffixes ] ]
1474                 foreach ( $modules as $module ) {
1475                         $pos = strrpos( $module, '.' );
1476                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1477                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1478                         $groups[$prefix][] = $suffix;
1479                 }
1480
1481                 $arr = [];
1482                 foreach ( $groups as $prefix => $suffixes ) {
1483                         $p = $prefix === '' ? '' : $prefix . '.';
1484                         $arr[] = $p . implode( ',', $suffixes );
1485                 }
1486                 $str = implode( '|', $arr );
1487                 return $str;
1488         }
1489
1490         /**
1491          * Determine whether debug mode was requested
1492          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1493          * @return bool
1494          */
1495         public static function inDebugMode() {
1496                 if ( self::$debugMode === null ) {
1497                         global $wgRequest, $wgResourceLoaderDebug;
1498                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1499                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1500                         );
1501                 }
1502                 return self::$debugMode;
1503         }
1504
1505         /**
1506          * Reset static members used for caching.
1507          *
1508          * Global state and $wgRequest are evil, but we're using it right
1509          * now and sometimes we need to be able to force ResourceLoader to
1510          * re-evaluate the context because it has changed (e.g. in the test suite).
1511          */
1512         public static function clearCache() {
1513                 self::$debugMode = null;
1514         }
1515
1516         /**
1517          * Build a load.php URL
1518          *
1519          * @since 1.24
1520          * @param string $source Name of the ResourceLoader source
1521          * @param ResourceLoaderContext $context
1522          * @param array $extraQuery
1523          * @return string URL to load.php. May be protocol-relative if $wgLoadScript is, too.
1524          */
1525         public function createLoaderURL( $source, ResourceLoaderContext $context,
1526                 $extraQuery = []
1527         ) {
1528                 $query = self::createLoaderQuery( $context, $extraQuery );
1529                 $script = $this->getLoadScript( $source );
1530
1531                 return wfAppendQuery( $script, $query );
1532         }
1533
1534         /**
1535          * Helper for createLoaderURL()
1536          *
1537          * @since 1.24
1538          * @see makeLoaderQuery
1539          * @param ResourceLoaderContext $context
1540          * @param array $extraQuery
1541          * @return array
1542          */
1543         protected static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = [] ) {
1544                 return self::makeLoaderQuery(
1545                         $context->getModules(),
1546                         $context->getLanguage(),
1547                         $context->getSkin(),
1548                         $context->getUser(),
1549                         $context->getVersion(),
1550                         $context->getDebug(),
1551                         $context->getOnly(),
1552                         $context->getRequest()->getBool( 'printable' ),
1553                         $context->getRequest()->getBool( 'handheld' ),
1554                         $extraQuery
1555                 );
1556         }
1557
1558         /**
1559          * Build a query array (array representation of query string) for load.php. Helper
1560          * function for createLoaderURL().
1561          *
1562          * @param array $modules
1563          * @param string $lang
1564          * @param string $skin
1565          * @param string $user
1566          * @param string $version
1567          * @param bool $debug
1568          * @param string $only
1569          * @param bool $printable
1570          * @param bool $handheld
1571          * @param array $extraQuery
1572          *
1573          * @return array
1574          */
1575         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1576                 $version = null, $debug = false, $only = null, $printable = false,
1577                 $handheld = false, $extraQuery = []
1578         ) {
1579                 $query = [
1580                         'modules' => self::makePackedModulesString( $modules ),
1581                         'lang' => $lang,
1582                         'skin' => $skin,
1583                         'debug' => $debug ? 'true' : 'false',
1584                 ];
1585                 if ( $user !== null ) {
1586                         $query['user'] = $user;
1587                 }
1588                 if ( $version !== null ) {
1589                         $query['version'] = $version;
1590                 }
1591                 if ( $only !== null ) {
1592                         $query['only'] = $only;
1593                 }
1594                 if ( $printable ) {
1595                         $query['printable'] = 1;
1596                 }
1597                 if ( $handheld ) {
1598                         $query['handheld'] = 1;
1599                 }
1600                 $query += $extraQuery;
1601
1602                 // Make queries uniform in order
1603                 ksort( $query );
1604                 return $query;
1605         }
1606
1607         /**
1608          * Check a module name for validity.
1609          *
1610          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1611          * at most 255 bytes.
1612          *
1613          * @param string $moduleName Module name to check
1614          * @return bool Whether $moduleName is a valid module name
1615          */
1616         public static function isValidModuleName( $moduleName ) {
1617                 return strcspn( $moduleName, '!,|', 0, 255 ) === strlen( $moduleName );
1618         }
1619
1620         /**
1621          * Returns LESS compiler set up for use with MediaWiki
1622          *
1623          * @since 1.27
1624          * @param array $extraVars Associative array of extra (i.e., other than the
1625          *   globally-configured ones) that should be used for compilation.
1626          * @throws MWException
1627          * @return Less_Parser
1628          */
1629         public function getLessCompiler( $extraVars = [] ) {
1630                 // When called from the installer, it is possible that a required PHP extension
1631                 // is missing (at least for now; see bug 47564). If this is the case, throw an
1632                 // exception (caught by the installer) to prevent a fatal error later on.
1633                 if ( !class_exists( 'Less_Parser' ) ) {
1634                         throw new MWException( 'MediaWiki requires the less.php parser' );
1635                 }
1636
1637                 $parser = new Less_Parser;
1638                 $parser->ModifyVars( array_merge( $this->getLessVars(), $extraVars ) );
1639                 $parser->SetImportDirs(
1640                         array_fill_keys( $this->config->get( 'ResourceLoaderLESSImportPaths' ), '' )
1641                 );
1642                 $parser->SetOption( 'relativeUrls', false );
1643
1644                 return $parser;
1645         }
1646
1647         /**
1648          * Get global LESS variables.
1649          *
1650          * @since 1.27
1651          * @return array Map of variable names to string CSS values.
1652          */
1653         public function getLessVars() {
1654                 if ( !$this->lessVars ) {
1655                         $lessVars = $this->config->get( 'ResourceLoaderLESSVars' );
1656                         Hooks::run( 'ResourceLoaderGetLessVars', [ &$lessVars ] );
1657                         $this->lessVars = $lessVars;
1658                 }
1659                 return $this->lessVars;
1660         }
1661 }