includes/resourceloader/ResourceLoader.php

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