includes/resourceloader/ResourceLoader.php

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