includes/resourceloader/ResourceLoader.php

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