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         const CACHE_VERSION = 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          * List of module names that contain QUnit test suites
  62          * @var string[]
  63          */
  64         protected $testSuiteModuleNames = [];
  65
  66         /**
  67          * E.g. [ 'source-id' => 'http://.../load.php' ]
  68          * @var array
  69          */
  70         protected $sources = [];
  71
  72         /**
  73          * Errors accumulated during current respond() call.
  74          * @var array
  75          */
  76         protected $errors = [];
  77
  78         /**
  79          * List of extra HTTP response headers provided by loaded modules.
  80          *
  81          * Populated by makeModuleResponse().
  82          *
  83          * @var array
  84          */
  85         protected $extraHeaders = [];
  86
  87         /**
  88          * @var MessageBlobStore
  89          */
  90         protected $blobStore;
  91
  92         /**
  93          * @var LoggerInterface
  94          */
  95         private $logger;
  96
  97         /** @var string JavaScript / CSS pragma to disable minification. **/
  98         const FILTER_NOMIN = '/*@nomin*/';
  99
 100         /**
 101          * Load information stored in the database about modules.
 102          *
 103          * This method grabs modules dependencies from the database and updates modules
 104          * objects.
 105          *
 106          * This is not inside the module code because it is much faster to
 107          * request all of the information at once than it is to have each module
 108          * requests its own information. This sacrifice of modularity yields a substantial
 109          * performance improvement.
 110          *
 111          * @param array $moduleNames List of module names to preload information for
 112          * @param ResourceLoaderContext $context Context to load the information within
 113          */
 114         public function preloadModuleInfo( array $moduleNames, ResourceLoaderContext $context ) {
 115                 if ( !$moduleNames ) {
 116                         // Or else Database*::select() will explode, plus it's cheaper!
 117                         return;
 118                 }
 119                 $dbr = wfGetDB( DB_REPLICA );
 120                 $lang = $context->getLanguage();
 121
 122                 // Batched version of ResourceLoaderModule::getFileDependencies
 123                 $vary = ResourceLoaderModule::getVary( $context );
 124                 $res = $dbr->select( 'module_deps', [ 'md_module', 'md_deps' ], [
 125                                 'md_module' => $moduleNames,
 126                                 'md_skin' => $vary,
 127                         ], __METHOD__
 128                 );
 129
 130                 // Prime in-object cache for file dependencies
 131                 $modulesWithDeps = [];
 132                 foreach ( $res as $row ) {
 133                         $module = $this->getModule( $row->md_module );
 134                         if ( $module ) {
 135                                 $module->setFileDependencies( $context, ResourceLoaderModule::expandRelativePaths(
 136                                         json_decode( $row->md_deps, true )
 137                                 ) );
 138                                 $modulesWithDeps[] = $row->md_module;
 139                         }
 140                 }
 141                 // Register the absence of a dependency row too
 142                 foreach ( array_diff( $moduleNames, $modulesWithDeps ) as $name ) {
 143                         $module = $this->getModule( $name );
 144                         if ( $module ) {
 145                                 $this->getModule( $name )->setFileDependencies( $context, [] );
 146                         }
 147                 }
 148
 149                 // Batched version of ResourceLoaderWikiModule::getTitleInfo
 150                 ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $moduleNames );
 151
 152                 // Prime in-object cache for message blobs for modules with messages
 153                 $modules = [];
 154                 foreach ( $moduleNames as $name ) {
 155                         $module = $this->getModule( $name );
 156                         if ( $module && $module->getMessages() ) {
 157                                 $modules[$name] = $module;
 158                         }
 159                 }
 160                 $store = $this->getMessageBlobStore();
 161                 $blobs = $store->getBlobs( $modules, $lang );
 162                 foreach ( $blobs as $name => $blob ) {
 163                         $modules[$name]->setMessageBlob( $blob, $lang );
 164                 }
 165         }
 166
 167         /**
 168          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 169          *
 170          * Available filters are:
 171          *
 172          *    - minify-js \see JavaScriptMinifier::minify
 173          *    - minify-css \see CSSMin::minify
 174          *
 175          * If $data is empty, only contains whitespace or the filter was unknown,
 176          * $data is returned unmodified.
 177          *
 178          * @param string $filter Name of filter to run
 179          * @param string $data Text to filter, such as JavaScript or CSS text
 180          * @param array $options Keys:
 181          *  - (bool) cache: Whether to allow caching this data. Default: true.
 182          * @return string Filtered data, or a comment containing an error message
 183          */
 184         public static function filter( $filter, $data, array $options = [] ) {
 185                 if ( strpos( $data, self::FILTER_NOMIN ) !== false ) {
 186                         return $data;
 187                 }
 188
 189                 if ( isset( $options['cache'] ) && $options['cache'] === false ) {
 190                         return self::applyFilter( $filter, $data );
 191                 }
 192
 193                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
 194                 $cache = ObjectCache::getLocalServerInstance( CACHE_ANYTHING );
 195
 196                 $key = $cache->makeGlobalKey(
 197                         'resourceloader-filter',
 198                         $filter,
 199                         self::CACHE_VERSION,
 200                         md5( $data )
 201                 );
 202
 203                 $result = $cache->get( $key );
 204                 if ( $result === false ) {
 205                         $stats->increment( "resourceloader_cache.$filter.miss" );
 206                         $result = self::applyFilter( $filter, $data );
 207                         $cache->set( $key, $result, 24 * 3600 );
 208                 } else {
 209                         $stats->increment( "resourceloader_cache.$filter.hit" );
 210                 }
 211                 if ( $result === null ) {
 212                         // Cached failure
 213                         $result = $data;
 214                 }
 215
 216                 return $result;
 217         }
 218
 219         private static function applyFilter( $filter, $data ) {
 220                 $data = trim( $data );
 221                 if ( $data ) {
 222                         try {
 223                                 $data = ( $filter === 'minify-css' )
 224                                         ? CSSMin::minify( $data )
 225                                         : JavaScriptMinifier::minify( $data );
 226                         } catch ( Exception $e ) {
 227                                 MWExceptionHandler::logException( $e );
 228                                 return null;
 229                         }
 230                 }
 231                 return $data;
 232         }
 233
 234         /**
 235          * Register core modules and runs registration hooks.
 236          * @param Config|null $config
 237          * @param LoggerInterface|null $logger [optional]
 238          */
 239         public function __construct( Config $config = null, LoggerInterface $logger = null ) {
 240                 $this->logger = $logger ?: new NullLogger();
 241
 242                 if ( !$config ) {
 243                         wfDeprecated( __METHOD__ . ' without a Config instance', '1.34' );
 244                         $config = MediaWikiServices::getInstance()->getMainConfig();
 245                 }
 246                 $this->config = $config;
 247
 248                 // Add 'local' source first
 249                 $this->addSource( 'local', $config->get( 'LoadScript' ) );
 250
 251                 // Special module that always exists
 252                 $this->register( 'startup', [ 'class' => ResourceLoaderStartUpModule::class ] );
 253
 254                 $this->setMessageBlobStore( new MessageBlobStore( $this, $this->logger ) );
 255         }
 256
 257         /**
 258          * @return Config
 259          */
 260         public function getConfig() {
 261                 return $this->config;
 262         }
 263
 264         /**
 265          * @since 1.26
 266          * @param LoggerInterface $logger
 267          */
 268         public function setLogger( LoggerInterface $logger ) {
 269                 $this->logger = $logger;
 270         }
 271
 272         /**
 273          * @since 1.27
 274          * @return LoggerInterface
 275          */
 276         public function getLogger() {
 277                 return $this->logger;
 278         }
 279
 280         /**
 281          * @since 1.26
 282          * @return MessageBlobStore
 283          */
 284         public function getMessageBlobStore() {
 285                 return $this->blobStore;
 286         }
 287
 288         /**
 289          * @since 1.25
 290          * @param MessageBlobStore $blobStore
 291          */
 292         public function setMessageBlobStore( MessageBlobStore $blobStore ) {
 293                 $this->blobStore = $blobStore;
 294         }
 295
 296         /**
 297          * Register a module with the ResourceLoader system.
 298          *
 299          * @param string|array[] $name Module name as a string or, array of module info arrays
 300          *  keyed by name.
 301          * @param array|null $info Module info array. When using the first parameter to register
 302          *  multiple modules at once, this parameter is optional.
 303          * @throws MWException If a duplicate module registration is attempted
 304          * @throws MWException If a module name contains illegal characters (pipes or commas)
 305          * @throws InvalidArgumentException If the module info is not an array
 306          */
 307         public function register( $name, $info = null ) {
 308                 $moduleSkinStyles = $this->config->get( 'ResourceModuleSkinStyles' );
 309
 310                 // Allow multiple modules to be registered in one call
 311                 $registrations = is_array( $name ) ? $name : [ $name => $info ];
 312                 foreach ( $registrations as $name => $info ) {
 313                         // Warn on duplicate registrations
 314                         if ( isset( $this->moduleInfos[$name] ) ) {
 315                                 // A module has already been registered by this name
 316                                 $this->logger->warning(
 317                                         'ResourceLoader duplicate registration warning. ' .
 318                                         'Another module has already been registered as ' . $name
 319                                 );
 320                         }
 321
 322                         // Check validity
 323                         if ( !self::isValidModuleName( $name ) ) {
 324                                 throw new MWException( "ResourceLoader module name '$name' is invalid, "
 325                                         . "see ResourceLoader::isValidModuleName()" );
 326                         }
 327                         if ( !is_array( $info ) ) {
 328                                 throw new InvalidArgumentException(
 329                                         'Invalid module info for "' . $name . '": expected array, got ' . gettype( $info )
 330                                 );
 331                         }
 332
 333                         // Attach module
 334                         $this->moduleInfos[$name] = $info;
 335
 336                         // Last-minute changes
 337                         // Apply custom skin-defined styles to existing modules.
 338                         if ( $this->isFileModule( $name ) ) {
 339                                 foreach ( $moduleSkinStyles as $skinName => $skinStyles ) {
 340                                         // If this module already defines skinStyles for this skin, ignore $wgResourceModuleSkinStyles.
 341                                         if ( isset( $this->moduleInfos[$name]['skinStyles'][$skinName] ) ) {
 342                                                 continue;
 343                                         }
 344
 345                                         // If $name is preceded with a '+', the defined style files will be added to 'default'
 346                                         // skinStyles, otherwise 'default' will be ignored as it normally would be.
 347                                         if ( isset( $skinStyles[$name] ) ) {
 348                                                 $paths = (array)$skinStyles[$name];
 349                                                 $styleFiles = [];
 350                                         } elseif ( isset( $skinStyles['+' . $name] ) ) {
 351                                                 $paths = (array)$skinStyles['+' . $name];
 352                                                 $styleFiles = isset( $this->moduleInfos[$name]['skinStyles']['default'] ) ?
 353                                                         (array)$this->moduleInfos[$name]['skinStyles']['default'] :
 354                                                         [];
 355                                         } else {
 356                                                 continue;
 357                                         }
 358
 359                                         // Add new file paths, remapping them to refer to our directories and not use settings
 360                                         // from the module we're modifying, which come from the base definition.
 361                                         list( $localBasePath, $remoteBasePath ) =
 362                                                 ResourceLoaderFileModule::extractBasePaths( $skinStyles );
 363
 364                                         foreach ( $paths as $path ) {
 365                                                 $styleFiles[] = new ResourceLoaderFilePath( $path, $localBasePath, $remoteBasePath );
 366                                         }
 367
 368                                         $this->moduleInfos[$name]['skinStyles'][$skinName] = $styleFiles;
 369                                 }
 370                         }
 371                 }
 372         }
 373
 374         /**
 375          * @internal For use by ServiceWiring only
 376          * @codeCoverageIgnore
 377          */
 378         public function registerTestModules() {
 379                 global $IP;
 380
 381                 if ( $this->config->get( 'EnableJavaScriptTest' ) !== true ) {
 382                         throw new MWException( 'Attempt to register JavaScript test modules '
 383                                 . 'but <code>$wgEnableJavaScriptTest</code> is false. '
 384                                 . 'Edit your <code>LocalSettings.php</code> to enable it.' );
 385                 }
 386
 387                 // This has a 'qunit' key for compat with the below hook.
 388                 $testModulesMeta = [ 'qunit' => [] ];
 389
 390                 // Get test suites from extensions
 391                 // Avoid PHP 7.1 warning from passing $this by reference
 392                 $rl = $this;
 393                 Hooks::run( 'ResourceLoaderTestModules', [ &$testModulesMeta, &$rl ] );
 394                 $extRegistry = ExtensionRegistry::getInstance();
 395                 // In case of conflict, the deprecated hook has precedence.
 396                 $testModules = $testModulesMeta['qunit'] + $extRegistry->getAttribute( 'QUnitTestModules' );
 397
 398                 $testSuiteModuleNames = [];
 399                 foreach ( $testModules as $name => &$module ) {
 400                         // Turn any single-module dependency into an array
 401                         if ( isset( $module['dependencies'] ) && is_string( $module['dependencies'] ) ) {
 402                                 $module['dependencies'] = [ $module['dependencies'] ];
 403                         }
 404
 405                         // Ensure the testrunner loads before any test suites
 406                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 407
 408                         // Keep track of the test suites to load on SpecialJavaScriptTest
 409                         $testSuiteModuleNames[] = $name;
 410                 }
 411
 412                 // Core test suites (their names have further precedence).
 413                 $testModules = ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules;
 414                 $testSuiteModuleNames[] = 'test.mediawiki.qunit.suites';
 415
 416                 $this->register( $testModules );
 417                 $this->testSuiteModuleNames = $testSuiteModuleNames;
 418         }
 419
 420         /**
 421          * Add a foreign source of modules.
 422          *
 423          * Source IDs are typically the same as the Wiki ID or database name (e.g. lowercase a-z).
 424          *
 425          * @param array|string $id Source ID (string), or [ id1 => loadUrl, id2 => loadUrl, ... ]
 426          * @param string|array|null $loadUrl load.php url (string), or array with loadUrl key for
 427          *  backwards-compatibility.
 428          * @throws MWException
 429          */
 430         public function addSource( $id, $loadUrl = null ) {
 431                 // Allow multiple sources to be registered in one call
 432                 if ( is_array( $id ) ) {
 433                         foreach ( $id as $key => $value ) {
 434                                 $this->addSource( $key, $value );
 435                         }
 436                         return;
 437                 }
 438
 439                 // Disallow duplicates
 440                 if ( isset( $this->sources[$id] ) ) {
 441                         throw new MWException(
 442                                 'ResourceLoader duplicate source addition error. ' .
 443                                 'Another source has already been registered as ' . $id
 444                         );
 445                 }
 446
 447                 // Pre 1.24 backwards-compatibility
 448                 if ( is_array( $loadUrl ) ) {
 449                         if ( !isset( $loadUrl['loadScript'] ) ) {
 450                                 throw new MWException(
 451                                         __METHOD__ . ' was passed an array with no "loadScript" key.'
 452                                 );
 453                         }
 454
 455                         $loadUrl = $loadUrl['loadScript'];
 456                 }
 457
 458                 $this->sources[$id] = $loadUrl;
 459         }
 460
 461         /**
 462          * Get a list of module names.
 463          *
 464          * @return array List of module names
 465          */
 466         public function getModuleNames() {
 467                 return array_keys( $this->moduleInfos );
 468         }
 469
 470         /**
 471          * Get a list of module names with QUnit test suites.
 472          *
 473          * @internal For use by SpecialJavaScriptTest only
 474          * @return array
 475          * @codeCoverageIgnore
 476          */
 477         public function getTestSuiteModuleNames() {
 478                 return $this->testSuiteModuleNames;
 479         }
 480
 481         /**
 482          * Check whether a ResourceLoader module is registered
 483          *
 484          * @since 1.25
 485          * @param string $name
 486          * @return bool
 487          */
 488         public function isModuleRegistered( $name ) {
 489                 return isset( $this->moduleInfos[$name] );
 490         }
 491
 492         /**
 493          * Get the ResourceLoaderModule object for a given module name.
 494          *
 495          * If an array of module parameters exists but a ResourceLoaderModule object has not
 496          * yet been instantiated, this method will instantiate and cache that object such that
 497          * subsequent calls simply return the same object.
 498          *
 499          * @param string $name Module name
 500          * @return ResourceLoaderModule|null If module has been registered, return a
 501          *  ResourceLoaderModule instance. Otherwise, return null.
 502          */
 503         public function getModule( $name ) {
 504                 if ( !isset( $this->modules[$name] ) ) {
 505                         if ( !isset( $this->moduleInfos[$name] ) ) {
 506                                 // No such module
 507                                 return null;
 508                         }
 509                         // Construct the requested module object
 510                         $info = $this->moduleInfos[$name];
 511                         if ( isset( $info['factory'] ) ) {
 512                                 /** @var ResourceLoaderModule $object */
 513                                 $object = call_user_func( $info['factory'], $info );
 514                         } else {
 515                                 $class = $info['class'] ?? ResourceLoaderFileModule::class;
 516                                 /** @var ResourceLoaderModule $object */
 517                                 $object = new $class( $info );
 518                         }
 519                         $object->setConfig( $this->getConfig() );
 520                         $object->setLogger( $this->logger );
 521                         $object->setName( $name );
 522                         $this->modules[$name] = $object;
 523                 }
 524
 525                 return $this->modules[$name];
 526         }
 527
 528         /**
 529          * Whether the module is a ResourceLoaderFileModule (including subclasses).
 530          *
 531          * @param string $name Module name
 532          * @return bool
 533          */
 534         protected function isFileModule( $name ) {
 535                 if ( !isset( $this->moduleInfos[$name] ) ) {
 536                         return false;
 537                 }
 538                 $info = $this->moduleInfos[$name];
 539                 return !isset( $info['factory'] ) && (
 540                         // The implied default for 'class' is ResourceLoaderFileModule
 541                         !isset( $info['class'] ) ||
 542                         // Explicit default
 543                         $info['class'] === ResourceLoaderFileModule::class ||
 544                         is_subclass_of( $info['class'], ResourceLoaderFileModule::class )
 545                 );
 546         }
 547
 548         /**
 549          * Get the list of sources.
 550          *
 551          * @return array Like [ id => load.php url, ... ]
 552          */
 553         public function getSources() {
 554                 return $this->sources;
 555         }
 556
 557         /**
 558          * Get the URL to the load.php endpoint for the given
 559          * ResourceLoader source
 560          *
 561          * @since 1.24
 562          * @param string $source
 563          * @throws MWException On an invalid $source name
 564          * @return string
 565          */
 566         public function getLoadScript( $source ) {
 567                 if ( !isset( $this->sources[$source] ) ) {
 568                         throw new MWException( "The $source source was never registered in ResourceLoader." );
 569                 }
 570                 return $this->sources[$source];
 571         }
 572
 573         /**
 574          * @since 1.26
 575          * @param string $value
 576          * @return string Hash
 577          */
 578         public static function makeHash( $value ) {
 579                 $hash = hash( 'fnv132', $value );
 580                 return Wikimedia\base_convert( $hash, 16, 36, 7 );
 581         }
 582
 583         /**
 584          * Add an error to the 'errors' array and log it.
 585          *
 586          * @private For internal use by ResourceLoader and ResourceLoaderStartUpModule.
 587          * @since 1.29
 588          * @param Exception $e
 589          * @param string $msg
 590          * @param array $context
 591          */
 592         public function outputErrorAndLog( Exception $e, $msg, array $context = [] ) {
 593                 MWExceptionHandler::logException( $e );
 594                 $this->logger->warning(
 595                         $msg,
 596                         $context + [ 'exception' => $e ]
 597                 );
 598                 $this->errors[] = self::formatExceptionNoComment( $e );
 599         }
 600
 601         /**
 602          * Helper method to get and combine versions of multiple modules.
 603          *
 604          * @since 1.26
 605          * @param ResourceLoaderContext $context
 606          * @param string[] $moduleNames List of known module names
 607          * @return string Hash
 608          */
 609         public function getCombinedVersion( ResourceLoaderContext $context, array $moduleNames ) {
 610                 if ( !$moduleNames ) {
 611                         return '';
 612                 }
 613                 $hashes = array_map( function ( $module ) use ( $context ) {
 614                         try {
 615                                 return $this->getModule( $module )->getVersionHash( $context );
 616                         } catch ( Exception $e ) {
 617                                 // If modules fail to compute a version, don't fail the request (T152266)
 618                                 // and still compute versions of other modules.
 619                                 $this->outputErrorAndLog( $e,
 620                                         'Calculating version for "{module}" failed: {exception}',
 621                                         [
 622                                                 'module' => $module,
 623                                         ]
 624                                 );
 625                                 return '';
 626                         }
 627                 }, $moduleNames );
 628                 return self::makeHash( implode( '', $hashes ) );
 629         }
 630
 631         /**
 632          * Get the expected value of the 'version' query parameter.
 633          *
 634          * This is used by respond() to set a short Cache-Control header for requests with
 635          * information newer than the current server has. This avoids pollution of edge caches.
 636          * Typically during deployment. (T117587)
 637          *
 638          * This MUST match return value of `mw.loader#getCombinedVersion()` client-side.
 639          *
 640          * @since 1.28
 641          * @param ResourceLoaderContext $context
 642          * @return string Hash
 643          */
 644         public function makeVersionQuery( ResourceLoaderContext $context ) {
 645                 // As of MediaWiki 1.28, the server and client use the same algorithm for combining
 646                 // version hashes. There is no technical reason for this to be same, and for years the
 647                 // implementations differed. If getCombinedVersion in PHP (used for StartupModule and
 648                 // E-Tag headers) differs in the future from getCombinedVersion in JS (used for 'version'
 649                 // query parameter), then this method must continue to match the JS one.
 650                 $moduleNames = [];
 651                 foreach ( $context->getModules() as $name ) {
 652                         if ( !$this->getModule( $name ) ) {
 653                                 // If a versioned request contains a missing module, the version is a mismatch
 654                                 // as the client considered a module (and version) we don't have.
 655                                 return '';
 656                         }
 657                         $moduleNames[] = $name;
 658                 }
 659                 return $this->getCombinedVersion( $context, $moduleNames );
 660         }
 661
 662         /**
 663          * Output a response to a load request, including the content-type header.
 664          *
 665          * @param ResourceLoaderContext $context Context in which a response should be formed
 666          */
 667         public function respond( ResourceLoaderContext $context ) {
 668                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 669                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 670                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 671                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 672                 // the whole thing in our own output buffer to be sure the active buffer
 673                 // doesn't use ob_gzhandler.
 674                 // See https://bugs.php.net/bug.php?id=36514
 675                 ob_start();
 676
 677                 $this->measureResponseTime( RequestContext::getMain()->getTiming() );
 678
 679                 // Find out which modules are missing and instantiate the others
 680                 $modules = [];
 681                 $missing = [];
 682                 foreach ( $context->getModules() as $name ) {
 683                         $module = $this->getModule( $name );
 684                         if ( $module ) {
 685                                 // Do not allow private modules to be loaded from the web.
 686                                 // This is a security issue, see T36907.
 687                                 if ( $module->getGroup() === 'private' ) {
 688                                         $this->logger->debug( "Request for private module '$name' denied" );
 689                                         $this->errors[] = "Cannot show private module \"$name\"";
 690                                         continue;
 691                                 }
 692                                 $modules[$name] = $module;
 693                         } else {
 694                                 $missing[] = $name;
 695                         }
 696                 }
 697
 698                 try {
 699                         // Preload for getCombinedVersion() and for batch makeModuleResponse()
 700                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 701                 } catch ( Exception $e ) {
 702                         $this->outputErrorAndLog( $e, 'Preloading module info failed: {exception}' );
 703                 }
 704
 705                 // Combine versions to propagate cache invalidation
 706                 $versionHash = '';
 707                 try {
 708                         $versionHash = $this->getCombinedVersion( $context, array_keys( $modules ) );
 709                 } catch ( Exception $e ) {
 710                         $this->outputErrorAndLog( $e, 'Calculating version hash failed: {exception}' );
 711                 }
 712
 713                 // See RFC 2616 § 3.11 Entity Tags
 714                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.11
 715                 $etag = 'W/"' . $versionHash . '"';
 716
 717                 // Try the client-side cache first
 718                 if ( $this->tryRespondNotModified( $context, $etag ) ) {
 719                         return; // output handled (buffers cleared)
 720                 }
 721
 722                 // Use file cache if enabled and available...
 723                 if ( $this->config->get( 'UseFileCache' ) ) {
 724                         $fileCache = ResourceFileCache::newFromContext( $context );
 725                         if ( $this->tryRespondFromFileCache( $fileCache, $context, $etag ) ) {
 726                                 return; // output handled
 727                         }
 728                 }
 729
 730                 // Generate a response
 731                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 732
 733                 // Capture any PHP warnings from the output buffer and append them to the
 734                 // error list if we're in debug mode.
 735                 if ( $context->getDebug() ) {
 736                         $warnings = ob_get_contents();
 737                         if ( strlen( $warnings ) ) {
 738                                 $this->errors[] = $warnings;
 739                         }
 740                 }
 741
 742                 // Save response to file cache unless there are errors
 743                 if ( isset( $fileCache ) && !$this->errors && $missing === [] ) {
 744                         // Cache single modules and images...and other requests if there are enough hits
 745                         if ( ResourceFileCache::useFileCache( $context ) ) {
 746                                 if ( $fileCache->isCacheWorthy() ) {
 747                                         $fileCache->saveText( $response );
 748                                 } else {
 749                                         $fileCache->incrMissesRecent( $context->getRequest() );
 750                                 }
 751                         }
 752                 }
 753
 754                 $this->sendResponseHeaders( $context, $etag, (bool)$this->errors, $this->extraHeaders );
 755
 756                 // Remove the output buffer and output the response
 757                 ob_end_clean();
 758
 759                 if ( $context->getImageObj() && $this->errors ) {
 760                         // We can't show both the error messages and the response when it's an image.
 761                         $response = implode( "\n\n", $this->errors );
 762                 } elseif ( $this->errors ) {
 763                         $errorText = implode( "\n\n", $this->errors );
 764                         $errorResponse = self::makeComment( $errorText );
 765                         if ( $context->shouldIncludeScripts() ) {
 766                                 $errorResponse .= 'if (window.console && console.error) {'
 767                                         . Xml::encodeJsCall( 'console.error', [ $errorText ] )
 768                                         . "}\n";
 769                         }
 770
 771                         // Prepend error info to the response
 772                         $response = $errorResponse . $response;
 773                 }
 774
 775                 $this->errors = [];
 776                 echo $response;
 777         }
 778
 779         protected function measureResponseTime( Timing $timing ) {
 780                 DeferredUpdates::addCallableUpdate( function () use ( $timing ) {
 781                         $measure = $timing->measure( 'responseTime', 'requestStart', 'requestShutdown' );
 782                         if ( $measure !== false ) {
 783                                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
 784                                 $stats->timing( 'resourceloader.responseTime', $measure['duration'] * 1000 );
 785                         }
 786                 } );
 787         }
 788
 789         /**
 790          * Send main response headers to the client.
 791          *
 792          * Deals with Content-Type, CORS (for stylesheets), and caching.
 793          *
 794          * @param ResourceLoaderContext $context
 795          * @param string $etag ETag header value
 796          * @param bool $errors Whether there are errors in the response
 797          * @param string[] $extra Array of extra HTTP response headers
 798          * @return void
 799          */
 800         protected function sendResponseHeaders(
 801                 ResourceLoaderContext $context, $etag, $errors, array $extra = []
 802         ) {
 803                 \MediaWiki\HeaderCallback::warnIfHeadersSent();
 804                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 805                 // Use a short cache expiry so that updates propagate to clients quickly, if:
 806                 // - No version specified (shared resources, e.g. stylesheets)
 807                 // - There were errors (recover quickly)
 808                 // - Version mismatch (T117587, T47877)
 809                 if ( is_null( $context->getVersion() )
 810                         || $errors
 811                         || $context->getVersion() !== $this->makeVersionQuery( $context )
 812                 ) {
 813                         $maxage = $rlMaxage['unversioned']['client'];
 814                         $smaxage = $rlMaxage['unversioned']['server'];
 815                 // If a version was specified we can use a longer expiry time since changing
 816                 // version numbers causes cache misses
 817                 } else {
 818                         $maxage = $rlMaxage['versioned']['client'];
 819                         $smaxage = $rlMaxage['versioned']['server'];
 820                 }
 821                 if ( $context->getImageObj() ) {
 822                         // Output different headers if we're outputting textual errors.
 823                         if ( $errors ) {
 824                                 header( 'Content-Type: text/plain; charset=utf-8' );
 825                         } else {
 826                                 $context->getImageObj()->sendResponseHeaders( $context );
 827                         }
 828                 } elseif ( $context->getOnly() === 'styles' ) {
 829                         header( 'Content-Type: text/css; charset=utf-8' );
 830                         header( 'Access-Control-Allow-Origin: *' );
 831                 } else {
 832                         header( 'Content-Type: text/javascript; charset=utf-8' );
 833                 }
 834                 // See RFC 2616 § 14.19 ETag
 835                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.19
 836                 header( 'ETag: ' . $etag );
 837                 if ( $context->getDebug() ) {
 838                         // Do not cache debug responses
 839                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 840                         header( 'Pragma: no-cache' );
 841                 } else {
 842                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 843                         $exp = min( $maxage, $smaxage );
 844                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 845                 }
 846                 foreach ( $extra as $header ) {
 847                         header( $header );
 848                 }
 849         }
 850
 851         /**
 852          * Respond with HTTP 304 Not Modified if appropiate.
 853          *
 854          * If there's an If-None-Match header, respond with a 304 appropriately
 855          * and clear out the output buffer. If the client cache is too old then do nothing.
 856          *
 857          * @param ResourceLoaderContext $context
 858          * @param string $etag ETag header value
 859          * @return bool True if HTTP 304 was sent and output handled
 860          */
 861         protected function tryRespondNotModified( ResourceLoaderContext $context, $etag ) {
 862                 // See RFC 2616 § 14.26 If-None-Match
 863                 // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
 864                 $clientKeys = $context->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST );
 865                 // Never send 304s in debug mode
 866                 if ( $clientKeys !== false && !$context->getDebug() && in_array( $etag, $clientKeys ) ) {
 867                         // There's another bug in ob_gzhandler (see also the comment at
 868                         // the top of this function) that causes it to gzip even empty
 869                         // responses, meaning it's impossible to produce a truly empty
 870                         // response (because the gzip header is always there). This is
 871                         // a problem because 304 responses have to be completely empty
 872                         // per the HTTP spec, and Firefox behaves buggily when they're not.
 873                         // See also https://bugs.php.net/bug.php?id=51579
 874                         // To work around this, we tear down all output buffering before
 875                         // sending the 304.
 876                         wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 877
 878                         HttpStatus::header( 304 );
 879
 880                         $this->sendResponseHeaders( $context, $etag, false );
 881                         return true;
 882                 }
 883                 return false;
 884         }
 885
 886         /**
 887          * Send out code for a response from file cache if possible.
 888          *
 889          * @param ResourceFileCache $fileCache Cache object for this request URL
 890          * @param ResourceLoaderContext $context Context in which to generate a response
 891          * @param string $etag ETag header value
 892          * @return bool If this found a cache file and handled the response
 893          */
 894         protected function tryRespondFromFileCache(
 895                 ResourceFileCache $fileCache,
 896                 ResourceLoaderContext $context,
 897                 $etag
 898         ) {
 899                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 900                 // Buffer output to catch warnings.
 901                 ob_start();
 902                 // Get the maximum age the cache can be
 903                 $maxage = is_null( $context->getVersion() )
 904                         ? $rlMaxage['unversioned']['server']
 905                         : $rlMaxage['versioned']['server'];
 906                 // Minimum timestamp the cache file must have
 907                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 908                 if ( !$good ) {
 909                         try { // RL always hits the DB on file cache miss...
 910                                 wfGetDB( DB_REPLICA );
 911                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 912                                 $good = $fileCache->isCacheGood(); // cache existence check
 913                         }
 914                 }
 915                 if ( $good ) {
 916                         $ts = $fileCache->cacheTimestamp();
 917                         // Send content type and cache headers
 918                         $this->sendResponseHeaders( $context, $etag, false );
 919                         $response = $fileCache->fetchText();
 920                         // Capture any PHP warnings from the output buffer and append them to the
 921                         // response in a comment if we're in debug mode.
 922                         if ( $context->getDebug() ) {
 923                                 $warnings = ob_get_contents();
 924                                 if ( strlen( $warnings ) ) {
 925                                         $response = self::makeComment( $warnings ) . $response;
 926                                 }
 927                         }
 928                         // Remove the output buffer and output the response
 929                         ob_end_clean();
 930                         echo $response . "\n/* Cached {$ts} */";
 931                         return true; // cache hit
 932                 }
 933                 // Clear buffer
 934                 ob_end_clean();
 935
 936                 return false; // cache miss
 937         }
 938
 939         /**
 940          * Generate a CSS or JS comment block.
 941          *
 942          * Only use this for public data, not error message details.
 943          *
 944          * @param string $text
 945          * @return string
 946          */
 947         public static function makeComment( $text ) {
 948                 $encText = str_replace( '*/', '* /', $text );
 949                 return "/*\n$encText\n*/\n";
 950         }
 951
 952         /**
 953          * Handle exception display.
 954          *
 955          * @param Exception $e Exception to be shown to the user
 956          * @return string Sanitized text in a CSS/JS comment that can be returned to the user
 957          */
 958         public static function formatException( $e ) {
 959                 return self::makeComment( self::formatExceptionNoComment( $e ) );
 960         }
 961
 962         /**
 963          * Handle exception display.
 964          *
 965          * @since 1.25
 966          * @param Exception $e Exception to be shown to the user
 967          * @return string Sanitized text that can be returned to the user
 968          */
 969         protected static function formatExceptionNoComment( $e ) {
 970                 global $wgShowExceptionDetails;
 971
 972                 if ( !$wgShowExceptionDetails ) {
 973                         return MWExceptionHandler::getPublicLogMessage( $e );
 974                 }
 975
 976                 return MWExceptionHandler::getLogMessage( $e ) .
 977                         "\nBacktrace:\n" .
 978                         MWExceptionHandler::getRedactedTraceAsString( $e );
 979         }
 980
 981         /**
 982          * Generate code for a response.
 983          *
 984          * Calling this method also populates the `errors` and `headers` members,
 985          * later used by respond().
 986          *
 987          * @param ResourceLoaderContext $context Context in which to generate a response
 988          * @param ResourceLoaderModule[] $modules List of module objects keyed by module name
 989          * @param string[] $missing List of requested module names that are unregistered (optional)
 990          * @return string Response data
 991          */
 992         public function makeModuleResponse( ResourceLoaderContext $context,
 993                 array $modules, array $missing = []
 994         ) {
 995                 $out = '';
 996                 $states = [];
 997
 998                 if ( $modules === [] && $missing === [] ) {
 999                         return <<<MESSAGE
1000 /* This file is the Web entry point for MediaWiki's ResourceLoader:
1001    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
1002    no modules were requested. Max made me put this here. */
1003 MESSAGE;
1004                 }
1005
1006                 $image = $context->getImageObj();
1007                 if ( $image ) {
1008                         $data = $image->getImageData( $context );
1009                         if ( $data === false ) {
1010                                 $data = '';
1011                                 $this->errors[] = 'Image generation failed';
1012                         }
1013                         return $data;
1014                 }
1015
1016                 foreach ( $missing as $name ) {
1017                         $states[$name] = 'missing';
1018                 }
1019
1020                 $filter = $context->getOnly() === 'styles' ? 'minify-css' : 'minify-js';
1021
1022                 foreach ( $modules as $name => $module ) {
1023                         try {
1024                                 $content = $module->getModuleContent( $context );
1025                                 $implementKey = $name . '@' . $module->getVersionHash( $context );
1026                                 $strContent = '';
1027
1028                                 if ( isset( $content['headers'] ) ) {
1029                                         $this->extraHeaders = array_merge( $this->extraHeaders, $content['headers'] );
1030                                 }
1031
1032                                 // Append output
1033                                 switch ( $context->getOnly() ) {
1034                                         case 'scripts':
1035                                                 $scripts = $content['scripts'];
1036                                                 if ( is_string( $scripts ) ) {
1037                                                         // Load scripts raw...
1038                                                         $strContent = $scripts;
1039                                                 } elseif ( is_array( $scripts ) ) {
1040                                                         // ...except when $scripts is an array of URLs or an associative array
1041                                                         $strContent = self::makeLoaderImplementScript( $implementKey, $scripts, [], [], [] );
1042                                                 }
1043                                                 break;
1044                                         case 'styles':
1045                                                 $styles = $content['styles'];
1046                                                 // We no longer separate into media, they are all combined now with
1047                                                 // custom media type groups into @media .. {} sections as part of the css string.
1048                                                 // Module returns either an empty array or a numerical array with css strings.
1049                                                 $strContent = isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
1050                                                 break;
1051                                         default:
1052                                                 $scripts = $content['scripts'] ?? '';
1053                                                 if ( is_string( $scripts ) ) {
1054                                                         if ( $name === 'site' || $name === 'user' ) {
1055                                                                 // Legacy scripts that run in the global scope without a closure.
1056                                                                 // mw.loader.implement will use globalEval if scripts is a string.
1057                                                                 // Minify manually here, because general response minification is
1058                                                                 // not effective due it being a string literal, not a function.
1059                                                                 if ( !$context->getDebug() ) {
1060                                                                         $scripts = self::filter( 'minify-js', $scripts ); // T107377
1061                                                                 }
1062                                                         } else {
1063                                                                 $scripts = new XmlJsCode( $scripts );
1064                                                         }
1065                                                 }
1066                                                 $strContent = self::makeLoaderImplementScript(
1067                                                         $implementKey,
1068                                                         $scripts,
1069                                                         $content['styles'] ?? [],
1070                                                         isset( $content['messagesBlob'] ) ? new XmlJsCode( $content['messagesBlob'] ) : [],
1071                                                         $content['templates'] ?? []
1072                                                 );
1073                                                 break;
1074                                 }
1075
1076                                 if ( !$context->getDebug() ) {
1077                                         $strContent = self::filter( $filter, $strContent );
1078                                 } else {
1079                                         // In debug mode, separate each response by a new line.
1080                                         // For example, between 'mw.loader.implement();' statements.
1081                                         $strContent = $this->ensureNewline( $strContent );
1082                                 }
1083
1084                                 if ( $context->getOnly() === 'scripts' ) {
1085                                         // Use a linebreak between module scripts (T162719)
1086                                         $out .= $this->ensureNewline( $strContent );
1087                                 } else {
1088                                         $out .= $strContent;
1089                                 }
1090
1091                         } catch ( Exception $e ) {
1092                                 $this->outputErrorAndLog( $e, 'Generating module package failed: {exception}' );
1093
1094                                 // Respond to client with error-state instead of module implementation
1095                                 $states[$name] = 'error';
1096                                 unset( $modules[$name] );
1097                         }
1098                 }
1099
1100                 // Update module states
1101                 if ( $context->shouldIncludeScripts() && !$context->getRaw() ) {
1102                         if ( $modules && $context->getOnly() === 'scripts' ) {
1103                                 // Set the state of modules loaded as only scripts to ready as
1104                                 // they don't have an mw.loader.implement wrapper that sets the state
1105                                 foreach ( $modules as $name => $module ) {
1106                                         $states[$name] = 'ready';
1107                                 }
1108                         }
1109
1110                         // Set the state of modules we didn't respond to with mw.loader.implement
1111                         if ( $states ) {
1112                                 $stateScript = self::makeLoaderStateScript( $states );
1113                                 if ( !$context->getDebug() ) {
1114                                         $stateScript = self::filter( 'minify-js', $stateScript );
1115                                 }
1116                                 // Use a linebreak between module script and state script (T162719)
1117                                 $out = $this->ensureNewline( $out ) . $stateScript;
1118                         }
1119                 } elseif ( $states ) {
1120                         $this->errors[] = 'Problematic modules: '
1121                                 . self::encodeJsonForScript( $states );
1122                 }
1123
1124                 return $out;
1125         }
1126
1127         /**
1128          * Ensure the string is either empty or ends in a line break
1129          * @param string $str
1130          * @return string
1131          */
1132         private function ensureNewline( $str ) {
1133                 $end = substr( $str, -1 );
1134                 if ( $end === false || $end === '' || $end === "\n" ) {
1135                         return $str;
1136                 }
1137                 return $str . "\n";
1138         }
1139
1140         /**
1141          * Get names of modules that use a certain message.
1142          *
1143          * @param string $messageKey
1144          * @return array List of module names
1145          */
1146         public function getModulesByMessage( $messageKey ) {
1147                 $moduleNames = [];
1148                 foreach ( $this->getModuleNames() as $moduleName ) {
1149                         $module = $this->getModule( $moduleName );
1150                         if ( in_array( $messageKey, $module->getMessages() ) ) {
1151                                 $moduleNames[] = $moduleName;
1152                         }
1153                 }
1154                 return $moduleNames;
1155         }
1156
1157         /**
1158          * Return JS code that calls mw.loader.implement with given module properties.
1159          *
1160          * @param string $name Module name or implement key (format "`[name]@[version]`")
1161          * @param XmlJsCode|array|string $scripts Code as XmlJsCode (to be wrapped in a closure),
1162          *  list of URLs to JavaScript files, string of JavaScript for `$.globalEval`, or array with
1163          *  'files' and 'main' properties (see ResourceLoaderModule::getScript())
1164          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1165          *   to CSS files keyed by media type
1166          * @param mixed $messages List of messages associated with this module. May either be an
1167          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1168          *   the same data, wrapped in an XmlJsCode object.
1169          * @param array $templates Keys are name of templates and values are the source of
1170          *   the template.
1171          * @throws MWException
1172          * @return string JavaScript code
1173          */
1174         protected static function makeLoaderImplementScript(
1175                 $name, $scripts, $styles, $messages, $templates
1176         ) {
1177                 if ( $scripts instanceof XmlJsCode ) {
1178                         if ( $scripts->value === '' ) {
1179                                 $scripts = null;
1180                         } elseif ( self::inDebugMode() ) {
1181                                 $scripts = new XmlJsCode( "function ( $, jQuery, require, module ) {\n{$scripts->value}\n}" );
1182                         } else {
1183                                 $scripts = new XmlJsCode( 'function($,jQuery,require,module){' . $scripts->value . '}' );
1184                         }
1185                 } elseif ( is_array( $scripts ) && isset( $scripts['files'] ) ) {
1186                         $files = $scripts['files'];
1187                         foreach ( $files as $path => &$file ) {
1188                                 // $file is changed (by reference) from a descriptor array to the content of the file
1189                                 // All of these essentially do $file = $file['content'];, some just have wrapping around it
1190                                 if ( $file['type'] === 'script' ) {
1191                                         // Multi-file modules only get two parameters ($ and jQuery are being phased out)
1192                                         if ( self::inDebugMode() ) {
1193                                                 $file = new XmlJsCode( "function ( require, module ) {\n{$file['content']}\n}" );
1194                                         } else {
1195                                                 $file = new XmlJsCode( 'function(require,module){' . $file['content'] . '}' );
1196                                         }
1197                                 } else {
1198                                         $file = $file['content'];
1199                                 }
1200                         }
1201                         $scripts = XmlJsCode::encodeObject( [
1202                                 'main' => $scripts['main'],
1203                                 'files' => XmlJsCode::encodeObject( $files, self::inDebugMode() )
1204                         ], self::inDebugMode() );
1205                 } elseif ( !is_string( $scripts ) && !is_array( $scripts ) ) {
1206                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1207                 }
1208
1209                 // mw.loader.implement requires 'styles', 'messages' and 'templates' to be objects (not
1210                 // arrays). json_encode considers empty arrays to be numerical and outputs "[]" instead
1211                 // of "{}". Force them to objects.
1212                 $module = [
1213                         $name,
1214                         $scripts,
1215                         (object)$styles,
1216                         (object)$messages,
1217                         (object)$templates
1218                 ];
1219                 self::trimArray( $module );
1220
1221                 return Xml::encodeJsCall( 'mw.loader.implement', $module, self::inDebugMode() );
1222         }
1223
1224         /**
1225          * Returns JS code which, when called, will register a given list of messages.
1226          *
1227          * @param mixed $messages Either an associative array mapping message key to value, or a
1228          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1229          * @return string JavaScript code
1230          */
1231         public static function makeMessageSetScript( $messages ) {
1232                 return 'mw.messages.set('
1233                         . self::encodeJsonForScript( (object)$messages )
1234                         . ');';
1235         }
1236
1237         /**
1238          * Combines an associative array mapping media type to CSS into a
1239          * single stylesheet with "@media" blocks.
1240          *
1241          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1242          * @return array
1243          */
1244         public static function makeCombinedStyles( array $stylePairs ) {
1245                 $out = [];
1246                 foreach ( $stylePairs as $media => $styles ) {
1247                         // ResourceLoaderFileModule::getStyle can return the styles
1248                         // as a string or an array of strings. This is to allow separation in
1249                         // the front-end.
1250                         $styles = (array)$styles;
1251                         foreach ( $styles as $style ) {
1252                                 $style = trim( $style );
1253                                 // Don't output an empty "@media print { }" block (T42498)
1254                                 if ( $style !== '' ) {
1255                                         // Transform the media type based on request params and config
1256                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1257                                         $media = OutputPage::transformCssMedia( $media );
1258
1259                                         if ( $media === '' || $media == 'all' ) {
1260                                                 $out[] = $style;
1261                                         } elseif ( is_string( $media ) ) {
1262                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1263                                         }
1264                                         // else: skip
1265                                 }
1266                         }
1267                 }
1268                 return $out;
1269         }
1270
1271         /**
1272          * Wrapper around json_encode that avoids needless escapes,
1273          * and pretty-prints in debug mode.
1274          *
1275          * @internal
1276          * @since 1.32
1277          * @param bool|string|array $data
1278          * @return string JSON
1279          */
1280         public static function encodeJsonForScript( $data ) {
1281                 // Keep output as small as possible by disabling needless escape modes
1282                 // that PHP uses by default.
1283                 // However, while most module scripts are only served on HTTP responses
1284                 // for JavaScript, some modules can also be embedded in the HTML as inline
1285                 // scripts. This, and the fact that we sometimes need to export strings
1286                 // containing user-generated content and labels that may genuinely contain
1287                 // a sequences like "</script>", we need to encode either '/' or '<'.
1288                 // By default PHP escapes '/'. Let's escape '<' instead which is less common
1289                 // and allows URLs to mostly remain readable.
1290                 $jsonFlags = JSON_UNESCAPED_SLASHES |
1291                         JSON_UNESCAPED_UNICODE |
1292                         JSON_HEX_TAG |
1293                         JSON_HEX_AMP;
1294                 if ( self::inDebugMode() ) {
1295                         $jsonFlags |= JSON_PRETTY_PRINT;
1296                 }
1297                 return json_encode( $data, $jsonFlags );
1298         }
1299
1300         /**
1301          * Returns a JS call to mw.loader.state, which sets the state of one
1302          * ore more modules to a given value. Has two calling conventions:
1303          *
1304          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1305          *         Set the state of a single module called $name to $state
1306          *
1307          *    - ResourceLoader::makeLoaderStateScript( [ $name => $state, ... ] ):
1308          *         Set the state of modules with the given names to the given states
1309          *
1310          * @param array|string $states
1311          * @param string|null $state
1312          * @return string JavaScript code
1313          */
1314         public static function makeLoaderStateScript( $states, $state = null ) {
1315                 if ( !is_array( $states ) ) {
1316                         $states = [ $states => $state ];
1317                 }
1318                 return 'mw.loader.state('
1319                         . self::encodeJsonForScript( $states )
1320                         . ');';
1321         }
1322
1323         private static function isEmptyObject( stdClass $obj ) {
1324                 foreach ( $obj as $key => $value ) {
1325                         return false;
1326                 }
1327                 return true;
1328         }
1329
1330         /**
1331          * Remove empty values from the end of an array.
1332          *
1333          * Values considered empty:
1334          *
1335          * - null
1336          * - []
1337          * - new XmlJsCode( '{}' )
1338          * - new stdClass() // (object) []
1339          *
1340          * @param array $array
1341          */
1342         private static function trimArray( array &$array ) {
1343                 $i = count( $array );
1344                 while ( $i-- ) {
1345                         if ( $array[$i] === null
1346                                 || $array[$i] === []
1347                                 || ( $array[$i] instanceof XmlJsCode && $array[$i]->value === '{}' )
1348                                 || ( $array[$i] instanceof stdClass && self::isEmptyObject( $array[$i] ) )
1349                         ) {
1350                                 unset( $array[$i] );
1351                         } else {
1352                                 break;
1353                         }
1354                 }
1355         }
1356
1357         /**
1358          * Returns JS code which calls mw.loader.register with the given
1359          * parameter.
1360          *
1361          * @par Example
1362          * @code
1363          *
1364          *     ResourceLoader::makeLoaderRegisterScript( [
1365          *        [ $name1, $version1, $dependencies1, $group1, $source1, $skip1 ],
1366          *        [ $name2, $version2, $dependencies1, $group2, $source2, $skip2 ],
1367          *        ...
1368          *     ] ):
1369          * @endcode
1370          *
1371          * @internal
1372          * @since 1.32
1373          * @param array $modules Array of module registration arrays, each containing
1374          *  - string: module name
1375          *  - string: module version
1376          *  - array|null: List of dependencies (optional)
1377          *  - string|null: Module group (optional)
1378          *  - string|null: Name of foreign module source, or 'local' (optional)
1379          *  - string|null: Script body of a skip function (optional)
1380          * @return string JavaScript code
1381          */
1382         public static function makeLoaderRegisterScript( array $modules ) {
1383                 // Optimisation: Transform dependency names into indexes when possible
1384                 // to produce smaller output. They are expanded by mw.loader.register on
1385                 // the other end using resolveIndexedDependencies().
1386                 $index = [];
1387                 foreach ( $modules as $i => &$module ) {
1388                         // Build module name index
1389                         $index[$module[0]] = $i;
1390                 }
1391                 foreach ( $modules as &$module ) {
1392                         if ( isset( $module[2] ) ) {
1393                                 foreach ( $module[2] as &$dependency ) {
1394                                         if ( isset( $index[$dependency] ) ) {
1395                                                 // Replace module name in dependency list with index
1396                                                 $dependency = $index[$dependency];
1397                                         }
1398                                 }
1399                         }
1400                 }
1401
1402                 array_walk( $modules, [ self::class, 'trimArray' ] );
1403
1404                 return 'mw.loader.register('
1405                         . self::encodeJsonForScript( $modules )
1406                         . ');';
1407         }
1408
1409         /**
1410          * Returns JS code which calls mw.loader.addSource() with the given
1411          * parameters. Has two calling conventions:
1412          *
1413          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1414          *       Register a single source
1415          *
1416          *   - ResourceLoader::makeLoaderSourcesScript( [ $id1 => $loadUrl, $id2 => $loadUrl, ... ] );
1417          *       Register sources with the given IDs and properties.
1418          *
1419          * @param string|array $sources Source ID
1420          * @param string|null $loadUrl load.php url
1421          * @return string JavaScript code
1422          */
1423         public static function makeLoaderSourcesScript( $sources, $loadUrl = null ) {
1424                 if ( !is_array( $sources ) ) {
1425                         $sources = [ $sources => $loadUrl ];
1426                 }
1427                 return 'mw.loader.addSource('
1428                         . self::encodeJsonForScript( $sources )
1429                         . ');';
1430         }
1431
1432         /**
1433          * Wraps JavaScript code to run after the startup module.
1434          *
1435          * @param string $script JavaScript code
1436          * @return string JavaScript code
1437          */
1438         public static function makeLoaderConditionalScript( $script ) {
1439                 // Adds a function to lazy-created RLQ
1440                 return '(RLQ=window.RLQ||[]).push(function(){' .
1441                         trim( $script ) . '});';
1442         }
1443
1444         /**
1445          * Wraps JavaScript code to run after a required module.
1446          *
1447          * @since 1.32
1448          * @param string|string[] $modules Module name(s)
1449          * @param string $script JavaScript code
1450          * @return string JavaScript code
1451          */
1452         public static function makeInlineCodeWithModule( $modules, $script ) {
1453                 // Adds an array to lazy-created RLQ
1454                 return '(RLQ=window.RLQ||[]).push(['
1455                         . self::encodeJsonForScript( $modules ) . ','
1456                         . 'function(){' . trim( $script ) . '}'
1457                         . ']);';
1458         }
1459
1460         /**
1461          * Returns an HTML script tag that runs given JS code after startup and base modules.
1462          *
1463          * The code will be wrapped in a closure, and it will be executed by ResourceLoader's
1464          * startup module if the client has adequate support for MediaWiki JavaScript code.
1465          *
1466          * @param string $script JavaScript code
1467          * @param string|null $nonce [optional] Content-Security-Policy nonce
1468          *  (from OutputPage::getCSPNonce)
1469          * @return string|WrappedString HTML
1470          */
1471         public static function makeInlineScript( $script, $nonce = null ) {
1472                 $js = self::makeLoaderConditionalScript( $script );
1473                 $escNonce = '';
1474                 if ( $nonce === null ) {
1475                         wfWarn( __METHOD__ . " did not get nonce. Will break CSP" );
1476                 } elseif ( $nonce !== false ) {
1477                         // If it was false, CSP is disabled, so no nonce attribute.
1478                         // Nonce should be only base64 characters, so should be safe,
1479                         // but better to be safely escaped than sorry.
1480                         $escNonce = ' nonce="' . htmlspecialchars( $nonce ) . '"';
1481                 }
1482
1483                 return new WrappedString(
1484                         Html::inlineScript( $js, $nonce ),
1485                         "<script$escNonce>(RLQ=window.RLQ||[]).push(function(){",
1486                         '});</script>'
1487                 );
1488         }
1489
1490         /**
1491          * Returns JS code which will set the MediaWiki configuration array to
1492          * the given value.
1493          *
1494          * @param array $configuration List of configuration values keyed by variable name
1495          * @return string JavaScript code
1496          * @throws Exception
1497          */
1498         public static function makeConfigSetScript( array $configuration ) {
1499                 $js = Xml::encodeJsCall(
1500                         'mw.config.set',
1501                         [ $configuration ],
1502                         self::inDebugMode()
1503                 );
1504                 if ( $js === false ) {
1505                         $e = new Exception(
1506                                 'JSON serialization of config data failed. ' .
1507                                 'This usually means the config data is not valid UTF-8.'
1508                         );
1509                         MWExceptionHandler::logException( $e );
1510                         $js = Xml::encodeJsCall( 'mw.log.error', [ $e->__toString() ] );
1511                 }
1512                 return $js;
1513         }
1514
1515         /**
1516          * Convert an array of module names to a packed query string.
1517          *
1518          * For example, `[ 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' ]`
1519          * becomes `'foo.bar,baz|bar.baz,quux'`.
1520          *
1521          * This process is reversed by ResourceLoader::expandModuleNames().
1522          * See also mw.loader#buildModulesString() which is a port of this, used
1523          * on the client-side.
1524          *
1525          * @param array $modules List of module names (strings)
1526          * @return string Packed query string
1527          */
1528         public static function makePackedModulesString( $modules ) {
1529                 $moduleMap = []; // [ prefix => [ suffixes ] ]
1530                 foreach ( $modules as $module ) {
1531                         $pos = strrpos( $module, '.' );
1532                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1533                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1534                         $moduleMap[$prefix][] = $suffix;
1535                 }
1536
1537                 $arr = [];
1538                 foreach ( $moduleMap as $prefix => $suffixes ) {
1539                         $p = $prefix === '' ? '' : $prefix . '.';
1540                         $arr[] = $p . implode( ',', $suffixes );
1541                 }
1542                 return implode( '|', $arr );
1543         }
1544
1545         /**
1546          * Expand a string of the form `jquery.foo,bar|jquery.ui.baz,quux` to
1547          * an array of module names like `[ 'jquery.foo', 'jquery.bar',
1548          * 'jquery.ui.baz', 'jquery.ui.quux' ]`.
1549          *
1550          * This process is reversed by ResourceLoader::makePackedModulesString().
1551          *
1552          * @since 1.33
1553          * @param string $modules Packed module name list
1554          * @return array Array of module names
1555          */
1556         public static function expandModuleNames( $modules ) {
1557                 $retval = [];
1558                 $exploded = explode( '|', $modules );
1559                 foreach ( $exploded as $group ) {
1560                         if ( strpos( $group, ',' ) === false ) {
1561                                 // This is not a set of modules in foo.bar,baz notation
1562                                 // but a single module
1563                                 $retval[] = $group;
1564                         } else {
1565                                 // This is a set of modules in foo.bar,baz notation
1566                                 $pos = strrpos( $group, '.' );
1567                                 if ( $pos === false ) {
1568                                         // Prefixless modules, i.e. without dots
1569                                         $retval = array_merge( $retval, explode( ',', $group ) );
1570                                 } else {
1571                                         // We have a prefix and a bunch of suffixes
1572                                         $prefix = substr( $group, 0, $pos ); // 'foo'
1573                                         $suffixes = explode( ',', substr( $group, $pos + 1 ) ); // [ 'bar', 'baz' ]
1574                                         foreach ( $suffixes as $suffix ) {
1575                                                 $retval[] = "$prefix.$suffix";
1576                                         }
1577                                 }
1578                         }
1579                 }
1580                 return $retval;
1581         }
1582
1583         /**
1584          * Determine whether debug mode was requested
1585          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1586          * @return bool
1587          */
1588         public static function inDebugMode() {
1589                 if ( self::$debugMode === null ) {
1590                         global $wgRequest, $wgResourceLoaderDebug;
1591                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1592                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1593                         );
1594                 }
1595                 return self::$debugMode;
1596         }
1597
1598         /**
1599          * Reset static members used for caching.
1600          *
1601          * Global state and $wgRequest are evil, but we're using it right
1602          * now and sometimes we need to be able to force ResourceLoader to
1603          * re-evaluate the context because it has changed (e.g. in the test suite).
1604          *
1605          * @internal For use by unit tests
1606          * @codeCoverageIgnore
1607          */
1608         public static function clearCache() {
1609                 self::$debugMode = null;
1610         }
1611
1612         /**
1613          * Build a load.php URL
1614          *
1615          * @since 1.24
1616          * @param string $source Name of the ResourceLoader source
1617          * @param ResourceLoaderContext $context
1618          * @param array $extraQuery
1619          * @return string URL to load.php. May be protocol-relative if $wgLoadScript is, too.
1620          */
1621         public function createLoaderURL( $source, ResourceLoaderContext $context,
1622                 $extraQuery = []
1623         ) {
1624                 $query = self::createLoaderQuery( $context, $extraQuery );
1625                 $script = $this->getLoadScript( $source );
1626
1627                 return wfAppendQuery( $script, $query );
1628         }
1629
1630         /**
1631          * Helper for createLoaderURL()
1632          *
1633          * @since 1.24
1634          * @see makeLoaderQuery
1635          * @param ResourceLoaderContext $context
1636          * @param array $extraQuery
1637          * @return array
1638          */
1639         protected static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = [] ) {
1640                 return self::makeLoaderQuery(
1641                         $context->getModules(),
1642                         $context->getLanguage(),
1643                         $context->getSkin(),
1644                         $context->getUser(),
1645                         $context->getVersion(),
1646                         $context->getDebug(),
1647                         $context->getOnly(),
1648                         $context->getRequest()->getBool( 'printable' ),
1649                         $context->getRequest()->getBool( 'handheld' ),
1650                         $extraQuery
1651                 );
1652         }
1653
1654         /**
1655          * Build a query array (array representation of query string) for load.php. Helper
1656          * function for createLoaderURL().
1657          *
1658          * @param array $modules
1659          * @param string $lang
1660          * @param string $skin
1661          * @param string|null $user
1662          * @param string|null $version
1663          * @param bool $debug
1664          * @param string|null $only
1665          * @param bool $printable
1666          * @param bool $handheld
1667          * @param array $extraQuery
1668          * @return array
1669          */
1670         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1671                 $version = null, $debug = false, $only = null, $printable = false,
1672                 $handheld = false, $extraQuery = []
1673         ) {
1674                 $query = [
1675                         'modules' => self::makePackedModulesString( $modules ),
1676                 ];
1677                 // Keep urls short by omitting query parameters that
1678                 // match the defaults assumed by ResourceLoaderContext.
1679                 // Note: This relies on the defaults either being insignificant or forever constant,
1680                 // as otherwise cached urls could change in meaning when the defaults change.
1681                 if ( $lang !== ResourceLoaderContext::DEFAULT_LANG ) {
1682                         $query['lang'] = $lang;
1683                 }
1684                 if ( $skin !== ResourceLoaderContext::DEFAULT_SKIN ) {
1685                         $query['skin'] = $skin;
1686                 }
1687                 if ( $debug === true ) {
1688                         $query['debug'] = 'true';
1689                 }
1690                 if ( $user !== null ) {
1691                         $query['user'] = $user;
1692                 }
1693                 if ( $version !== null ) {
1694                         $query['version'] = $version;
1695                 }
1696                 if ( $only !== null ) {
1697                         $query['only'] = $only;
1698                 }
1699                 if ( $printable ) {
1700                         $query['printable'] = 1;
1701                 }
1702                 if ( $handheld ) {
1703                         $query['handheld'] = 1;
1704                 }
1705                 $query += $extraQuery;
1706
1707                 // Make queries uniform in order
1708                 ksort( $query );
1709                 return $query;
1710         }
1711
1712         /**
1713          * Check a module name for validity.
1714          *
1715          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1716          * at most 255 bytes.
1717          *
1718          * @param string $moduleName Module name to check
1719          * @return bool Whether $moduleName is a valid module name
1720          */
1721         public static function isValidModuleName( $moduleName ) {
1722                 return strcspn( $moduleName, '!,|', 0, 255 ) === strlen( $moduleName );
1723         }
1724
1725         /**
1726          * Returns LESS compiler set up for use with MediaWiki
1727          *
1728          * @since 1.27
1729          * @param array $vars Associative array of variables that should be used
1730          *  for compilation. Since 1.32, this method no longer automatically includes
1731          *  global LESS vars from ResourceLoader::getLessVars (T191937).
1732          * @throws MWException
1733          * @return Less_Parser
1734          */
1735         public function getLessCompiler( $vars = [] ) {
1736                 global $IP;
1737                 // When called from the installer, it is possible that a required PHP extension
1738                 // is missing (at least for now; see T49564). If this is the case, throw an
1739                 // exception (caught by the installer) to prevent a fatal error later on.
1740                 if ( !class_exists( 'Less_Parser' ) ) {
1741                         throw new MWException( 'MediaWiki requires the less.php parser' );
1742                 }
1743
1744                 $parser = new Less_Parser;
1745                 $parser->ModifyVars( $vars );
1746                 $parser->SetImportDirs( [
1747                         "$IP/resources/src/mediawiki.less/" => '',
1748                 ] );
1749                 $parser->SetOption( 'relativeUrls', false );
1750
1751                 return $parser;
1752         }
1753
1754         /**
1755          * Get global LESS variables.
1756          *
1757          * @since 1.27
1758          * @deprecated since 1.32 Use ResourceLoderModule::getLessVars() instead.
1759          * @return array Map of variable names to string CSS values.
1760          */
1761         public function getLessVars() {
1762                 return [];
1763         }
1764 }