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 Psr\Log\LoggerAwareInterface;
  26 use Psr\Log\LoggerInterface;
  27 use Psr\Log\NullLogger;
  28
  29 /**
  30  * Dynamic JavaScript and CSS resource loading system.
  31  *
  32  * Most of the documentation is on the MediaWiki documentation wiki starting at:
  33  *    https://www.mediawiki.org/wiki/ResourceLoader
  34  */
  35 class ResourceLoader implements LoggerAwareInterface {
  36         /** @var int */
  37         protected static $filterCacheVersion = 7;
  38
  39         /** @var bool */
  40         protected static $debugMode = null;
  41
  42         /** @var array */
  43         private static $lessVars = null;
  44
  45         /**
  46          * Module name/ResourceLoaderModule object pairs
  47          * @var array
  48          */
  49         protected $modules = array();
  50
  51         /**
  52          * Associative array mapping module name to info associative array
  53          * @var array
  54          */
  55         protected $moduleInfos = array();
  56
  57         /** @var Config $config */
  58         private $config;
  59
  60         /**
  61          * Associative array mapping framework ids to a list of names of test suite modules
  62          * like array( 'qunit' => array( 'mediawiki.tests.qunit.suites', 'ext.foo.tests', .. ), .. )
  63          * @var array
  64          */
  65         protected $testModuleNames = array();
  66
  67         /**
  68          * E.g. array( 'source-id' => 'http://.../load.php' )
  69          * @var array
  70          */
  71         protected $sources = array();
  72
  73         /**
  74          * Errors accumulated during current respond() call.
  75          * @var array
  76          */
  77         protected $errors = array();
  78
  79         /**
  80          * @var MessageBlobStore
  81          */
  82         protected $blobStore;
  83
  84         /**
  85          * @var LoggerInterface
  86          */
  87         private $logger;
  88
  89         /**
  90          * Load information stored in the database about modules.
  91          *
  92          * This method grabs modules dependencies from the database and updates modules
  93          * objects.
  94          *
  95          * This is not inside the module code because it is much faster to
  96          * request all of the information at once than it is to have each module
  97          * requests its own information. This sacrifice of modularity yields a substantial
  98          * performance improvement.
  99          *
 100          * @param array $modules List of module names to preload information for
 101          * @param ResourceLoaderContext $context Context to load the information within
 102          */
 103         public function preloadModuleInfo( array $modules, ResourceLoaderContext $context ) {
 104                 if ( !count( $modules ) ) {
 105                         // Or else Database*::select() will explode, plus it's cheaper!
 106                         return;
 107                 }
 108                 $dbr = wfGetDB( DB_SLAVE );
 109                 $skin = $context->getSkin();
 110                 $lang = $context->getLanguage();
 111
 112                 // Get file dependency information
 113                 $res = $dbr->select( 'module_deps', array( 'md_module', 'md_deps' ), array(
 114                                 'md_module' => $modules,
 115                                 'md_skin' => $skin
 116                         ), __METHOD__
 117                 );
 118
 119                 // Set modules' dependencies
 120                 $modulesWithDeps = array();
 121                 foreach ( $res as $row ) {
 122                         $module = $this->getModule( $row->md_module );
 123                         if ( $module ) {
 124                                 $module->setFileDependencies( $skin, FormatJson::decode( $row->md_deps, true ) );
 125                                 $modulesWithDeps[] = $row->md_module;
 126                         }
 127                 }
 128
 129                 // Register the absence of a dependency row too
 130                 foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
 131                         $module = $this->getModule( $name );
 132                         if ( $module ) {
 133                                 $this->getModule( $name )->setFileDependencies( $skin, array() );
 134                         }
 135                 }
 136
 137                 // Get message blob mtimes. Only do this for modules with messages
 138                 $modulesWithMessages = array();
 139                 foreach ( $modules as $name ) {
 140                         $module = $this->getModule( $name );
 141                         if ( $module && count( $module->getMessages() ) ) {
 142                                 $modulesWithMessages[] = $name;
 143                         }
 144                 }
 145                 $modulesWithoutMessages = array_flip( $modules ); // Will be trimmed down by the loop below
 146                 if ( count( $modulesWithMessages ) ) {
 147                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
 148                                         'mr_resource' => $modulesWithMessages,
 149                                         'mr_lang' => $lang
 150                                 ), __METHOD__
 151                         );
 152                         foreach ( $res as $row ) {
 153                                 $module = $this->getModule( $row->mr_resource );
 154                                 if ( $module ) {
 155                                         $module->setMsgBlobMtime( $lang, wfTimestamp( TS_UNIX, $row->mr_timestamp ) );
 156                                         unset( $modulesWithoutMessages[$row->mr_resource] );
 157                                 }
 158                         }
 159                 }
 160                 foreach ( array_keys( $modulesWithoutMessages ) as $name ) {
 161                         $module = $this->getModule( $name );
 162                         if ( $module ) {
 163                                 $module->setMsgBlobMtime( $lang, 1 );
 164                         }
 165                 }
 166         }
 167
 168         /**
 169          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 170          *
 171          * Available filters are:
 172          *
 173          *    - minify-js \see JavaScriptMinifier::minify
 174          *    - minify-css \see CSSMin::minify
 175          *
 176          * If $data is empty, only contains whitespace or the filter was unknown,
 177          * $data is returned unmodified.
 178          *
 179          * @param string $filter Name of filter to run
 180          * @param string $data Text to filter, such as JavaScript or CSS text
 181          * @param array $options For back-compat, can also be the boolean value for "cacheReport". Keys:
 182          *  - (bool) cache: Whether to allow caching this data. Default: true.
 183          *  - (bool) cacheReport: Whether to include the "cache key" report comment. Default: true.
 184          * @return string Filtered data, or a comment containing an error message
 185          */
 186         public function filter( $filter, $data, $options = array() ) {
 187                 // Back-compat
 188                 if ( is_bool( $options ) ) {
 189                         $options = array( 'cacheReport' => $options );
 190                 }
 191                 // Defaults
 192                 $options += array( 'cache' => true, 'cacheReport' => true );
 193
 194                 // Don't filter empty content
 195                 if ( trim( $data ) === '' ) {
 196                         return $data;
 197                 }
 198
 199                 if ( !in_array( $filter, array( 'minify-js', 'minify-css' ) ) ) {
 200                         $this->logger->warning( 'Invalid filter {filter}', array(
 201                                 'filter' => $filter
 202                         ) );
 203                         return $data;
 204                 }
 205
 206                 if ( !$options['cache'] ) {
 207                         $result = $this->applyFilter( $filter, $data );
 208                 } else {
 209                         $key = wfMemcKey( 'resourceloader', 'filter', $filter, self::$filterCacheVersion, md5( $data ) );
 210                         $cache = wfGetCache( wfIsHHVM() ? CACHE_ACCEL : CACHE_ANYTHING );
 211                         $cacheEntry = $cache->get( $key );
 212                         if ( is_string( $cacheEntry ) ) {
 213                                 wfIncrStats( "resourceloader_cache.$filter.hit" );
 214                                 return $cacheEntry;
 215                         }
 216                         $result = '';
 217                         try {
 218                                 $result = $this->applyFilter( $filter, $data );
 219                                 if ( $options['cacheReport'] ) {
 220                                         $result .= "\n/* cache key: $key */";
 221                                 }
 222                                 $cache->set( $key, $result );
 223                         } catch ( Exception $e ) {
 224                                 MWExceptionHandler::logException( $e );
 225                                 $this->logger->warning( 'Minification failed: {exception}', array(
 226                                         'exception' => $e
 227                                 ) );
 228                                 $this->errors[] = self::formatExceptionNoComment( $e );
 229                         }
 230                 }
 231
 232                 return $result;
 233         }
 234
 235         private function applyFilter( $filter, $data ) {
 236                 $stats = RequestContext::getMain()->getStats();
 237                 $statStart = microtime( true );
 238
 239                 switch ( $filter ) {
 240                         case 'minify-js':
 241                                 $data = JavaScriptMinifier::minify( $data,
 242                                         $this->config->get( 'ResourceLoaderMinifierStatementsOnOwnLine' ),
 243                                         $this->config->get( 'ResourceLoaderMinifierMaxLineLength' )
 244                                 );
 245                                 break;
 246                         case 'minify-css':
 247                                 $data = CSSMin::minify( $data );
 248                                 break;
 249                 }
 250
 251                 $stats->timing( "resourceloader_cache.$filter.miss", microtime( true ) - $statStart );
 252                 return $data;
 253         }
 254
 255         /* Methods */
 256
 257         /**
 258          * Register core modules and runs registration hooks.
 259          * @param Config|null $config
 260          */
 261         public function __construct( Config $config = null, LoggerInterface $logger = null ) {
 262                 global $IP;
 263
 264                 if ( !$logger ) {
 265                         $logger = new NullLogger();
 266                 }
 267                 $this->setLogger( $logger );
 268
 269                 if ( !$config ) {
 270                         $this->logger->debug( __METHOD__ . ' was called without providing a Config instance' );
 271                         $config = ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
 272                 }
 273                 $this->config = $config;
 274
 275                 // Add 'local' source first
 276                 $this->addSource( 'local', wfScript( 'load' ) );
 277
 278                 // Add other sources
 279                 $this->addSource( $config->get( 'ResourceLoaderSources' ) );
 280
 281                 // Register core modules
 282                 $this->register( include "$IP/resources/Resources.php" );
 283                 $this->register( include "$IP/resources/ResourcesOOUI.php" );
 284                 // Register extension modules
 285                 Hooks::run( 'ResourceLoaderRegisterModules', array( &$this ) );
 286                 $this->register( $config->get( 'ResourceModules' ) );
 287
 288                 if ( $config->get( 'EnableJavaScriptTest' ) === true ) {
 289                         $this->registerTestModules();
 290                 }
 291
 292                 $this->setMessageBlobStore( new MessageBlobStore() );
 293         }
 294
 295         /**
 296          * @return Config
 297          */
 298         public function getConfig() {
 299                 return $this->config;
 300         }
 301
 302         public function setLogger( LoggerInterface $logger ) {
 303                 $this->logger = $logger;
 304         }
 305
 306         /**
 307          * @since 1.26
 308          * @return MessageBlobStore
 309          */
 310         public function getMessageBlobStore() {
 311                 return $this->blobStore;
 312         }
 313
 314         /**
 315          * @since 1.25
 316          * @param MessageBlobStore $blobStore
 317          */
 318         public function setMessageBlobStore( MessageBlobStore $blobStore ) {
 319                 $this->blobStore = $blobStore;
 320         }
 321
 322         /**
 323          * Register a module with the ResourceLoader system.
 324          *
 325          * @param mixed $name Name of module as a string or List of name/object pairs as an array
 326          * @param array $info Module info array. For backwards compatibility with 1.17alpha,
 327          *   this may also be a ResourceLoaderModule object. Optional when using
 328          *   multiple-registration calling style.
 329          * @throws MWException If a duplicate module registration is attempted
 330          * @throws MWException If a module name contains illegal characters (pipes or commas)
 331          * @throws MWException If something other than a ResourceLoaderModule is being registered
 332          * @return bool False if there were any errors, in which case one or more modules were
 333          *   not registered
 334          */
 335         public function register( $name, $info = null ) {
 336
 337                 // Allow multiple modules to be registered in one call
 338                 $registrations = is_array( $name ) ? $name : array( $name => $info );
 339                 foreach ( $registrations as $name => $info ) {
 340                         // Disallow duplicate registrations
 341                         if ( isset( $this->moduleInfos[$name] ) ) {
 342                                 // A module has already been registered by this name
 343                                 throw new MWException(
 344                                         'ResourceLoader duplicate registration error. ' .
 345                                         'Another module has already been registered as ' . $name
 346                                 );
 347                         }
 348
 349                         // Check $name for validity
 350                         if ( !self::isValidModuleName( $name ) ) {
 351                                 throw new MWException( "ResourceLoader module name '$name' is invalid, "
 352                                         . "see ResourceLoader::isValidModuleName()" );
 353                         }
 354
 355                         // Attach module
 356                         if ( $info instanceof ResourceLoaderModule ) {
 357                                 $this->moduleInfos[$name] = array( 'object' => $info );
 358                                 $info->setName( $name );
 359                                 $this->modules[$name] = $info;
 360                         } elseif ( is_array( $info ) ) {
 361                                 // New calling convention
 362                                 $this->moduleInfos[$name] = $info;
 363                         } else {
 364                                 throw new MWException(
 365                                         'ResourceLoader module info type error for module \'' . $name .
 366                                         '\': expected ResourceLoaderModule or array (got: ' . gettype( $info ) . ')'
 367                                 );
 368                         }
 369
 370                         // Last-minute changes
 371
 372                         // Apply custom skin-defined styles to existing modules.
 373                         if ( $this->isFileModule( $name ) ) {
 374                                 foreach ( $this->config->get( 'ResourceModuleSkinStyles' ) as $skinName => $skinStyles ) {
 375                                         // If this module already defines skinStyles for this skin, ignore $wgResourceModuleSkinStyles.
 376                                         if ( isset( $this->moduleInfos[$name]['skinStyles'][$skinName] ) ) {
 377                                                 continue;
 378                                         }
 379
 380                                         // If $name is preceded with a '+', the defined style files will be added to 'default'
 381                                         // skinStyles, otherwise 'default' will be ignored as it normally would be.
 382                                         if ( isset( $skinStyles[$name] ) ) {
 383                                                 $paths = (array)$skinStyles[$name];
 384                                                 $styleFiles = array();
 385                                         } elseif ( isset( $skinStyles['+' . $name] ) ) {
 386                                                 $paths = (array)$skinStyles['+' . $name];
 387                                                 $styleFiles = isset( $this->moduleInfos[$name]['skinStyles']['default'] ) ?
 388                                                         (array)$this->moduleInfos[$name]['skinStyles']['default'] :
 389                                                         array();
 390                                         } else {
 391                                                 continue;
 392                                         }
 393
 394                                         // Add new file paths, remapping them to refer to our directories and not use settings
 395                                         // from the module we're modifying, which come from the base definition.
 396                                         list( $localBasePath, $remoteBasePath ) =
 397                                                 ResourceLoaderFileModule::extractBasePaths( $skinStyles );
 398
 399                                         foreach ( $paths as $path ) {
 400                                                 $styleFiles[] = new ResourceLoaderFilePath( $path, $localBasePath, $remoteBasePath );
 401                                         }
 402
 403                                         $this->moduleInfos[$name]['skinStyles'][$skinName] = $styleFiles;
 404                                 }
 405                         }
 406                 }
 407
 408         }
 409
 410         /**
 411          */
 412         public function registerTestModules() {
 413                 global $IP;
 414
 415                 if ( $this->config->get( 'EnableJavaScriptTest' ) !== true ) {
 416                         throw new MWException( 'Attempt to register JavaScript test modules '
 417                                 . 'but <code>$wgEnableJavaScriptTest</code> is false. '
 418                                 . 'Edit your <code>LocalSettings.php</code> to enable it.' );
 419                 }
 420
 421                 // Get core test suites
 422                 $testModules = array();
 423                 $testModules['qunit'] = array();
 424                 // Get other test suites (e.g. from extensions)
 425                 Hooks::run( 'ResourceLoaderTestModules', array( &$testModules, &$this ) );
 426
 427                 // Add the testrunner (which configures QUnit) to the dependencies.
 428                 // Since it must be ready before any of the test suites are executed.
 429                 foreach ( $testModules['qunit'] as &$module ) {
 430                         // Make sure all test modules are top-loading so that when QUnit starts
 431                         // on document-ready, it will run once and finish. If some tests arrive
 432                         // later (possibly after QUnit has already finished) they will be ignored.
 433                         $module['position'] = 'top';
 434                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 435                 }
 436
 437                 $testModules['qunit'] =
 438                         ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules['qunit'];
 439
 440                 foreach ( $testModules as $id => $names ) {
 441                         // Register test modules
 442                         $this->register( $testModules[$id] );
 443
 444                         // Keep track of their names so that they can be loaded together
 445                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 446                 }
 447
 448         }
 449
 450         /**
 451          * Add a foreign source of modules.
 452          *
 453          * @param array|string $id Source ID (string), or array( id1 => loadUrl, id2 => loadUrl, ... )
 454          * @param string|array $loadUrl load.php url (string), or array with loadUrl key for
 455          *  backwards-compatibility.
 456          * @throws MWException
 457          */
 458         public function addSource( $id, $loadUrl = null ) {
 459                 // Allow multiple sources to be registered in one call
 460                 if ( is_array( $id ) ) {
 461                         foreach ( $id as $key => $value ) {
 462                                 $this->addSource( $key, $value );
 463                         }
 464                         return;
 465                 }
 466
 467                 // Disallow duplicates
 468                 if ( isset( $this->sources[$id] ) ) {
 469                         throw new MWException(
 470                                 'ResourceLoader duplicate source addition error. ' .
 471                                 'Another source has already been registered as ' . $id
 472                         );
 473                 }
 474
 475                 // Pre 1.24 backwards-compatibility
 476                 if ( is_array( $loadUrl ) ) {
 477                         if ( !isset( $loadUrl['loadScript'] ) ) {
 478                                 throw new MWException(
 479                                         __METHOD__ . ' was passed an array with no "loadScript" key.'
 480                                 );
 481                         }
 482
 483                         $loadUrl = $loadUrl['loadScript'];
 484                 }
 485
 486                 $this->sources[$id] = $loadUrl;
 487         }
 488
 489         /**
 490          * Get a list of module names.
 491          *
 492          * @return array List of module names
 493          */
 494         public function getModuleNames() {
 495                 return array_keys( $this->moduleInfos );
 496         }
 497
 498         /**
 499          * Get a list of test module names for one (or all) frameworks.
 500          *
 501          * If the given framework id is unknkown, or if the in-object variable is not an array,
 502          * then it will return an empty array.
 503          *
 504          * @param string $framework Get only the test module names for one
 505          *   particular framework (optional)
 506          * @return array
 507          */
 508         public function getTestModuleNames( $framework = 'all' ) {
 509                 /** @todo api siteinfo prop testmodulenames modulenames */
 510                 if ( $framework == 'all' ) {
 511                         return $this->testModuleNames;
 512                 } elseif ( isset( $this->testModuleNames[$framework] )
 513                         && is_array( $this->testModuleNames[$framework] )
 514                 ) {
 515                         return $this->testModuleNames[$framework];
 516                 } else {
 517                         return array();
 518                 }
 519         }
 520
 521         /**
 522          * Check whether a ResourceLoader module is registered
 523          *
 524          * @since 1.25
 525          * @param string $name
 526          * @return bool
 527          */
 528         public function isModuleRegistered( $name ) {
 529                 return isset( $this->moduleInfos[$name] );
 530         }
 531
 532         /**
 533          * Get the ResourceLoaderModule object for a given module name.
 534          *
 535          * If an array of module parameters exists but a ResourceLoaderModule object has not
 536          * yet been instantiated, this method will instantiate and cache that object such that
 537          * subsequent calls simply return the same object.
 538          *
 539          * @param string $name Module name
 540          * @return ResourceLoaderModule|null If module has been registered, return a
 541          *  ResourceLoaderModule instance. Otherwise, return null.
 542          */
 543         public function getModule( $name ) {
 544                 if ( !isset( $this->modules[$name] ) ) {
 545                         if ( !isset( $this->moduleInfos[$name] ) ) {
 546                                 // No such module
 547                                 return null;
 548                         }
 549                         // Construct the requested object
 550                         $info = $this->moduleInfos[$name];
 551                         /** @var ResourceLoaderModule $object */
 552                         if ( isset( $info['object'] ) ) {
 553                                 // Object given in info array
 554                                 $object = $info['object'];
 555                         } else {
 556                                 if ( !isset( $info['class'] ) ) {
 557                                         $class = 'ResourceLoaderFileModule';
 558                                 } else {
 559                                         $class = $info['class'];
 560                                 }
 561                                 /** @var ResourceLoaderModule $object */
 562                                 $object = new $class( $info );
 563                                 $object->setConfig( $this->getConfig() );
 564                         }
 565                         $object->setName( $name );
 566                         $this->modules[$name] = $object;
 567                 }
 568
 569                 return $this->modules[$name];
 570         }
 571
 572         /**
 573          * Return whether the definition of a module corresponds to a simple ResourceLoaderFileModule.
 574          *
 575          * @param string $name Module name
 576          * @return bool
 577          */
 578         protected function isFileModule( $name ) {
 579                 if ( !isset( $this->moduleInfos[$name] ) ) {
 580                         return false;
 581                 }
 582                 $info = $this->moduleInfos[$name];
 583                 if ( isset( $info['object'] ) || isset( $info['class'] ) ) {
 584                         return false;
 585                 }
 586                 return true;
 587         }
 588
 589         /**
 590          * Get the list of sources.
 591          *
 592          * @return array Like array( id => load.php url, .. )
 593          */
 594         public function getSources() {
 595                 return $this->sources;
 596         }
 597
 598         /**
 599          * Get the URL to the load.php endpoint for the given
 600          * ResourceLoader source
 601          *
 602          * @since 1.24
 603          * @param string $source
 604          * @throws MWException On an invalid $source name
 605          * @return string
 606          */
 607         public function getLoadScript( $source ) {
 608                 if ( !isset( $this->sources[$source] ) ) {
 609                         throw new MWException( "The $source source was never registered in ResourceLoader." );
 610                 }
 611                 return $this->sources[$source];
 612         }
 613
 614         /**
 615          * @since 1.26
 616          * @param string $value
 617          * @return string Hash
 618          */
 619         public static function makeHash( $value ) {
 620                 // Use base64 to output more entropy in a more compact string (default hex is only base16).
 621                 // The first 8 chars of a base64 encoded digest represent the same binary as
 622                 // the first 12 chars of a hex encoded digest.
 623                 return substr( base64_encode( sha1( $value, true ) ), 0, 8 );
 624         }
 625
 626         /**
 627          * Helper method to get and combine versions of multiple modules.
 628          *
 629          * @since 1.26
 630          * @param ResourceLoaderContext $context
 631          * @param array $modules List of ResourceLoaderModule objects
 632          * @return string Hash
 633          */
 634         public function getCombinedVersion( ResourceLoaderContext $context, Array $modules ) {
 635                 if ( !$modules ) {
 636                         return '';
 637                 }
 638                 // Support: PHP 5.3 ("$this" for anonymous functions was added in PHP 5.4.0)
 639                 // http://php.net/functions.anonymous
 640                 $rl = $this;
 641                 $hashes = array_map( function ( $module ) use ( $rl, $context ) {
 642                         return $rl->getModule( $module )->getVersionHash( $context );
 643                 }, $modules );
 644                 return self::makeHash( implode( $hashes ) );
 645         }
 646
 647         /**
 648          * Output a response to a load request, including the content-type header.
 649          *
 650          * @param ResourceLoaderContext $context Context in which a response should be formed
 651          */
 652         public function respond( ResourceLoaderContext $context ) {
 653                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 654                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 655                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 656                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 657                 // the whole thing in our own output buffer to be sure the active buffer
 658                 // doesn't use ob_gzhandler.
 659                 // See http://bugs.php.net/bug.php?id=36514
 660                 ob_start();
 661
 662                 // Find out which modules are missing and instantiate the others
 663                 $modules = array();
 664                 $missing = array();
 665                 foreach ( $context->getModules() as $name ) {
 666                         $module = $this->getModule( $name );
 667                         if ( $module ) {
 668                                 // Do not allow private modules to be loaded from the web.
 669                                 // This is a security issue, see bug 34907.
 670                                 if ( $module->getGroup() === 'private' ) {
 671                                         $this->logger->debug( "Request for private module '$name' denied" );
 672                                         $this->errors[] = "Cannot show private module \"$name\"";
 673                                         continue;
 674                                 }
 675                                 $modules[$name] = $module;
 676                         } else {
 677                                 $missing[] = $name;
 678                         }
 679                 }
 680
 681                 try {
 682                         // Preload for getCombinedVersion()
 683                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 684                 } catch ( Exception $e ) {
 685                         MWExceptionHandler::logException( $e );
 686                         $this->logger->warning( 'Preloading module info failed: {exception}', array(
 687                                 'exception' => $e
 688                         ) );
 689                         $this->errors[] = self::formatExceptionNoComment( $e );
 690                 }
 691
 692                 // Combine versions to propagate cache invalidation
 693                 $versionHash = '';
 694                 try {
 695                         $versionHash = $this->getCombinedVersion( $context, array_keys( $modules ) );
 696                 } catch ( Exception $e ) {
 697                         MWExceptionHandler::logException( $e );
 698                         $this->logger->warning( 'Calculating version hash failed: {exception}', array(
 699                                 'exception' => $e
 700                         ) );
 701                         $this->errors[] = self::formatExceptionNoComment( $e );
 702                 }
 703
 704                 // See RFC 2616 § 3.11 Entity Tags
 705                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.11
 706                 $etag = 'W/"' . $versionHash . '"';
 707
 708                 // Try the client-side cache first
 709                 if ( $this->tryRespondNotModified( $context, $etag ) ) {
 710                         return; // output handled (buffers cleared)
 711                 }
 712
 713                 // Use file cache if enabled and available...
 714                 if ( $this->config->get( 'UseFileCache' ) ) {
 715                         $fileCache = ResourceFileCache::newFromContext( $context );
 716                         if ( $this->tryRespondFromFileCache( $fileCache, $context, $etag ) ) {
 717                                 return; // output handled
 718                         }
 719                 }
 720
 721                 // Generate a response
 722                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 723
 724                 // Capture any PHP warnings from the output buffer and append them to the
 725                 // error list if we're in debug mode.
 726                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 727                         $this->errors[] = $warnings;
 728                 }
 729
 730                 // Save response to file cache unless there are errors
 731                 if ( isset( $fileCache ) && !$this->errors && !count( $missing ) ) {
 732                         // Cache single modules and images...and other requests if there are enough hits
 733                         if ( ResourceFileCache::useFileCache( $context ) ) {
 734                                 if ( $fileCache->isCacheWorthy() ) {
 735                                         $fileCache->saveText( $response );
 736                                 } else {
 737                                         $fileCache->incrMissesRecent( $context->getRequest() );
 738                                 }
 739                         }
 740                 }
 741
 742                 $this->sendResponseHeaders( $context, $etag, (bool)$this->errors );
 743
 744                 // Remove the output buffer and output the response
 745                 ob_end_clean();
 746
 747                 if ( $context->getImageObj() && $this->errors ) {
 748                         // We can't show both the error messages and the response when it's an image.
 749                         $errorText = '';
 750                         foreach ( $this->errors as $error ) {
 751                                 $errorText .= $error . "\n";
 752                         }
 753                         $response = $errorText;
 754                 } elseif ( $this->errors ) {
 755                         // Prepend comments indicating errors
 756                         $errorText = '';
 757                         foreach ( $this->errors as $error ) {
 758                                 $errorText .= self::makeComment( $error );
 759                         }
 760                         $response = $errorText . $response;
 761                 }
 762
 763                 $this->errors = array();
 764                 echo $response;
 765
 766         }
 767
 768         /**
 769          * Send main response headers to the client.
 770          *
 771          * Deals with Content-Type, CORS (for stylesheets), and caching.
 772          *
 773          * @param ResourceLoaderContext $context
 774          * @param string $etag ETag header value
 775          * @param bool $errors Whether there are errors in the response
 776          * @return void
 777          */
 778         protected function sendResponseHeaders( ResourceLoaderContext $context, $etag, $errors ) {
 779                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 780                 // If a version wasn't specified we need a shorter expiry time for updates
 781                 // to propagate to clients quickly
 782                 // If there were errors, we also need a shorter expiry time so we can recover quickly
 783                 if ( is_null( $context->getVersion() ) || $errors ) {
 784                         $maxage = $rlMaxage['unversioned']['client'];
 785                         $smaxage = $rlMaxage['unversioned']['server'];
 786                 // If a version was specified we can use a longer expiry time since changing
 787                 // version numbers causes cache misses
 788                 } else {
 789                         $maxage = $rlMaxage['versioned']['client'];
 790                         $smaxage = $rlMaxage['versioned']['server'];
 791                 }
 792                 if ( $context->getImageObj() ) {
 793                         // Output different headers if we're outputting textual errors.
 794                         if ( $errors ) {
 795                                 header( 'Content-Type: text/plain; charset=utf-8' );
 796                         } else {
 797                                 $context->getImageObj()->sendResponseHeaders( $context );
 798                         }
 799                 } elseif ( $context->getOnly() === 'styles' ) {
 800                         header( 'Content-Type: text/css; charset=utf-8' );
 801                         header( 'Access-Control-Allow-Origin: *' );
 802                 } else {
 803                         header( 'Content-Type: text/javascript; charset=utf-8' );
 804                 }
 805                 // See RFC 2616 § 14.19 ETag
 806                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.19
 807                 header( 'ETag: ' . $etag );
 808                 if ( $context->getDebug() ) {
 809                         // Do not cache debug responses
 810                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 811                         header( 'Pragma: no-cache' );
 812                 } else {
 813                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 814                         $exp = min( $maxage, $smaxage );
 815                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 816                 }
 817         }
 818
 819         /**
 820          * Respond with HTTP 304 Not Modified if appropiate.
 821          *
 822          * If there's an If-None-Match header, respond with a 304 appropriately
 823          * and clear out the output buffer. If the client cache is too old then do nothing.
 824          *
 825          * @param ResourceLoaderContext $context
 826          * @param string $etag ETag header value
 827          * @return bool True if HTTP 304 was sent and output handled
 828          */
 829         protected function tryRespondNotModified( ResourceLoaderContext $context, $etag ) {
 830                 // See RFC 2616 § 14.26 If-None-Match
 831                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
 832                 $clientKeys = $context->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST );
 833                 // Never send 304s in debug mode
 834                 if ( $clientKeys !== false && !$context->getDebug() && in_array( $etag, $clientKeys ) ) {
 835                         // There's another bug in ob_gzhandler (see also the comment at
 836                         // the top of this function) that causes it to gzip even empty
 837                         // responses, meaning it's impossible to produce a truly empty
 838                         // response (because the gzip header is always there). This is
 839                         // a problem because 304 responses have to be completely empty
 840                         // per the HTTP spec, and Firefox behaves buggily when they're not.
 841                         // See also http://bugs.php.net/bug.php?id=51579
 842                         // To work around this, we tear down all output buffering before
 843                         // sending the 304.
 844                         wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 845
 846                         HttpStatus::header( 304 );
 847
 848                         $this->sendResponseHeaders( $context, $etag, false );
 849                         return true;
 850                 }
 851                 return false;
 852         }
 853
 854         /**
 855          * Send out code for a response from file cache if possible.
 856          *
 857          * @param ResourceFileCache $fileCache Cache object for this request URL
 858          * @param ResourceLoaderContext $context Context in which to generate a response
 859          * @param string $etag ETag header value
 860          * @return bool If this found a cache file and handled the response
 861          */
 862         protected function tryRespondFromFileCache(
 863                 ResourceFileCache $fileCache,
 864                 ResourceLoaderContext $context,
 865                 $etag
 866         ) {
 867                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 868                 // Buffer output to catch warnings.
 869                 ob_start();
 870                 // Get the maximum age the cache can be
 871                 $maxage = is_null( $context->getVersion() )
 872                         ? $rlMaxage['unversioned']['server']
 873                         : $rlMaxage['versioned']['server'];
 874                 // Minimum timestamp the cache file must have
 875                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 876                 if ( !$good ) {
 877                         try { // RL always hits the DB on file cache miss...
 878                                 wfGetDB( DB_SLAVE );
 879                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 880                                 $good = $fileCache->isCacheGood(); // cache existence check
 881                         }
 882                 }
 883                 if ( $good ) {
 884                         $ts = $fileCache->cacheTimestamp();
 885                         // Send content type and cache headers
 886                         $this->sendResponseHeaders( $context, $etag, false );
 887                         $response = $fileCache->fetchText();
 888                         // Capture any PHP warnings from the output buffer and append them to the
 889                         // response in a comment if we're in debug mode.
 890                         if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 891                                 $response = self::makeComment( $warnings ) . $response;
 892                         }
 893                         // Remove the output buffer and output the response
 894                         ob_end_clean();
 895                         echo $response . "\n/* Cached {$ts} */";
 896                         return true; // cache hit
 897                 }
 898                 // Clear buffer
 899                 ob_end_clean();
 900
 901                 return false; // cache miss
 902         }
 903
 904         /**
 905          * Generate a CSS or JS comment block.
 906          *
 907          * Only use this for public data, not error message details.
 908          *
 909          * @param string $text
 910          * @return string
 911          */
 912         public static function makeComment( $text ) {
 913                 $encText = str_replace( '*/', '* /', $text );
 914                 return "/*\n$encText\n*/\n";
 915         }
 916
 917         /**
 918          * Handle exception display.
 919          *
 920          * @param Exception $e Exception to be shown to the user
 921          * @return string Sanitized text in a CSS/JS comment that can be returned to the user
 922          */
 923         public static function formatException( $e ) {
 924                 return self::makeComment( self::formatExceptionNoComment( $e ) );
 925         }
 926
 927         /**
 928          * Handle exception display.
 929          *
 930          * @since 1.25
 931          * @param Exception $e Exception to be shown to the user
 932          * @return string Sanitized text that can be returned to the user
 933          */
 934         protected static function formatExceptionNoComment( $e ) {
 935                 global $wgShowExceptionDetails;
 936
 937                 if ( $wgShowExceptionDetails ) {
 938                         return $e->__toString();
 939                 } else {
 940                         return wfMessage( 'internalerror' )->text();
 941                 }
 942         }
 943
 944         /**
 945          * Generate code for a response.
 946          *
 947          * @param ResourceLoaderContext $context Context in which to generate a response
 948          * @param array $modules List of module objects keyed by module name
 949          * @param array $missing List of requested module names that are unregistered (optional)
 950          * @return string Response data
 951          */
 952         public function makeModuleResponse( ResourceLoaderContext $context,
 953                 array $modules, array $missing = array()
 954         ) {
 955                 $out = '';
 956                 $states = array();
 957
 958                 if ( !count( $modules ) && !count( $missing ) ) {
 959                         return <<<MESSAGE
 960 /* This file is the Web entry point for MediaWiki's ResourceLoader:
 961    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
 962    no modules were requested. Max made me put this here. */
 963 MESSAGE;
 964                 }
 965
 966                 $image = $context->getImageObj();
 967                 if ( $image ) {
 968                         $data = $image->getImageData( $context );
 969                         if ( $data === false ) {
 970                                 $data = '';
 971                                 $this->errors[] = 'Image generation failed';
 972                         }
 973                         return $data;
 974                 }
 975
 976                 // Pre-fetch blobs
 977                 if ( $context->shouldIncludeMessages() ) {
 978                         try {
 979                                 $this->blobStore->get( $this, $modules, $context->getLanguage() );
 980                         } catch ( Exception $e ) {
 981                                 MWExceptionHandler::logException( $e );
 982                                 $this->logger->warning( 'Prefetching MessageBlobStore failed: {exception}', array(
 983                                         'exception' => $e
 984                                 ) );
 985                                 $this->errors[] = self::formatExceptionNoComment( $e );
 986                         }
 987                 }
 988
 989                 foreach ( $missing as $name ) {
 990                         $states[$name] = 'missing';
 991                 }
 992
 993                 // Generate output
 994                 $isRaw = false;
 995                 foreach ( $modules as $name => $module ) {
 996                         try {
 997                                 $content = $module->getModuleContent( $context );
 998
 999                                 // Append output
1000                                 switch ( $context->getOnly() ) {
1001                                         case 'scripts':
1002                                                 $scripts = $content['scripts'];
1003                                                 if ( is_string( $scripts ) ) {
1004                                                         // Load scripts raw...
1005                                                         $out .= $scripts;
1006                                                 } elseif ( is_array( $scripts ) ) {
1007                                                         // ...except when $scripts is an array of URLs
1008                                                         $out .= self::makeLoaderImplementScript( $name, $scripts, array(), array() );
1009                                                 }
1010                                                 break;
1011                                         case 'styles':
1012                                                 $styles = $content['styles'];
1013                                                 // We no longer seperate into media, they are all combined now with
1014                                                 // custom media type groups into @media .. {} sections as part of the css string.
1015                                                 // Module returns either an empty array or a numerical array with css strings.
1016                                                 $out .= isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
1017                                                 break;
1018                                         default:
1019                                                 $out .= self::makeLoaderImplementScript(
1020                                                         $name,
1021                                                         isset( $content['scripts'] ) ? $content['scripts'] : '',
1022                                                         isset( $content['styles'] ) ? $content['styles'] : array(),
1023                                                         isset( $content['messagesBlob'] ) ? new XmlJsCode( $content['messagesBlob'] ) : array(),
1024                                                         isset( $content['templates'] ) ? $content['templates'] : array()
1025                                                 );
1026                                                 break;
1027                                 }
1028                         } catch ( Exception $e ) {
1029                                 MWExceptionHandler::logException( $e );
1030                                 $this->logger->warning( 'Generating module package failed: {exception}', array(
1031                                         'exception' => $e
1032                                 ) );
1033                                 $this->errors[] = self::formatExceptionNoComment( $e );
1034
1035                                 // Respond to client with error-state instead of module implementation
1036                                 $states[$name] = 'error';
1037                                 unset( $modules[$name] );
1038                         }
1039                         $isRaw |= $module->isRaw();
1040                 }
1041
1042                 // Update module states
1043                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
1044                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
1045                                 // Set the state of modules loaded as only scripts to ready as
1046                                 // they don't have an mw.loader.implement wrapper that sets the state
1047                                 foreach ( $modules as $name => $module ) {
1048                                         $states[$name] = 'ready';
1049                                 }
1050                         }
1051
1052                         // Set the state of modules we didn't respond to with mw.loader.implement
1053                         if ( count( $states ) ) {
1054                                 $out .= self::makeLoaderStateScript( $states );
1055                         }
1056                 } else {
1057                         if ( count( $states ) ) {
1058                                 $this->errors[] = 'Problematic modules: ' .
1059                                         FormatJson::encode( $states, ResourceLoader::inDebugMode() );
1060                         }
1061                 }
1062
1063                 $enableFilterCache = true;
1064                 if ( count( $modules ) === 1 && reset( $modules ) instanceof ResourceLoaderUserTokensModule ) {
1065                         // If we're building the embedded user.tokens, don't cache (T84960)
1066                         $enableFilterCache = false;
1067                 }
1068
1069                 if ( !$context->getDebug() ) {
1070                         if ( $context->getOnly() === 'styles' ) {
1071                                 $out = $this->filter( 'minify-css', $out );
1072                         } else {
1073                                 $out = $this->filter( 'minify-js', $out, array(
1074                                         'cache' => $enableFilterCache
1075                                 ) );
1076                         }
1077                 }
1078
1079                 return $out;
1080         }
1081
1082         /* Static Methods */
1083
1084         /**
1085          * Return JS code that calls mw.loader.implement with given module properties.
1086          *
1087          * @param string $name Module name
1088          * @param mixed $scripts List of URLs to JavaScript files or String of JavaScript code
1089          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1090          *   to CSS files keyed by media type
1091          * @param mixed $messages List of messages associated with this module. May either be an
1092          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1093          *   the same data, wrapped in an XmlJsCode object.
1094          * @param array $templates Keys are name of templates and values are the source of
1095          *   the template.
1096          * @throws MWException
1097          * @return string
1098          */
1099         public static function makeLoaderImplementScript(
1100                 $name, $scripts, $styles, $messages, $templates
1101         ) {
1102                 if ( is_string( $scripts ) ) {
1103                         $scripts = new XmlJsCode( "function ( $, jQuery ) {\n{$scripts}\n}" );
1104                 } elseif ( !is_array( $scripts ) ) {
1105                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1106                 }
1107                 // mw.loader.implement requires 'styles', 'messages' and 'templates' to be objects (not
1108                 // arrays). json_encode considers empty arrays to be numerical and outputs "[]" instead
1109                 // of "{}". Force them to objects.
1110                 $module = array(
1111                         $name,
1112                         $scripts,
1113                         (object)$styles,
1114                         (object)$messages,
1115                         (object)$templates,
1116                 );
1117                 self::trimArray( $module );
1118
1119                 return Xml::encodeJsCall( 'mw.loader.implement', $module, ResourceLoader::inDebugMode() );
1120         }
1121
1122         /**
1123          * Returns JS code which, when called, will register a given list of messages.
1124          *
1125          * @param mixed $messages Either an associative array mapping message key to value, or a
1126          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1127          * @return string
1128          */
1129         public static function makeMessageSetScript( $messages ) {
1130                 return Xml::encodeJsCall(
1131                         'mw.messages.set',
1132                         array( (object)$messages ),
1133                         ResourceLoader::inDebugMode()
1134                 );
1135         }
1136
1137         /**
1138          * Combines an associative array mapping media type to CSS into a
1139          * single stylesheet with "@media" blocks.
1140          *
1141          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1142          * @return array
1143          */
1144         public static function makeCombinedStyles( array $stylePairs ) {
1145                 $out = array();
1146                 foreach ( $stylePairs as $media => $styles ) {
1147                         // ResourceLoaderFileModule::getStyle can return the styles
1148                         // as a string or an array of strings. This is to allow separation in
1149                         // the front-end.
1150                         $styles = (array)$styles;
1151                         foreach ( $styles as $style ) {
1152                                 $style = trim( $style );
1153                                 // Don't output an empty "@media print { }" block (bug 40498)
1154                                 if ( $style !== '' ) {
1155                                         // Transform the media type based on request params and config
1156                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1157                                         $media = OutputPage::transformCssMedia( $media );
1158
1159                                         if ( $media === '' || $media == 'all' ) {
1160                                                 $out[] = $style;
1161                                         } elseif ( is_string( $media ) ) {
1162                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1163                                         }
1164                                         // else: skip
1165                                 }
1166                         }
1167                 }
1168                 return $out;
1169         }
1170
1171         /**
1172          * Returns a JS call to mw.loader.state, which sets the state of a
1173          * module or modules to a given value. Has two calling conventions:
1174          *
1175          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1176          *         Set the state of a single module called $name to $state
1177          *
1178          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
1179          *         Set the state of modules with the given names to the given states
1180          *
1181          * @param string $name
1182          * @param string $state
1183          * @return string
1184          */
1185         public static function makeLoaderStateScript( $name, $state = null ) {
1186                 if ( is_array( $name ) ) {
1187                         return Xml::encodeJsCall(
1188                                 'mw.loader.state',
1189                                 array( $name ),
1190                                 ResourceLoader::inDebugMode()
1191                         );
1192                 } else {
1193                         return Xml::encodeJsCall(
1194                                 'mw.loader.state',
1195                                 array( $name, $state ),
1196                                 ResourceLoader::inDebugMode()
1197                         );
1198                 }
1199         }
1200
1201         /**
1202          * Returns JS code which calls the script given by $script. The script will
1203          * be called with local variables name, version, dependencies and group,
1204          * which will have values corresponding to $name, $version, $dependencies
1205          * and $group as supplied.
1206          *
1207          * @param string $name Module name
1208          * @param string $version Module version hash
1209          * @param array $dependencies List of module names on which this module depends
1210          * @param string $group Group which the module is in.
1211          * @param string $source Source of the module, or 'local' if not foreign.
1212          * @param string $script JavaScript code
1213          * @return string
1214          */
1215         public static function makeCustomLoaderScript( $name, $version, $dependencies,
1216                 $group, $source, $script
1217         ) {
1218                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1219                 return Xml::encodeJsCall(
1220                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1221                         array( $name, $version, $dependencies, $group, $source ),
1222                         ResourceLoader::inDebugMode()
1223                 );
1224         }
1225
1226         private static function isEmptyObject( stdClass $obj ) {
1227                 foreach ( $obj as $key => &$value ) {
1228                         return false;
1229                 }
1230                 return true;
1231         }
1232
1233         /**
1234          * Remove empty values from the end of an array.
1235          *
1236          * Values considered empty:
1237          *
1238          * - null
1239          * - array()
1240          * - new XmlJsCode( '{}' )
1241          * - new stdClass() // (object) array()
1242          *
1243          * @param Array $array
1244          */
1245         private static function trimArray( Array &$array ) {
1246                 $i = count( $array );
1247                 while ( $i-- ) {
1248                         if ( $array[$i] === null
1249                                 || $array[$i] === array()
1250                                 || ( $array[$i] instanceof XmlJsCode && $array[$i]->value === '{}' )
1251                                 || ( $array[$i] instanceof stdClass && self::isEmptyObject( $array[$i] ) )
1252                         ) {
1253                                 unset( $array[$i] );
1254                         } else {
1255                                 break;
1256                         }
1257                 }
1258         }
1259
1260         /**
1261          * Returns JS code which calls mw.loader.register with the given
1262          * parameters. Has three calling conventions:
1263          *
1264          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version,
1265          *        $dependencies, $group, $source, $skip
1266          *     ):
1267          *        Register a single module.
1268          *
1269          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
1270          *        Register modules with the given names.
1271          *
1272          *   - ResourceLoader::makeLoaderRegisterScript( array(
1273          *        array( $name1, $version1, $dependencies1, $group1, $source1, $skip1 ),
1274          *        array( $name2, $version2, $dependencies1, $group2, $source2, $skip2 ),
1275          *        ...
1276          *     ) ):
1277          *        Registers modules with the given names and parameters.
1278          *
1279          * @param string $name Module name
1280          * @param string $version Module version hash
1281          * @param array $dependencies List of module names on which this module depends
1282          * @param string $group Group which the module is in
1283          * @param string $source Source of the module, or 'local' if not foreign
1284          * @param string $skip Script body of the skip function
1285          * @return string
1286          */
1287         public static function makeLoaderRegisterScript( $name, $version = null,
1288                 $dependencies = null, $group = null, $source = null, $skip = null
1289         ) {
1290                 if ( is_array( $name ) ) {
1291                         // Build module name index
1292                         $index = array();
1293                         foreach ( $name as $i => &$module ) {
1294                                 $index[$module[0]] = $i;
1295                         }
1296
1297                         // Transform dependency names into indexes when possible, they will be resolved by
1298                         // mw.loader.register on the other end
1299                         foreach ( $name as &$module ) {
1300                                 if ( isset( $module[2] ) ) {
1301                                         foreach ( $module[2] as &$dependency ) {
1302                                                 if ( isset( $index[$dependency] ) ) {
1303                                                         $dependency = $index[$dependency];
1304                                                 }
1305                                         }
1306                                 }
1307                         }
1308
1309                         array_walk( $name, array( 'self', 'trimArray' ) );
1310
1311                         return Xml::encodeJsCall(
1312                                 'mw.loader.register',
1313                                 array( $name ),
1314                                 ResourceLoader::inDebugMode()
1315                         );
1316                 } else {
1317                         $registration = array( $name, $version, $dependencies, $group, $source, $skip );
1318                         self::trimArray( $registration );
1319                         return Xml::encodeJsCall(
1320                                 'mw.loader.register',
1321                                 $registration,
1322                                 ResourceLoader::inDebugMode()
1323                         );
1324                 }
1325         }
1326
1327         /**
1328          * Returns JS code which calls mw.loader.addSource() with the given
1329          * parameters. Has two calling conventions:
1330          *
1331          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1332          *       Register a single source
1333          *
1334          *   - ResourceLoader::makeLoaderSourcesScript( array( $id1 => $loadUrl, $id2 => $loadUrl, ... ) );
1335          *       Register sources with the given IDs and properties.
1336          *
1337          * @param string $id Source ID
1338          * @param array $properties Source properties (see addSource())
1339          * @return string
1340          */
1341         public static function makeLoaderSourcesScript( $id, $properties = null ) {
1342                 if ( is_array( $id ) ) {
1343                         return Xml::encodeJsCall(
1344                                 'mw.loader.addSource',
1345                                 array( $id ),
1346                                 ResourceLoader::inDebugMode()
1347                         );
1348                 } else {
1349                         return Xml::encodeJsCall(
1350                                 'mw.loader.addSource',
1351                                 array( $id, $properties ),
1352                                 ResourceLoader::inDebugMode()
1353                         );
1354                 }
1355         }
1356
1357         /**
1358          * Returns JS code which runs given JS code if the client-side framework is
1359          * present.
1360          *
1361          * @deprecated since 1.25; use makeInlineScript instead
1362          * @param string $script JavaScript code
1363          * @return string
1364          */
1365         public static function makeLoaderConditionalScript( $script ) {
1366                 return "if(window.mw){\n" . trim( $script ) . "\n}";
1367         }
1368
1369         /**
1370          * Construct an inline script tag with given JS code.
1371          *
1372          * The code will be wrapped in a closure, and it will be executed by ResourceLoader
1373          * only if the client has adequate support for MediaWiki JavaScript code.
1374          *
1375          * @param string $script JavaScript code
1376          * @return string HTML
1377          */
1378         public static function makeInlineScript( $script ) {
1379                 $js = self::makeLoaderConditionalScript( $script );
1380                 return Html::inlineScript( $js );
1381         }
1382
1383         /**
1384          * Returns JS code which will set the MediaWiki configuration array to
1385          * the given value.
1386          *
1387          * @param array $configuration List of configuration values keyed by variable name
1388          * @return string
1389          */
1390         public static function makeConfigSetScript( array $configuration ) {
1391                 return Xml::encodeJsCall(
1392                         'mw.config.set',
1393                         array( $configuration ),
1394                         ResourceLoader::inDebugMode()
1395                 );
1396         }
1397
1398         /**
1399          * Convert an array of module names to a packed query string.
1400          *
1401          * For example, array( 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' )
1402          * becomes 'foo.bar,baz|bar.baz,quux'
1403          * @param array $modules List of module names (strings)
1404          * @return string Packed query string
1405          */
1406         public static function makePackedModulesString( $modules ) {
1407                 $groups = array(); // array( prefix => array( suffixes ) )
1408                 foreach ( $modules as $module ) {
1409                         $pos = strrpos( $module, '.' );
1410                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1411                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1412                         $groups[$prefix][] = $suffix;
1413                 }
1414
1415                 $arr = array();
1416                 foreach ( $groups as $prefix => $suffixes ) {
1417                         $p = $prefix === '' ? '' : $prefix . '.';
1418                         $arr[] = $p . implode( ',', $suffixes );
1419                 }
1420                 $str = implode( '|', $arr );
1421                 return $str;
1422         }
1423
1424         /**
1425          * Determine whether debug mode was requested
1426          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1427          * @return bool
1428          */
1429         public static function inDebugMode() {
1430                 if ( self::$debugMode === null ) {
1431                         global $wgRequest, $wgResourceLoaderDebug;
1432                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1433                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1434                         );
1435                 }
1436                 return self::$debugMode;
1437         }
1438
1439         /**
1440          * Reset static members used for caching.
1441          *
1442          * Global state and $wgRequest are evil, but we're using it right
1443          * now and sometimes we need to be able to force ResourceLoader to
1444          * re-evaluate the context because it has changed (e.g. in the test suite).
1445          */
1446         public static function clearCache() {
1447                 self::$debugMode = null;
1448         }
1449
1450         /**
1451          * Build a load.php URL
1452          *
1453          * @since 1.24
1454          * @param string $source Name of the ResourceLoader source
1455          * @param ResourceLoaderContext $context
1456          * @param array $extraQuery
1457          * @return string URL to load.php. May be protocol-relative (if $wgLoadScript is procol-relative)
1458          */
1459         public function createLoaderURL( $source, ResourceLoaderContext $context,
1460                 $extraQuery = array()
1461         ) {
1462                 $query = self::createLoaderQuery( $context, $extraQuery );
1463                 $script = $this->getLoadScript( $source );
1464
1465                 // Prevent the IE6 extension check from being triggered (bug 28840)
1466                 // by appending a character that's invalid in Windows extensions ('*')
1467                 return wfExpandUrl( wfAppendQuery( $script, $query ) . '&*', PROTO_RELATIVE );
1468         }
1469
1470         /**
1471          * Build a load.php URL
1472          * @deprecated since 1.24 Use createLoaderURL() instead
1473          * @param array $modules Array of module names (strings)
1474          * @param string $lang Language code
1475          * @param string $skin Skin name
1476          * @param string|null $user User name. If null, the &user= parameter is omitted
1477          * @param string|null $version Versioning timestamp
1478          * @param bool $debug Whether the request should be in debug mode
1479          * @param string|null $only &only= parameter
1480          * @param bool $printable Printable mode
1481          * @param bool $handheld Handheld mode
1482          * @param array $extraQuery Extra query parameters to add
1483          * @return string URL to load.php. May be protocol-relative (if $wgLoadScript is procol-relative)
1484          */
1485         public static function makeLoaderURL( $modules, $lang, $skin, $user = null,
1486                 $version = null, $debug = false, $only = null, $printable = false,
1487                 $handheld = false, $extraQuery = array()
1488         ) {
1489                 global $wgLoadScript;
1490
1491                 $query = self::makeLoaderQuery( $modules, $lang, $skin, $user, $version, $debug,
1492                         $only, $printable, $handheld, $extraQuery
1493                 );
1494
1495                 // Prevent the IE6 extension check from being triggered (bug 28840)
1496                 // by appending a character that's invalid in Windows extensions ('*')
1497                 return wfExpandUrl( wfAppendQuery( $wgLoadScript, $query ) . '&*', PROTO_RELATIVE );
1498         }
1499
1500         /**
1501          * Helper for createLoaderURL()
1502          *
1503          * @since 1.24
1504          * @see makeLoaderQuery
1505          * @param ResourceLoaderContext $context
1506          * @param array $extraQuery
1507          * @return array
1508          */
1509         public static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = array() ) {
1510                 return self::makeLoaderQuery(
1511                         $context->getModules(),
1512                         $context->getLanguage(),
1513                         $context->getSkin(),
1514                         $context->getUser(),
1515                         $context->getVersion(),
1516                         $context->getDebug(),
1517                         $context->getOnly(),
1518                         $context->getRequest()->getBool( 'printable' ),
1519                         $context->getRequest()->getBool( 'handheld' ),
1520                         $extraQuery
1521                 );
1522         }
1523
1524         /**
1525          * Build a query array (array representation of query string) for load.php. Helper
1526          * function for makeLoaderURL().
1527          *
1528          * @param array $modules
1529          * @param string $lang
1530          * @param string $skin
1531          * @param string $user
1532          * @param string $version
1533          * @param bool $debug
1534          * @param string $only
1535          * @param bool $printable
1536          * @param bool $handheld
1537          * @param array $extraQuery
1538          *
1539          * @return array
1540          */
1541         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1542                 $version = null, $debug = false, $only = null, $printable = false,
1543                 $handheld = false, $extraQuery = array()
1544         ) {
1545                 $query = array(
1546                         'modules' => self::makePackedModulesString( $modules ),
1547                         'lang' => $lang,
1548                         'skin' => $skin,
1549                         'debug' => $debug ? 'true' : 'false',
1550                 );
1551                 if ( $user !== null ) {
1552                         $query['user'] = $user;
1553                 }
1554                 if ( $version !== null ) {
1555                         $query['version'] = $version;
1556                 }
1557                 if ( $only !== null ) {
1558                         $query['only'] = $only;
1559                 }
1560                 if ( $printable ) {
1561                         $query['printable'] = 1;
1562                 }
1563                 if ( $handheld ) {
1564                         $query['handheld'] = 1;
1565                 }
1566                 $query += $extraQuery;
1567
1568                 // Make queries uniform in order
1569                 ksort( $query );
1570                 return $query;
1571         }
1572
1573         /**
1574          * Check a module name for validity.
1575          *
1576          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1577          * at most 255 bytes.
1578          *
1579          * @param string $moduleName Module name to check
1580          * @return bool Whether $moduleName is a valid module name
1581          */
1582         public static function isValidModuleName( $moduleName ) {
1583                 return !preg_match( '/[|,!]/', $moduleName ) && strlen( $moduleName ) <= 255;
1584         }
1585
1586         /**
1587          * Returns LESS compiler set up for use with MediaWiki
1588          *
1589          * @param Config $config
1590          * @throws MWException
1591          * @since 1.22
1592          * @return lessc
1593          */
1594         public static function getLessCompiler( Config $config ) {
1595                 // When called from the installer, it is possible that a required PHP extension
1596                 // is missing (at least for now; see bug 47564). If this is the case, throw an
1597                 // exception (caught by the installer) to prevent a fatal error later on.
1598                 if ( !class_exists( 'lessc' ) ) {
1599                         throw new MWException( 'MediaWiki requires the lessphp compiler' );
1600                 }
1601                 if ( !function_exists( 'ctype_digit' ) ) {
1602                         throw new MWException( 'lessc requires the Ctype extension' );
1603                 }
1604
1605                 $less = new lessc();
1606                 $less->setPreserveComments( true );
1607                 $less->setVariables( self::getLessVars( $config ) );
1608                 $less->setImportDir( $config->get( 'ResourceLoaderLESSImportPaths' ) );
1609                 foreach ( $config->get( 'ResourceLoaderLESSFunctions' ) as $name => $func ) {
1610                         $less->registerFunction( $name, $func );
1611                 }
1612                 return $less;
1613         }
1614
1615         /**
1616          * Get global LESS variables.
1617          *
1618          * @param Config $config
1619          * @since 1.22
1620          * @return array Map of variable names to string CSS values.
1621          */
1622         public static function getLessVars( Config $config ) {
1623                 if ( !self::$lessVars ) {
1624                         $lessVars = $config->get( 'ResourceLoaderLESSVars' );
1625                         Hooks::run( 'ResourceLoaderGetLessVars', array( &$lessVars ) );
1626                         // Sort by key to ensure consistent hashing for cache lookups.
1627                         ksort( $lessVars );
1628                         self::$lessVars = $lessVars;
1629                 }
1630                 return self::$lessVars;
1631         }
1632 }