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