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 use WrappedString\WrappedString;
  29
  30 /**
  31  * Dynamic JavaScript and CSS resource loading system.
  32  *
  33  * Most of the documentation is on the MediaWiki documentation wiki starting at:
  34  *    https://www.mediawiki.org/wiki/ResourceLoader
  35  */
  36 class ResourceLoader implements LoggerAwareInterface {
  37         /** @var int */
  38         protected static $filterCacheVersion = 7;
  39
  40         /** @var bool */
  41         protected static $debugMode = null;
  42
  43         /** @var array */
  44         private static $lessVars = null;
  45
  46         /**
  47          * Module name/ResourceLoaderModule object pairs
  48          * @var array
  49          */
  50         protected $modules = array();
  51
  52         /**
  53          * Associative array mapping module name to info associative array
  54          * @var array
  55          */
  56         protected $moduleInfos = array();
  57
  58         /** @var Config $config */
  59         private $config;
  60
  61         /**
  62          * Associative array mapping framework ids to a list of names of test suite modules
  63          * like array( 'qunit' => array( 'mediawiki.tests.qunit.suites', 'ext.foo.tests', .. ), .. )
  64          * @var array
  65          */
  66         protected $testModuleNames = array();
  67
  68         /**
  69          * E.g. array( 'source-id' => 'http://.../load.php' )
  70          * @var array
  71          */
  72         protected $sources = array();
  73
  74         /**
  75          * Errors accumulated during current respond() call.
  76          * @var array
  77          */
  78         protected $errors = array();
  79
  80         /**
  81          * @var MessageBlobStore
  82          */
  83         protected $blobStore;
  84
  85         /**
  86          * @var LoggerInterface
  87          */
  88         private $logger;
  89
  90         /**
  91          * Load information stored in the database about modules.
  92          *
  93          * This method grabs modules dependencies from the database and updates modules
  94          * objects.
  95          *
  96          * This is not inside the module code because it is much faster to
  97          * request all of the information at once than it is to have each module
  98          * requests its own information. This sacrifice of modularity yields a substantial
  99          * performance improvement.
 100          *
 101          * @param array $modules List of module names to preload information for
 102          * @param ResourceLoaderContext $context Context to load the information within
 103          */
 104         public function preloadModuleInfo( array $modules, ResourceLoaderContext $context ) {
 105                 if ( !count( $modules ) ) {
 106                         // Or else Database*::select() will explode, plus it's cheaper!
 107                         return;
 108                 }
 109                 $dbr = wfGetDB( DB_SLAVE );
 110                 $skin = $context->getSkin();
 111                 $lang = $context->getLanguage();
 112
 113                 // Get file dependency information
 114                 $res = $dbr->select( 'module_deps', array( 'md_module', 'md_deps' ), array(
 115                                 'md_module' => $modules,
 116                                 'md_skin' => $skin
 117                         ), __METHOD__
 118                 );
 119
 120                 // Set modules' dependencies
 121                 $modulesWithDeps = array();
 122                 foreach ( $res as $row ) {
 123                         $module = $this->getModule( $row->md_module );
 124                         if ( $module ) {
 125                                 $module->setFileDependencies( $skin, FormatJson::decode( $row->md_deps, true ) );
 126                                 $modulesWithDeps[] = $row->md_module;
 127                         }
 128                 }
 129
 130                 // Register the absence of a dependency row too
 131                 foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
 132                         $module = $this->getModule( $name );
 133                         if ( $module ) {
 134                                 $this->getModule( $name )->setFileDependencies( $skin, array() );
 135                         }
 136                 }
 137
 138                 // Get message blob mtimes. Only do this for modules with messages
 139                 $modulesWithMessages = array();
 140                 foreach ( $modules as $name ) {
 141                         $module = $this->getModule( $name );
 142                         if ( $module && count( $module->getMessages() ) ) {
 143                                 $modulesWithMessages[] = $name;
 144                         }
 145                 }
 146                 $modulesWithoutMessages = array_flip( $modules ); // Will be trimmed down by the loop below
 147                 if ( count( $modulesWithMessages ) ) {
 148                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
 149                                         'mr_resource' => $modulesWithMessages,
 150                                         'mr_lang' => $lang
 151                                 ), __METHOD__
 152                         );
 153                         foreach ( $res as $row ) {
 154                                 $module = $this->getModule( $row->mr_resource );
 155                                 if ( $module ) {
 156                                         $module->setMsgBlobMtime( $lang, wfTimestamp( TS_UNIX, $row->mr_timestamp ) );
 157                                         unset( $modulesWithoutMessages[$row->mr_resource] );
 158                                 }
 159                         }
 160                 }
 161                 foreach ( array_keys( $modulesWithoutMessages ) as $name ) {
 162                         $module = $this->getModule( $name );
 163                         if ( $module ) {
 164                                 $module->setMsgBlobMtime( $lang, 1 );
 165                         }
 166                 }
 167         }
 168
 169         /**
 170          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 171          *
 172          * Available filters are:
 173          *
 174          *    - minify-js \see JavaScriptMinifier::minify
 175          *    - minify-css \see CSSMin::minify
 176          *
 177          * If $data is empty, only contains whitespace or the filter was unknown,
 178          * $data is returned unmodified.
 179          *
 180          * @param string $filter Name of filter to run
 181          * @param string $data Text to filter, such as JavaScript or CSS text
 182          * @param array $options For back-compat, can also be the boolean value for "cacheReport". Keys:
 183          *  - (bool) cache: Whether to allow caching this data. Default: true.
 184          *  - (bool) cacheReport: Whether to include the "cache key" report comment. Default: false.
 185          * @return string Filtered data, or a comment containing an error message
 186          */
 187         public function filter( $filter, $data, $options = array() ) {
 188                 // Back-compat
 189                 if ( is_bool( $options ) ) {
 190                         $options = array( 'cacheReport' => $options );
 191                 }
 192                 // Defaults
 193                 $options += array( 'cache' => true, 'cacheReport' => false );
 194                 $stats = RequestContext::getMain()->getStats();
 195
 196                 // Don't filter empty content
 197                 if ( trim( $data ) === '' ) {
 198                         return $data;
 199                 }
 200
 201                 if ( !in_array( $filter, array( 'minify-js', 'minify-css' ) ) ) {
 202                         $this->logger->warning( 'Invalid filter {filter}', array(
 203                                 'filter' => $filter
 204                         ) );
 205                         return $data;
 206                 }
 207
 208                 if ( !$options['cache'] ) {
 209                         $result = self::applyFilter( $filter, $data, $this->config );
 210                 } else {
 211                         $key = wfGlobalCacheKey( 'resourceloader', 'filter', $filter, self::$filterCacheVersion, md5( $data ) );
 212                         $cache = wfGetCache( wfIsHHVM() ? CACHE_ACCEL : CACHE_ANYTHING );
 213                         $cacheEntry = $cache->get( $key );
 214                         if ( is_string( $cacheEntry ) ) {
 215                                 $stats->increment( "resourceloader_cache.$filter.hit" );
 216                                 return $cacheEntry;
 217                         }
 218                         $result = '';
 219                         try {
 220                                 $statStart = microtime( true );
 221                                 $result = self::applyFilter( $filter, $data, $this->config );
 222                                 $statTiming = microtime( true ) - $statStart;
 223                                 $stats->increment( "resourceloader_cache.$filter.miss" );
 224                                 $stats->timing( "resourceloader_cache.$filter.timing", 1000 * $statTiming );
 225                                 if ( $options['cacheReport'] ) {
 226                                         $result .= "\n/* cache key: $key */";
 227                                 }
 228                                 // Set a TTL since HHVM's APC doesn't have any limitation or eviction logic.
 229                                 $cache->set( $key, $result, 24 * 3600 );
 230                         } catch ( Exception $e ) {
 231                                 MWExceptionHandler::logException( $e );
 232                                 $this->logger->warning( 'Minification failed: {exception}', array(
 233                                         'exception' => $e
 234                                 ) );
 235                                 $this->errors[] = self::formatExceptionNoComment( $e );
 236                         }
 237                 }
 238
 239                 return $result;
 240         }
 241
 242         private static function applyFilter( $filter, $data, Config $config ) {
 243                 switch ( $filter ) {
 244                         case 'minify-js':
 245                                 return JavaScriptMinifier::minify( $data,
 246                                         $config->get( 'ResourceLoaderMinifierStatementsOnOwnLine' ),
 247                                         $config->get( 'ResourceLoaderMinifierMaxLineLength' )
 248                                 );
 249                         case 'minify-css':
 250                                 return CSSMin::minify( $data );
 251                 }
 252
 253                 return $data;
 254         }
 255
 256         /* Methods */
 257
 258         /**
 259          * Register core modules and runs registration hooks.
 260          * @param Config|null $config
 261          */
 262         public function __construct( Config $config = null, LoggerInterface $logger = null ) {
 263                 global $IP;
 264
 265                 if ( !$logger ) {
 266                         $logger = new NullLogger();
 267                 }
 268                 $this->setLogger( $logger );
 269
 270                 if ( !$config ) {
 271                         $this->logger->debug( __METHOD__ . ' was called without providing a Config instance' );
 272                         $config = ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
 273                 }
 274                 $this->config = $config;
 275
 276                 // Add 'local' source first
 277                 $this->addSource( 'local', wfScript( 'load' ) );
 278
 279                 // Add other sources
 280                 $this->addSource( $config->get( 'ResourceLoaderSources' ) );
 281
 282                 // Register core modules
 283                 $this->register( include "$IP/resources/Resources.php" );
 284                 $this->register( include "$IP/resources/ResourcesOOUI.php" );
 285                 // Register extension modules
 286                 Hooks::run( 'ResourceLoaderRegisterModules', array( &$this ) );
 287                 $this->register( $config->get( 'ResourceModules' ) );
 288
 289                 if ( $config->get( 'EnableJavaScriptTest' ) === true ) {
 290                         $this->registerTestModules();
 291                 }
 292
 293                 $this->setMessageBlobStore( new MessageBlobStore() );
 294         }
 295
 296         /**
 297          * @return Config
 298          */
 299         public function getConfig() {
 300                 return $this->config;
 301         }
 302
 303         public function setLogger( LoggerInterface $logger ) {
 304                 $this->logger = $logger;
 305         }
 306
 307         /**
 308          * @since 1.26
 309          * @return MessageBlobStore
 310          */
 311         public function getMessageBlobStore() {
 312                 return $this->blobStore;
 313         }
 314
 315         /**
 316          * @since 1.25
 317          * @param MessageBlobStore $blobStore
 318          */
 319         public function setMessageBlobStore( MessageBlobStore $blobStore ) {
 320                 $this->blobStore = $blobStore;
 321         }
 322
 323         /**
 324          * Register a module with the ResourceLoader system.
 325          *
 326          * @param mixed $name Name of module as a string or List of name/object pairs as an array
 327          * @param array $info Module info array. For backwards compatibility with 1.17alpha,
 328          *   this may also be a ResourceLoaderModule object. Optional when using
 329          *   multiple-registration calling style.
 330          * @throws MWException If a duplicate module registration is attempted
 331          * @throws MWException If a module name contains illegal characters (pipes or commas)
 332          * @throws MWException If something other than a ResourceLoaderModule is being registered
 333          * @return bool False if there were any errors, in which case one or more modules were
 334          *   not registered
 335          */
 336         public function register( $name, $info = null ) {
 337
 338                 // Allow multiple modules to be registered in one call
 339                 $registrations = is_array( $name ) ? $name : array( $name => $info );
 340                 foreach ( $registrations as $name => $info ) {
 341                         // Disallow duplicate registrations
 342                         if ( isset( $this->moduleInfos[$name] ) ) {
 343                                 // A module has already been registered by this name
 344                                 throw new MWException(
 345                                         'ResourceLoader duplicate registration error. ' .
 346                                         'Another module has already been registered as ' . $name
 347                                 );
 348                         }
 349
 350                         // Check $name for validity
 351                         if ( !self::isValidModuleName( $name ) ) {
 352                                 throw new MWException( "ResourceLoader module name '$name' is invalid, "
 353                                         . "see ResourceLoader::isValidModuleName()" );
 354                         }
 355
 356                         // Attach module
 357                         if ( $info instanceof ResourceLoaderModule ) {
 358                                 $this->moduleInfos[$name] = array( 'object' => $info );
 359                                 $info->setName( $name );
 360                                 $this->modules[$name] = $info;
 361                         } elseif ( is_array( $info ) ) {
 362                                 // New calling convention
 363                                 $this->moduleInfos[$name] = $info;
 364                         } else {
 365                                 throw new MWException(
 366                                         'ResourceLoader module info type error for module \'' . $name .
 367                                         '\': expected ResourceLoaderModule or array (got: ' . gettype( $info ) . ')'
 368                                 );
 369                         }
 370
 371                         // Last-minute changes
 372
 373                         // Apply custom skin-defined styles to existing modules.
 374                         if ( $this->isFileModule( $name ) ) {
 375                                 foreach ( $this->config->get( 'ResourceModuleSkinStyles' ) as $skinName => $skinStyles ) {
 376                                         // If this module already defines skinStyles for this skin, ignore $wgResourceModuleSkinStyles.
 377                                         if ( isset( $this->moduleInfos[$name]['skinStyles'][$skinName] ) ) {
 378                                                 continue;
 379                                         }
 380
 381                                         // If $name is preceded with a '+', the defined style files will be added to 'default'
 382                                         // skinStyles, otherwise 'default' will be ignored as it normally would be.
 383                                         if ( isset( $skinStyles[$name] ) ) {
 384                                                 $paths = (array)$skinStyles[$name];
 385                                                 $styleFiles = array();
 386                                         } elseif ( isset( $skinStyles['+' . $name] ) ) {
 387                                                 $paths = (array)$skinStyles['+' . $name];
 388                                                 $styleFiles = isset( $this->moduleInfos[$name]['skinStyles']['default'] ) ?
 389                                                         (array)$this->moduleInfos[$name]['skinStyles']['default'] :
 390                                                         array();
 391                                         } else {
 392                                                 continue;
 393                                         }
 394
 395                                         // Add new file paths, remapping them to refer to our directories and not use settings
 396                                         // from the module we're modifying, which come from the base definition.
 397                                         list( $localBasePath, $remoteBasePath ) =
 398                                                 ResourceLoaderFileModule::extractBasePaths( $skinStyles );
 399
 400                                         foreach ( $paths as $path ) {
 401                                                 $styleFiles[] = new ResourceLoaderFilePath( $path, $localBasePath, $remoteBasePath );
 402                                         }
 403
 404                                         $this->moduleInfos[$name]['skinStyles'][$skinName] = $styleFiles;
 405                                 }
 406                         }
 407                 }
 408
 409         }
 410
 411         /**
 412          */
 413         public function registerTestModules() {
 414                 global $IP;
 415
 416                 if ( $this->config->get( 'EnableJavaScriptTest' ) !== true ) {
 417                         throw new MWException( 'Attempt to register JavaScript test modules '
 418                                 . 'but <code>$wgEnableJavaScriptTest</code> is false. '
 419                                 . 'Edit your <code>LocalSettings.php</code> to enable it.' );
 420                 }
 421
 422                 // Get core test suites
 423                 $testModules = array();
 424                 $testModules['qunit'] = array();
 425                 // Get other test suites (e.g. from extensions)
 426                 Hooks::run( 'ResourceLoaderTestModules', array( &$testModules, &$this ) );
 427
 428                 // Add the testrunner (which configures QUnit) to the dependencies.
 429                 // Since it must be ready before any of the test suites are executed.
 430                 foreach ( $testModules['qunit'] as &$module ) {
 431                         // Make sure all test modules are top-loading so that when QUnit starts
 432                         // on document-ready, it will run once and finish. If some tests arrive
 433                         // later (possibly after QUnit has already finished) they will be ignored.
 434                         $module['position'] = 'top';
 435                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 436                 }
 437
 438                 $testModules['qunit'] =
 439                         ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules['qunit'];
 440
 441                 foreach ( $testModules as $id => $names ) {
 442                         // Register test modules
 443                         $this->register( $testModules[$id] );
 444
 445                         // Keep track of their names so that they can be loaded together
 446                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 447                 }
 448
 449         }
 450
 451         /**
 452          * Add a foreign source of modules.
 453          *
 454          * @param array|string $id Source ID (string), or array( id1 => loadUrl, id2 => loadUrl, ... )
 455          * @param string|array $loadUrl load.php url (string), or array with loadUrl key for
 456          *  backwards-compatibility.
 457          * @throws MWException
 458          */
 459         public function addSource( $id, $loadUrl = null ) {
 460                 // Allow multiple sources to be registered in one call
 461                 if ( is_array( $id ) ) {
 462                         foreach ( $id as $key => $value ) {
 463                                 $this->addSource( $key, $value );
 464                         }
 465                         return;
 466                 }
 467
 468                 // Disallow duplicates
 469                 if ( isset( $this->sources[$id] ) ) {
 470                         throw new MWException(
 471                                 'ResourceLoader duplicate source addition error. ' .
 472                                 'Another source has already been registered as ' . $id
 473                         );
 474                 }
 475
 476                 // Pre 1.24 backwards-compatibility
 477                 if ( is_array( $loadUrl ) ) {
 478                         if ( !isset( $loadUrl['loadScript'] ) ) {
 479                                 throw new MWException(
 480                                         __METHOD__ . ' was passed an array with no "loadScript" key.'
 481                                 );
 482                         }
 483
 484                         $loadUrl = $loadUrl['loadScript'];
 485                 }
 486
 487                 $this->sources[$id] = $loadUrl;
 488         }
 489
 490         /**
 491          * Get a list of module names.
 492          *
 493          * @return array List of module names
 494          */
 495         public function getModuleNames() {
 496                 return array_keys( $this->moduleInfos );
 497         }
 498
 499         /**
 500          * Get a list of test module names for one (or all) frameworks.
 501          *
 502          * If the given framework id is unknkown, or if the in-object variable is not an array,
 503          * then it will return an empty array.
 504          *
 505          * @param string $framework Get only the test module names for one
 506          *   particular framework (optional)
 507          * @return array
 508          */
 509         public function getTestModuleNames( $framework = 'all' ) {
 510                 /** @todo api siteinfo prop testmodulenames modulenames */
 511                 if ( $framework == 'all' ) {
 512                         return $this->testModuleNames;
 513                 } elseif ( isset( $this->testModuleNames[$framework] )
 514                         && is_array( $this->testModuleNames[$framework] )
 515                 ) {
 516                         return $this->testModuleNames[$framework];
 517                 } else {
 518                         return array();
 519                 }
 520         }
 521
 522         /**
 523          * Check whether a ResourceLoader module is registered
 524          *
 525          * @since 1.25
 526          * @param string $name
 527          * @return bool
 528          */
 529         public function isModuleRegistered( $name ) {
 530                 return isset( $this->moduleInfos[$name] );
 531         }
 532
 533         /**
 534          * Get the ResourceLoaderModule object for a given module name.
 535          *
 536          * If an array of module parameters exists but a ResourceLoaderModule object has not
 537          * yet been instantiated, this method will instantiate and cache that object such that
 538          * subsequent calls simply return the same object.
 539          *
 540          * @param string $name Module name
 541          * @return ResourceLoaderModule|null If module has been registered, return a
 542          *  ResourceLoaderModule instance. Otherwise, return null.
 543          */
 544         public function getModule( $name ) {
 545                 if ( !isset( $this->modules[$name] ) ) {
 546                         if ( !isset( $this->moduleInfos[$name] ) ) {
 547                                 // No such module
 548                                 return null;
 549                         }
 550                         // Construct the requested object
 551                         $info = $this->moduleInfos[$name];
 552                         /** @var ResourceLoaderModule $object */
 553                         if ( isset( $info['object'] ) ) {
 554                                 // Object given in info array
 555                                 $object = $info['object'];
 556                         } else {
 557                                 if ( !isset( $info['class'] ) ) {
 558                                         $class = 'ResourceLoaderFileModule';
 559                                 } else {
 560                                         $class = $info['class'];
 561                                 }
 562                                 /** @var ResourceLoaderModule $object */
 563                                 $object = new $class( $info );
 564                                 $object->setConfig( $this->getConfig() );
 565                         }
 566                         $object->setName( $name );
 567                         $this->modules[$name] = $object;
 568                 }
 569
 570                 return $this->modules[$name];
 571         }
 572
 573         /**
 574          * Return whether the definition of a module corresponds to a simple ResourceLoaderFileModule.
 575          *
 576          * @param string $name Module name
 577          * @return bool
 578          */
 579         protected function isFileModule( $name ) {
 580                 if ( !isset( $this->moduleInfos[$name] ) ) {
 581                         return false;
 582                 }
 583                 $info = $this->moduleInfos[$name];
 584                 if ( isset( $info['object'] ) || isset( $info['class'] ) ) {
 585                         return false;
 586                 }
 587                 return true;
 588         }
 589
 590         /**
 591          * Get the list of sources.
 592          *
 593          * @return array Like array( id => load.php url, .. )
 594          */
 595         public function getSources() {
 596                 return $this->sources;
 597         }
 598
 599         /**
 600          * Get the URL to the load.php endpoint for the given
 601          * ResourceLoader source
 602          *
 603          * @since 1.24
 604          * @param string $source
 605          * @throws MWException On an invalid $source name
 606          * @return string
 607          */
 608         public function getLoadScript( $source ) {
 609                 if ( !isset( $this->sources[$source] ) ) {
 610                         throw new MWException( "The $source source was never registered in ResourceLoader." );
 611                 }
 612                 return $this->sources[$source];
 613         }
 614
 615         /**
 616          * @since 1.26
 617          * @param string $value
 618          * @return string Hash
 619          */
 620         public static function makeHash( $value ) {
 621                 // Use base64 to output more entropy in a more compact string (default hex is only base16).
 622                 // The first 8 chars of a base64 encoded digest represent the same binary as
 623                 // the first 12 chars of a hex encoded digest.
 624                 return substr( base64_encode( sha1( $value, true ) ), 0, 8 );
 625         }
 626
 627         /**
 628          * Helper method to get and combine versions of multiple modules.
 629          *
 630          * @since 1.26
 631          * @param ResourceLoaderContext $context
 632          * @param array $modules List of ResourceLoaderModule objects
 633          * @return string Hash
 634          */
 635         public function getCombinedVersion( ResourceLoaderContext $context, Array $modules ) {
 636                 if ( !$modules ) {
 637                         return '';
 638                 }
 639                 // Support: PHP 5.3 ("$this" for anonymous functions was added in PHP 5.4.0)
 640                 // http://php.net/functions.anonymous
 641                 $rl = $this;
 642                 $hashes = array_map( function ( $module ) use ( $rl, $context ) {
 643                         return $rl->getModule( $module )->getVersionHash( $context );
 644                 }, $modules );
 645                 return self::makeHash( implode( $hashes ) );
 646         }
 647
 648         /**
 649          * Output a response to a load request, including the content-type header.
 650          *
 651          * @param ResourceLoaderContext $context Context in which a response should be formed
 652          */
 653         public function respond( ResourceLoaderContext $context ) {
 654                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 655                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 656                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 657                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 658                 // the whole thing in our own output buffer to be sure the active buffer
 659                 // doesn't use ob_gzhandler.
 660                 // See http://bugs.php.net/bug.php?id=36514
 661                 ob_start();
 662
 663                 // Find out which modules are missing and instantiate the others
 664                 $modules = array();
 665                 $missing = array();
 666                 foreach ( $context->getModules() as $name ) {
 667                         $module = $this->getModule( $name );
 668                         if ( $module ) {
 669                                 // Do not allow private modules to be loaded from the web.
 670                                 // This is a security issue, see bug 34907.
 671                                 if ( $module->getGroup() === 'private' ) {
 672                                         $this->logger->debug( "Request for private module '$name' denied" );
 673                                         $this->errors[] = "Cannot show private module \"$name\"";
 674                                         continue;
 675                                 }
 676                                 $modules[$name] = $module;
 677                         } else {
 678                                 $missing[] = $name;
 679                         }
 680                 }
 681
 682                 try {
 683                         // Preload for getCombinedVersion()
 684                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 685                 } catch ( Exception $e ) {
 686                         MWExceptionHandler::logException( $e );
 687                         $this->logger->warning( 'Preloading module info failed: {exception}', array(
 688                                 'exception' => $e
 689                         ) );
 690                         $this->errors[] = self::formatExceptionNoComment( $e );
 691                 }
 692
 693                 // Combine versions to propagate cache invalidation
 694                 $versionHash = '';
 695                 try {
 696                         $versionHash = $this->getCombinedVersion( $context, array_keys( $modules ) );
 697                 } catch ( Exception $e ) {
 698                         MWExceptionHandler::logException( $e );
 699                         $this->logger->warning( 'Calculating version hash failed: {exception}', array(
 700                                 'exception' => $e
 701                         ) );
 702                         $this->errors[] = self::formatExceptionNoComment( $e );
 703                 }
 704
 705                 // See RFC 2616 § 3.11 Entity Tags
 706                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.11
 707                 $etag = 'W/"' . $versionHash . '"';
 708
 709                 // Try the client-side cache first
 710                 if ( $this->tryRespondNotModified( $context, $etag ) ) {
 711                         return; // output handled (buffers cleared)
 712                 }
 713
 714                 // Use file cache if enabled and available...
 715                 if ( $this->config->get( 'UseFileCache' ) ) {
 716                         $fileCache = ResourceFileCache::newFromContext( $context );
 717                         if ( $this->tryRespondFromFileCache( $fileCache, $context, $etag ) ) {
 718                                 return; // output handled
 719                         }
 720                 }
 721
 722                 // Generate a response
 723                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 724
 725                 // Capture any PHP warnings from the output buffer and append them to the
 726                 // error list if we're in debug mode.
 727                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 728                         $this->errors[] = $warnings;
 729                 }
 730
 731                 // Save response to file cache unless there are errors
 732                 if ( isset( $fileCache ) && !$this->errors && !count( $missing ) ) {
 733                         // Cache single modules and images...and other requests if there are enough hits
 734                         if ( ResourceFileCache::useFileCache( $context ) ) {
 735                                 if ( $fileCache->isCacheWorthy() ) {
 736                                         $fileCache->saveText( $response );
 737                                 } else {
 738                                         $fileCache->incrMissesRecent( $context->getRequest() );
 739                                 }
 740                         }
 741                 }
 742
 743                 $this->sendResponseHeaders( $context, $etag, (bool)$this->errors );
 744
 745                 // Remove the output buffer and output the response
 746                 ob_end_clean();
 747
 748                 if ( $context->getImageObj() && $this->errors ) {
 749                         // We can't show both the error messages and the response when it's an image.
 750                         $errorText = '';
 751                         foreach ( $this->errors as $error ) {
 752                                 $errorText .= $error . "\n";
 753                         }
 754                         $response = $errorText;
 755                 } elseif ( $this->errors ) {
 756                         // Prepend comments indicating errors
 757                         $errorText = '';
 758                         foreach ( $this->errors as $error ) {
 759                                 $errorText .= self::makeComment( $error );
 760                         }
 761                         $response = $errorText . $response;
 762                 }
 763
 764                 $this->errors = array();
 765                 echo $response;
 766
 767         }
 768
 769         /**
 770          * Send main response headers to the client.
 771          *
 772          * Deals with Content-Type, CORS (for stylesheets), and caching.
 773          *
 774          * @param ResourceLoaderContext $context
 775          * @param string $etag ETag header value
 776          * @param bool $errors Whether there are errors in the response
 777          * @return void
 778          */
 779         protected function sendResponseHeaders( ResourceLoaderContext $context, $etag, $errors ) {
 780                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 781                 // If a version wasn't specified we need a shorter expiry time for updates
 782                 // to propagate to clients quickly
 783                 // If there were errors, we also need a shorter expiry time so we can recover quickly
 784                 if ( is_null( $context->getVersion() ) || $errors ) {
 785                         $maxage = $rlMaxage['unversioned']['client'];
 786                         $smaxage = $rlMaxage['unversioned']['server'];
 787                 // If a version was specified we can use a longer expiry time since changing
 788                 // version numbers causes cache misses
 789                 } else {
 790                         $maxage = $rlMaxage['versioned']['client'];
 791                         $smaxage = $rlMaxage['versioned']['server'];
 792                 }
 793                 if ( $context->getImageObj() ) {
 794                         // Output different headers if we're outputting textual errors.
 795                         if ( $errors ) {
 796                                 header( 'Content-Type: text/plain; charset=utf-8' );
 797                         } else {
 798                                 $context->getImageObj()->sendResponseHeaders( $context );
 799                         }
 800                 } elseif ( $context->getOnly() === 'styles' ) {
 801                         header( 'Content-Type: text/css; charset=utf-8' );
 802                         header( 'Access-Control-Allow-Origin: *' );
 803                 } else {
 804                         header( 'Content-Type: text/javascript; charset=utf-8' );
 805                 }
 806                 // See RFC 2616 § 14.19 ETag
 807                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.19
 808                 header( 'ETag: ' . $etag );
 809                 if ( $context->getDebug() ) {
 810                         // Do not cache debug responses
 811                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 812                         header( 'Pragma: no-cache' );
 813                 } else {
 814                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 815                         $exp = min( $maxage, $smaxage );
 816                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 817                 }
 818
 819                 // Send the current time expressed as fractional seconds since epoch,
 820                 // with microsecond precision. This helps distinguish hits from misses
 821                 // in edge caches.
 822                 header( 'MediaWiki-Timestamp: ' . microtime( true ) );
 823         }
 824
 825         /**
 826          * Respond with HTTP 304 Not Modified if appropiate.
 827          *
 828          * If there's an If-None-Match header, respond with a 304 appropriately
 829          * and clear out the output buffer. If the client cache is too old then do nothing.
 830          *
 831          * @param ResourceLoaderContext $context
 832          * @param string $etag ETag header value
 833          * @return bool True if HTTP 304 was sent and output handled
 834          */
 835         protected function tryRespondNotModified( ResourceLoaderContext $context, $etag ) {
 836                 // See RFC 2616 § 14.26 If-None-Match
 837                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
 838                 $clientKeys = $context->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST );
 839                 // Never send 304s in debug mode
 840                 if ( $clientKeys !== false && !$context->getDebug() && in_array( $etag, $clientKeys ) ) {
 841                         // There's another bug in ob_gzhandler (see also the comment at
 842                         // the top of this function) that causes it to gzip even empty
 843                         // responses, meaning it's impossible to produce a truly empty
 844                         // response (because the gzip header is always there). This is
 845                         // a problem because 304 responses have to be completely empty
 846                         // per the HTTP spec, and Firefox behaves buggily when they're not.
 847                         // See also http://bugs.php.net/bug.php?id=51579
 848                         // To work around this, we tear down all output buffering before
 849                         // sending the 304.
 850                         wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 851
 852                         HttpStatus::header( 304 );
 853
 854                         $this->sendResponseHeaders( $context, $etag, false );
 855                         return true;
 856                 }
 857                 return false;
 858         }
 859
 860         /**
 861          * Send out code for a response from file cache if possible.
 862          *
 863          * @param ResourceFileCache $fileCache Cache object for this request URL
 864          * @param ResourceLoaderContext $context Context in which to generate a response
 865          * @param string $etag ETag header value
 866          * @return bool If this found a cache file and handled the response
 867          */
 868         protected function tryRespondFromFileCache(
 869                 ResourceFileCache $fileCache,
 870                 ResourceLoaderContext $context,
 871                 $etag
 872         ) {
 873                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 874                 // Buffer output to catch warnings.
 875                 ob_start();
 876                 // Get the maximum age the cache can be
 877                 $maxage = is_null( $context->getVersion() )
 878                         ? $rlMaxage['unversioned']['server']
 879                         : $rlMaxage['versioned']['server'];
 880                 // Minimum timestamp the cache file must have
 881                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 882                 if ( !$good ) {
 883                         try { // RL always hits the DB on file cache miss...
 884                                 wfGetDB( DB_SLAVE );
 885                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 886                                 $good = $fileCache->isCacheGood(); // cache existence check
 887                         }
 888                 }
 889                 if ( $good ) {
 890                         $ts = $fileCache->cacheTimestamp();
 891                         // Send content type and cache headers
 892                         $this->sendResponseHeaders( $context, $etag, false );
 893                         $response = $fileCache->fetchText();
 894                         // Capture any PHP warnings from the output buffer and append them to the
 895                         // response in a comment if we're in debug mode.
 896                         if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 897                                 $response = self::makeComment( $warnings ) . $response;
 898                         }
 899                         // Remove the output buffer and output the response
 900                         ob_end_clean();
 901                         echo $response . "\n/* Cached {$ts} */";
 902                         return true; // cache hit
 903                 }
 904                 // Clear buffer
 905                 ob_end_clean();
 906
 907                 return false; // cache miss
 908         }
 909
 910         /**
 911          * Generate a CSS or JS comment block.
 912          *
 913          * Only use this for public data, not error message details.
 914          *
 915          * @param string $text
 916          * @return string
 917          */
 918         public static function makeComment( $text ) {
 919                 $encText = str_replace( '*/', '* /', $text );
 920                 return "/*\n$encText\n*/\n";
 921         }
 922
 923         /**
 924          * Handle exception display.
 925          *
 926          * @param Exception $e Exception to be shown to the user
 927          * @return string Sanitized text in a CSS/JS comment that can be returned to the user
 928          */
 929         public static function formatException( $e ) {
 930                 return self::makeComment( self::formatExceptionNoComment( $e ) );
 931         }
 932
 933         /**
 934          * Handle exception display.
 935          *
 936          * @since 1.25
 937          * @param Exception $e Exception to be shown to the user
 938          * @return string Sanitized text that can be returned to the user
 939          */
 940         protected static function formatExceptionNoComment( $e ) {
 941                 global $wgShowExceptionDetails;
 942
 943                 if ( !$wgShowExceptionDetails ) {
 944                         return 'Internal error';
 945                 }
 946
 947                 return $e->__toString();
 948         }
 949
 950         /**
 951          * Generate code for a response.
 952          *
 953          * @param ResourceLoaderContext $context Context in which to generate a response
 954          * @param array $modules List of module objects keyed by module name
 955          * @param array $missing List of requested module names that are unregistered (optional)
 956          * @return string Response data
 957          */
 958         public function makeModuleResponse( ResourceLoaderContext $context,
 959                 array $modules, array $missing = array()
 960         ) {
 961                 $out = '';
 962                 $states = array();
 963
 964                 if ( !count( $modules ) && !count( $missing ) ) {
 965                         return <<<MESSAGE
 966 /* This file is the Web entry point for MediaWiki's ResourceLoader:
 967    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
 968    no modules were requested. Max made me put this here. */
 969 MESSAGE;
 970                 }
 971
 972                 $image = $context->getImageObj();
 973                 if ( $image ) {
 974                         $data = $image->getImageData( $context );
 975                         if ( $data === false ) {
 976                                 $data = '';
 977                                 $this->errors[] = 'Image generation failed';
 978                         }
 979                         return $data;
 980                 }
 981
 982                 // Pre-fetch blobs
 983                 if ( $context->shouldIncludeMessages() ) {
 984                         try {
 985                                 $this->blobStore->get( $this, $modules, $context->getLanguage() );
 986                         } catch ( Exception $e ) {
 987                                 MWExceptionHandler::logException( $e );
 988                                 $this->logger->warning( 'Prefetching MessageBlobStore failed: {exception}', array(
 989                                         'exception' => $e
 990                                 ) );
 991                                 $this->errors[] = self::formatExceptionNoComment( $e );
 992                         }
 993                 }
 994
 995                 foreach ( $missing as $name ) {
 996                         $states[$name] = 'missing';
 997                 }
 998
 999                 // Generate output
1000                 $isRaw = false;
1001                 foreach ( $modules as $name => $module ) {
1002                         try {
1003                                 $content = $module->getModuleContent( $context );
1004
1005                                 // Append output
1006                                 switch ( $context->getOnly() ) {
1007                                         case 'scripts':
1008                                                 $scripts = $content['scripts'];
1009                                                 if ( is_string( $scripts ) ) {
1010                                                         // Load scripts raw...
1011                                                         $out .= $scripts;
1012                                                 } elseif ( is_array( $scripts ) ) {
1013                                                         // ...except when $scripts is an array of URLs
1014                                                         $out .= self::makeLoaderImplementScript( $name, $scripts, array(), array(), array() );
1015                                                 }
1016                                                 break;
1017                                         case 'styles':
1018                                                 $styles = $content['styles'];
1019                                                 // We no longer seperate into media, they are all combined now with
1020                                                 // custom media type groups into @media .. {} sections as part of the css string.
1021                                                 // Module returns either an empty array or a numerical array with css strings.
1022                                                 $out .= isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
1023                                                 break;
1024                                         default:
1025                                                 $out .= self::makeLoaderImplementScript(
1026                                                         $name,
1027                                                         isset( $content['scripts'] ) ? $content['scripts'] : '',
1028                                                         isset( $content['styles'] ) ? $content['styles'] : array(),
1029                                                         isset( $content['messagesBlob'] ) ? new XmlJsCode( $content['messagesBlob'] ) : array(),
1030                                                         isset( $content['templates'] ) ? $content['templates'] : array()
1031                                                 );
1032                                                 break;
1033                                 }
1034                         } catch ( Exception $e ) {
1035                                 MWExceptionHandler::logException( $e );
1036                                 $this->logger->warning( 'Generating module package failed: {exception}', array(
1037                                         'exception' => $e
1038                                 ) );
1039                                 $this->errors[] = self::formatExceptionNoComment( $e );
1040
1041                                 // Respond to client with error-state instead of module implementation
1042                                 $states[$name] = 'error';
1043                                 unset( $modules[$name] );
1044                         }
1045                         $isRaw |= $module->isRaw();
1046                 }
1047
1048                 // Update module states
1049                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
1050                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
1051                                 // Set the state of modules loaded as only scripts to ready as
1052                                 // they don't have an mw.loader.implement wrapper that sets the state
1053                                 foreach ( $modules as $name => $module ) {
1054                                         $states[$name] = 'ready';
1055                                 }
1056                         }
1057
1058                         // Set the state of modules we didn't respond to with mw.loader.implement
1059                         if ( count( $states ) ) {
1060                                 $out .= self::makeLoaderStateScript( $states );
1061                         }
1062                 } else {
1063                         if ( count( $states ) ) {
1064                                 $this->errors[] = 'Problematic modules: ' .
1065                                         FormatJson::encode( $states, ResourceLoader::inDebugMode() );
1066                         }
1067                 }
1068
1069                 $enableFilterCache = true;
1070                 if ( count( $modules ) === 1 && reset( $modules ) instanceof ResourceLoaderUserTokensModule ) {
1071                         // If we're building the embedded user.tokens, don't cache (T84960)
1072                         $enableFilterCache = false;
1073                 }
1074
1075                 if ( !$context->getDebug() ) {
1076                         if ( $context->getOnly() === 'styles' ) {
1077                                 $out = $this->filter( 'minify-css', $out );
1078                         } else {
1079                                 $out = $this->filter( 'minify-js', $out, array(
1080                                         'cache' => $enableFilterCache
1081                                 ) );
1082                         }
1083                 }
1084
1085                 return $out;
1086         }
1087
1088         /* Static Methods */
1089
1090         /**
1091          * Return JS code that calls mw.loader.implement with given module properties.
1092          *
1093          * @param string $name Module name
1094          * @param mixed $scripts List of URLs to JavaScript files or String of JavaScript code
1095          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1096          *   to CSS files keyed by media type
1097          * @param mixed $messages List of messages associated with this module. May either be an
1098          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1099          *   the same data, wrapped in an XmlJsCode object.
1100          * @param array $templates Keys are name of templates and values are the source of
1101          *   the template.
1102          * @throws MWException
1103          * @return string
1104          */
1105         public static function makeLoaderImplementScript(
1106                 $name, $scripts, $styles, $messages, $templates
1107         ) {
1108                 if ( is_string( $scripts ) ) {
1109                         // Site and user module are a legacy scripts that run in the global scope (no closure).
1110                         // Transportation as string instructs mw.loader.implement to use globalEval.
1111                         if ( $name === 'site' || $name === 'user' ) {
1112                                 // Minify manually because the general makeModuleResponse() minification won't be
1113                                 // effective here due to the script being a string instead of a function. (T107377)
1114                                 if ( !ResourceLoader::inDebugMode() ) {
1115                                         $scripts = self::applyFilter( 'minify-js', $scripts,
1116                                                 ConfigFactory::getDefaultInstance()->makeConfig( 'main' ) );
1117                                 }
1118                         } else {
1119                                 $scripts = new XmlJsCode( "function ( $, jQuery ) {\n{$scripts}\n}" );
1120                         }
1121                 } elseif ( !is_array( $scripts ) ) {
1122                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1123                 }
1124                 // mw.loader.implement requires 'styles', 'messages' and 'templates' to be objects (not
1125                 // arrays). json_encode considers empty arrays to be numerical and outputs "[]" instead
1126                 // of "{}". Force them to objects.
1127                 $module = array(
1128                         $name,
1129                         $scripts,
1130                         (object)$styles,
1131                         (object)$messages,
1132                         (object)$templates,
1133                 );
1134                 self::trimArray( $module );
1135
1136                 return Xml::encodeJsCall( 'mw.loader.implement', $module, ResourceLoader::inDebugMode() );
1137         }
1138
1139         /**
1140          * Returns JS code which, when called, will register a given list of messages.
1141          *
1142          * @param mixed $messages Either an associative array mapping message key to value, or a
1143          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1144          * @return string
1145          */
1146         public static function makeMessageSetScript( $messages ) {
1147                 return Xml::encodeJsCall(
1148                         'mw.messages.set',
1149                         array( (object)$messages ),
1150                         ResourceLoader::inDebugMode()
1151                 );
1152         }
1153
1154         /**
1155          * Combines an associative array mapping media type to CSS into a
1156          * single stylesheet with "@media" blocks.
1157          *
1158          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1159          * @return array
1160          */
1161         public static function makeCombinedStyles( array $stylePairs ) {
1162                 $out = array();
1163                 foreach ( $stylePairs as $media => $styles ) {
1164                         // ResourceLoaderFileModule::getStyle can return the styles
1165                         // as a string or an array of strings. This is to allow separation in
1166                         // the front-end.
1167                         $styles = (array)$styles;
1168                         foreach ( $styles as $style ) {
1169                                 $style = trim( $style );
1170                                 // Don't output an empty "@media print { }" block (bug 40498)
1171                                 if ( $style !== '' ) {
1172                                         // Transform the media type based on request params and config
1173                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1174                                         $media = OutputPage::transformCssMedia( $media );
1175
1176                                         if ( $media === '' || $media == 'all' ) {
1177                                                 $out[] = $style;
1178                                         } elseif ( is_string( $media ) ) {
1179                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1180                                         }
1181                                         // else: skip
1182                                 }
1183                         }
1184                 }
1185                 return $out;
1186         }
1187
1188         /**
1189          * Returns a JS call to mw.loader.state, which sets the state of a
1190          * module or modules to a given value. Has two calling conventions:
1191          *
1192          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1193          *         Set the state of a single module called $name to $state
1194          *
1195          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
1196          *         Set the state of modules with the given names to the given states
1197          *
1198          * @param string $name
1199          * @param string $state
1200          * @return string
1201          */
1202         public static function makeLoaderStateScript( $name, $state = null ) {
1203                 if ( is_array( $name ) ) {
1204                         return Xml::encodeJsCall(
1205                                 'mw.loader.state',
1206                                 array( $name ),
1207                                 ResourceLoader::inDebugMode()
1208                         );
1209                 } else {
1210                         return Xml::encodeJsCall(
1211                                 'mw.loader.state',
1212                                 array( $name, $state ),
1213                                 ResourceLoader::inDebugMode()
1214                         );
1215                 }
1216         }
1217
1218         /**
1219          * Returns JS code which calls the script given by $script. The script will
1220          * be called with local variables name, version, dependencies and group,
1221          * which will have values corresponding to $name, $version, $dependencies
1222          * and $group as supplied.
1223          *
1224          * @param string $name Module name
1225          * @param string $version Module version hash
1226          * @param array $dependencies List of module names on which this module depends
1227          * @param string $group Group which the module is in.
1228          * @param string $source Source of the module, or 'local' if not foreign.
1229          * @param string $script JavaScript code
1230          * @return string
1231          */
1232         public static function makeCustomLoaderScript( $name, $version, $dependencies,
1233                 $group, $source, $script
1234         ) {
1235                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1236                 return Xml::encodeJsCall(
1237                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1238                         array( $name, $version, $dependencies, $group, $source ),
1239                         ResourceLoader::inDebugMode()
1240                 );
1241         }
1242
1243         private static function isEmptyObject( stdClass $obj ) {
1244                 foreach ( $obj as $key => &$value ) {
1245                         return false;
1246                 }
1247                 return true;
1248         }
1249
1250         /**
1251          * Remove empty values from the end of an array.
1252          *
1253          * Values considered empty:
1254          *
1255          * - null
1256          * - array()
1257          * - new XmlJsCode( '{}' )
1258          * - new stdClass() // (object) array()
1259          *
1260          * @param Array $array
1261          */
1262         private static function trimArray( Array &$array ) {
1263                 $i = count( $array );
1264                 while ( $i-- ) {
1265                         if ( $array[$i] === null
1266                                 || $array[$i] === array()
1267                                 || ( $array[$i] instanceof XmlJsCode && $array[$i]->value === '{}' )
1268                                 || ( $array[$i] instanceof stdClass && self::isEmptyObject( $array[$i] ) )
1269                         ) {
1270                                 unset( $array[$i] );
1271                         } else {
1272                                 break;
1273                         }
1274                 }
1275         }
1276
1277         /**
1278          * Returns JS code which calls mw.loader.register with the given
1279          * parameters. Has three calling conventions:
1280          *
1281          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version,
1282          *        $dependencies, $group, $source, $skip
1283          *     ):
1284          *        Register a single module.
1285          *
1286          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
1287          *        Register modules with the given names.
1288          *
1289          *   - ResourceLoader::makeLoaderRegisterScript( array(
1290          *        array( $name1, $version1, $dependencies1, $group1, $source1, $skip1 ),
1291          *        array( $name2, $version2, $dependencies1, $group2, $source2, $skip2 ),
1292          *        ...
1293          *     ) ):
1294          *        Registers modules with the given names and parameters.
1295          *
1296          * @param string $name Module name
1297          * @param string $version Module version hash
1298          * @param array $dependencies List of module names on which this module depends
1299          * @param string $group Group which the module is in
1300          * @param string $source Source of the module, or 'local' if not foreign
1301          * @param string $skip Script body of the skip function
1302          * @return string
1303          */
1304         public static function makeLoaderRegisterScript( $name, $version = null,
1305                 $dependencies = null, $group = null, $source = null, $skip = null
1306         ) {
1307                 if ( is_array( $name ) ) {
1308                         // Build module name index
1309                         $index = array();
1310                         foreach ( $name as $i => &$module ) {
1311                                 $index[$module[0]] = $i;
1312                         }
1313
1314                         // Transform dependency names into indexes when possible, they will be resolved by
1315                         // mw.loader.register on the other end
1316                         foreach ( $name as &$module ) {
1317                                 if ( isset( $module[2] ) ) {
1318                                         foreach ( $module[2] as &$dependency ) {
1319                                                 if ( isset( $index[$dependency] ) ) {
1320                                                         $dependency = $index[$dependency];
1321                                                 }
1322                                         }
1323                                 }
1324                         }
1325
1326                         array_walk( $name, array( 'self', 'trimArray' ) );
1327
1328                         return Xml::encodeJsCall(
1329                                 'mw.loader.register',
1330                                 array( $name ),
1331                                 ResourceLoader::inDebugMode()
1332                         );
1333                 } else {
1334                         $registration = array( $name, $version, $dependencies, $group, $source, $skip );
1335                         self::trimArray( $registration );
1336                         return Xml::encodeJsCall(
1337                                 'mw.loader.register',
1338                                 $registration,
1339                                 ResourceLoader::inDebugMode()
1340                         );
1341                 }
1342         }
1343
1344         /**
1345          * Returns JS code which calls mw.loader.addSource() with the given
1346          * parameters. Has two calling conventions:
1347          *
1348          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1349          *       Register a single source
1350          *
1351          *   - ResourceLoader::makeLoaderSourcesScript( array( $id1 => $loadUrl, $id2 => $loadUrl, ... ) );
1352          *       Register sources with the given IDs and properties.
1353          *
1354          * @param string $id Source ID
1355          * @param array $properties Source properties (see addSource())
1356          * @return string
1357          */
1358         public static function makeLoaderSourcesScript( $id, $properties = null ) {
1359                 if ( is_array( $id ) ) {
1360                         return Xml::encodeJsCall(
1361                                 'mw.loader.addSource',
1362                                 array( $id ),
1363                                 ResourceLoader::inDebugMode()
1364                         );
1365                 } else {
1366                         return Xml::encodeJsCall(
1367                                 'mw.loader.addSource',
1368                                 array( $id, $properties ),
1369                                 ResourceLoader::inDebugMode()
1370                         );
1371                 }
1372         }
1373
1374         /**
1375          * Returns JS code which runs given JS code if the client-side framework is
1376          * present.
1377          *
1378          * @deprecated since 1.25; use makeInlineScript instead
1379          * @param string $script JavaScript code
1380          * @return string
1381          */
1382         public static function makeLoaderConditionalScript( $script ) {
1383                 return "window.RLQ = window.RLQ || []; window.RLQ.push( function () {\n" . trim( $script ) . "\n} );";
1384         }
1385
1386         /**
1387          * Construct an inline script tag with given JS code.
1388          *
1389          * The code will be wrapped in a closure, and it will be executed by ResourceLoader
1390          * only if the client has adequate support for MediaWiki JavaScript code.
1391          *
1392          * @param string $script JavaScript code
1393          * @return WrappedString HTML
1394          */
1395         public static function makeInlineScript( $script ) {
1396                 $js = self::makeLoaderConditionalScript( $script );
1397                 return new WrappedString(
1398                         Html::inlineScript( $js ),
1399                         "<script>window.RLQ = window.RLQ || []; window.RLQ.push( function () {\n",
1400                         "\n} );</script>"
1401                 );
1402         }
1403
1404         /**
1405          * Returns JS code which will set the MediaWiki configuration array to
1406          * the given value.
1407          *
1408          * @param array $configuration List of configuration values keyed by variable name
1409          * @return string
1410          */
1411         public static function makeConfigSetScript( array $configuration ) {
1412                 if ( ResourceLoader::inDebugMode() ) {
1413                         return Xml::encodeJsCall( 'mw.config.set', array( $configuration ), true );
1414                 }
1415
1416                 $config = RequestContext::getMain()->getConfig();
1417                 $js = Xml::encodeJsCall( 'mw.config.set', array( $configuration ), false );
1418                 return self::applyFilter( 'minify-js', $js, $config );
1419         }
1420
1421         /**
1422          * Convert an array of module names to a packed query string.
1423          *
1424          * For example, array( 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' )
1425          * becomes 'foo.bar,baz|bar.baz,quux'
1426          * @param array $modules List of module names (strings)
1427          * @return string Packed query string
1428          */
1429         public static function makePackedModulesString( $modules ) {
1430                 $groups = array(); // array( prefix => array( suffixes ) )
1431                 foreach ( $modules as $module ) {
1432                         $pos = strrpos( $module, '.' );
1433                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1434                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1435                         $groups[$prefix][] = $suffix;
1436                 }
1437
1438                 $arr = array();
1439                 foreach ( $groups as $prefix => $suffixes ) {
1440                         $p = $prefix === '' ? '' : $prefix . '.';
1441                         $arr[] = $p . implode( ',', $suffixes );
1442                 }
1443                 $str = implode( '|', $arr );
1444                 return $str;
1445         }
1446
1447         /**
1448          * Determine whether debug mode was requested
1449          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1450          * @return bool
1451          */
1452         public static function inDebugMode() {
1453                 if ( self::$debugMode === null ) {
1454                         global $wgRequest, $wgResourceLoaderDebug;
1455                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1456                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1457                         );
1458                 }
1459                 return self::$debugMode;
1460         }
1461
1462         /**
1463          * Reset static members used for caching.
1464          *
1465          * Global state and $wgRequest are evil, but we're using it right
1466          * now and sometimes we need to be able to force ResourceLoader to
1467          * re-evaluate the context because it has changed (e.g. in the test suite).
1468          */
1469         public static function clearCache() {
1470                 self::$debugMode = null;
1471         }
1472
1473         /**
1474          * Build a load.php URL
1475          *
1476          * @since 1.24
1477          * @param string $source Name of the ResourceLoader source
1478          * @param ResourceLoaderContext $context
1479          * @param array $extraQuery
1480          * @return string URL to load.php. May be protocol-relative if $wgLoadScript is, too.
1481          */
1482         public function createLoaderURL( $source, ResourceLoaderContext $context,
1483                 $extraQuery = array()
1484         ) {
1485                 $query = self::createLoaderQuery( $context, $extraQuery );
1486                 $script = $this->getLoadScript( $source );
1487
1488                 return wfAppendQuery( $script, $query );
1489         }
1490
1491         /**
1492          * Build a load.php URL
1493          * @deprecated since 1.24 Use createLoaderURL() instead
1494          * @param array $modules Array of module names (strings)
1495          * @param string $lang Language code
1496          * @param string $skin Skin name
1497          * @param string|null $user User name. If null, the &user= parameter is omitted
1498          * @param string|null $version Versioning timestamp
1499          * @param bool $debug Whether the request should be in debug mode
1500          * @param string|null $only &only= parameter
1501          * @param bool $printable Printable mode
1502          * @param bool $handheld Handheld mode
1503          * @param array $extraQuery Extra query parameters to add
1504          * @return string URL to load.php. May be protocol-relative if $wgLoadScript is, too.
1505          */
1506         public static function makeLoaderURL( $modules, $lang, $skin, $user = null,
1507                 $version = null, $debug = false, $only = null, $printable = false,
1508                 $handheld = false, $extraQuery = array()
1509         ) {
1510                 global $wgLoadScript;
1511
1512                 $query = self::makeLoaderQuery( $modules, $lang, $skin, $user, $version, $debug,
1513                         $only, $printable, $handheld, $extraQuery
1514                 );
1515
1516                 return wfAppendQuery( $wgLoadScript, $query );
1517         }
1518
1519         /**
1520          * Helper for createLoaderURL()
1521          *
1522          * @since 1.24
1523          * @see makeLoaderQuery
1524          * @param ResourceLoaderContext $context
1525          * @param array $extraQuery
1526          * @return array
1527          */
1528         public static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = array() ) {
1529                 return self::makeLoaderQuery(
1530                         $context->getModules(),
1531                         $context->getLanguage(),
1532                         $context->getSkin(),
1533                         $context->getUser(),
1534                         $context->getVersion(),
1535                         $context->getDebug(),
1536                         $context->getOnly(),
1537                         $context->getRequest()->getBool( 'printable' ),
1538                         $context->getRequest()->getBool( 'handheld' ),
1539                         $extraQuery
1540                 );
1541         }
1542
1543         /**
1544          * Build a query array (array representation of query string) for load.php. Helper
1545          * function for makeLoaderURL().
1546          *
1547          * @param array $modules
1548          * @param string $lang
1549          * @param string $skin
1550          * @param string $user
1551          * @param string $version
1552          * @param bool $debug
1553          * @param string $only
1554          * @param bool $printable
1555          * @param bool $handheld
1556          * @param array $extraQuery
1557          *
1558          * @return array
1559          */
1560         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1561                 $version = null, $debug = false, $only = null, $printable = false,
1562                 $handheld = false, $extraQuery = array()
1563         ) {
1564                 $query = array(
1565                         'modules' => self::makePackedModulesString( $modules ),
1566                         'lang' => $lang,
1567                         'skin' => $skin,
1568                         'debug' => $debug ? 'true' : 'false',
1569                 );
1570                 if ( $user !== null ) {
1571                         $query['user'] = $user;
1572                 }
1573                 if ( $version !== null ) {
1574                         $query['version'] = $version;
1575                 }
1576                 if ( $only !== null ) {
1577                         $query['only'] = $only;
1578                 }
1579                 if ( $printable ) {
1580                         $query['printable'] = 1;
1581                 }
1582                 if ( $handheld ) {
1583                         $query['handheld'] = 1;
1584                 }
1585                 $query += $extraQuery;
1586
1587                 // Make queries uniform in order
1588                 ksort( $query );
1589                 return $query;
1590         }
1591
1592         /**
1593          * Check a module name for validity.
1594          *
1595          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1596          * at most 255 bytes.
1597          *
1598          * @param string $moduleName Module name to check
1599          * @return bool Whether $moduleName is a valid module name
1600          */
1601         public static function isValidModuleName( $moduleName ) {
1602                 return !preg_match( '/[|,!]/', $moduleName ) && strlen( $moduleName ) <= 255;
1603         }
1604
1605         /**
1606          * Returns LESS compiler set up for use with MediaWiki
1607          *
1608          * @param Config $config
1609          * @throws MWException
1610          * @since 1.22
1611          * @return lessc
1612          */
1613         public static function getLessCompiler( Config $config ) {
1614                 // When called from the installer, it is possible that a required PHP extension
1615                 // is missing (at least for now; see bug 47564). If this is the case, throw an
1616                 // exception (caught by the installer) to prevent a fatal error later on.
1617                 if ( !class_exists( 'lessc' ) ) {
1618                         throw new MWException( 'MediaWiki requires the lessphp compiler' );
1619                 }
1620                 if ( !function_exists( 'ctype_digit' ) ) {
1621                         throw new MWException( 'lessc requires the Ctype extension' );
1622                 }
1623
1624                 $less = new lessc();
1625                 $less->setPreserveComments( true );
1626                 $less->setVariables( self::getLessVars( $config ) );
1627                 $less->setImportDir( $config->get( 'ResourceLoaderLESSImportPaths' ) );
1628                 return $less;
1629         }
1630
1631         /**
1632          * Get global LESS variables.
1633          *
1634          * @param Config $config
1635          * @since 1.22
1636          * @return array Map of variable names to string CSS values.
1637          */
1638         public static function getLessVars( Config $config ) {
1639                 if ( !self::$lessVars ) {
1640                         $lessVars = $config->get( 'ResourceLoaderLESSVars' );
1641                         Hooks::run( 'ResourceLoaderGetLessVars', array( &$lessVars ) );
1642                         // Sort by key to ensure consistent hashing for cache lookups.
1643                         ksort( $lessVars );
1644                         self::$lessVars = $lessVars;
1645                 }
1646                 return self::$lessVars;
1647         }
1648 }