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 /**
  26  * Dynamic JavaScript and CSS resource loading system.
  27  *
  28  * Most of the documentation is on the MediaWiki documentation wiki starting at:
  29  *    https://www.mediawiki.org/wiki/ResourceLoader
  30  */
  31 class ResourceLoader {
  32         /** @var int */
  33         protected static $filterCacheVersion = 7;
  34
  35         /** @var bool */
  36         protected static $debugMode = null;
  37
  38         /** @var array */
  39         private static $lessVars = null;
  40
  41         /**
  42          * Module name/ResourceLoaderModule object pairs
  43          * @var array
  44          */
  45         protected $modules = array();
  46
  47         /**
  48          * Associative array mapping module name to info associative array
  49          * @var array
  50          */
  51         protected $moduleInfos = array();
  52
  53         /** @var Config $config */
  54         private $config;
  55
  56         /**
  57          * Associative array mapping framework ids to a list of names of test suite modules
  58          * like array( 'qunit' => array( 'mediawiki.tests.qunit.suites', 'ext.foo.tests', .. ), .. )
  59          * @var array
  60          */
  61         protected $testModuleNames = array();
  62
  63         /**
  64          * E.g. array( 'source-id' => 'http://.../load.php' )
  65          * @var array
  66          */
  67         protected $sources = array();
  68
  69         /**
  70          * Errors accumulated during current respond() call.
  71          * @var array
  72          */
  73         protected $errors = array();
  74
  75         /**
  76          * @var MessageBlobStore
  77          */
  78         protected $blobStore;
  79
  80         /**
  81          * Load information stored in the database about modules.
  82          *
  83          * This method grabs modules dependencies from the database and updates modules
  84          * objects.
  85          *
  86          * This is not inside the module code because it is much faster to
  87          * request all of the information at once than it is to have each module
  88          * requests its own information. This sacrifice of modularity yields a substantial
  89          * performance improvement.
  90          *
  91          * @param array $modules List of module names to preload information for
  92          * @param ResourceLoaderContext $context Context to load the information within
  93          */
  94         public function preloadModuleInfo( array $modules, ResourceLoaderContext $context ) {
  95                 if ( !count( $modules ) ) {
  96                         // Or else Database*::select() will explode, plus it's cheaper!
  97                         return;
  98                 }
  99                 $dbr = wfGetDB( DB_SLAVE );
 100                 $skin = $context->getSkin();
 101                 $lang = $context->getLanguage();
 102
 103                 // Get file dependency information
 104                 $res = $dbr->select( 'module_deps', array( 'md_module', 'md_deps' ), array(
 105                                 'md_module' => $modules,
 106                                 'md_skin' => $skin
 107                         ), __METHOD__
 108                 );
 109
 110                 // Set modules' dependencies
 111                 $modulesWithDeps = array();
 112                 foreach ( $res as $row ) {
 113                         $module = $this->getModule( $row->md_module );
 114                         if ( $module ) {
 115                                 $module->setFileDependencies( $skin, FormatJson::decode( $row->md_deps, true ) );
 116                                 $modulesWithDeps[] = $row->md_module;
 117                         }
 118                 }
 119
 120                 // Register the absence of a dependency row too
 121                 foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
 122                         $module = $this->getModule( $name );
 123                         if ( $module ) {
 124                                 $this->getModule( $name )->setFileDependencies( $skin, array() );
 125                         }
 126                 }
 127
 128                 // Get message blob mtimes. Only do this for modules with messages
 129                 $modulesWithMessages = array();
 130                 foreach ( $modules as $name ) {
 131                         $module = $this->getModule( $name );
 132                         if ( $module && count( $module->getMessages() ) ) {
 133                                 $modulesWithMessages[] = $name;
 134                         }
 135                 }
 136                 $modulesWithoutMessages = array_flip( $modules ); // Will be trimmed down by the loop below
 137                 if ( count( $modulesWithMessages ) ) {
 138                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
 139                                         'mr_resource' => $modulesWithMessages,
 140                                         'mr_lang' => $lang
 141                                 ), __METHOD__
 142                         );
 143                         foreach ( $res as $row ) {
 144                                 $module = $this->getModule( $row->mr_resource );
 145                                 if ( $module ) {
 146                                         $module->setMsgBlobMtime( $lang, wfTimestamp( TS_UNIX, $row->mr_timestamp ) );
 147                                         unset( $modulesWithoutMessages[$row->mr_resource] );
 148                                 }
 149                         }
 150                 }
 151                 foreach ( array_keys( $modulesWithoutMessages ) as $name ) {
 152                         $module = $this->getModule( $name );
 153                         if ( $module ) {
 154                                 $module->setMsgBlobMtime( $lang, 1 );
 155                         }
 156                 }
 157         }
 158
 159         /**
 160          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 161          *
 162          * Available filters are:
 163          *
 164          *    - minify-js \see JavaScriptMinifier::minify
 165          *    - minify-css \see CSSMin::minify
 166          *
 167          * If $data is empty, only contains whitespace or the filter was unknown,
 168          * $data is returned unmodified.
 169          *
 170          * @param string $filter Name of filter to run
 171          * @param string $data Text to filter, such as JavaScript or CSS text
 172          * @param array $options For back-compat, can also be the boolean value for "cacheReport". Keys:
 173          *  - (bool) cache: Whether to allow caching this data. Default: true.
 174          *  - (bool) cacheReport: Whether to include the "cache key" report comment. Default: true.
 175          * @return string Filtered data, or a comment containing an error message
 176          */
 177         public function filter( $filter, $data, $options = array() ) {
 178                 // Back-compat
 179                 if ( is_bool( $options ) ) {
 180                         $options = array( 'cacheReport' => $options );
 181                 }
 182                 // Defaults
 183                 $options += array( 'cache' => true, 'cacheReport' => true );
 184
 185                 // Don't filter empty content
 186                 if ( trim( $data ) === '' ) {
 187                         return $data;
 188                 }
 189
 190                 if ( !in_array( $filter, array( 'minify-js', 'minify-css' ) ) ) {
 191                         wfDebugLog( 'resourceloader', __METHOD__ . ": Invalid filter: $filter" );
 192                         return $data;
 193                 }
 194
 195                 if ( !$options['cache'] ) {
 196                         $result = $this->applyFilter( $filter, $data );
 197                 } else {
 198                         $key = wfMemcKey( 'resourceloader', 'filter', $filter, self::$filterCacheVersion, md5( $data ) );
 199                         $cache = wfGetCache( wfIsHHVM() ? CACHE_ACCEL : CACHE_ANYTHING );
 200                         $cacheEntry = $cache->get( $key );
 201                         if ( is_string( $cacheEntry ) ) {
 202                                 wfIncrStats( "resourceloader_cache.$filter.hit" );
 203                                 return $cacheEntry;
 204                         }
 205                         $result = '';
 206                         try {
 207                                 wfIncrStats( "resourceloader_cache.$filter.miss" );
 208                                 $result = $this->applyFilter( $filter, $data );
 209                                 if ( $options['cacheReport'] ) {
 210                                         $result .= "\n/* cache key: $key */";
 211                                 }
 212                                 $cache->set( $key, $result );
 213                         } catch ( Exception $e ) {
 214                                 MWExceptionHandler::logException( $e );
 215                                 wfDebugLog( 'resourceloader', __METHOD__ . ": minification failed: $e" );
 216                                 $this->errors[] = self::formatExceptionNoComment( $e );
 217                         }
 218                 }
 219
 220                 return $result;
 221         }
 222
 223         private function applyFilter( $filter, $data ) {
 224                         switch ( $filter ) {
 225                                 case 'minify-js':
 226                                         return JavaScriptMinifier::minify( $data,
 227                                                 $this->config->get( 'ResourceLoaderMinifierStatementsOnOwnLine' ),
 228                                                 $this->config->get( 'ResourceLoaderMinifierMaxLineLength' )
 229                                         );
 230                                 case 'minify-css':
 231                                         return CSSMin::minify( $data );
 232                         }
 233                         return $data;
 234         }
 235
 236         /* Methods */
 237
 238         /**
 239          * Register core modules and runs registration hooks.
 240          * @param Config|null $config
 241          */
 242         public function __construct( Config $config = null ) {
 243                 global $IP;
 244
 245                 if ( $config === null ) {
 246                         wfDebug( __METHOD__ . ' was called without providing a Config instance' );
 247                         $config = ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
 248                 }
 249
 250                 $this->config = $config;
 251
 252                 // Add 'local' source first
 253                 $this->addSource( 'local', wfScript( 'load' ) );
 254
 255                 // Add other sources
 256                 $this->addSource( $config->get( 'ResourceLoaderSources' ) );
 257
 258                 // Register core modules
 259                 $this->register( include "$IP/resources/Resources.php" );
 260                 $this->register( include "$IP/resources/ResourcesOOUI.php" );
 261                 // Register extension modules
 262                 Hooks::run( 'ResourceLoaderRegisterModules', array( &$this ) );
 263                 $this->register( $config->get( 'ResourceModules' ) );
 264
 265                 if ( $config->get( 'EnableJavaScriptTest' ) === true ) {
 266                         $this->registerTestModules();
 267                 }
 268
 269                 $this->setMessageBlobStore( new MessageBlobStore() );
 270         }
 271
 272         /**
 273          * @return Config
 274          */
 275         public function getConfig() {
 276                 return $this->config;
 277         }
 278
 279         /**
 280          * @param MessageBlobStore $blobStore
 281          * @since 1.25
 282          */
 283         public function setMessageBlobStore( MessageBlobStore $blobStore ) {
 284                 $this->blobStore = $blobStore;
 285         }
 286
 287         /**
 288          * Register a module with the ResourceLoader system.
 289          *
 290          * @param mixed $name Name of module as a string or List of name/object pairs as an array
 291          * @param array $info Module info array. For backwards compatibility with 1.17alpha,
 292          *   this may also be a ResourceLoaderModule object. Optional when using
 293          *   multiple-registration calling style.
 294          * @throws MWException If a duplicate module registration is attempted
 295          * @throws MWException If a module name contains illegal characters (pipes or commas)
 296          * @throws MWException If something other than a ResourceLoaderModule is being registered
 297          * @return bool False if there were any errors, in which case one or more modules were
 298          *   not registered
 299          */
 300         public function register( $name, $info = null ) {
 301
 302                 // Allow multiple modules to be registered in one call
 303                 $registrations = is_array( $name ) ? $name : array( $name => $info );
 304                 foreach ( $registrations as $name => $info ) {
 305                         // Disallow duplicate registrations
 306                         if ( isset( $this->moduleInfos[$name] ) ) {
 307                                 // A module has already been registered by this name
 308                                 throw new MWException(
 309                                         'ResourceLoader duplicate registration error. ' .
 310                                         'Another module has already been registered as ' . $name
 311                                 );
 312                         }
 313
 314                         // Check $name for validity
 315                         if ( !self::isValidModuleName( $name ) ) {
 316                                 throw new MWException( "ResourceLoader module name '$name' is invalid, "
 317                                         . "see ResourceLoader::isValidModuleName()" );
 318                         }
 319
 320                         // Attach module
 321                         if ( $info instanceof ResourceLoaderModule ) {
 322                                 $this->moduleInfos[$name] = array( 'object' => $info );
 323                                 $info->setName( $name );
 324                                 $this->modules[$name] = $info;
 325                         } elseif ( is_array( $info ) ) {
 326                                 // New calling convention
 327                                 $this->moduleInfos[$name] = $info;
 328                         } else {
 329                                 throw new MWException(
 330                                         'ResourceLoader module info type error for module \'' . $name .
 331                                         '\': expected ResourceLoaderModule or array (got: ' . gettype( $info ) . ')'
 332                                 );
 333                         }
 334
 335                         // Last-minute changes
 336
 337                         // Apply custom skin-defined styles to existing modules.
 338                         if ( $this->isFileModule( $name ) ) {
 339                                 foreach ( $this->config->get( 'ResourceModuleSkinStyles' ) as $skinName => $skinStyles ) {
 340                                         // If this module already defines skinStyles for this skin, ignore $wgResourceModuleSkinStyles.
 341                                         if ( isset( $this->moduleInfos[$name]['skinStyles'][$skinName] ) ) {
 342                                                 continue;
 343                                         }
 344
 345                                         // If $name is preceded with a '+', the defined style files will be added to 'default'
 346                                         // skinStyles, otherwise 'default' will be ignored as it normally would be.
 347                                         if ( isset( $skinStyles[$name] ) ) {
 348                                                 $paths = (array)$skinStyles[$name];
 349                                                 $styleFiles = array();
 350                                         } elseif ( isset( $skinStyles['+' . $name] ) ) {
 351                                                 $paths = (array)$skinStyles['+' . $name];
 352                                                 $styleFiles = isset( $this->moduleInfos[$name]['skinStyles']['default'] ) ?
 353                                                         (array)$this->moduleInfos[$name]['skinStyles']['default'] :
 354                                                         array();
 355                                         } else {
 356                                                 continue;
 357                                         }
 358
 359                                         // Add new file paths, remapping them to refer to our directories and not use settings
 360                                         // from the module we're modifying, which come from the base definition.
 361                                         list( $localBasePath, $remoteBasePath ) =
 362                                                 ResourceLoaderFileModule::extractBasePaths( $skinStyles );
 363
 364                                         foreach ( $paths as $path ) {
 365                                                 $styleFiles[] = new ResourceLoaderFilePath( $path, $localBasePath, $remoteBasePath );
 366                                         }
 367
 368                                         $this->moduleInfos[$name]['skinStyles'][$skinName] = $styleFiles;
 369                                 }
 370                         }
 371                 }
 372
 373         }
 374
 375         /**
 376          */
 377         public function registerTestModules() {
 378                 global $IP;
 379
 380                 if ( $this->config->get( 'EnableJavaScriptTest' ) !== true ) {
 381                         throw new MWException( 'Attempt to register JavaScript test modules '
 382                                 . 'but <code>$wgEnableJavaScriptTest</code> is false. '
 383                                 . 'Edit your <code>LocalSettings.php</code> to enable it.' );
 384                 }
 385
 386                 // Get core test suites
 387                 $testModules = array();
 388                 $testModules['qunit'] = array();
 389                 // Get other test suites (e.g. from extensions)
 390                 Hooks::run( 'ResourceLoaderTestModules', array( &$testModules, &$this ) );
 391
 392                 // Add the testrunner (which configures QUnit) to the dependencies.
 393                 // Since it must be ready before any of the test suites are executed.
 394                 foreach ( $testModules['qunit'] as &$module ) {
 395                         // Make sure all test modules are top-loading so that when QUnit starts
 396                         // on document-ready, it will run once and finish. If some tests arrive
 397                         // later (possibly after QUnit has already finished) they will be ignored.
 398                         $module['position'] = 'top';
 399                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 400                 }
 401
 402                 $testModules['qunit'] =
 403                         ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules['qunit'];
 404
 405                 foreach ( $testModules as $id => $names ) {
 406                         // Register test modules
 407                         $this->register( $testModules[$id] );
 408
 409                         // Keep track of their names so that they can be loaded together
 410                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 411                 }
 412
 413         }
 414
 415         /**
 416          * Add a foreign source of modules.
 417          *
 418          * @param array|string $id Source ID (string), or array( id1 => loadUrl, id2 => loadUrl, ... )
 419          * @param string|array $loadUrl load.php url (string), or array with loadUrl key for
 420          *  backwards-compatibility.
 421          * @throws MWException
 422          */
 423         public function addSource( $id, $loadUrl = null ) {
 424                 // Allow multiple sources to be registered in one call
 425                 if ( is_array( $id ) ) {
 426                         foreach ( $id as $key => $value ) {
 427                                 $this->addSource( $key, $value );
 428                         }
 429                         return;
 430                 }
 431
 432                 // Disallow duplicates
 433                 if ( isset( $this->sources[$id] ) ) {
 434                         throw new MWException(
 435                                 'ResourceLoader duplicate source addition error. ' .
 436                                 'Another source has already been registered as ' . $id
 437                         );
 438                 }
 439
 440                 // Pre 1.24 backwards-compatibility
 441                 if ( is_array( $loadUrl ) ) {
 442                         if ( !isset( $loadUrl['loadScript'] ) ) {
 443                                 throw new MWException(
 444                                         __METHOD__ . ' was passed an array with no "loadScript" key.'
 445                                 );
 446                         }
 447
 448                         $loadUrl = $loadUrl['loadScript'];
 449                 }
 450
 451                 $this->sources[$id] = $loadUrl;
 452         }
 453
 454         /**
 455          * Get a list of module names.
 456          *
 457          * @return array List of module names
 458          */
 459         public function getModuleNames() {
 460                 return array_keys( $this->moduleInfos );
 461         }
 462
 463         /**
 464          * Get a list of test module names for one (or all) frameworks.
 465          *
 466          * If the given framework id is unknkown, or if the in-object variable is not an array,
 467          * then it will return an empty array.
 468          *
 469          * @param string $framework Get only the test module names for one
 470          *   particular framework (optional)
 471          * @return array
 472          */
 473         public function getTestModuleNames( $framework = 'all' ) {
 474                 /** @todo api siteinfo prop testmodulenames modulenames */
 475                 if ( $framework == 'all' ) {
 476                         return $this->testModuleNames;
 477                 } elseif ( isset( $this->testModuleNames[$framework] )
 478                         && is_array( $this->testModuleNames[$framework] )
 479                 ) {
 480                         return $this->testModuleNames[$framework];
 481                 } else {
 482                         return array();
 483                 }
 484         }
 485
 486         /**
 487          * Check whether a ResourceLoader module is registered
 488          *
 489          * @since 1.25
 490          * @param string $name
 491          * @return bool
 492          */
 493         public function isModuleRegistered( $name ) {
 494                 return isset( $this->moduleInfos[$name] );
 495         }
 496
 497         /**
 498          * Get the ResourceLoaderModule object for a given module name.
 499          *
 500          * If an array of module parameters exists but a ResourceLoaderModule object has not
 501          * yet been instantiated, this method will instantiate and cache that object such that
 502          * subsequent calls simply return the same object.
 503          *
 504          * @param string $name Module name
 505          * @return ResourceLoaderModule|null If module has been registered, return a
 506          *  ResourceLoaderModule instance. Otherwise, return null.
 507          */
 508         public function getModule( $name ) {
 509                 if ( !isset( $this->modules[$name] ) ) {
 510                         if ( !isset( $this->moduleInfos[$name] ) ) {
 511                                 // No such module
 512                                 return null;
 513                         }
 514                         // Construct the requested object
 515                         $info = $this->moduleInfos[$name];
 516                         /** @var ResourceLoaderModule $object */
 517                         if ( isset( $info['object'] ) ) {
 518                                 // Object given in info array
 519                                 $object = $info['object'];
 520                         } else {
 521                                 if ( !isset( $info['class'] ) ) {
 522                                         $class = 'ResourceLoaderFileModule';
 523                                 } else {
 524                                         $class = $info['class'];
 525                                 }
 526                                 /** @var ResourceLoaderModule $object */
 527                                 $object = new $class( $info );
 528                                 $object->setConfig( $this->getConfig() );
 529                         }
 530                         $object->setName( $name );
 531                         $this->modules[$name] = $object;
 532                 }
 533
 534                 return $this->modules[$name];
 535         }
 536
 537         /**
 538          * Return whether the definition of a module corresponds to a simple ResourceLoaderFileModule.
 539          *
 540          * @param string $name Module name
 541          * @return bool
 542          */
 543         protected function isFileModule( $name ) {
 544                 if ( !isset( $this->moduleInfos[$name] ) ) {
 545                         return false;
 546                 }
 547                 $info = $this->moduleInfos[$name];
 548                 if ( isset( $info['object'] ) || isset( $info['class'] ) ) {
 549                         return false;
 550                 }
 551                 return true;
 552         }
 553
 554         /**
 555          * Get the list of sources.
 556          *
 557          * @return array Like array( id => load.php url, .. )
 558          */
 559         public function getSources() {
 560                 return $this->sources;
 561         }
 562
 563         /**
 564          * Get the URL to the load.php endpoint for the given
 565          * ResourceLoader source
 566          *
 567          * @since 1.24
 568          * @param string $source
 569          * @throws MWException On an invalid $source name
 570          * @return string
 571          */
 572         public function getLoadScript( $source ) {
 573                 if ( !isset( $this->sources[$source] ) ) {
 574                         throw new MWException( "The $source source was never registered in ResourceLoader." );
 575                 }
 576                 return $this->sources[$source];
 577         }
 578
 579         /**
 580          * @since 1.26
 581          * @param string $value
 582          * @return string Hash
 583          */
 584         public static function makeHash( $value ) {
 585                 // Use base64 to output more entropy in a more compact string (default hex is only base16).
 586                 // The first 8 chars of a base64 encoded digest represent the same binary as
 587                 // the first 12 chars of a hex encoded digest.
 588                 return substr( base64_encode( sha1( $value, true ) ), 0, 8 );
 589         }
 590
 591         /**
 592          * Helper method to get and combine versions of multiple modules.
 593          *
 594          * @since 1.26
 595          * @param ResourceLoaderContext $context
 596          * @param array $modules List of ResourceLoaderModule objects
 597          * @return string Hash
 598          */
 599         public function getCombinedVersion( ResourceLoaderContext $context, Array $modules ) {
 600                 if ( !$modules ) {
 601                         return '';
 602                 }
 603                 // Support: PHP 5.3 ("$this" for anonymous functions was added in PHP 5.4.0)
 604                 // http://php.net/functions.anonymous
 605                 $rl = $this;
 606                 $hashes = array_map( function ( $module ) use ( $rl, $context ) {
 607                         return $rl->getModule( $module )->getVersionHash( $context );
 608                 }, $modules );
 609                 return self::makeHash( implode( $hashes ) );
 610         }
 611
 612         /**
 613          * Output a response to a load request, including the content-type header.
 614          *
 615          * @param ResourceLoaderContext $context Context in which a response should be formed
 616          */
 617         public function respond( ResourceLoaderContext $context ) {
 618                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 619                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 620                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 621                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 622                 // the whole thing in our own output buffer to be sure the active buffer
 623                 // doesn't use ob_gzhandler.
 624                 // See http://bugs.php.net/bug.php?id=36514
 625                 ob_start();
 626
 627                 // Find out which modules are missing and instantiate the others
 628                 $modules = array();
 629                 $missing = array();
 630                 foreach ( $context->getModules() as $name ) {
 631                         $module = $this->getModule( $name );
 632                         if ( $module ) {
 633                                 // Do not allow private modules to be loaded from the web.
 634                                 // This is a security issue, see bug 34907.
 635                                 if ( $module->getGroup() === 'private' ) {
 636                                         wfDebugLog( 'resourceloader', __METHOD__ . ": request for private module '$name' denied" );
 637                                         $this->errors[] = "Cannot show private module \"$name\"";
 638                                         continue;
 639                                 }
 640                                 $modules[$name] = $module;
 641                         } else {
 642                                 $missing[] = $name;
 643                         }
 644                 }
 645
 646                 try {
 647                         // Preload for getCombinedVersion()
 648                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 649                 } catch ( Exception $e ) {
 650                         MWExceptionHandler::logException( $e );
 651                         wfDebugLog( 'resourceloader', __METHOD__ . ": preloading module info failed: $e" );
 652                         $this->errors[] = self::formatExceptionNoComment( $e );
 653                 }
 654
 655                 // Combine versions to propagate cache invalidation
 656                 $versionHash = '';
 657                 try {
 658                         $versionHash = $this->getCombinedVersion( $context, array_keys( $modules ) );
 659                 } catch ( Exception $e ) {
 660                         MWExceptionHandler::logException( $e );
 661                         wfDebugLog( 'resourceloader', __METHOD__ . ": calculating version hash failed: $e" );
 662                         $this->errors[] = self::formatExceptionNoComment( $e );
 663                 }
 664
 665                 // See RFC 2616 § 3.11 Entity Tags
 666                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.11
 667                 $etag = 'W/"' . $versionHash . '"';
 668
 669                 // Try the client-side cache first
 670                 if ( $this->tryRespondNotModified( $context, $etag ) ) {
 671                         return; // output handled (buffers cleared)
 672                 }
 673
 674                 // Use file cache if enabled and available...
 675                 if ( $this->config->get( 'UseFileCache' ) ) {
 676                         $fileCache = ResourceFileCache::newFromContext( $context );
 677                         if ( $this->tryRespondFromFileCache( $fileCache, $context, $etag ) ) {
 678                                 return; // output handled
 679                         }
 680                 }
 681
 682                 // Generate a response
 683                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 684
 685                 // Capture any PHP warnings from the output buffer and append them to the
 686                 // error list if we're in debug mode.
 687                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 688                         $this->errors[] = $warnings;
 689                 }
 690
 691                 // Save response to file cache unless there are errors
 692                 if ( isset( $fileCache ) && !$this->errors && !count( $missing ) ) {
 693                         // Cache single modules and images...and other requests if there are enough hits
 694                         if ( ResourceFileCache::useFileCache( $context ) ) {
 695                                 if ( $fileCache->isCacheWorthy() ) {
 696                                         $fileCache->saveText( $response );
 697                                 } else {
 698                                         $fileCache->incrMissesRecent( $context->getRequest() );
 699                                 }
 700                         }
 701                 }
 702
 703                 $this->sendResponseHeaders( $context, $etag, (bool)$this->errors );
 704
 705                 // Remove the output buffer and output the response
 706                 ob_end_clean();
 707
 708                 if ( $context->getImageObj() && $this->errors ) {
 709                         // We can't show both the error messages and the response when it's an image.
 710                         $errorText = '';
 711                         foreach ( $this->errors as $error ) {
 712                                 $errorText .= $error . "\n";
 713                         }
 714                         $response = $errorText;
 715                 } elseif ( $this->errors ) {
 716                         // Prepend comments indicating errors
 717                         $errorText = '';
 718                         foreach ( $this->errors as $error ) {
 719                                 $errorText .= self::makeComment( $error );
 720                         }
 721                         $response = $errorText . $response;
 722                 }
 723
 724                 $this->errors = array();
 725                 echo $response;
 726
 727         }
 728
 729         /**
 730          * Send main response headers to the client.
 731          *
 732          * Deals with Content-Type, CORS (for stylesheets), and caching.
 733          *
 734          * @param ResourceLoaderContext $context
 735          * @param string $etag ETag header value
 736          * @param bool $errors Whether there are errors in the response
 737          * @return void
 738          */
 739         protected function sendResponseHeaders( ResourceLoaderContext $context, $etag, $errors ) {
 740                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 741                 // If a version wasn't specified we need a shorter expiry time for updates
 742                 // to propagate to clients quickly
 743                 // If there were errors, we also need a shorter expiry time so we can recover quickly
 744                 if ( is_null( $context->getVersion() ) || $errors ) {
 745                         $maxage = $rlMaxage['unversioned']['client'];
 746                         $smaxage = $rlMaxage['unversioned']['server'];
 747                 // If a version was specified we can use a longer expiry time since changing
 748                 // version numbers causes cache misses
 749                 } else {
 750                         $maxage = $rlMaxage['versioned']['client'];
 751                         $smaxage = $rlMaxage['versioned']['server'];
 752                 }
 753                 if ( $context->getImageObj() ) {
 754                         // Output different headers if we're outputting textual errors.
 755                         if ( $errors ) {
 756                                 header( 'Content-Type: text/plain; charset=utf-8' );
 757                         } else {
 758                                 $context->getImageObj()->sendResponseHeaders( $context );
 759                         }
 760                 } elseif ( $context->getOnly() === 'styles' ) {
 761                         header( 'Content-Type: text/css; charset=utf-8' );
 762                         header( 'Access-Control-Allow-Origin: *' );
 763                 } else {
 764                         header( 'Content-Type: text/javascript; charset=utf-8' );
 765                 }
 766                 // See RFC 2616 § 14.19 ETag
 767                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.19
 768                 header( 'ETag: ' . $etag );
 769                 if ( $context->getDebug() ) {
 770                         // Do not cache debug responses
 771                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 772                         header( 'Pragma: no-cache' );
 773                 } else {
 774                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 775                         $exp = min( $maxage, $smaxage );
 776                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 777                 }
 778         }
 779
 780         /**
 781          * Respond with HTTP 304 Not Modified if appropiate.
 782          *
 783          * If there's an If-None-Match header, respond with a 304 appropriately
 784          * and clear out the output buffer. If the client cache is too old then do nothing.
 785          *
 786          * @param ResourceLoaderContext $context
 787          * @param string $etag ETag header value
 788          * @return bool True if HTTP 304 was sent and output handled
 789          */
 790         protected function tryRespondNotModified( ResourceLoaderContext $context, $etag ) {
 791                 // See RFC 2616 § 14.26 If-None-Match
 792                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
 793                 $clientKeys = $context->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST );
 794                 // Never send 304s in debug mode
 795                 if ( $clientKeys !== false && !$context->getDebug() && in_array( $etag, $clientKeys ) ) {
 796                         // There's another bug in ob_gzhandler (see also the comment at
 797                         // the top of this function) that causes it to gzip even empty
 798                         // responses, meaning it's impossible to produce a truly empty
 799                         // response (because the gzip header is always there). This is
 800                         // a problem because 304 responses have to be completely empty
 801                         // per the HTTP spec, and Firefox behaves buggily when they're not.
 802                         // See also http://bugs.php.net/bug.php?id=51579
 803                         // To work around this, we tear down all output buffering before
 804                         // sending the 304.
 805                         wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 806
 807                         header( 'HTTP/1.0 304 Not Modified' );
 808                         header( 'Status: 304 Not Modified' );
 809
 810                         $this->sendResponseHeaders( $context, $etag, false );
 811                         return true;
 812                 }
 813                 return false;
 814         }
 815
 816         /**
 817          * Send out code for a response from file cache if possible.
 818          *
 819          * @param ResourceFileCache $fileCache Cache object for this request URL
 820          * @param ResourceLoaderContext $context Context in which to generate a response
 821          * @param string $etag ETag header value
 822          * @return bool If this found a cache file and handled the response
 823          */
 824         protected function tryRespondFromFileCache(
 825                 ResourceFileCache $fileCache,
 826                 ResourceLoaderContext $context,
 827                 $etag
 828         ) {
 829                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 830                 // Buffer output to catch warnings.
 831                 ob_start();
 832                 // Get the maximum age the cache can be
 833                 $maxage = is_null( $context->getVersion() )
 834                         ? $rlMaxage['unversioned']['server']
 835                         : $rlMaxage['versioned']['server'];
 836                 // Minimum timestamp the cache file must have
 837                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 838                 if ( !$good ) {
 839                         try { // RL always hits the DB on file cache miss...
 840                                 wfGetDB( DB_SLAVE );
 841                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 842                                 $good = $fileCache->isCacheGood(); // cache existence check
 843                         }
 844                 }
 845                 if ( $good ) {
 846                         $ts = $fileCache->cacheTimestamp();
 847                         // Send content type and cache headers
 848                         $this->sendResponseHeaders( $context, $etag, false );
 849                         $response = $fileCache->fetchText();
 850                         // Capture any PHP warnings from the output buffer and append them to the
 851                         // response in a comment if we're in debug mode.
 852                         if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 853                                 $response = self::makeComment( $warnings ) . $response;
 854                         }
 855                         // Remove the output buffer and output the response
 856                         ob_end_clean();
 857                         echo $response . "\n/* Cached {$ts} */";
 858                         return true; // cache hit
 859                 }
 860                 // Clear buffer
 861                 ob_end_clean();
 862
 863                 return false; // cache miss
 864         }
 865
 866         /**
 867          * Generate a CSS or JS comment block.
 868          *
 869          * Only use this for public data, not error message details.
 870          *
 871          * @param string $text
 872          * @return string
 873          */
 874         public static function makeComment( $text ) {
 875                 $encText = str_replace( '*/', '* /', $text );
 876                 return "/*\n$encText\n*/\n";
 877         }
 878
 879         /**
 880          * Handle exception display.
 881          *
 882          * @param Exception $e Exception to be shown to the user
 883          * @return string Sanitized text in a CSS/JS comment that can be returned to the user
 884          */
 885         public static function formatException( $e ) {
 886                 return self::makeComment( self::formatExceptionNoComment( $e ) );
 887         }
 888
 889         /**
 890          * Handle exception display.
 891          *
 892          * @since 1.25
 893          * @param Exception $e Exception to be shown to the user
 894          * @return string Sanitized text that can be returned to the user
 895          */
 896         protected static function formatExceptionNoComment( $e ) {
 897                 global $wgShowExceptionDetails;
 898
 899                 if ( $wgShowExceptionDetails ) {
 900                         return $e->__toString();
 901                 } else {
 902                         return wfMessage( 'internalerror' )->text();
 903                 }
 904         }
 905
 906         /**
 907          * Generate code for a response.
 908          *
 909          * @param ResourceLoaderContext $context Context in which to generate a response
 910          * @param array $modules List of module objects keyed by module name
 911          * @param array $missing List of requested module names that are unregistered (optional)
 912          * @return string Response data
 913          */
 914         public function makeModuleResponse( ResourceLoaderContext $context,
 915                 array $modules, array $missing = array()
 916         ) {
 917                 $out = '';
 918                 $states = array();
 919
 920                 if ( !count( $modules ) && !count( $missing ) ) {
 921                         return <<<MESSAGE
 922 /* This file is the Web entry point for MediaWiki's ResourceLoader:
 923    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
 924    no modules were requested. Max made me put this here. */
 925 MESSAGE;
 926                 }
 927
 928                 $image = $context->getImageObj();
 929                 if ( $image ) {
 930                         $data = $image->getImageData( $context );
 931                         if ( $data === false ) {
 932                                 $data = '';
 933                                 $this->errors[] = 'Image generation failed';
 934                         }
 935                         return $data;
 936                 }
 937
 938                 // Pre-fetch blobs
 939                 if ( $context->shouldIncludeMessages() ) {
 940                         try {
 941                                 $blobs = $this->blobStore->get( $this, $modules, $context->getLanguage() );
 942                         } catch ( Exception $e ) {
 943                                 MWExceptionHandler::logException( $e );
 944                                 wfDebugLog(
 945                                         'resourceloader',
 946                                         __METHOD__ . ": pre-fetching blobs from MessageBlobStore failed: $e"
 947                                 );
 948                                 $this->errors[] = self::formatExceptionNoComment( $e );
 949                         }
 950                 } else {
 951                         $blobs = array();
 952                 }
 953
 954                 foreach ( $missing as $name ) {
 955                         $states[$name] = 'missing';
 956                 }
 957
 958                 // Generate output
 959                 $isRaw = false;
 960                 foreach ( $modules as $name => $module ) {
 961                         /**
 962                          * @var $module ResourceLoaderModule
 963                          */
 964
 965                         try {
 966                                 $scripts = '';
 967                                 if ( $context->shouldIncludeScripts() ) {
 968                                         // If we are in debug mode, we'll want to return an array of URLs if possible
 969                                         // However, we can't do this if the module doesn't support it
 970                                         // We also can't do this if there is an only= parameter, because we have to give
 971                                         // the module a way to return a load.php URL without causing an infinite loop
 972                                         if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
 973                                                 $scripts = $module->getScriptURLsForDebug( $context );
 974                                         } else {
 975                                                 $scripts = $module->getScript( $context );
 976                                                 // rtrim() because there are usually a few line breaks
 977                                                 // after the last ';'. A new line at EOF, a new line
 978                                                 // added by ResourceLoaderFileModule::readScriptFiles, etc.
 979                                                 if ( is_string( $scripts )
 980                                                         && strlen( $scripts )
 981                                                         && substr( rtrim( $scripts ), -1 ) !== ';'
 982                                                 ) {
 983                                                         // Append semicolon to prevent weird bugs caused by files not
 984                                                         // terminating their statements right (bug 27054)
 985                                                         $scripts .= ";\n";
 986                                                 }
 987                                         }
 988                                 }
 989                                 // Styles
 990                                 $styles = array();
 991                                 if ( $context->shouldIncludeStyles() ) {
 992                                         // Don't create empty stylesheets like array( '' => '' ) for modules
 993                                         // that don't *have* any stylesheets (bug 38024).
 994                                         $stylePairs = $module->getStyles( $context );
 995                                         if ( count( $stylePairs ) ) {
 996                                                 // If we are in debug mode without &only= set, we'll want to return an array of URLs
 997                                                 // See comment near shouldIncludeScripts() for more details
 998                                                 if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
 999                                                         $styles = array(
1000                                                                 'url' => $module->getStyleURLsForDebug( $context )
1001                                                         );
1002                                                 } else {
1003                                                         // Minify CSS before embedding in mw.loader.implement call
1004                                                         // (unless in debug mode)
1005                                                         if ( !$context->getDebug() ) {
1006                                                                 foreach ( $stylePairs as $media => $style ) {
1007                                                                         // Can be either a string or an array of strings.
1008                                                                         if ( is_array( $style ) ) {
1009                                                                                 $stylePairs[$media] = array();
1010                                                                                 foreach ( $style as $cssText ) {
1011                                                                                         if ( is_string( $cssText ) ) {
1012                                                                                                 $stylePairs[$media][] = $this->filter( 'minify-css', $cssText );
1013                                                                                         }
1014                                                                                 }
1015                                                                         } elseif ( is_string( $style ) ) {
1016                                                                                 $stylePairs[$media] = $this->filter( 'minify-css', $style );
1017                                                                         }
1018                                                                 }
1019                                                         }
1020                                                         // Wrap styles into @media groups as needed and flatten into a numerical array
1021                                                         $styles = array(
1022                                                                 'css' => self::makeCombinedStyles( $stylePairs )
1023                                                         );
1024                                                 }
1025                                         }
1026                                 }
1027
1028                                 // Messages
1029                                 $messagesBlob = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
1030
1031                                 // Append output
1032                                 switch ( $context->getOnly() ) {
1033                                         case 'scripts':
1034                                                 if ( is_string( $scripts ) ) {
1035                                                         // Load scripts raw...
1036                                                         $out .= $scripts;
1037                                                 } elseif ( is_array( $scripts ) ) {
1038                                                         // ...except when $scripts is an array of URLs
1039                                                         $out .= self::makeLoaderImplementScript( $name, $scripts, array(), array() );
1040                                                 }
1041                                                 break;
1042                                         case 'styles':
1043                                                 // We no longer seperate into media, they are all combined now with
1044                                                 // custom media type groups into @media .. {} sections as part of the css string.
1045                                                 // Module returns either an empty array or a numerical array with css strings.
1046                                                 $out .= isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
1047                                                 break;
1048                                         default:
1049                                                 $out .= self::makeLoaderImplementScript(
1050                                                         $name,
1051                                                         $scripts,
1052                                                         $styles,
1053                                                         new XmlJsCode( $messagesBlob ),
1054                                                         $module->getTemplates()
1055                                                 );
1056                                                 break;
1057                                 }
1058                         } catch ( Exception $e ) {
1059                                 MWExceptionHandler::logException( $e );
1060                                 wfDebugLog( 'resourceloader', __METHOD__ . ": generating module package failed: $e" );
1061                                 $this->errors[] = self::formatExceptionNoComment( $e );
1062
1063                                 // Respond to client with error-state instead of module implementation
1064                                 $states[$name] = 'error';
1065                                 unset( $modules[$name] );
1066                         }
1067                         $isRaw |= $module->isRaw();
1068                 }
1069
1070                 // Update module states
1071                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
1072                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
1073                                 // Set the state of modules loaded as only scripts to ready as
1074                                 // they don't have an mw.loader.implement wrapper that sets the state
1075                                 foreach ( $modules as $name => $module ) {
1076                                         $states[$name] = 'ready';
1077                                 }
1078                         }
1079
1080                         // Set the state of modules we didn't respond to with mw.loader.implement
1081                         if ( count( $states ) ) {
1082                                 $out .= self::makeLoaderStateScript( $states );
1083                         }
1084                 } else {
1085                         if ( count( $states ) ) {
1086                                 $this->errors[] = 'Problematic modules: ' .
1087                                         FormatJson::encode( $states, ResourceLoader::inDebugMode() );
1088                         }
1089                 }
1090
1091                 $enableFilterCache = true;
1092                 if ( count( $modules ) === 1 && reset( $modules ) instanceof ResourceLoaderUserTokensModule ) {
1093                         // If we're building the embedded user.tokens, don't cache (T84960)
1094                         $enableFilterCache = false;
1095                 }
1096
1097                 if ( !$context->getDebug() ) {
1098                         if ( $context->getOnly() === 'styles' ) {
1099                                 $out = $this->filter( 'minify-css', $out );
1100                         } else {
1101                                 $out = $this->filter( 'minify-js', $out, array(
1102                                         'cache' => $enableFilterCache
1103                                 ) );
1104                         }
1105                 }
1106
1107                 return $out;
1108         }
1109
1110         /* Static Methods */
1111
1112         /**
1113          * Return JS code that calls mw.loader.implement with given module properties.
1114          *
1115          * @param string $name Module name
1116          * @param mixed $scripts List of URLs to JavaScript files or String of JavaScript code
1117          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1118          *   to CSS files keyed by media type
1119          * @param mixed $messages List of messages associated with this module. May either be an
1120          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1121          *   the same data, wrapped in an XmlJsCode object.
1122          * @param array $templates Keys are name of templates and values are the source of
1123          *   the template.
1124          * @throws MWException
1125          * @return string
1126          */
1127         public static function makeLoaderImplementScript(
1128                 $name, $scripts, $styles, $messages, $templates
1129         ) {
1130                 if ( is_string( $scripts ) ) {
1131                         $scripts = new XmlJsCode( "function ( $, jQuery ) {\n{$scripts}\n}" );
1132                 } elseif ( !is_array( $scripts ) ) {
1133                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1134                 }
1135                 // mw.loader.implement requires 'styles', 'messages' and 'templates' to be objects (not
1136                 // arrays). json_encode considers empty arrays to be numerical and outputs "[]" instead
1137                 // of "{}". Force them to objects.
1138                 $module = array(
1139                         $name,
1140                         $scripts,
1141                         (object) $styles,
1142                         (object) $messages,
1143                         (object) $templates,
1144                 );
1145                 self::trimArray( $module );
1146
1147                 return Xml::encodeJsCall( 'mw.loader.implement', $module, ResourceLoader::inDebugMode() );
1148         }
1149
1150         /**
1151          * Returns JS code which, when called, will register a given list of messages.
1152          *
1153          * @param mixed $messages Either an associative array mapping message key to value, or a
1154          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1155          * @return string
1156          */
1157         public static function makeMessageSetScript( $messages ) {
1158                 return Xml::encodeJsCall(
1159                         'mw.messages.set',
1160                         array( (object)$messages ),
1161                         ResourceLoader::inDebugMode()
1162                 );
1163         }
1164
1165         /**
1166          * Combines an associative array mapping media type to CSS into a
1167          * single stylesheet with "@media" blocks.
1168          *
1169          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1170          * @return array
1171          */
1172         public static function makeCombinedStyles( array $stylePairs ) {
1173                 $out = array();
1174                 foreach ( $stylePairs as $media => $styles ) {
1175                         // ResourceLoaderFileModule::getStyle can return the styles
1176                         // as a string or an array of strings. This is to allow separation in
1177                         // the front-end.
1178                         $styles = (array)$styles;
1179                         foreach ( $styles as $style ) {
1180                                 $style = trim( $style );
1181                                 // Don't output an empty "@media print { }" block (bug 40498)
1182                                 if ( $style !== '' ) {
1183                                         // Transform the media type based on request params and config
1184                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1185                                         $media = OutputPage::transformCssMedia( $media );
1186
1187                                         if ( $media === '' || $media == 'all' ) {
1188                                                 $out[] = $style;
1189                                         } elseif ( is_string( $media ) ) {
1190                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1191                                         }
1192                                         // else: skip
1193                                 }
1194                         }
1195                 }
1196                 return $out;
1197         }
1198
1199         /**
1200          * Returns a JS call to mw.loader.state, which sets the state of a
1201          * module or modules to a given value. Has two calling conventions:
1202          *
1203          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1204          *         Set the state of a single module called $name to $state
1205          *
1206          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
1207          *         Set the state of modules with the given names to the given states
1208          *
1209          * @param string $name
1210          * @param string $state
1211          * @return string
1212          */
1213         public static function makeLoaderStateScript( $name, $state = null ) {
1214                 if ( is_array( $name ) ) {
1215                         return Xml::encodeJsCall(
1216                                 'mw.loader.state',
1217                                 array( $name ),
1218                                 ResourceLoader::inDebugMode()
1219                         );
1220                 } else {
1221                         return Xml::encodeJsCall(
1222                                 'mw.loader.state',
1223                                 array( $name, $state ),
1224                                 ResourceLoader::inDebugMode()
1225                         );
1226                 }
1227         }
1228
1229         /**
1230          * Returns JS code which calls the script given by $script. The script will
1231          * be called with local variables name, version, dependencies and group,
1232          * which will have values corresponding to $name, $version, $dependencies
1233          * and $group as supplied.
1234          *
1235          * @param string $name Module name
1236          * @param string $version Module version hash
1237          * @param array $dependencies List of module names on which this module depends
1238          * @param string $group Group which the module is in.
1239          * @param string $source Source of the module, or 'local' if not foreign.
1240          * @param string $script JavaScript code
1241          * @return string
1242          */
1243         public static function makeCustomLoaderScript( $name, $version, $dependencies,
1244                 $group, $source, $script
1245         ) {
1246                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1247                 return Xml::encodeJsCall(
1248                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1249                         array( $name, $version, $dependencies, $group, $source ),
1250                         ResourceLoader::inDebugMode()
1251                 );
1252         }
1253
1254         private static function isEmptyObject( stdClass $obj ) {
1255                 foreach ( $obj as $key => &$value ) {
1256                         return false;
1257                 }
1258                 return true;
1259         }
1260
1261         /**
1262          * Remove empty values from the end of an array.
1263          *
1264          * Values considered empty:
1265          *
1266          * - null
1267          * - array()
1268          * - new XmlJsCode( '{}' )
1269          * - new stdClass() // (object) array()
1270          *
1271          * @param Array $array
1272          */
1273         private static function trimArray( Array &$array ) {
1274                 $i = count( $array );
1275                 while ( $i-- ) {
1276                         if ( $array[$i] === null
1277                                 || $array[$i] === array()
1278                                 || ( $array[$i] instanceof XmlJsCode && $array[$i]->value === '{}' )
1279                                 || ( $array[$i] instanceof stdClass && self::isEmptyObject( $array[$i] ) )
1280                         ) {
1281                                 unset( $array[$i] );
1282                         } else {
1283                                 break;
1284                         }
1285                 }
1286         }
1287
1288         /**
1289          * Returns JS code which calls mw.loader.register with the given
1290          * parameters. Has three calling conventions:
1291          *
1292          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version,
1293          *        $dependencies, $group, $source, $skip
1294          *     ):
1295          *        Register a single module.
1296          *
1297          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
1298          *        Register modules with the given names.
1299          *
1300          *   - ResourceLoader::makeLoaderRegisterScript( array(
1301          *        array( $name1, $version1, $dependencies1, $group1, $source1, $skip1 ),
1302          *        array( $name2, $version2, $dependencies1, $group2, $source2, $skip2 ),
1303          *        ...
1304          *     ) ):
1305          *        Registers modules with the given names and parameters.
1306          *
1307          * @param string $name Module name
1308          * @param string $version Module version hash
1309          * @param array $dependencies List of module names on which this module depends
1310          * @param string $group Group which the module is in
1311          * @param string $source Source of the module, or 'local' if not foreign
1312          * @param string $skip Script body of the skip function
1313          * @return string
1314          */
1315         public static function makeLoaderRegisterScript( $name, $version = null,
1316                 $dependencies = null, $group = null, $source = null, $skip = null
1317         ) {
1318                 if ( is_array( $name ) ) {
1319                         // Build module name index
1320                         $index = array();
1321                         foreach ( $name as $i => &$module ) {
1322                                 $index[$module[0]] = $i;
1323                         }
1324
1325                         // Transform dependency names into indexes when possible, they will be resolved by
1326                         // mw.loader.register on the other end
1327                         foreach ( $name as &$module ) {
1328                                 if ( isset( $module[2] ) ) {
1329                                         foreach ( $module[2] as &$dependency ) {
1330                                                 if ( isset( $index[$dependency] ) ) {
1331                                                         $dependency = $index[$dependency];
1332                                                 }
1333                                         }
1334                                 }
1335                         }
1336
1337                         array_walk( $name, array( 'self', 'trimArray' ) );
1338
1339                         return Xml::encodeJsCall(
1340                                 'mw.loader.register',
1341                                 array( $name ),
1342                                 ResourceLoader::inDebugMode()
1343                         );
1344                 } else {
1345                         $registration = array( $name, $version, $dependencies, $group, $source, $skip );
1346                         self::trimArray( $registration );
1347                         return Xml::encodeJsCall(
1348                                 'mw.loader.register',
1349                                 $registration,
1350                                 ResourceLoader::inDebugMode()
1351                         );
1352                 }
1353         }
1354
1355         /**
1356          * Returns JS code which calls mw.loader.addSource() with the given
1357          * parameters. Has two calling conventions:
1358          *
1359          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1360          *       Register a single source
1361          *
1362          *   - ResourceLoader::makeLoaderSourcesScript( array( $id1 => $loadUrl, $id2 => $loadUrl, ... ) );
1363          *       Register sources with the given IDs and properties.
1364          *
1365          * @param string $id Source ID
1366          * @param array $properties Source properties (see addSource())
1367          * @return string
1368          */
1369         public static function makeLoaderSourcesScript( $id, $properties = null ) {
1370                 if ( is_array( $id ) ) {
1371                         return Xml::encodeJsCall(
1372                                 'mw.loader.addSource',
1373                                 array( $id ),
1374                                 ResourceLoader::inDebugMode()
1375                         );
1376                 } else {
1377                         return Xml::encodeJsCall(
1378                                 'mw.loader.addSource',
1379                                 array( $id, $properties ),
1380                                 ResourceLoader::inDebugMode()
1381                         );
1382                 }
1383         }
1384
1385         /**
1386          * Returns JS code which runs given JS code if the client-side framework is
1387          * present.
1388          *
1389          * @deprecated since 1.25; use makeInlineScript instead
1390          * @param string $script JavaScript code
1391          * @return string
1392          */
1393         public static function makeLoaderConditionalScript( $script ) {
1394                 return "if(window.mw){\n" . trim( $script ) . "\n}";
1395         }
1396
1397         /**
1398          * Construct an inline script tag with given JS code.
1399          *
1400          * The code will be wrapped in a closure, and it will be executed by ResourceLoader
1401          * only if the client has adequate support for MediaWiki JavaScript code.
1402          *
1403          * @param string $script JavaScript code
1404          * @return string HTML
1405          */
1406         public static function makeInlineScript( $script ) {
1407                 $js = self::makeLoaderConditionalScript( $script );
1408                 return Html::inlineScript( $js );
1409         }
1410
1411         /**
1412          * Returns JS code which will set the MediaWiki configuration array to
1413          * the given value.
1414          *
1415          * @param array $configuration List of configuration values keyed by variable name
1416          * @return string
1417          */
1418         public static function makeConfigSetScript( array $configuration ) {
1419                 return Xml::encodeJsCall(
1420                         'mw.config.set',
1421                         array( $configuration ),
1422                         ResourceLoader::inDebugMode()
1423                 );
1424         }
1425
1426         /**
1427          * Convert an array of module names to a packed query string.
1428          *
1429          * For example, array( 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' )
1430          * becomes 'foo.bar,baz|bar.baz,quux'
1431          * @param array $modules List of module names (strings)
1432          * @return string Packed query string
1433          */
1434         public static function makePackedModulesString( $modules ) {
1435                 $groups = array(); // array( prefix => array( suffixes ) )
1436                 foreach ( $modules as $module ) {
1437                         $pos = strrpos( $module, '.' );
1438                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1439                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1440                         $groups[$prefix][] = $suffix;
1441                 }
1442
1443                 $arr = array();
1444                 foreach ( $groups as $prefix => $suffixes ) {
1445                         $p = $prefix === '' ? '' : $prefix . '.';
1446                         $arr[] = $p . implode( ',', $suffixes );
1447                 }
1448                 $str = implode( '|', $arr );
1449                 return $str;
1450         }
1451
1452         /**
1453          * Determine whether debug mode was requested
1454          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1455          * @return bool
1456          */
1457         public static function inDebugMode() {
1458                 if ( self::$debugMode === null ) {
1459                         global $wgRequest, $wgResourceLoaderDebug;
1460                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1461                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1462                         );
1463                 }
1464                 return self::$debugMode;
1465         }
1466
1467         /**
1468          * Reset static members used for caching.
1469          *
1470          * Global state and $wgRequest are evil, but we're using it right
1471          * now and sometimes we need to be able to force ResourceLoader to
1472          * re-evaluate the context because it has changed (e.g. in the test suite).
1473          */
1474         public static function clearCache() {
1475                 self::$debugMode = null;
1476         }
1477
1478         /**
1479          * Build a load.php URL
1480          *
1481          * @since 1.24
1482          * @param string $source Name of the ResourceLoader source
1483          * @param ResourceLoaderContext $context
1484          * @param array $extraQuery
1485          * @return string URL to load.php. May be protocol-relative (if $wgLoadScript is procol-relative)
1486          */
1487         public function createLoaderURL( $source, ResourceLoaderContext $context,
1488                 $extraQuery = array()
1489         ) {
1490                 $query = self::createLoaderQuery( $context, $extraQuery );
1491                 $script = $this->getLoadScript( $source );
1492
1493                 // Prevent the IE6 extension check from being triggered (bug 28840)
1494                 // by appending a character that's invalid in Windows extensions ('*')
1495                 return wfExpandUrl( wfAppendQuery( $script, $query ) . '&*', PROTO_RELATIVE );
1496         }
1497
1498         /**
1499          * Build a load.php URL
1500          * @deprecated since 1.24 Use createLoaderURL() instead
1501          * @param array $modules Array of module names (strings)
1502          * @param string $lang Language code
1503          * @param string $skin Skin name
1504          * @param string|null $user User name. If null, the &user= parameter is omitted
1505          * @param string|null $version Versioning timestamp
1506          * @param bool $debug Whether the request should be in debug mode
1507          * @param string|null $only &only= parameter
1508          * @param bool $printable Printable mode
1509          * @param bool $handheld Handheld mode
1510          * @param array $extraQuery Extra query parameters to add
1511          * @return string URL to load.php. May be protocol-relative (if $wgLoadScript is procol-relative)
1512          */
1513         public static function makeLoaderURL( $modules, $lang, $skin, $user = null,
1514                 $version = null, $debug = false, $only = null, $printable = false,
1515                 $handheld = false, $extraQuery = array()
1516         ) {
1517                 global $wgLoadScript;
1518
1519                 $query = self::makeLoaderQuery( $modules, $lang, $skin, $user, $version, $debug,
1520                         $only, $printable, $handheld, $extraQuery
1521                 );
1522
1523                 // Prevent the IE6 extension check from being triggered (bug 28840)
1524                 // by appending a character that's invalid in Windows extensions ('*')
1525                 return wfExpandUrl( wfAppendQuery( $wgLoadScript, $query ) . '&*', PROTO_RELATIVE );
1526         }
1527
1528         /**
1529          * Helper for createLoaderURL()
1530          *
1531          * @since 1.24
1532          * @see makeLoaderQuery
1533          * @param ResourceLoaderContext $context
1534          * @param array $extraQuery
1535          * @return array
1536          */
1537         public static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = array() ) {
1538                 return self::makeLoaderQuery(
1539                         $context->getModules(),
1540                         $context->getLanguage(),
1541                         $context->getSkin(),
1542                         $context->getUser(),
1543                         $context->getVersion(),
1544                         $context->getDebug(),
1545                         $context->getOnly(),
1546                         $context->getRequest()->getBool( 'printable' ),
1547                         $context->getRequest()->getBool( 'handheld' ),
1548                         $extraQuery
1549                 );
1550         }
1551
1552         /**
1553          * Build a query array (array representation of query string) for load.php. Helper
1554          * function for makeLoaderURL().
1555          *
1556          * @param array $modules
1557          * @param string $lang
1558          * @param string $skin
1559          * @param string $user
1560          * @param string $version
1561          * @param bool $debug
1562          * @param string $only
1563          * @param bool $printable
1564          * @param bool $handheld
1565          * @param array $extraQuery
1566          *
1567          * @return array
1568          */
1569         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1570                 $version = null, $debug = false, $only = null, $printable = false,
1571                 $handheld = false, $extraQuery = array()
1572         ) {
1573                 $query = array(
1574                         'modules' => self::makePackedModulesString( $modules ),
1575                         'lang' => $lang,
1576                         'skin' => $skin,
1577                         'debug' => $debug ? 'true' : 'false',
1578                 );
1579                 if ( $user !== null ) {
1580                         $query['user'] = $user;
1581                 }
1582                 if ( $version !== null ) {
1583                         $query['version'] = $version;
1584                 }
1585                 if ( $only !== null ) {
1586                         $query['only'] = $only;
1587                 }
1588                 if ( $printable ) {
1589                         $query['printable'] = 1;
1590                 }
1591                 if ( $handheld ) {
1592                         $query['handheld'] = 1;
1593                 }
1594                 $query += $extraQuery;
1595
1596                 // Make queries uniform in order
1597                 ksort( $query );
1598                 return $query;
1599         }
1600
1601         /**
1602          * Check a module name for validity.
1603          *
1604          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1605          * at most 255 bytes.
1606          *
1607          * @param string $moduleName Module name to check
1608          * @return bool Whether $moduleName is a valid module name
1609          */
1610         public static function isValidModuleName( $moduleName ) {
1611                 return !preg_match( '/[|,!]/', $moduleName ) && strlen( $moduleName ) <= 255;
1612         }
1613
1614         /**
1615          * Returns LESS compiler set up for use with MediaWiki
1616          *
1617          * @param Config $config
1618          * @throws MWException
1619          * @since 1.22
1620          * @return lessc
1621          */
1622         public static function getLessCompiler( Config $config ) {
1623                 // When called from the installer, it is possible that a required PHP extension
1624                 // is missing (at least for now; see bug 47564). If this is the case, throw an
1625                 // exception (caught by the installer) to prevent a fatal error later on.
1626                 if ( !class_exists( 'lessc' ) ) {
1627                         throw new MWException( 'MediaWiki requires the lessphp compiler' );
1628                 }
1629                 if ( !function_exists( 'ctype_digit' ) ) {
1630                         throw new MWException( 'lessc requires the Ctype extension' );
1631                 }
1632
1633                 $less = new lessc();
1634                 $less->setPreserveComments( true );
1635                 $less->setVariables( self::getLessVars( $config ) );
1636                 $less->setImportDir( $config->get( 'ResourceLoaderLESSImportPaths' ) );
1637                 foreach ( $config->get( 'ResourceLoaderLESSFunctions' ) as $name => $func ) {
1638                         $less->registerFunction( $name, $func );
1639                 }
1640                 return $less;
1641         }
1642
1643         /**
1644          * Get global LESS variables.
1645          *
1646          * @param Config $config
1647          * @since 1.22
1648          * @return array Map of variable names to string CSS values.
1649          */
1650         public static function getLessVars( Config $config ) {
1651                 if ( !self::$lessVars ) {
1652                         $lessVars = $config->get( 'ResourceLoaderLESSVars' );
1653                         Hooks::run( 'ResourceLoaderGetLessVars', array( &$lessVars ) );
1654                         // Sort by key to ensure consistent hashing for cache lookups.
1655                         ksort( $lessVars );
1656                         self::$lessVars = $lessVars;
1657                 }
1658                 return self::$lessVars;
1659         }
1660 }