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