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 array */
  36         protected static $requiredSourceProperties = array( 'loadScript' );
  37
  38         /** @var bool */
  39         protected static $debugMode = null;
  40
  41         /** @var array Module name/ResourceLoaderModule object pairs */
  42         protected $modules = array();
  43
  44         /** @var array Associative array mapping module name to info associative array */
  45         protected $moduleInfos = array();
  46
  47         /**
  48          * @var array Associative array mapping framework ids to a list of names of test suite modules
  49          *      like array( 'qunit' => array( 'mediawiki.tests.qunit.suites', 'ext.foo.tests', .. ), .. )
  50          */
  51         protected $testModuleNames = array();
  52
  53         /** @var array E.g. array( 'source-id' => array( 'loadScript' => 'http://.../load.php' ) ) */
  54         protected $sources = array();
  55
  56         /** @var bool */
  57         protected $hasErrors = false;
  58
  59         /**
  60          * Load information stored in the database about modules.
  61          *
  62          * This method grabs modules dependencies from the database and updates modules
  63          * objects.
  64          *
  65          * This is not inside the module code because it is much faster to
  66          * request all of the information at once than it is to have each module
  67          * requests its own information. This sacrifice of modularity yields a substantial
  68          * performance improvement.
  69          *
  70          * @param array $modules List of module names to preload information for
  71          * @param ResourceLoaderContext $context Context to load the information within
  72          */
  73         public function preloadModuleInfo( array $modules, ResourceLoaderContext $context ) {
  74                 if ( !count( $modules ) ) {
  75                         // Or else Database*::select() will explode, plus it's cheaper!
  76                         return;
  77                 }
  78                 $dbr = wfGetDB( DB_SLAVE );
  79                 $skin = $context->getSkin();
  80                 $lang = $context->getLanguage();
  81
  82                 // Get file dependency information
  83                 $res = $dbr->select( 'module_deps', array( 'md_module', 'md_deps' ), array(
  84                                 'md_module' => $modules,
  85                                 'md_skin' => $skin
  86                         ), __METHOD__
  87                 );
  88
  89                 // Set modules' dependencies
  90                 $modulesWithDeps = array();
  91                 foreach ( $res as $row ) {
  92                         $module = $this->getModule( $row->md_module );
  93                         if ( $module ) {
  94                                 $module->setFileDependencies( $skin, FormatJson::decode( $row->md_deps, true ) );
  95                                 $modulesWithDeps[] = $row->md_module;
  96                         }
  97                 }
  98
  99                 // Register the absence of a dependency row too
 100                 foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
 101                         $module = $this->getModule( $name );
 102                         if ( $module ) {
 103                                 $this->getModule( $name )->setFileDependencies( $skin, array() );
 104                         }
 105                 }
 106
 107                 // Get message blob mtimes. Only do this for modules with messages
 108                 $modulesWithMessages = array();
 109                 foreach ( $modules as $name ) {
 110                         $module = $this->getModule( $name );
 111                         if ( $module && count( $module->getMessages() ) ) {
 112                                 $modulesWithMessages[] = $name;
 113                         }
 114                 }
 115                 $modulesWithoutMessages = array_flip( $modules ); // Will be trimmed down by the loop below
 116                 if ( count( $modulesWithMessages ) ) {
 117                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
 118                                         'mr_resource' => $modulesWithMessages,
 119                                         'mr_lang' => $lang
 120                                 ), __METHOD__
 121                         );
 122                         foreach ( $res as $row ) {
 123                                 $module = $this->getModule( $row->mr_resource );
 124                                 if ( $module ) {
 125                                         $module->setMsgBlobMtime( $lang, wfTimestamp( TS_UNIX, $row->mr_timestamp ) );
 126                                         unset( $modulesWithoutMessages[$row->mr_resource] );
 127                                 }
 128                         }
 129                 }
 130                 foreach ( array_keys( $modulesWithoutMessages ) as $name ) {
 131                         $module = $this->getModule( $name );
 132                         if ( $module ) {
 133                                 $module->setMsgBlobMtime( $lang, 0 );
 134                         }
 135                 }
 136         }
 137
 138         /**
 139          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 140          *
 141          * Available filters are:
 142          *
 143          *    - minify-js \see JavaScriptMinifier::minify
 144          *    - minify-css \see CSSMin::minify
 145          *
 146          * If $data is empty, only contains whitespace or the filter was unknown,
 147          * $data is returned unmodified.
 148          *
 149          * @param string $filter Name of filter to run
 150          * @param string $data Text to filter, such as JavaScript or CSS text
 151          * @param string $cacheReport Whether to include the cache key report
 152          * @return string Filtered data, or a comment containing an error message
 153          */
 154         public function filter( $filter, $data, $cacheReport = true ) {
 155                 global $wgResourceLoaderMinifierStatementsOnOwnLine, $wgResourceLoaderMinifierMaxLineLength;
 156                 wfProfileIn( __METHOD__ );
 157
 158                 // For empty/whitespace-only data or for unknown filters, don't perform
 159                 // any caching or processing
 160                 if ( trim( $data ) === '' || !in_array( $filter, array( 'minify-js', 'minify-css' ) ) ) {
 161                         wfProfileOut( __METHOD__ );
 162                         return $data;
 163                 }
 164
 165                 // Try for cache hit
 166                 // Use CACHE_ANYTHING since filtering is very slow compared to DB queries
 167                 $key = wfMemcKey( 'resourceloader', 'filter', $filter, self::$filterCacheVersion, md5( $data ) );
 168                 $cache = wfGetCache( CACHE_ANYTHING );
 169                 $cacheEntry = $cache->get( $key );
 170                 if ( is_string( $cacheEntry ) ) {
 171                         wfIncrStats( "rl-$filter-cache-hits" );
 172                         wfProfileOut( __METHOD__ );
 173                         return $cacheEntry;
 174                 }
 175
 176                 $result = '';
 177                 // Run the filter - we've already verified one of these will work
 178                 try {
 179                         wfIncrStats( "rl-$filter-cache-misses" );
 180                         switch ( $filter ) {
 181                                 case 'minify-js':
 182                                         $result = JavaScriptMinifier::minify( $data,
 183                                                 $wgResourceLoaderMinifierStatementsOnOwnLine,
 184                                                 $wgResourceLoaderMinifierMaxLineLength
 185                                         );
 186                                         if ( $cacheReport ) {
 187                                                 $result .= "\n/* cache key: $key */";
 188                                         }
 189                                         break;
 190                                 case 'minify-css':
 191                                         $result = CSSMin::minify( $data );
 192                                         if ( $cacheReport ) {
 193                                                 $result .= "\n/* cache key: $key */";
 194                                         }
 195                                         break;
 196                         }
 197
 198                         // Save filtered text to Memcached
 199                         $cache->set( $key, $result );
 200                 } catch ( Exception $e ) {
 201                         MWExceptionHandler::logException( $e );
 202                         wfDebugLog( 'resourceloader', __METHOD__ . ": minification failed: $e" );
 203                         $this->hasErrors = true;
 204                         // Return exception as a comment
 205                         $result = self::formatException( $e );
 206                 }
 207
 208                 wfProfileOut( __METHOD__ );
 209
 210                 return $result;
 211         }
 212
 213         /* Methods */
 214
 215         /**
 216          * Register core modules and runs registration hooks.
 217          */
 218         public function __construct() {
 219                 global $IP, $wgResourceModules, $wgResourceLoaderSources, $wgLoadScript, $wgEnableJavaScriptTest;
 220
 221                 wfProfileIn( __METHOD__ );
 222
 223                 // Add 'local' source first
 224                 $this->addSource(
 225                         'local',
 226                         array( 'loadScript' => $wgLoadScript, 'apiScript' => wfScript( 'api' ) )
 227                 );
 228
 229                 // Add other sources
 230                 $this->addSource( $wgResourceLoaderSources );
 231
 232                 // Register core modules
 233                 $this->register( include "$IP/resources/Resources.php" );
 234                 // Register extension modules
 235                 wfRunHooks( 'ResourceLoaderRegisterModules', array( &$this ) );
 236                 $this->register( $wgResourceModules );
 237
 238                 if ( $wgEnableJavaScriptTest === true ) {
 239                         $this->registerTestModules();
 240                 }
 241
 242                 wfProfileOut( __METHOD__ );
 243         }
 244
 245         /**
 246          * Register a module with the ResourceLoader system.
 247          *
 248          * @param mixed $name Name of module as a string or List of name/object pairs as an array
 249          * @param array $info Module info array. For backwards compatibility with 1.17alpha,
 250          *   this may also be a ResourceLoaderModule object. Optional when using
 251          *   multiple-registration calling style.
 252          * @throws MWException If a duplicate module registration is attempted
 253          * @throws MWException If a module name contains illegal characters (pipes or commas)
 254          * @throws MWException If something other than a ResourceLoaderModule is being registered
 255          * @return bool False if there were any errors, in which case one or more modules were
 256          *   not registered
 257          */
 258         public function register( $name, $info = null ) {
 259                 wfProfileIn( __METHOD__ );
 260
 261                 // Allow multiple modules to be registered in one call
 262                 $registrations = is_array( $name ) ? $name : array( $name => $info );
 263                 foreach ( $registrations as $name => $info ) {
 264                         // Disallow duplicate registrations
 265                         if ( isset( $this->moduleInfos[$name] ) ) {
 266                                 wfProfileOut( __METHOD__ );
 267                                 // A module has already been registered by this name
 268                                 throw new MWException(
 269                                         'ResourceLoader duplicate registration error. ' .
 270                                         'Another module has already been registered as ' . $name
 271                                 );
 272                         }
 273
 274                         // Check $name for validity
 275                         if ( !self::isValidModuleName( $name ) ) {
 276                                 wfProfileOut( __METHOD__ );
 277                                 throw new MWException( "ResourceLoader module name '$name' is invalid, "
 278                                         . "see ResourceLoader::isValidModuleName()" );
 279                         }
 280
 281                         // Attach module
 282                         if ( $info instanceof ResourceLoaderModule ) {
 283                                 $this->moduleInfos[$name] = array( 'object' => $info );
 284                                 $info->setName( $name );
 285                                 $this->modules[$name] = $info;
 286                         } elseif ( is_array( $info ) ) {
 287                                 // New calling convention
 288                                 $this->moduleInfos[$name] = $info;
 289                         } else {
 290                                 wfProfileOut( __METHOD__ );
 291                                 throw new MWException(
 292                                         'ResourceLoader module info type error for module \'' . $name .
 293                                         '\': expected ResourceLoaderModule or array (got: ' . gettype( $info ) . ')'
 294                                 );
 295                         }
 296
 297                         // Last-minute changes
 298
 299                         // Apply custom skin-defined styles to existing modules.
 300                         if ( $this->isFileModule( $name ) ) {
 301                                 global $wgResourceModuleSkinStyles;
 302                                 foreach ( $wgResourceModuleSkinStyles as $skinName => $skinStyles ) {
 303                                         // If this module already defines skinStyles for this skin, ignore $wgResourceModuleSkinStyles.
 304                                         if ( isset( $this->moduleInfos[$name]['skinStyles'][$skinName] ) ) {
 305                                                 continue;
 306                                         }
 307
 308                                         // If $name is preceded with a '+', the defined style files will be added to 'default'
 309                                         // skinStyles, otherwise 'default' will be ignored as it normally would be.
 310                                         if ( isset( $skinStyles[$name] ) ) {
 311                                                 $paths = (array)$skinStyles[$name];
 312                                                 $styleFiles = array();
 313                                         } elseif ( isset( $skinStyles['+' . $name] ) ) {
 314                                                 $paths = (array)$skinStyles['+' . $name];
 315                                                 $styleFiles = isset( $this->moduleInfos[$name]['skinStyles']['default'] ) ?
 316                                                         $this->moduleInfos[$name]['skinStyles']['default'] :
 317                                                         array();
 318                                         } else {
 319                                                 continue;
 320                                         }
 321
 322                                         // Add new file paths, remapping them to refer to our directories and not use settings
 323                                         // from the module we're modifying. These can come from the base definition or be defined
 324                                         // for each module.
 325                                         list( $localBasePath, $remoteBasePath ) =
 326                                                 ResourceLoaderFileModule::extractBasePaths( $skinStyles );
 327                                         list( $localBasePath, $remoteBasePath ) =
 328                                                 ResourceLoaderFileModule::extractBasePaths( $paths, $localBasePath, $remoteBasePath );
 329
 330                                         foreach ( $paths as $path ) {
 331                                                 $styleFiles[] = new ResourceLoaderFilePath( $path, $localBasePath, $remoteBasePath );
 332                                         }
 333
 334                                         $this->moduleInfos[$name]['skinStyles'][$skinName] = $styleFiles;
 335                                 }
 336                         }
 337                 }
 338
 339                 wfProfileOut( __METHOD__ );
 340         }
 341
 342         /**
 343          */
 344         public function registerTestModules() {
 345                 global $IP, $wgEnableJavaScriptTest;
 346
 347                 if ( $wgEnableJavaScriptTest !== true ) {
 348                         throw new MWException( 'Attempt to register JavaScript test modules '
 349                                 . 'but <code>$wgEnableJavaScriptTest</code> is false. '
 350                                 . 'Edit your <code>LocalSettings.php</code> to enable it.' );
 351                 }
 352
 353                 wfProfileIn( __METHOD__ );
 354
 355                 // Get core test suites
 356                 $testModules = array();
 357                 $testModules['qunit'] = array();
 358                 // Get other test suites (e.g. from extensions)
 359                 wfRunHooks( 'ResourceLoaderTestModules', array( &$testModules, &$this ) );
 360
 361                 // Add the testrunner (which configures QUnit) to the dependencies.
 362                 // Since it must be ready before any of the test suites are executed.
 363                 foreach ( $testModules['qunit'] as &$module ) {
 364                         // Make sure all test modules are top-loading so that when QUnit starts
 365                         // on document-ready, it will run once and finish. If some tests arrive
 366                         // later (possibly after QUnit has already finished) they will be ignored.
 367                         $module['position'] = 'top';
 368                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 369                 }
 370
 371                 $testModules['qunit'] =
 372                         ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules['qunit'];
 373
 374                 foreach ( $testModules as $id => $names ) {
 375                         // Register test modules
 376                         $this->register( $testModules[$id] );
 377
 378                         // Keep track of their names so that they can be loaded together
 379                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 380                 }
 381
 382                 wfProfileOut( __METHOD__ );
 383         }
 384
 385         /**
 386          * Add a foreign source of modules.
 387          *
 388          * Source properties:
 389          * 'loadScript': URL (either fully-qualified or protocol-relative) of load.php for this source
 390          *
 391          * @param mixed $id Source ID (string), or array( id1 => props1, id2 => props2, ... )
 392          * @param array $properties Source properties
 393          * @throws MWException
 394          */
 395         public function addSource( $id, $properties = null ) {
 396                 // Allow multiple sources to be registered in one call
 397                 if ( is_array( $id ) ) {
 398                         foreach ( $id as $key => $value ) {
 399                                 $this->addSource( $key, $value );
 400                         }
 401                         return;
 402                 }
 403
 404                 // Disallow duplicates
 405                 if ( isset( $this->sources[$id] ) ) {
 406                         throw new MWException(
 407                                 'ResourceLoader duplicate source addition error. ' .
 408                                 'Another source has already been registered as ' . $id
 409                         );
 410                 }
 411
 412                 // Validate properties
 413                 foreach ( self::$requiredSourceProperties as $prop ) {
 414                         if ( !isset( $properties[$prop] ) ) {
 415                                 throw new MWException( "Required property $prop missing from source ID $id" );
 416                         }
 417                 }
 418
 419                 $this->sources[$id] = $properties;
 420         }
 421
 422         /**
 423          * Get a list of module names.
 424          *
 425          * @return array List of module names
 426          */
 427         public function getModuleNames() {
 428                 return array_keys( $this->moduleInfos );
 429         }
 430
 431         /**
 432          * Get a list of test module names for one (or all) frameworks.
 433          *
 434          * If the given framework id is unknkown, or if the in-object variable is not an array,
 435          * then it will return an empty array.
 436          *
 437          * @param string $framework Get only the test module names for one
 438          *   particular framework (optional)
 439          * @return array
 440          */
 441         public function getTestModuleNames( $framework = 'all' ) {
 442                 /** @todo api siteinfo prop testmodulenames modulenames */
 443                 if ( $framework == 'all' ) {
 444                         return $this->testModuleNames;
 445                 } elseif ( isset( $this->testModuleNames[$framework] )
 446                         && is_array( $this->testModuleNames[$framework] )
 447                 ) {
 448                         return $this->testModuleNames[$framework];
 449                 } else {
 450                         return array();
 451                 }
 452         }
 453
 454         /**
 455          * Get the ResourceLoaderModule object for a given module name.
 456          *
 457          * If an array of module parameters exists but a ResourceLoaderModule object has not
 458          * yet been instantiated, this method will instantiate and cache that object such that
 459          * subsequent calls simply return the same object.
 460          *
 461          * @param string $name Module name
 462          * @return ResourceLoaderModule|null If module has been registered, return a
 463          *  ResourceLoaderModule instance. Otherwise, return null.
 464          */
 465         public function getModule( $name ) {
 466                 if ( !isset( $this->modules[$name] ) ) {
 467                         if ( !isset( $this->moduleInfos[$name] ) ) {
 468                                 // No such module
 469                                 return null;
 470                         }
 471                         // Construct the requested object
 472                         $info = $this->moduleInfos[$name];
 473                         /** @var ResourceLoaderModule $object */
 474                         if ( isset( $info['object'] ) ) {
 475                                 // Object given in info array
 476                                 $object = $info['object'];
 477                         } else {
 478                                 if ( !isset( $info['class'] ) ) {
 479                                         $class = 'ResourceLoaderFileModule';
 480                                 } else {
 481                                         $class = $info['class'];
 482                                 }
 483                                 $object = new $class( $info );
 484                         }
 485                         $object->setName( $name );
 486                         $this->modules[$name] = $object;
 487                 }
 488
 489                 return $this->modules[$name];
 490         }
 491
 492         /**
 493          * Return whether the definition of a module corresponds to a simple ResourceLoaderFileModule.
 494          *
 495          * @param string $name Module name
 496          * @return bool
 497          */
 498         protected function isFileModule( $name ) {
 499                 if ( !isset( $this->moduleInfos[$name] ) ) {
 500                         return false;
 501                 }
 502                 $info = $this->moduleInfos[$name];
 503                 if ( isset( $info['object'] ) || isset( $info['class'] ) ) {
 504                         return false;
 505                 }
 506                 return true;
 507         }
 508
 509         /**
 510          * Get the list of sources.
 511          *
 512          * @return array Like array( id => array of properties, .. )
 513          */
 514         public function getSources() {
 515                 return $this->sources;
 516         }
 517
 518         /**
 519          * Get the URL to the load.php endpoint for the given
 520          * ResourceLoader source
 521          *
 522          * @since 1.24
 523          * @param string $source
 524          * @throws MWException On an invalid $source name
 525          * @return string
 526          */
 527         public function getLoadScript( $source ) {
 528                 if ( !isset( $this->sources[$source] ) ) {
 529                         throw new MWException( "The $source source was never registered in ResourceLoader." );
 530                 }
 531                 return $this->sources[$source]['loadScript'];
 532         }
 533
 534         /**
 535          * Output a response to a load request, including the content-type header.
 536          *
 537          * @param ResourceLoaderContext $context Context in which a response should be formed
 538          */
 539         public function respond( ResourceLoaderContext $context ) {
 540                 global $wgCacheEpoch, $wgUseFileCache;
 541
 542                 // Use file cache if enabled and available...
 543                 if ( $wgUseFileCache ) {
 544                         $fileCache = ResourceFileCache::newFromContext( $context );
 545                         if ( $this->tryRespondFromFileCache( $fileCache, $context ) ) {
 546                                 return; // output handled
 547                         }
 548                 }
 549
 550                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 551                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 552                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 553                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 554                 // the whole thing in our own output buffer to be sure the active buffer
 555                 // doesn't use ob_gzhandler.
 556                 // See http://bugs.php.net/bug.php?id=36514
 557                 ob_start();
 558
 559                 wfProfileIn( __METHOD__ );
 560                 $errors = '';
 561
 562                 // Find out which modules are missing and instantiate the others
 563                 $modules = array();
 564                 $missing = array();
 565                 foreach ( $context->getModules() as $name ) {
 566                         $module = $this->getModule( $name );
 567                         if ( $module ) {
 568                                 // Do not allow private modules to be loaded from the web.
 569                                 // This is a security issue, see bug 34907.
 570                                 if ( $module->getGroup() === 'private' ) {
 571                                         wfDebugLog( 'resourceloader', __METHOD__ . ": request for private module '$name' denied" );
 572                                         $this->hasErrors = true;
 573                                         // Add exception to the output as a comment
 574                                         $errors .= self::makeComment( "Cannot show private module \"$name\"" );
 575
 576                                         continue;
 577                                 }
 578                                 $modules[$name] = $module;
 579                         } else {
 580                                 $missing[] = $name;
 581                         }
 582                 }
 583
 584                 // Preload information needed to the mtime calculation below
 585                 try {
 586                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 587                 } catch ( Exception $e ) {
 588                         MWExceptionHandler::logException( $e );
 589                         wfDebugLog( 'resourceloader', __METHOD__ . ": preloading module info failed: $e" );
 590                         $this->hasErrors = true;
 591                         // Add exception to the output as a comment
 592                         $errors .= self::formatException( $e );
 593                 }
 594
 595                 wfProfileIn( __METHOD__ . '-getModifiedTime' );
 596
 597                 // To send Last-Modified and support If-Modified-Since, we need to detect
 598                 // the last modified time
 599                 $mtime = wfTimestamp( TS_UNIX, $wgCacheEpoch );
 600                 foreach ( $modules as $module ) {
 601                         /**
 602                          * @var $module ResourceLoaderModule
 603                          */
 604                         try {
 605                                 // Calculate maximum modified time
 606                                 $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 607                         } catch ( Exception $e ) {
 608                                 MWExceptionHandler::logException( $e );
 609                                 wfDebugLog( 'resourceloader', __METHOD__ . ": calculating maximum modified time failed: $e" );
 610                                 $this->hasErrors = true;
 611                                 // Add exception to the output as a comment
 612                                 $errors .= self::formatException( $e );
 613                         }
 614                 }
 615
 616                 wfProfileOut( __METHOD__ . '-getModifiedTime' );
 617
 618                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 619                 if ( $this->tryRespondLastModified( $context, $mtime ) ) {
 620                         wfProfileOut( __METHOD__ );
 621                         return; // output handled (buffers cleared)
 622                 }
 623
 624                 // Generate a response
 625                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 626
 627                 // Prepend comments indicating exceptions
 628                 $response = $errors . $response;
 629
 630                 // Capture any PHP warnings from the output buffer and append them to the
 631                 // response in a comment if we're in debug mode.
 632                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 633                         $response = self::makeComment( $warnings ) . $response;
 634                         $this->hasErrors = true;
 635                 }
 636
 637                 // Save response to file cache unless there are errors
 638                 if ( isset( $fileCache ) && !$errors && !count( $missing ) ) {
 639                         // Cache single modules...and other requests if there are enough hits
 640                         if ( ResourceFileCache::useFileCache( $context ) ) {
 641                                 if ( $fileCache->isCacheWorthy() ) {
 642                                         $fileCache->saveText( $response );
 643                                 } else {
 644                                         $fileCache->incrMissesRecent( $context->getRequest() );
 645                                 }
 646                         }
 647                 }
 648
 649                 // Send content type and cache related headers
 650                 $this->sendResponseHeaders( $context, $mtime, $this->hasErrors );
 651
 652                 // Remove the output buffer and output the response
 653                 ob_end_clean();
 654                 echo $response;
 655
 656                 wfProfileOut( __METHOD__ );
 657         }
 658
 659         /**
 660          * Send content type and last modified headers to the client.
 661          * @param ResourceLoaderContext $context
 662          * @param string $mtime TS_MW timestamp to use for last-modified
 663          * @param bool $errors Whether there are commented-out errors in the response
 664          * @return void
 665          */
 666         protected function sendResponseHeaders( ResourceLoaderContext $context, $mtime, $errors ) {
 667                 global $wgResourceLoaderMaxage;
 668                 // If a version wasn't specified we need a shorter expiry time for updates
 669                 // to propagate to clients quickly
 670                 // If there were errors, we also need a shorter expiry time so we can recover quickly
 671                 if ( is_null( $context->getVersion() ) || $errors ) {
 672                         $maxage = $wgResourceLoaderMaxage['unversioned']['client'];
 673                         $smaxage = $wgResourceLoaderMaxage['unversioned']['server'];
 674                 // If a version was specified we can use a longer expiry time since changing
 675                 // version numbers causes cache misses
 676                 } else {
 677                         $maxage = $wgResourceLoaderMaxage['versioned']['client'];
 678                         $smaxage = $wgResourceLoaderMaxage['versioned']['server'];
 679                 }
 680                 if ( $context->getOnly() === 'styles' ) {
 681                         header( 'Content-Type: text/css; charset=utf-8' );
 682                         header( 'Access-Control-Allow-Origin: *' );
 683                 } else {
 684                         header( 'Content-Type: text/javascript; charset=utf-8' );
 685                 }
 686                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 687                 if ( $context->getDebug() ) {
 688                         // Do not cache debug responses
 689                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 690                         header( 'Pragma: no-cache' );
 691                 } else {
 692                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 693                         $exp = min( $maxage, $smaxage );
 694                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 695                 }
 696         }
 697
 698         /**
 699          * Respond with 304 Last Modified if appropiate.
 700          *
 701          * If there's an If-Modified-Since header, respond with a 304 appropriately
 702          * and clear out the output buffer. If the client cache is too old then do nothing.
 703          *
 704          * @param ResourceLoaderContext $context
 705          * @param string $mtime The TS_MW timestamp to check the header against
 706          * @return bool True if 304 header sent and output handled
 707          */
 708         protected function tryRespondLastModified( ResourceLoaderContext $context, $mtime ) {
 709                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 710                 // Some clients send "timestamp;length=123". Strip the part after the first ';'
 711                 // so we get a valid timestamp.
 712                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 713                 // Never send 304s in debug mode
 714                 if ( $ims !== false && !$context->getDebug() ) {
 715                         $imsTS = strtok( $ims, ';' );
 716                         if ( $mtime <= wfTimestamp( TS_UNIX, $imsTS ) ) {
 717                                 // There's another bug in ob_gzhandler (see also the comment at
 718                                 // the top of this function) that causes it to gzip even empty
 719                                 // responses, meaning it's impossible to produce a truly empty
 720                                 // response (because the gzip header is always there). This is
 721                                 // a problem because 304 responses have to be completely empty
 722                                 // per the HTTP spec, and Firefox behaves buggily when they're not.
 723                                 // See also http://bugs.php.net/bug.php?id=51579
 724                                 // To work around this, we tear down all output buffering before
 725                                 // sending the 304.
 726                                 wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 727
 728                                 header( 'HTTP/1.0 304 Not Modified' );
 729                                 header( 'Status: 304 Not Modified' );
 730                                 return true;
 731                         }
 732                 }
 733                 return false;
 734         }
 735
 736         /**
 737          * Send out code for a response from file cache if possible.
 738          *
 739          * @param ResourceFileCache $fileCache Cache object for this request URL
 740          * @param ResourceLoaderContext $context Context in which to generate a response
 741          * @return bool If this found a cache file and handled the response
 742          */
 743         protected function tryRespondFromFileCache(
 744                 ResourceFileCache $fileCache, ResourceLoaderContext $context
 745         ) {
 746                 global $wgResourceLoaderMaxage;
 747                 // Buffer output to catch warnings.
 748                 ob_start();
 749                 // Get the maximum age the cache can be
 750                 $maxage = is_null( $context->getVersion() )
 751                         ? $wgResourceLoaderMaxage['unversioned']['server']
 752                         : $wgResourceLoaderMaxage['versioned']['server'];
 753                 // Minimum timestamp the cache file must have
 754                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 755                 if ( !$good ) {
 756                         try { // RL always hits the DB on file cache miss...
 757                                 wfGetDB( DB_SLAVE );
 758                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 759                                 $good = $fileCache->isCacheGood(); // cache existence check
 760                         }
 761                 }
 762                 if ( $good ) {
 763                         $ts = $fileCache->cacheTimestamp();
 764                         // Send content type and cache headers
 765                         $this->sendResponseHeaders( $context, $ts, false );
 766                         // If there's an If-Modified-Since header, respond with a 304 appropriately
 767                         if ( $this->tryRespondLastModified( $context, $ts ) ) {
 768                                 return false; // output handled (buffers cleared)
 769                         }
 770                         $response = $fileCache->fetchText();
 771                         // Capture any PHP warnings from the output buffer and append them to the
 772                         // response in a comment if we're in debug mode.
 773                         if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 774                                 $response = "/*\n$warnings\n*/\n" . $response;
 775                         }
 776                         // Remove the output buffer and output the response
 777                         ob_end_clean();
 778                         echo $response . "\n/* Cached {$ts} */";
 779                         return true; // cache hit
 780                 }
 781                 // Clear buffer
 782                 ob_end_clean();
 783
 784                 return false; // cache miss
 785         }
 786
 787         /**
 788          * Generate a CSS or JS comment block.
 789          *
 790          * Only use this for public data, not error message details.
 791          *
 792          * @param string $text
 793          * @return string
 794          */
 795         public static function makeComment( $text ) {
 796                 $encText = str_replace( '*/', '* /', $text );
 797                 return "/*\n$encText\n*/\n";
 798         }
 799
 800         /**
 801          * Handle exception display.
 802          *
 803          * @param Exception $e Exception to be shown to the user
 804          * @return string Sanitized text that can be returned to the user
 805          */
 806         public static function formatException( $e ) {
 807                 global $wgShowExceptionDetails;
 808
 809                 if ( $wgShowExceptionDetails ) {
 810                         return self::makeComment( $e->__toString() );
 811                 } else {
 812                         return self::makeComment( wfMessage( 'internalerror' )->text() );
 813                 }
 814         }
 815
 816         /**
 817          * Generate code for a response.
 818          *
 819          * @param ResourceLoaderContext $context Context in which to generate a response
 820          * @param array $modules List of module objects keyed by module name
 821          * @param array $missing List of requested module names that are unregistered (optional)
 822          * @return string Response data
 823          */
 824         public function makeModuleResponse( ResourceLoaderContext $context,
 825                 array $modules, array $missing = array()
 826         ) {
 827                 $out = '';
 828                 $exceptions = '';
 829                 $states = array();
 830
 831                 if ( !count( $modules ) && !count( $missing ) ) {
 832                         return "/* This file is the Web entry point for MediaWiki's ResourceLoader:
 833    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
 834    no modules were requested. Max made me put this here. */";
 835                 }
 836
 837                 wfProfileIn( __METHOD__ );
 838
 839                 // Pre-fetch blobs
 840                 if ( $context->shouldIncludeMessages() ) {
 841                         try {
 842                                 $blobs = MessageBlobStore::get( $this, $modules, $context->getLanguage() );
 843                         } catch ( Exception $e ) {
 844                                 MWExceptionHandler::logException( $e );
 845                                 wfDebugLog(
 846                                         'resourceloader',
 847                                         __METHOD__ . ": pre-fetching blobs from MessageBlobStore failed: $e"
 848                                 );
 849                                 $this->hasErrors = true;
 850                                 // Add exception to the output as a comment
 851                                 $exceptions .= self::formatException( $e );
 852                         }
 853                 } else {
 854                         $blobs = array();
 855                 }
 856
 857                 foreach ( $missing as $name ) {
 858                         $states[$name] = 'missing';
 859                 }
 860
 861                 // Generate output
 862                 $isRaw = false;
 863                 foreach ( $modules as $name => $module ) {
 864                         /**
 865                          * @var $module ResourceLoaderModule
 866                          */
 867
 868                         wfProfileIn( __METHOD__ . '-' . $name );
 869                         try {
 870                                 $scripts = '';
 871                                 if ( $context->shouldIncludeScripts() ) {
 872                                         // If we are in debug mode, we'll want to return an array of URLs if possible
 873                                         // However, we can't do this if the module doesn't support it
 874                                         // We also can't do this if there is an only= parameter, because we have to give
 875                                         // the module a way to return a load.php URL without causing an infinite loop
 876                                         if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
 877                                                 $scripts = $module->getScriptURLsForDebug( $context );
 878                                         } else {
 879                                                 $scripts = $module->getScript( $context );
 880                                                 // rtrim() because there are usually a few line breaks
 881                                                 // after the last ';'. A new line at EOF, a new line
 882                                                 // added by ResourceLoaderFileModule::readScriptFiles, etc.
 883                                                 if ( is_string( $scripts )
 884                                                         && strlen( $scripts )
 885                                                         && substr( rtrim( $scripts ), -1 ) !== ';'
 886                                                 ) {
 887                                                         // Append semicolon to prevent weird bugs caused by files not
 888                                                         // terminating their statements right (bug 27054)
 889                                                         $scripts .= ";\n";
 890                                                 }
 891                                         }
 892                                 }
 893                                 // Styles
 894                                 $styles = array();
 895                                 if ( $context->shouldIncludeStyles() ) {
 896                                         // Don't create empty stylesheets like array( '' => '' ) for modules
 897                                         // that don't *have* any stylesheets (bug 38024).
 898                                         $stylePairs = $module->getStyles( $context );
 899                                         if ( count( $stylePairs ) ) {
 900                                                 // If we are in debug mode without &only= set, we'll want to return an array of URLs
 901                                                 // See comment near shouldIncludeScripts() for more details
 902                                                 if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
 903                                                         $styles = array(
 904                                                                 'url' => $module->getStyleURLsForDebug( $context )
 905                                                         );
 906                                                 } else {
 907                                                         // Minify CSS before embedding in mw.loader.implement call
 908                                                         // (unless in debug mode)
 909                                                         if ( !$context->getDebug() ) {
 910                                                                 foreach ( $stylePairs as $media => $style ) {
 911                                                                         // Can be either a string or an array of strings.
 912                                                                         if ( is_array( $style ) ) {
 913                                                                                 $stylePairs[$media] = array();
 914                                                                                 foreach ( $style as $cssText ) {
 915                                                                                         if ( is_string( $cssText ) ) {
 916                                                                                                 $stylePairs[$media][] = $this->filter( 'minify-css', $cssText );
 917                                                                                         }
 918                                                                                 }
 919                                                                         } elseif ( is_string( $style ) ) {
 920                                                                                 $stylePairs[$media] = $this->filter( 'minify-css', $style );
 921                                                                         }
 922                                                                 }
 923                                                         }
 924                                                         // Wrap styles into @media groups as needed and flatten into a numerical array
 925                                                         $styles = array(
 926                                                                 'css' => self::makeCombinedStyles( $stylePairs )
 927                                                         );
 928                                                 }
 929                                         }
 930                                 }
 931
 932                                 // Messages
 933                                 $messagesBlob = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 934
 935                                 // Append output
 936                                 switch ( $context->getOnly() ) {
 937                                         case 'scripts':
 938                                                 if ( is_string( $scripts ) ) {
 939                                                         // Load scripts raw...
 940                                                         $out .= $scripts;
 941                                                 } elseif ( is_array( $scripts ) ) {
 942                                                         // ...except when $scripts is an array of URLs
 943                                                         $out .= self::makeLoaderImplementScript( $name, $scripts, array(), array() );
 944                                                 }
 945                                                 break;
 946                                         case 'styles':
 947                                                 // We no longer seperate into media, they are all combined now with
 948                                                 // custom media type groups into @media .. {} sections as part of the css string.
 949                                                 // Module returns either an empty array or a numerical array with css strings.
 950                                                 $out .= isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
 951                                                 break;
 952                                         case 'messages':
 953                                                 $out .= self::makeMessageSetScript( new XmlJsCode( $messagesBlob ) );
 954                                                 break;
 955                                         default:
 956                                                 $out .= self::makeLoaderImplementScript(
 957                                                         $name,
 958                                                         $scripts,
 959                                                         $styles,
 960                                                         new XmlJsCode( $messagesBlob )
 961                                                 );
 962                                                 break;
 963                                 }
 964                         } catch ( Exception $e ) {
 965                                 MWExceptionHandler::logException( $e );
 966                                 wfDebugLog( 'resourceloader', __METHOD__ . ": generating module package failed: $e" );
 967                                 $this->hasErrors = true;
 968                                 // Add exception to the output as a comment
 969                                 $exceptions .= self::formatException( $e );
 970
 971                                 // Respond to client with error-state instead of module implementation
 972                                 $states[$name] = 'error';
 973                                 unset( $modules[$name] );
 974                         }
 975                         $isRaw |= $module->isRaw();
 976                         wfProfileOut( __METHOD__ . '-' . $name );
 977                 }
 978
 979                 // Update module states
 980                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
 981                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
 982                                 // Set the state of modules loaded as only scripts to ready as
 983                                 // they don't have an mw.loader.implement wrapper that sets the state
 984                                 foreach ( $modules as $name => $module ) {
 985                                         $states[$name] = 'ready';
 986                                 }
 987                         }
 988
 989                         // Set the state of modules we didn't respond to with mw.loader.implement
 990                         if ( count( $states ) ) {
 991                                 $out .= self::makeLoaderStateScript( $states );
 992                         }
 993                 } else {
 994                         if ( count( $states ) ) {
 995                                 $exceptions .= self::makeComment(
 996                                         'Problematic modules: ' . FormatJson::encode( $states, ResourceLoader::inDebugMode() )
 997                                 );
 998                         }
 999                 }
1000
1001                 if ( !$context->getDebug() ) {
1002                         if ( $context->getOnly() === 'styles' ) {
1003                                 $out = $this->filter( 'minify-css', $out );
1004                         } else {
1005                                 $out = $this->filter( 'minify-js', $out );
1006                         }
1007                 }
1008
1009                 wfProfileOut( __METHOD__ );
1010                 return $exceptions . $out;
1011         }
1012
1013         /* Static Methods */
1014
1015         /**
1016          * Return JS code that calls mw.loader.implement with given module properties.
1017          *
1018          * @param string $name Module name
1019          * @param mixed $scripts List of URLs to JavaScript files or String of JavaScript code
1020          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1021          *   to CSS files keyed by media type
1022          * @param mixed $messages List of messages associated with this module. May either be an
1023          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1024          *   the same data, wrapped in an XmlJsCode object.
1025          * @throws MWException
1026          * @return string
1027          */
1028         public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
1029                 if ( is_string( $scripts ) ) {
1030                         $scripts = new XmlJsCode( "function ( $, jQuery ) {\n{$scripts}\n}" );
1031                 } elseif ( !is_array( $scripts ) ) {
1032                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1033                 }
1034                 return Xml::encodeJsCall(
1035                         'mw.loader.implement',
1036                         array(
1037                                 $name,
1038                                 $scripts,
1039                                 // Force objects. mw.loader.implement requires them to be javascript objects.
1040                                 // Although these variables are associative arrays, which become javascript
1041                                 // objects through json_encode. In many cases they will be empty arrays, and
1042                                 // PHP/json_encode() consider empty arrays to be numerical arrays and
1043                                 // output javascript "[]" instead of "{}". This fixes that.
1044                                 (object)$styles,
1045                                 (object)$messages
1046                         ),
1047                         ResourceLoader::inDebugMode()
1048                 );
1049         }
1050
1051         /**
1052          * Returns JS code which, when called, will register a given list of messages.
1053          *
1054          * @param mixed $messages Either an associative array mapping message key to value, or a
1055          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1056          * @return string
1057          */
1058         public static function makeMessageSetScript( $messages ) {
1059                 return Xml::encodeJsCall(
1060                         'mw.messages.set',
1061                         array( (object)$messages ),
1062                         ResourceLoader::inDebugMode()
1063                 );
1064         }
1065
1066         /**
1067          * Combines an associative array mapping media type to CSS into a
1068          * single stylesheet with "@media" blocks.
1069          *
1070          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1071          * @return array
1072          */
1073         public static function makeCombinedStyles( array $stylePairs ) {
1074                 $out = array();
1075                 foreach ( $stylePairs as $media => $styles ) {
1076                         // ResourceLoaderFileModule::getStyle can return the styles
1077                         // as a string or an array of strings. This is to allow separation in
1078                         // the front-end.
1079                         $styles = (array)$styles;
1080                         foreach ( $styles as $style ) {
1081                                 $style = trim( $style );
1082                                 // Don't output an empty "@media print { }" block (bug 40498)
1083                                 if ( $style !== '' ) {
1084                                         // Transform the media type based on request params and config
1085                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1086                                         $media = OutputPage::transformCssMedia( $media );
1087
1088                                         if ( $media === '' || $media == 'all' ) {
1089                                                 $out[] = $style;
1090                                         } elseif ( is_string( $media ) ) {
1091                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1092                                         }
1093                                         // else: skip
1094                                 }
1095                         }
1096                 }
1097                 return $out;
1098         }
1099
1100         /**
1101          * Returns a JS call to mw.loader.state, which sets the state of a
1102          * module or modules to a given value. Has two calling conventions:
1103          *
1104          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1105          *         Set the state of a single module called $name to $state
1106          *
1107          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
1108          *         Set the state of modules with the given names to the given states
1109          *
1110          * @param string $name
1111          * @param string $state
1112          * @return string
1113          */
1114         public static function makeLoaderStateScript( $name, $state = null ) {
1115                 if ( is_array( $name ) ) {
1116                         return Xml::encodeJsCall(
1117                                 'mw.loader.state',
1118                                 array( $name ),
1119                                 ResourceLoader::inDebugMode()
1120                         );
1121                 } else {
1122                         return Xml::encodeJsCall(
1123                                 'mw.loader.state',
1124                                 array( $name, $state ),
1125                                 ResourceLoader::inDebugMode()
1126                         );
1127                 }
1128         }
1129
1130         /**
1131          * Returns JS code which calls the script given by $script. The script will
1132          * be called with local variables name, version, dependencies and group,
1133          * which will have values corresponding to $name, $version, $dependencies
1134          * and $group as supplied.
1135          *
1136          * @param string $name Module name
1137          * @param int $version Module version number as a timestamp
1138          * @param array $dependencies List of module names on which this module depends
1139          * @param string $group Group which the module is in.
1140          * @param string $source Source of the module, or 'local' if not foreign.
1141          * @param string $script JavaScript code
1142          * @return string
1143          */
1144         public static function makeCustomLoaderScript( $name, $version, $dependencies,
1145                 $group, $source, $script
1146         ) {
1147                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1148                 return Xml::encodeJsCall(
1149                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1150                         array( $name, $version, $dependencies, $group, $source ),
1151                         ResourceLoader::inDebugMode()
1152                 );
1153         }
1154
1155         /**
1156          * Returns JS code which calls mw.loader.register with the given
1157          * parameters. Has three calling conventions:
1158          *
1159          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version, $dependencies, $group, $source, $skip ):
1160          *       Register a single module.
1161          *
1162          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
1163          *       Register modules with the given names.
1164          *
1165          *   - ResourceLoader::makeLoaderRegisterScript( array(
1166          *        array( $name1, $version1, $dependencies1, $group1, $source1, $skip1 ),
1167          *        array( $name2, $version2, $dependencies1, $group2, $source2, $skip2 ),
1168          *        ...
1169          *     ) ):
1170          *        Registers modules with the given names and parameters.
1171          *
1172          * @param string $name Module name
1173          * @param int $version Module version number as a timestamp
1174          * @param array $dependencies List of module names on which this module depends
1175          * @param string $group Group which the module is in
1176          * @param string $source Source of the module, or 'local' if not foreign
1177          * @param string $skip Script body of the skip function
1178          * @return string
1179          */
1180         public static function makeLoaderRegisterScript( $name, $version = null,
1181                 $dependencies = null, $group = null, $source = null, $skip = null
1182         ) {
1183                 if ( is_array( $name ) ) {
1184                         return Xml::encodeJsCall(
1185                                 'mw.loader.register',
1186                                 array( $name ),
1187                                 ResourceLoader::inDebugMode()
1188                         );
1189                 } else {
1190                         $version = (int)$version > 1 ? (int)$version : 1;
1191                         return Xml::encodeJsCall(
1192                                 'mw.loader.register',
1193                                 array( $name, $version, $dependencies, $group, $source, $skip ),
1194                                 ResourceLoader::inDebugMode()
1195                         );
1196                 }
1197         }
1198
1199         /**
1200          * Returns JS code which calls mw.loader.addSource() with the given
1201          * parameters. Has two calling conventions:
1202          *
1203          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1204          *       Register a single source
1205          *
1206          *   - ResourceLoader::makeLoaderSourcesScript( array( $id1 => $props1, $id2 => $props2, ... ) );
1207          *       Register sources with the given IDs and properties.
1208          *
1209          * @param string $id Source ID
1210          * @param array $properties Source properties (see addSource())
1211          * @return string
1212          */
1213         public static function makeLoaderSourcesScript( $id, $properties = null ) {
1214                 if ( is_array( $id ) ) {
1215                         return Xml::encodeJsCall(
1216                                 'mw.loader.addSource',
1217                                 array( $id ),
1218                                 ResourceLoader::inDebugMode()
1219                         );
1220                 } else {
1221                         return Xml::encodeJsCall(
1222                                 'mw.loader.addSource',
1223                                 array( $id, $properties ),
1224                                 ResourceLoader::inDebugMode()
1225                         );
1226                 }
1227         }
1228
1229         /**
1230          * Returns JS code which runs given JS code if the client-side framework is
1231          * present.
1232          *
1233          * @param string $script JavaScript code
1234          * @return string
1235          */
1236         public static function makeLoaderConditionalScript( $script ) {
1237                 return "if(window.mw){\n" . trim( $script ) . "\n}";
1238         }
1239
1240         /**
1241          * Returns JS code which will set the MediaWiki configuration array to
1242          * the given value.
1243          *
1244          * @param array $configuration List of configuration values keyed by variable name
1245          * @return string
1246          */
1247         public static function makeConfigSetScript( array $configuration ) {
1248                 return Xml::encodeJsCall(
1249                         'mw.config.set',
1250                         array( $configuration ),
1251                         ResourceLoader::inDebugMode()
1252                 );
1253         }
1254
1255         /**
1256          * Convert an array of module names to a packed query string.
1257          *
1258          * For example, array( 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' )
1259          * becomes 'foo.bar,baz|bar.baz,quux'
1260          * @param array $modules List of module names (strings)
1261          * @return string Packed query string
1262          */
1263         public static function makePackedModulesString( $modules ) {
1264                 $groups = array(); // array( prefix => array( suffixes ) )
1265                 foreach ( $modules as $module ) {
1266                         $pos = strrpos( $module, '.' );
1267                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1268                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1269                         $groups[$prefix][] = $suffix;
1270                 }
1271
1272                 $arr = array();
1273                 foreach ( $groups as $prefix => $suffixes ) {
1274                         $p = $prefix === '' ? '' : $prefix . '.';
1275                         $arr[] = $p . implode( ',', $suffixes );
1276                 }
1277                 $str = implode( '|', $arr );
1278                 return $str;
1279         }
1280
1281         /**
1282          * Determine whether debug mode was requested
1283          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1284          * @return bool
1285          */
1286         public static function inDebugMode() {
1287                 if ( self::$debugMode === null ) {
1288                         global $wgRequest, $wgResourceLoaderDebug;
1289                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1290                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1291                         );
1292                 }
1293                 return self::$debugMode;
1294         }
1295
1296         /**
1297          * Reset static members used for caching.
1298          *
1299          * Global state and $wgRequest are evil, but we're using it right
1300          * now and sometimes we need to be able to force ResourceLoader to
1301          * re-evaluate the context because it has changed (e.g. in the test suite).
1302          */
1303         public static function clearCache() {
1304                 self::$debugMode = null;
1305         }
1306
1307         /**
1308          * Build a load.php URL
1309          *
1310          * @since 1.24
1311          * @param string $source Name of the ResourceLoader source
1312          * @param ResourceLoaderContext $context
1313          * @param array $extraQuery
1314          * @return string URL to load.php. May be protocol-relative (if $wgLoadScript is procol-relative)
1315          */
1316         public function createLoaderURL( $source, ResourceLoaderContext $context,
1317                 $extraQuery = array()
1318         ) {
1319                 $query = self::createLoaderQuery( $context, $extraQuery );
1320                 $script = $this->getLoadScript( $source );
1321
1322                 // Prevent the IE6 extension check from being triggered (bug 28840)
1323                 // by appending a character that's invalid in Windows extensions ('*')
1324                 return wfExpandUrl( wfAppendQuery( $script, $query ) . '&*', PROTO_RELATIVE );
1325         }
1326
1327         /**
1328          * Build a load.php URL
1329          * @deprecated since 1.24, use createLoaderURL instead
1330          * @param array $modules Array of module names (strings)
1331          * @param string $lang Language code
1332          * @param string $skin Skin name
1333          * @param string|null $user User name. If null, the &user= parameter is omitted
1334          * @param string|null $version Versioning timestamp
1335          * @param bool $debug Whether the request should be in debug mode
1336          * @param string|null $only &only= parameter
1337          * @param bool $printable Printable mode
1338          * @param bool $handheld Handheld mode
1339          * @param array $extraQuery Extra query parameters to add
1340          * @return string URL to load.php. May be protocol-relative (if $wgLoadScript is procol-relative)
1341          */
1342         public static function makeLoaderURL( $modules, $lang, $skin, $user = null,
1343                 $version = null, $debug = false, $only = null, $printable = false,
1344                 $handheld = false, $extraQuery = array()
1345         ) {
1346                 global $wgLoadScript;
1347
1348                 $query = self::makeLoaderQuery( $modules, $lang, $skin, $user, $version, $debug,
1349                         $only, $printable, $handheld, $extraQuery
1350                 );
1351
1352                 // Prevent the IE6 extension check from being triggered (bug 28840)
1353                 // by appending a character that's invalid in Windows extensions ('*')
1354                 return wfExpandUrl( wfAppendQuery( $wgLoadScript, $query ) . '&*', PROTO_RELATIVE );
1355         }
1356
1357         /**
1358          * Helper for createLoaderURL()
1359          *
1360          * @since 1.24
1361          * @see makeLoaderQuery
1362          * @param ResourceLoaderContext $context
1363          * @param array $extraQuery
1364          * @return array
1365          */
1366         public static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = array() ) {
1367                 return self::makeLoaderQuery(
1368                         $context->getModules(),
1369                         $context->getLanguage(),
1370                         $context->getSkin(),
1371                         $context->getUser(),
1372                         $context->getVersion(),
1373                         $context->getDebug(),
1374                         $context->getOnly(),
1375                         $context->getRequest()->getBool( 'printable' ),
1376                         $context->getRequest()->getBool( 'handheld' ),
1377                         $extraQuery
1378                 );
1379         }
1380
1381         /**
1382          * Build a query array (array representation of query string) for load.php. Helper
1383          * function for makeLoaderURL().
1384          *
1385          * @param array $modules
1386          * @param string $lang
1387          * @param string $skin
1388          * @param string $user
1389          * @param string $version
1390          * @param bool $debug
1391          * @param string $only
1392          * @param bool $printable
1393          * @param bool $handheld
1394          * @param array $extraQuery
1395          *
1396          * @return array
1397          */
1398         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1399                 $version = null, $debug = false, $only = null, $printable = false,
1400                 $handheld = false, $extraQuery = array()
1401         ) {
1402                 $query = array(
1403                         'modules' => self::makePackedModulesString( $modules ),
1404                         'lang' => $lang,
1405                         'skin' => $skin,
1406                         'debug' => $debug ? 'true' : 'false',
1407                 );
1408                 if ( $user !== null ) {
1409                         $query['user'] = $user;
1410                 }
1411                 if ( $version !== null ) {
1412                         $query['version'] = $version;
1413                 }
1414                 if ( $only !== null ) {
1415                         $query['only'] = $only;
1416                 }
1417                 if ( $printable ) {
1418                         $query['printable'] = 1;
1419                 }
1420                 if ( $handheld ) {
1421                         $query['handheld'] = 1;
1422                 }
1423                 $query += $extraQuery;
1424
1425                 // Make queries uniform in order
1426                 ksort( $query );
1427                 return $query;
1428         }
1429
1430         /**
1431          * Check a module name for validity.
1432          *
1433          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1434          * at most 255 bytes.
1435          *
1436          * @param string $moduleName Module name to check
1437          * @return bool Whether $moduleName is a valid module name
1438          */
1439         public static function isValidModuleName( $moduleName ) {
1440                 return !preg_match( '/[|,!]/', $moduleName ) && strlen( $moduleName ) <= 255;
1441         }
1442
1443         /**
1444          * Returns LESS compiler set up for use with MediaWiki
1445          *
1446          * @since 1.22
1447          * @return lessc
1448          */
1449         public static function getLessCompiler() {
1450                 global $wgResourceLoaderLESSFunctions, $wgResourceLoaderLESSImportPaths;
1451
1452                 // When called from the installer, it is possible that a required PHP extension
1453                 // is missing (at least for now; see bug 47564). If this is the case, throw an
1454                 // exception (caught by the installer) to prevent a fatal error later on.
1455                 if ( !function_exists( 'ctype_digit' ) ) {
1456                         throw new MWException( 'lessc requires the Ctype extension' );
1457                 }
1458
1459                 $less = new lessc();
1460                 $less->setPreserveComments( true );
1461                 $less->setVariables( self::getLESSVars() );
1462                 $less->setImportDir( $wgResourceLoaderLESSImportPaths );
1463                 foreach ( $wgResourceLoaderLESSFunctions as $name => $func ) {
1464                         $less->registerFunction( $name, $func );
1465                 }
1466                 return $less;
1467         }
1468
1469         /**
1470          * Get global LESS variables.
1471          *
1472          * $since 1.22
1473          * @return array Map of variable names to string CSS values.
1474          */
1475         public static function getLESSVars() {
1476                 global $wgResourceLoaderLESSVars;
1477
1478                 $lessVars = $wgResourceLoaderLESSVars;
1479                 // Sort by key to ensure consistent hashing for cache lookups.
1480                 ksort( $lessVars );
1481                 return $lessVars;
1482         }
1483 }