includes/resourceloader/ResourceLoader.php

   1 <?php
   2 /**
   3  * Base class for resource loading system.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @author Roan Kattouw
  22  * @author Trevor Parscal
  23  */
  24
  25 use Psr\Log\LoggerAwareInterface;
  26 use Psr\Log\LoggerInterface;
  27 use Psr\Log\NullLogger;
  28
  29 /**
  30  * Dynamic JavaScript and CSS resource loading system.
  31  *
  32  * Most of the documentation is on the MediaWiki documentation wiki starting at:
  33  *    https://www.mediawiki.org/wiki/ResourceLoader
  34  */
  35 class ResourceLoader implements LoggerAwareInterface {
  36         /** @var int */
  37         protected static $filterCacheVersion = 7;
  38
  39         /** @var bool */
  40         protected static $debugMode = null;
  41
  42         /** @var array */
  43         private static $lessVars = null;
  44
  45         /**
  46          * Module name/ResourceLoaderModule object pairs
  47          * @var array
  48          */
  49         protected $modules = array();
  50
  51         /**
  52          * Associative array mapping module name to info associative array
  53          * @var array
  54          */
  55         protected $moduleInfos = array();
  56
  57         /** @var Config $config */
  58         private $config;
  59
  60         /**
  61          * Associative array mapping framework ids to a list of names of test suite modules
  62          * like array( 'qunit' => array( 'mediawiki.tests.qunit.suites', 'ext.foo.tests', .. ), .. )
  63          * @var array
  64          */
  65         protected $testModuleNames = array();
  66
  67         /**
  68          * E.g. array( 'source-id' => 'http://.../load.php' )
  69          * @var array
  70          */
  71         protected $sources = array();
  72
  73         /**
  74          * Errors accumulated during current respond() call.
  75          * @var array
  76          */
  77         protected $errors = array();
  78
  79         /**
  80          * @var MessageBlobStore
  81          */
  82         protected $blobStore;
  83
  84         /**
  85          * @var LoggerInterface
  86          */
  87         private $logger;
  88
  89         /**
  90          * Load information stored in the database about modules.
  91          *
  92          * This method grabs modules dependencies from the database and updates modules
  93          * objects.
  94          *
  95          * This is not inside the module code because it is much faster to
  96          * request all of the information at once than it is to have each module
  97          * requests its own information. This sacrifice of modularity yields a substantial
  98          * performance improvement.
  99          *
 100          * @param array $modules List of module names to preload information for
 101          * @param ResourceLoaderContext $context Context to load the information within
 102          */
 103         public function preloadModuleInfo( array $modules, ResourceLoaderContext $context ) {
 104                 if ( !count( $modules ) ) {
 105                         // Or else Database*::select() will explode, plus it's cheaper!
 106                         return;
 107                 }
 108                 $dbr = wfGetDB( DB_SLAVE );
 109                 $skin = $context->getSkin();
 110                 $lang = $context->getLanguage();
 111
 112                 // Get file dependency information
 113                 $res = $dbr->select( 'module_deps', array( 'md_module', 'md_deps' ), array(
 114                                 'md_module' => $modules,
 115                                 'md_skin' => $skin
 116                         ), __METHOD__
 117                 );
 118
 119                 // Set modules' dependencies
 120                 $modulesWithDeps = array();
 121                 foreach ( $res as $row ) {
 122                         $module = $this->getModule( $row->md_module );
 123                         if ( $module ) {
 124                                 $module->setFileDependencies( $skin, FormatJson::decode( $row->md_deps, true ) );
 125                                 $modulesWithDeps[] = $row->md_module;
 126                         }
 127                 }
 128
 129                 // Register the absence of a dependency row too
 130                 foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
 131                         $module = $this->getModule( $name );
 132                         if ( $module ) {
 133                                 $this->getModule( $name )->setFileDependencies( $skin, array() );
 134                         }
 135                 }
 136
 137                 // Get message blob mtimes. Only do this for modules with messages
 138                 $modulesWithMessages = array();
 139                 foreach ( $modules as $name ) {
 140                         $module = $this->getModule( $name );
 141                         if ( $module && count( $module->getMessages() ) ) {
 142                                 $modulesWithMessages[] = $name;
 143                         }
 144                 }
 145                 $modulesWithoutMessages = array_flip( $modules ); // Will be trimmed down by the loop below
 146                 if ( count( $modulesWithMessages ) ) {
 147                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
 148                                         'mr_resource' => $modulesWithMessages,
 149                                         'mr_lang' => $lang
 150                                 ), __METHOD__
 151                         );
 152                         foreach ( $res as $row ) {
 153                                 $module = $this->getModule( $row->mr_resource );
 154                                 if ( $module ) {
 155                                         $module->setMsgBlobMtime( $lang, wfTimestamp( TS_UNIX, $row->mr_timestamp ) );
 156                                         unset( $modulesWithoutMessages[$row->mr_resource] );
 157                                 }
 158                         }
 159                 }
 160                 foreach ( array_keys( $modulesWithoutMessages ) as $name ) {
 161                         $module = $this->getModule( $name );
 162                         if ( $module ) {
 163                                 $module->setMsgBlobMtime( $lang, 1 );
 164                         }
 165                 }
 166         }
 167
 168         /**
 169          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 170          *
 171          * Available filters are:
 172          *
 173          *    - minify-js \see JavaScriptMinifier::minify
 174          *    - minify-css \see CSSMin::minify
 175          *
 176          * If $data is empty, only contains whitespace or the filter was unknown,
 177          * $data is returned unmodified.
 178          *
 179          * @param string $filter Name of filter to run
 180          * @param string $data Text to filter, such as JavaScript or CSS text
 181          * @param array $options For back-compat, can also be the boolean value for "cacheReport". Keys:
 182          *  - (bool) cache: Whether to allow caching this data. Default: true.
 183          *  - (bool) cacheReport: Whether to include the "cache key" report comment. Default: true.
 184          * @return string Filtered data, or a comment containing an error message
 185          */
 186         public function filter( $filter, $data, $options = array() ) {
 187                 // Back-compat
 188                 if ( is_bool( $options ) ) {
 189                         $options = array( 'cacheReport' => $options );
 190                 }
 191                 // Defaults
 192                 $options += array( 'cache' => true, 'cacheReport' => true );
 193
 194                 // Don't filter empty content
 195                 if ( trim( $data ) === '' ) {
 196                         return $data;
 197                 }
 198
 199                 if ( !in_array( $filter, array( 'minify-js', 'minify-css' ) ) ) {
 200                         $this->logger->info( __METHOD__ . ": Invalid filter: $filter" );
 201                         return $data;
 202                 }
 203
 204                 if ( !$options['cache'] ) {
 205                         $result = $this->applyFilter( $filter, $data );
 206                 } else {
 207                         $key = wfMemcKey( 'resourceloader', 'filter', $filter, self::$filterCacheVersion, md5( $data ) );
 208                         $cache = wfGetCache( wfIsHHVM() ? CACHE_ACCEL : CACHE_ANYTHING );
 209                         $cacheEntry = $cache->get( $key );
 210                         if ( is_string( $cacheEntry ) ) {
 211                                 wfIncrStats( "resourceloader_cache.$filter.hit" );
 212                                 return $cacheEntry;
 213                         }
 214                         $result = '';
 215                         try {
 216                                 wfIncrStats( "resourceloader_cache.$filter.miss" );
 217                                 $result = $this->applyFilter( $filter, $data );
 218                                 if ( $options['cacheReport'] ) {
 219                                         $result .= "\n/* cache key: $key */";
 220                                 }
 221                                 $cache->set( $key, $result );
 222                         } catch ( Exception $e ) {
 223                                 MWExceptionHandler::logException( $e );
 224                                 $this->logger->info( __METHOD__ . ": minification failed: $e" );
 225                                 $this->errors[] = self::formatExceptionNoComment( $e );
 226                         }
 227                 }
 228
 229                 return $result;
 230         }
 231
 232         private function applyFilter( $filter, $data ) {
 233                         switch ( $filter ) {
 234                                 case 'minify-js':
 235                                         return JavaScriptMinifier::minify( $data,
 236                                                 $this->config->get( 'ResourceLoaderMinifierStatementsOnOwnLine' ),
 237                                                 $this->config->get( 'ResourceLoaderMinifierMaxLineLength' )
 238                                         );
 239                                 case 'minify-css':
 240                                         return CSSMin::minify( $data );
 241                         }
 242                         return $data;
 243         }
 244
 245         /* Methods */
 246
 247         /**
 248          * Register core modules and runs registration hooks.
 249          * @param Config|null $config
 250          */
 251         public function __construct( Config $config = null, LoggerInterface $logger = null ) {
 252                 global $IP;
 253
 254                 if ( !$logger ) {
 255                         $logger = new NullLogger();
 256                 }
 257                 $this->setLogger( $logger );
 258
 259                 if ( !$config ) {
 260                         $this->logger->info( __METHOD__ . ' was called without providing a Config instance' );
 261                         $config = ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
 262                 }
 263                 $this->config = $config;
 264
 265                 // Add 'local' source first
 266                 $this->addSource( 'local', wfScript( 'load' ) );
 267
 268                 // Add other sources
 269                 $this->addSource( $config->get( 'ResourceLoaderSources' ) );
 270
 271                 // Register core modules
 272                 $this->register( include "$IP/resources/Resources.php" );
 273                 $this->register( include "$IP/resources/ResourcesOOUI.php" );
 274                 // Register extension modules
 275                 Hooks::run( 'ResourceLoaderRegisterModules', array( &$this ) );
 276                 $this->register( $config->get( 'ResourceModules' ) );
 277
 278                 if ( $config->get( 'EnableJavaScriptTest' ) === true ) {
 279                         $this->registerTestModules();
 280                 }
 281
 282                 $this->setMessageBlobStore( new MessageBlobStore() );
 283         }
 284
 285         /**
 286          * @return Config
 287          */
 288         public function getConfig() {
 289                 return $this->config;
 290         }
 291
 292         public function setLogger( LoggerInterface $logger ) {
 293                 $this->logger = $logger;
 294         }
 295
 296         /**
 297          * @param MessageBlobStore $blobStore
 298          * @since 1.25
 299          */
 300         public function setMessageBlobStore( MessageBlobStore $blobStore ) {
 301                 $this->blobStore = $blobStore;
 302         }
 303
 304         /**
 305          * Register a module with the ResourceLoader system.
 306          *
 307          * @param mixed $name Name of module as a string or List of name/object pairs as an array
 308          * @param array $info Module info array. For backwards compatibility with 1.17alpha,
 309          *   this may also be a ResourceLoaderModule object. Optional when using
 310          *   multiple-registration calling style.
 311          * @throws MWException If a duplicate module registration is attempted
 312          * @throws MWException If a module name contains illegal characters (pipes or commas)
 313          * @throws MWException If something other than a ResourceLoaderModule is being registered
 314          * @return bool False if there were any errors, in which case one or more modules were
 315          *   not registered
 316          */
 317         public function register( $name, $info = null ) {
 318
 319                 // Allow multiple modules to be registered in one call
 320                 $registrations = is_array( $name ) ? $name : array( $name => $info );
 321                 foreach ( $registrations as $name => $info ) {
 322                         // Disallow duplicate registrations
 323                         if ( isset( $this->moduleInfos[$name] ) ) {
 324                                 // A module has already been registered by this name
 325                                 throw new MWException(
 326                                         'ResourceLoader duplicate registration error. ' .
 327                                         'Another module has already been registered as ' . $name
 328                                 );
 329                         }
 330
 331                         // Check $name for validity
 332                         if ( !self::isValidModuleName( $name ) ) {
 333                                 throw new MWException( "ResourceLoader module name '$name' is invalid, "
 334                                         . "see ResourceLoader::isValidModuleName()" );
 335                         }
 336
 337                         // Attach module
 338                         if ( $info instanceof ResourceLoaderModule ) {
 339                                 $this->moduleInfos[$name] = array( 'object' => $info );
 340                                 $info->setName( $name );
 341                                 $this->modules[$name] = $info;
 342                         } elseif ( is_array( $info ) ) {
 343                                 // New calling convention
 344                                 $this->moduleInfos[$name] = $info;
 345                         } else {
 346                                 throw new MWException(
 347                                         'ResourceLoader module info type error for module \'' . $name .
 348                                         '\': expected ResourceLoaderModule or array (got: ' . gettype( $info ) . ')'
 349                                 );
 350                         }
 351
 352                         // Last-minute changes
 353
 354                         // Apply custom skin-defined styles to existing modules.
 355                         if ( $this->isFileModule( $name ) ) {
 356                                 foreach ( $this->config->get( 'ResourceModuleSkinStyles' ) as $skinName => $skinStyles ) {
 357                                         // If this module already defines skinStyles for this skin, ignore $wgResourceModuleSkinStyles.
 358                                         if ( isset( $this->moduleInfos[$name]['skinStyles'][$skinName] ) ) {
 359                                                 continue;
 360                                         }
 361
 362                                         // If $name is preceded with a '+', the defined style files will be added to 'default'
 363                                         // skinStyles, otherwise 'default' will be ignored as it normally would be.
 364                                         if ( isset( $skinStyles[$name] ) ) {
 365                                                 $paths = (array)$skinStyles[$name];
 366                                                 $styleFiles = array();
 367                                         } elseif ( isset( $skinStyles['+' . $name] ) ) {
 368                                                 $paths = (array)$skinStyles['+' . $name];
 369                                                 $styleFiles = isset( $this->moduleInfos[$name]['skinStyles']['default'] ) ?
 370                                                         (array)$this->moduleInfos[$name]['skinStyles']['default'] :
 371                                                         array();
 372                                         } else {
 373                                                 continue;
 374                                         }
 375
 376                                         // Add new file paths, remapping them to refer to our directories and not use settings
 377                                         // from the module we're modifying, which come from the base definition.
 378                                         list( $localBasePath, $remoteBasePath ) =
 379                                                 ResourceLoaderFileModule::extractBasePaths( $skinStyles );
 380
 381                                         foreach ( $paths as $path ) {
 382                                                 $styleFiles[] = new ResourceLoaderFilePath( $path, $localBasePath, $remoteBasePath );
 383                                         }
 384
 385                                         $this->moduleInfos[$name]['skinStyles'][$skinName] = $styleFiles;
 386                                 }
 387                         }
 388                 }
 389
 390         }
 391
 392         /**
 393          */
 394         public function registerTestModules() {
 395                 global $IP;
 396
 397                 if ( $this->config->get( 'EnableJavaScriptTest' ) !== true ) {
 398                         throw new MWException( 'Attempt to register JavaScript test modules '
 399                                 . 'but <code>$wgEnableJavaScriptTest</code> is false. '
 400                                 . 'Edit your <code>LocalSettings.php</code> to enable it.' );
 401                 }
 402
 403                 // Get core test suites
 404                 $testModules = array();
 405                 $testModules['qunit'] = array();
 406                 // Get other test suites (e.g. from extensions)
 407                 Hooks::run( 'ResourceLoaderTestModules', array( &$testModules, &$this ) );
 408
 409                 // Add the testrunner (which configures QUnit) to the dependencies.
 410                 // Since it must be ready before any of the test suites are executed.
 411                 foreach ( $testModules['qunit'] as &$module ) {
 412                         // Make sure all test modules are top-loading so that when QUnit starts
 413                         // on document-ready, it will run once and finish. If some tests arrive
 414                         // later (possibly after QUnit has already finished) they will be ignored.
 415                         $module['position'] = 'top';
 416                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 417                 }
 418
 419                 $testModules['qunit'] =
 420                         ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules['qunit'];
 421
 422                 foreach ( $testModules as $id => $names ) {
 423                         // Register test modules
 424                         $this->register( $testModules[$id] );
 425
 426                         // Keep track of their names so that they can be loaded together
 427                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 428                 }
 429
 430         }
 431
 432         /**
 433          * Add a foreign source of modules.
 434          *
 435          * @param array|string $id Source ID (string), or array( id1 => loadUrl, id2 => loadUrl, ... )
 436          * @param string|array $loadUrl load.php url (string), or array with loadUrl key for
 437          *  backwards-compatibility.
 438          * @throws MWException
 439          */
 440         public function addSource( $id, $loadUrl = null ) {
 441                 // Allow multiple sources to be registered in one call
 442                 if ( is_array( $id ) ) {
 443                         foreach ( $id as $key => $value ) {
 444                                 $this->addSource( $key, $value );
 445                         }
 446                         return;
 447                 }
 448
 449                 // Disallow duplicates
 450                 if ( isset( $this->sources[$id] ) ) {
 451                         throw new MWException(
 452                                 'ResourceLoader duplicate source addition error. ' .
 453                                 'Another source has already been registered as ' . $id
 454                         );
 455                 }
 456
 457                 // Pre 1.24 backwards-compatibility
 458                 if ( is_array( $loadUrl ) ) {
 459                         if ( !isset( $loadUrl['loadScript'] ) ) {
 460                                 throw new MWException(
 461                                         __METHOD__ . ' was passed an array with no "loadScript" key.'
 462                                 );
 463                         }
 464
 465                         $loadUrl = $loadUrl['loadScript'];
 466                 }
 467
 468                 $this->sources[$id] = $loadUrl;
 469         }
 470
 471         /**
 472          * Get a list of module names.
 473          *
 474          * @return array List of module names
 475          */
 476         public function getModuleNames() {
 477                 return array_keys( $this->moduleInfos );
 478         }
 479
 480         /**
 481          * Get a list of test module names for one (or all) frameworks.
 482          *
 483          * If the given framework id is unknkown, or if the in-object variable is not an array,
 484          * then it will return an empty array.
 485          *
 486          * @param string $framework Get only the test module names for one
 487          *   particular framework (optional)
 488          * @return array
 489          */
 490         public function getTestModuleNames( $framework = 'all' ) {
 491                 /** @todo api siteinfo prop testmodulenames modulenames */
 492                 if ( $framework == 'all' ) {
 493                         return $this->testModuleNames;
 494                 } elseif ( isset( $this->testModuleNames[$framework] )
 495                         && is_array( $this->testModuleNames[$framework] )
 496                 ) {
 497                         return $this->testModuleNames[$framework];
 498                 } else {
 499                         return array();
 500                 }
 501         }
 502
 503         /**
 504          * Check whether a ResourceLoader module is registered
 505          *
 506          * @since 1.25
 507          * @param string $name
 508          * @return bool
 509          */
 510         public function isModuleRegistered( $name ) {
 511                 return isset( $this->moduleInfos[$name] );
 512         }
 513
 514         /**
 515          * Get the ResourceLoaderModule object for a given module name.
 516          *
 517          * If an array of module parameters exists but a ResourceLoaderModule object has not
 518          * yet been instantiated, this method will instantiate and cache that object such that
 519          * subsequent calls simply return the same object.
 520          *
 521          * @param string $name Module name
 522          * @return ResourceLoaderModule|null If module has been registered, return a
 523          *  ResourceLoaderModule instance. Otherwise, return null.
 524          */
 525         public function getModule( $name ) {
 526                 if ( !isset( $this->modules[$name] ) ) {
 527                         if ( !isset( $this->moduleInfos[$name] ) ) {
 528                                 // No such module
 529                                 return null;
 530                         }
 531                         // Construct the requested object
 532                         $info = $this->moduleInfos[$name];
 533                         /** @var ResourceLoaderModule $object */
 534                         if ( isset( $info['object'] ) ) {
 535                                 // Object given in info array
 536                                 $object = $info['object'];
 537                         } else {
 538                                 if ( !isset( $info['class'] ) ) {
 539                                         $class = 'ResourceLoaderFileModule';
 540                                 } else {
 541                                         $class = $info['class'];
 542                                 }
 543                                 /** @var ResourceLoaderModule $object */
 544                                 $object = new $class( $info );
 545                                 $object->setConfig( $this->getConfig() );
 546                         }
 547                         $object->setName( $name );
 548                         $this->modules[$name] = $object;
 549                 }
 550
 551                 return $this->modules[$name];
 552         }
 553
 554         /**
 555          * Return whether the definition of a module corresponds to a simple ResourceLoaderFileModule.
 556          *
 557          * @param string $name Module name
 558          * @return bool
 559          */
 560         protected function isFileModule( $name ) {
 561                 if ( !isset( $this->moduleInfos[$name] ) ) {
 562                         return false;
 563                 }
 564                 $info = $this->moduleInfos[$name];
 565                 if ( isset( $info['object'] ) || isset( $info['class'] ) ) {
 566                         return false;
 567                 }
 568                 return true;
 569         }
 570
 571         /**
 572          * Get the list of sources.
 573          *
 574          * @return array Like array( id => load.php url, .. )
 575          */
 576         public function getSources() {
 577                 return $this->sources;
 578         }
 579
 580         /**
 581          * Get the URL to the load.php endpoint for the given
 582          * ResourceLoader source
 583          *
 584          * @since 1.24
 585          * @param string $source
 586          * @throws MWException On an invalid $source name
 587          * @return string
 588          */
 589         public function getLoadScript( $source ) {
 590                 if ( !isset( $this->sources[$source] ) ) {
 591                         throw new MWException( "The $source source was never registered in ResourceLoader." );
 592                 }
 593                 return $this->sources[$source];
 594         }
 595
 596         /**
 597          * @since 1.26
 598          * @param string $value
 599          * @return string Hash
 600          */
 601         public static function makeHash( $value ) {
 602                 // Use base64 to output more entropy in a more compact string (default hex is only base16).
 603                 // The first 8 chars of a base64 encoded digest represent the same binary as
 604                 // the first 12 chars of a hex encoded digest.
 605                 return substr( base64_encode( sha1( $value, true ) ), 0, 8 );
 606         }
 607
 608         /**
 609          * Helper method to get and combine versions of multiple modules.
 610          *
 611          * @since 1.26
 612          * @param ResourceLoaderContext $context
 613          * @param array $modules List of ResourceLoaderModule objects
 614          * @return string Hash
 615          */
 616         public function getCombinedVersion( ResourceLoaderContext $context, Array $modules ) {
 617                 if ( !$modules ) {
 618                         return '';
 619                 }
 620                 // Support: PHP 5.3 ("$this" for anonymous functions was added in PHP 5.4.0)
 621                 // http://php.net/functions.anonymous
 622                 $rl = $this;
 623                 $hashes = array_map( function ( $module ) use ( $rl, $context ) {
 624                         return $rl->getModule( $module )->getVersionHash( $context );
 625                 }, $modules );
 626                 return self::makeHash( implode( $hashes ) );
 627         }
 628
 629         /**
 630          * Output a response to a load request, including the content-type header.
 631          *
 632          * @param ResourceLoaderContext $context Context in which a response should be formed
 633          */
 634         public function respond( ResourceLoaderContext $context ) {
 635                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 636                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 637                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 638                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 639                 // the whole thing in our own output buffer to be sure the active buffer
 640                 // doesn't use ob_gzhandler.
 641                 // See http://bugs.php.net/bug.php?id=36514
 642                 ob_start();
 643
 644                 // Find out which modules are missing and instantiate the others
 645                 $modules = array();
 646                 $missing = array();
 647                 foreach ( $context->getModules() as $name ) {
 648                         $module = $this->getModule( $name );
 649                         if ( $module ) {
 650                                 // Do not allow private modules to be loaded from the web.
 651                                 // This is a security issue, see bug 34907.
 652                                 if ( $module->getGroup() === 'private' ) {
 653                                         $this->logger->info( __METHOD__ . ": request for private module '$name' denied" );
 654                                         $this->errors[] = "Cannot show private module \"$name\"";
 655                                         continue;
 656                                 }
 657                                 $modules[$name] = $module;
 658                         } else {
 659                                 $missing[] = $name;
 660                         }
 661                 }
 662
 663                 try {
 664                         // Preload for getCombinedVersion()
 665                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 666                 } catch ( Exception $e ) {
 667                         MWExceptionHandler::logException( $e );
 668                         $this->logger->info( __METHOD__ . ": preloading module info failed: $e" );
 669                         $this->errors[] = self::formatExceptionNoComment( $e );
 670                 }
 671
 672                 // Combine versions to propagate cache invalidation
 673                 $versionHash = '';
 674                 try {
 675                         $versionHash = $this->getCombinedVersion( $context, array_keys( $modules ) );
 676                 } catch ( Exception $e ) {
 677                         MWExceptionHandler::logException( $e );
 678                         $this->logger->info( __METHOD__ . ": calculating version hash failed: $e" );
 679                         $this->errors[] = self::formatExceptionNoComment( $e );
 680                 }
 681
 682                 // See RFC 2616 § 3.11 Entity Tags
 683                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.11
 684                 $etag = 'W/"' . $versionHash . '"';
 685
 686                 // Try the client-side cache first
 687                 if ( $this->tryRespondNotModified( $context, $etag ) ) {
 688                         return; // output handled (buffers cleared)
 689                 }
 690
 691                 // Use file cache if enabled and available...
 692                 if ( $this->config->get( 'UseFileCache' ) ) {
 693                         $fileCache = ResourceFileCache::newFromContext( $context );
 694                         if ( $this->tryRespondFromFileCache( $fileCache, $context, $etag ) ) {
 695                                 return; // output handled
 696                         }
 697                 }
 698
 699                 // Generate a response
 700                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 701
 702                 // Capture any PHP warnings from the output buffer and append them to the
 703                 // error list if we're in debug mode.
 704                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 705                         $this->errors[] = $warnings;
 706                 }
 707
 708                 // Save response to file cache unless there are errors
 709                 if ( isset( $fileCache ) && !$this->errors && !count( $missing ) ) {
 710                         // Cache single modules and images...and other requests if there are enough hits
 711                         if ( ResourceFileCache::useFileCache( $context ) ) {
 712                                 if ( $fileCache->isCacheWorthy() ) {
 713                                         $fileCache->saveText( $response );
 714                                 } else {
 715                                         $fileCache->incrMissesRecent( $context->getRequest() );
 716                                 }
 717                         }
 718                 }
 719
 720                 $this->sendResponseHeaders( $context, $etag, (bool)$this->errors );
 721
 722                 // Remove the output buffer and output the response
 723                 ob_end_clean();
 724
 725                 if ( $context->getImageObj() && $this->errors ) {
 726                         // We can't show both the error messages and the response when it's an image.
 727                         $errorText = '';
 728                         foreach ( $this->errors as $error ) {
 729                                 $errorText .= $error . "\n";
 730                         }
 731                         $response = $errorText;
 732                 } elseif ( $this->errors ) {
 733                         // Prepend comments indicating errors
 734                         $errorText = '';
 735                         foreach ( $this->errors as $error ) {
 736                                 $errorText .= self::makeComment( $error );
 737                         }
 738                         $response = $errorText . $response;
 739                 }
 740
 741                 $this->errors = array();
 742                 echo $response;
 743
 744         }
 745
 746         /**
 747          * Send main response headers to the client.
 748          *
 749          * Deals with Content-Type, CORS (for stylesheets), and caching.
 750          *
 751          * @param ResourceLoaderContext $context
 752          * @param string $etag ETag header value
 753          * @param bool $errors Whether there are errors in the response
 754          * @return void
 755          */
 756         protected function sendResponseHeaders( ResourceLoaderContext $context, $etag, $errors ) {
 757                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 758                 // If a version wasn't specified we need a shorter expiry time for updates
 759                 // to propagate to clients quickly
 760                 // If there were errors, we also need a shorter expiry time so we can recover quickly
 761                 if ( is_null( $context->getVersion() ) || $errors ) {
 762                         $maxage = $rlMaxage['unversioned']['client'];
 763                         $smaxage = $rlMaxage['unversioned']['server'];
 764                 // If a version was specified we can use a longer expiry time since changing
 765                 // version numbers causes cache misses
 766                 } else {
 767                         $maxage = $rlMaxage['versioned']['client'];
 768                         $smaxage = $rlMaxage['versioned']['server'];
 769                 }
 770                 if ( $context->getImageObj() ) {
 771                         // Output different headers if we're outputting textual errors.
 772                         if ( $errors ) {
 773                                 header( 'Content-Type: text/plain; charset=utf-8' );
 774                         } else {
 775                                 $context->getImageObj()->sendResponseHeaders( $context );
 776                         }
 777                 } elseif ( $context->getOnly() === 'styles' ) {
 778                         header( 'Content-Type: text/css; charset=utf-8' );
 779                         header( 'Access-Control-Allow-Origin: *' );
 780                 } else {
 781                         header( 'Content-Type: text/javascript; charset=utf-8' );
 782                 }
 783                 // See RFC 2616 § 14.19 ETag
 784                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.19
 785                 header( 'ETag: ' . $etag );
 786                 if ( $context->getDebug() ) {
 787                         // Do not cache debug responses
 788                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 789                         header( 'Pragma: no-cache' );
 790                 } else {
 791                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 792                         $exp = min( $maxage, $smaxage );
 793                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 794                 }
 795         }
 796
 797         /**
 798          * Respond with HTTP 304 Not Modified if appropiate.
 799          *
 800          * If there's an If-None-Match header, respond with a 304 appropriately
 801          * and clear out the output buffer. If the client cache is too old then do nothing.
 802          *
 803          * @param ResourceLoaderContext $context
 804          * @param string $etag ETag header value
 805          * @return bool True if HTTP 304 was sent and output handled
 806          */
 807         protected function tryRespondNotModified( ResourceLoaderContext $context, $etag ) {
 808                 // See RFC 2616 § 14.26 If-None-Match
 809                 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
 810                 $clientKeys = $context->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST );
 811                 // Never send 304s in debug mode
 812                 if ( $clientKeys !== false && !$context->getDebug() && in_array( $etag, $clientKeys ) ) {
 813                         // There's another bug in ob_gzhandler (see also the comment at
 814                         // the top of this function) that causes it to gzip even empty
 815                         // responses, meaning it's impossible to produce a truly empty
 816                         // response (because the gzip header is always there). This is
 817                         // a problem because 304 responses have to be completely empty
 818                         // per the HTTP spec, and Firefox behaves buggily when they're not.
 819                         // See also http://bugs.php.net/bug.php?id=51579
 820                         // To work around this, we tear down all output buffering before
 821                         // sending the 304.
 822                         wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 823
 824                         header( 'HTTP/1.0 304 Not Modified' );
 825                         header( 'Status: 304 Not Modified' );
 826
 827                         $this->sendResponseHeaders( $context, $etag, false );
 828                         return true;
 829                 }
 830                 return false;
 831         }
 832
 833         /**
 834          * Send out code for a response from file cache if possible.
 835          *
 836          * @param ResourceFileCache $fileCache Cache object for this request URL
 837          * @param ResourceLoaderContext $context Context in which to generate a response
 838          * @param string $etag ETag header value
 839          * @return bool If this found a cache file and handled the response
 840          */
 841         protected function tryRespondFromFileCache(
 842                 ResourceFileCache $fileCache,
 843                 ResourceLoaderContext $context,
 844                 $etag
 845         ) {
 846                 $rlMaxage = $this->config->get( 'ResourceLoaderMaxage' );
 847                 // Buffer output to catch warnings.
 848                 ob_start();
 849                 // Get the maximum age the cache can be
 850                 $maxage = is_null( $context->getVersion() )
 851                         ? $rlMaxage['unversioned']['server']
 852                         : $rlMaxage['versioned']['server'];
 853                 // Minimum timestamp the cache file must have
 854                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 855                 if ( !$good ) {
 856                         try { // RL always hits the DB on file cache miss...
 857                                 wfGetDB( DB_SLAVE );
 858                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 859                                 $good = $fileCache->isCacheGood(); // cache existence check
 860                         }
 861                 }
 862                 if ( $good ) {
 863                         $ts = $fileCache->cacheTimestamp();
 864                         // Send content type and cache headers
 865                         $this->sendResponseHeaders( $context, $etag, false );
 866                         $response = $fileCache->fetchText();
 867                         // Capture any PHP warnings from the output buffer and append them to the
 868                         // response in a comment if we're in debug mode.
 869                         if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 870                                 $response = self::makeComment( $warnings ) . $response;
 871                         }
 872                         // Remove the output buffer and output the response
 873                         ob_end_clean();
 874                         echo $response . "\n/* Cached {$ts} */";
 875                         return true; // cache hit
 876                 }
 877                 // Clear buffer
 878                 ob_end_clean();
 879
 880                 return false; // cache miss
 881         }
 882
 883         /**
 884          * Generate a CSS or JS comment block.
 885          *
 886          * Only use this for public data, not error message details.
 887          *
 888          * @param string $text
 889          * @return string
 890          */
 891         public static function makeComment( $text ) {
 892                 $encText = str_replace( '*/', '* /', $text );
 893                 return "/*\n$encText\n*/\n";
 894         }
 895
 896         /**
 897          * Handle exception display.
 898          *
 899          * @param Exception $e Exception to be shown to the user
 900          * @return string Sanitized text in a CSS/JS comment that can be returned to the user
 901          */
 902         public static function formatException( $e ) {
 903                 return self::makeComment( self::formatExceptionNoComment( $e ) );
 904         }
 905
 906         /**
 907          * Handle exception display.
 908          *
 909          * @since 1.25
 910          * @param Exception $e Exception to be shown to the user
 911          * @return string Sanitized text that can be returned to the user
 912          */
 913         protected static function formatExceptionNoComment( $e ) {
 914                 global $wgShowExceptionDetails;
 915
 916                 if ( $wgShowExceptionDetails ) {
 917                         return $e->__toString();
 918                 } else {
 919                         return wfMessage( 'internalerror' )->text();
 920                 }
 921         }
 922
 923         /**
 924          * Generate code for a response.
 925          *
 926          * @param ResourceLoaderContext $context Context in which to generate a response
 927          * @param array $modules List of module objects keyed by module name
 928          * @param array $missing List of requested module names that are unregistered (optional)
 929          * @return string Response data
 930          */
 931         public function makeModuleResponse( ResourceLoaderContext $context,
 932                 array $modules, array $missing = array()
 933         ) {
 934                 $out = '';
 935                 $states = array();
 936
 937                 if ( !count( $modules ) && !count( $missing ) ) {
 938                         return <<<MESSAGE
 939 /* This file is the Web entry point for MediaWiki's ResourceLoader:
 940    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
 941    no modules were requested. Max made me put this here. */
 942 MESSAGE;
 943                 }
 944
 945                 $image = $context->getImageObj();
 946                 if ( $image ) {
 947                         $data = $image->getImageData( $context );
 948                         if ( $data === false ) {
 949                                 $data = '';
 950                                 $this->errors[] = 'Image generation failed';
 951                         }
 952                         return $data;
 953                 }
 954
 955                 // Pre-fetch blobs
 956                 if ( $context->shouldIncludeMessages() ) {
 957                         try {
 958                                 $blobs = $this->blobStore->get( $this, $modules, $context->getLanguage() );
 959                         } catch ( Exception $e ) {
 960                                 MWExceptionHandler::logException( $e );
 961                                 $this->logger->info(
 962                                         __METHOD__ . ": pre-fetching blobs from MessageBlobStore failed: $e"
 963                                 );
 964                                 $this->errors[] = self::formatExceptionNoComment( $e );
 965                         }
 966                 } else {
 967                         $blobs = array();
 968                 }
 969
 970                 foreach ( $missing as $name ) {
 971                         $states[$name] = 'missing';
 972                 }
 973
 974                 // Generate output
 975                 $isRaw = false;
 976                 foreach ( $modules as $name => $module ) {
 977                         /**
 978                          * @var $module ResourceLoaderModule
 979                          */
 980
 981                         try {
 982                                 $scripts = '';
 983                                 if ( $context->shouldIncludeScripts() ) {
 984                                         // If we are in debug mode, we'll want to return an array of URLs if possible
 985                                         // However, we can't do this if the module doesn't support it
 986                                         // We also can't do this if there is an only= parameter, because we have to give
 987                                         // the module a way to return a load.php URL without causing an infinite loop
 988                                         if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
 989                                                 $scripts = $module->getScriptURLsForDebug( $context );
 990                                         } else {
 991                                                 $scripts = $module->getScript( $context );
 992                                                 // rtrim() because there are usually a few line breaks
 993                                                 // after the last ';'. A new line at EOF, a new line
 994                                                 // added by ResourceLoaderFileModule::readScriptFiles, etc.
 995                                                 if ( is_string( $scripts )
 996                                                         && strlen( $scripts )
 997                                                         && substr( rtrim( $scripts ), -1 ) !== ';'
 998                                                 ) {
 999                                                         // Append semicolon to prevent weird bugs caused by files not
1000                                                         // terminating their statements right (bug 27054)
1001                                                         $scripts .= ";\n";
1002                                                 }
1003                                         }
1004                                 }
1005                                 // Styles
1006                                 $styles = array();
1007                                 if ( $context->shouldIncludeStyles() ) {
1008                                         // Don't create empty stylesheets like array( '' => '' ) for modules
1009                                         // that don't *have* any stylesheets (bug 38024).
1010                                         $stylePairs = $module->getStyles( $context );
1011                                         if ( count( $stylePairs ) ) {
1012                                                 // If we are in debug mode without &only= set, we'll want to return an array of URLs
1013                                                 // See comment near shouldIncludeScripts() for more details
1014                                                 if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
1015                                                         $styles = array(
1016                                                                 'url' => $module->getStyleURLsForDebug( $context )
1017                                                         );
1018                                                 } else {
1019                                                         // Minify CSS before embedding in mw.loader.implement call
1020                                                         // (unless in debug mode)
1021                                                         if ( !$context->getDebug() ) {
1022                                                                 foreach ( $stylePairs as $media => $style ) {
1023                                                                         // Can be either a string or an array of strings.
1024                                                                         if ( is_array( $style ) ) {
1025                                                                                 $stylePairs[$media] = array();
1026                                                                                 foreach ( $style as $cssText ) {
1027                                                                                         if ( is_string( $cssText ) ) {
1028                                                                                                 $stylePairs[$media][] = $this->filter( 'minify-css', $cssText );
1029                                                                                         }
1030                                                                                 }
1031                                                                         } elseif ( is_string( $style ) ) {
1032                                                                                 $stylePairs[$media] = $this->filter( 'minify-css', $style );
1033                                                                         }
1034                                                                 }
1035                                                         }
1036                                                         // Wrap styles into @media groups as needed and flatten into a numerical array
1037                                                         $styles = array(
1038                                                                 'css' => self::makeCombinedStyles( $stylePairs )
1039                                                         );
1040                                                 }
1041                                         }
1042                                 }
1043
1044                                 // Messages
1045                                 $messagesBlob = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
1046
1047                                 // Append output
1048                                 switch ( $context->getOnly() ) {
1049                                         case 'scripts':
1050                                                 if ( is_string( $scripts ) ) {
1051                                                         // Load scripts raw...
1052                                                         $out .= $scripts;
1053                                                 } elseif ( is_array( $scripts ) ) {
1054                                                         // ...except when $scripts is an array of URLs
1055                                                         $out .= self::makeLoaderImplementScript( $name, $scripts, array(), array() );
1056                                                 }
1057                                                 break;
1058                                         case 'styles':
1059                                                 // We no longer seperate into media, they are all combined now with
1060                                                 // custom media type groups into @media .. {} sections as part of the css string.
1061                                                 // Module returns either an empty array or a numerical array with css strings.
1062                                                 $out .= isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
1063                                                 break;
1064                                         default:
1065                                                 $out .= self::makeLoaderImplementScript(
1066                                                         $name,
1067                                                         $scripts,
1068                                                         $styles,
1069                                                         new XmlJsCode( $messagesBlob ),
1070                                                         $module->getTemplates()
1071                                                 );
1072                                                 break;
1073                                 }
1074                         } catch ( Exception $e ) {
1075                                 MWExceptionHandler::logException( $e );
1076                                 $this->logger->info( __METHOD__ . ": generating module package failed: $e" );
1077                                 $this->errors[] = self::formatExceptionNoComment( $e );
1078
1079                                 // Respond to client with error-state instead of module implementation
1080                                 $states[$name] = 'error';
1081                                 unset( $modules[$name] );
1082                         }
1083                         $isRaw |= $module->isRaw();
1084                 }
1085
1086                 // Update module states
1087                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
1088                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
1089                                 // Set the state of modules loaded as only scripts to ready as
1090                                 // they don't have an mw.loader.implement wrapper that sets the state
1091                                 foreach ( $modules as $name => $module ) {
1092                                         $states[$name] = 'ready';
1093                                 }
1094                         }
1095
1096                         // Set the state of modules we didn't respond to with mw.loader.implement
1097                         if ( count( $states ) ) {
1098                                 $out .= self::makeLoaderStateScript( $states );
1099                         }
1100                 } else {
1101                         if ( count( $states ) ) {
1102                                 $this->errors[] = 'Problematic modules: ' .
1103                                         FormatJson::encode( $states, ResourceLoader::inDebugMode() );
1104                         }
1105                 }
1106
1107                 $enableFilterCache = true;
1108                 if ( count( $modules ) === 1 && reset( $modules ) instanceof ResourceLoaderUserTokensModule ) {
1109                         // If we're building the embedded user.tokens, don't cache (T84960)
1110                         $enableFilterCache = false;
1111                 }
1112
1113                 if ( !$context->getDebug() ) {
1114                         if ( $context->getOnly() === 'styles' ) {
1115                                 $out = $this->filter( 'minify-css', $out );
1116                         } else {
1117                                 $out = $this->filter( 'minify-js', $out, array(
1118                                         'cache' => $enableFilterCache
1119                                 ) );
1120                         }
1121                 }
1122
1123                 return $out;
1124         }
1125
1126         /* Static Methods */
1127
1128         /**
1129          * Return JS code that calls mw.loader.implement with given module properties.
1130          *
1131          * @param string $name Module name
1132          * @param mixed $scripts List of URLs to JavaScript files or String of JavaScript code
1133          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
1134          *   to CSS files keyed by media type
1135          * @param mixed $messages List of messages associated with this module. May either be an
1136          *   associative array mapping message key to value, or a JSON-encoded message blob containing
1137          *   the same data, wrapped in an XmlJsCode object.
1138          * @param array $templates Keys are name of templates and values are the source of
1139          *   the template.
1140          * @throws MWException
1141          * @return string
1142          */
1143         public static function makeLoaderImplementScript(
1144                 $name, $scripts, $styles, $messages, $templates
1145         ) {
1146                 if ( is_string( $scripts ) ) {
1147                         $scripts = new XmlJsCode( "function ( $, jQuery ) {\n{$scripts}\n}" );
1148                 } elseif ( !is_array( $scripts ) ) {
1149                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
1150                 }
1151                 // mw.loader.implement requires 'styles', 'messages' and 'templates' to be objects (not
1152                 // arrays). json_encode considers empty arrays to be numerical and outputs "[]" instead
1153                 // of "{}". Force them to objects.
1154                 $module = array(
1155                         $name,
1156                         $scripts,
1157                         (object) $styles,
1158                         (object) $messages,
1159                         (object) $templates,
1160                 );
1161                 self::trimArray( $module );
1162
1163                 return Xml::encodeJsCall( 'mw.loader.implement', $module, ResourceLoader::inDebugMode() );
1164         }
1165
1166         /**
1167          * Returns JS code which, when called, will register a given list of messages.
1168          *
1169          * @param mixed $messages Either an associative array mapping message key to value, or a
1170          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
1171          * @return string
1172          */
1173         public static function makeMessageSetScript( $messages ) {
1174                 return Xml::encodeJsCall(
1175                         'mw.messages.set',
1176                         array( (object)$messages ),
1177                         ResourceLoader::inDebugMode()
1178                 );
1179         }
1180
1181         /**
1182          * Combines an associative array mapping media type to CSS into a
1183          * single stylesheet with "@media" blocks.
1184          *
1185          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
1186          * @return array
1187          */
1188         public static function makeCombinedStyles( array $stylePairs ) {
1189                 $out = array();
1190                 foreach ( $stylePairs as $media => $styles ) {
1191                         // ResourceLoaderFileModule::getStyle can return the styles
1192                         // as a string or an array of strings. This is to allow separation in
1193                         // the front-end.
1194                         $styles = (array)$styles;
1195                         foreach ( $styles as $style ) {
1196                                 $style = trim( $style );
1197                                 // Don't output an empty "@media print { }" block (bug 40498)
1198                                 if ( $style !== '' ) {
1199                                         // Transform the media type based on request params and config
1200                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1201                                         $media = OutputPage::transformCssMedia( $media );
1202
1203                                         if ( $media === '' || $media == 'all' ) {
1204                                                 $out[] = $style;
1205                                         } elseif ( is_string( $media ) ) {
1206                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1207                                         }
1208                                         // else: skip
1209                                 }
1210                         }
1211                 }
1212                 return $out;
1213         }
1214
1215         /**
1216          * Returns a JS call to mw.loader.state, which sets the state of a
1217          * module or modules to a given value. Has two calling conventions:
1218          *
1219          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1220          *         Set the state of a single module called $name to $state
1221          *
1222          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
1223          *         Set the state of modules with the given names to the given states
1224          *
1225          * @param string $name
1226          * @param string $state
1227          * @return string
1228          */
1229         public static function makeLoaderStateScript( $name, $state = null ) {
1230                 if ( is_array( $name ) ) {
1231                         return Xml::encodeJsCall(
1232                                 'mw.loader.state',
1233                                 array( $name ),
1234                                 ResourceLoader::inDebugMode()
1235                         );
1236                 } else {
1237                         return Xml::encodeJsCall(
1238                                 'mw.loader.state',
1239                                 array( $name, $state ),
1240                                 ResourceLoader::inDebugMode()
1241                         );
1242                 }
1243         }
1244
1245         /**
1246          * Returns JS code which calls the script given by $script. The script will
1247          * be called with local variables name, version, dependencies and group,
1248          * which will have values corresponding to $name, $version, $dependencies
1249          * and $group as supplied.
1250          *
1251          * @param string $name Module name
1252          * @param string $version Module version hash
1253          * @param array $dependencies List of module names on which this module depends
1254          * @param string $group Group which the module is in.
1255          * @param string $source Source of the module, or 'local' if not foreign.
1256          * @param string $script JavaScript code
1257          * @return string
1258          */
1259         public static function makeCustomLoaderScript( $name, $version, $dependencies,
1260                 $group, $source, $script
1261         ) {
1262                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1263                 return Xml::encodeJsCall(
1264                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1265                         array( $name, $version, $dependencies, $group, $source ),
1266                         ResourceLoader::inDebugMode()
1267                 );
1268         }
1269
1270         private static function isEmptyObject( stdClass $obj ) {
1271                 foreach ( $obj as $key => &$value ) {
1272                         return false;
1273                 }
1274                 return true;
1275         }
1276
1277         /**
1278          * Remove empty values from the end of an array.
1279          *
1280          * Values considered empty:
1281          *
1282          * - null
1283          * - array()
1284          * - new XmlJsCode( '{}' )
1285          * - new stdClass() // (object) array()
1286          *
1287          * @param Array $array
1288          */
1289         private static function trimArray( Array &$array ) {
1290                 $i = count( $array );
1291                 while ( $i-- ) {
1292                         if ( $array[$i] === null
1293                                 || $array[$i] === array()
1294                                 || ( $array[$i] instanceof XmlJsCode && $array[$i]->value === '{}' )
1295                                 || ( $array[$i] instanceof stdClass && self::isEmptyObject( $array[$i] ) )
1296                         ) {
1297                                 unset( $array[$i] );
1298                         } else {
1299                                 break;
1300                         }
1301                 }
1302         }
1303
1304         /**
1305          * Returns JS code which calls mw.loader.register with the given
1306          * parameters. Has three calling conventions:
1307          *
1308          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version,
1309          *        $dependencies, $group, $source, $skip
1310          *     ):
1311          *        Register a single module.
1312          *
1313          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
1314          *        Register modules with the given names.
1315          *
1316          *   - ResourceLoader::makeLoaderRegisterScript( array(
1317          *        array( $name1, $version1, $dependencies1, $group1, $source1, $skip1 ),
1318          *        array( $name2, $version2, $dependencies1, $group2, $source2, $skip2 ),
1319          *        ...
1320          *     ) ):
1321          *        Registers modules with the given names and parameters.
1322          *
1323          * @param string $name Module name
1324          * @param string $version Module version hash
1325          * @param array $dependencies List of module names on which this module depends
1326          * @param string $group Group which the module is in
1327          * @param string $source Source of the module, or 'local' if not foreign
1328          * @param string $skip Script body of the skip function
1329          * @return string
1330          */
1331         public static function makeLoaderRegisterScript( $name, $version = null,
1332                 $dependencies = null, $group = null, $source = null, $skip = null
1333         ) {
1334                 if ( is_array( $name ) ) {
1335                         // Build module name index
1336                         $index = array();
1337                         foreach ( $name as $i => &$module ) {
1338                                 $index[$module[0]] = $i;
1339                         }
1340
1341                         // Transform dependency names into indexes when possible, they will be resolved by
1342                         // mw.loader.register on the other end
1343                         foreach ( $name as &$module ) {
1344                                 if ( isset( $module[2] ) ) {
1345                                         foreach ( $module[2] as &$dependency ) {
1346                                                 if ( isset( $index[$dependency] ) ) {
1347                                                         $dependency = $index[$dependency];
1348                                                 }
1349                                         }
1350                                 }
1351                         }
1352
1353                         array_walk( $name, array( 'self', 'trimArray' ) );
1354
1355                         return Xml::encodeJsCall(
1356                                 'mw.loader.register',
1357                                 array( $name ),
1358                                 ResourceLoader::inDebugMode()
1359                         );
1360                 } else {
1361                         $registration = array( $name, $version, $dependencies, $group, $source, $skip );
1362                         self::trimArray( $registration );
1363                         return Xml::encodeJsCall(
1364                                 'mw.loader.register',
1365                                 $registration,
1366                                 ResourceLoader::inDebugMode()
1367                         );
1368                 }
1369         }
1370
1371         /**
1372          * Returns JS code which calls mw.loader.addSource() with the given
1373          * parameters. Has two calling conventions:
1374          *
1375          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1376          *       Register a single source
1377          *
1378          *   - ResourceLoader::makeLoaderSourcesScript( array( $id1 => $loadUrl, $id2 => $loadUrl, ... ) );
1379          *       Register sources with the given IDs and properties.
1380          *
1381          * @param string $id Source ID
1382          * @param array $properties Source properties (see addSource())
1383          * @return string
1384          */
1385         public static function makeLoaderSourcesScript( $id, $properties = null ) {
1386                 if ( is_array( $id ) ) {
1387                         return Xml::encodeJsCall(
1388                                 'mw.loader.addSource',
1389                                 array( $id ),
1390                                 ResourceLoader::inDebugMode()
1391                         );
1392                 } else {
1393                         return Xml::encodeJsCall(
1394                                 'mw.loader.addSource',
1395                                 array( $id, $properties ),
1396                                 ResourceLoader::inDebugMode()
1397                         );
1398                 }
1399         }
1400
1401         /**
1402          * Returns JS code which runs given JS code if the client-side framework is
1403          * present.
1404          *
1405          * @deprecated since 1.25; use makeInlineScript instead
1406          * @param string $script JavaScript code
1407          * @return string
1408          */
1409         public static function makeLoaderConditionalScript( $script ) {
1410                 return "if(window.mw){\n" . trim( $script ) . "\n}";
1411         }
1412
1413         /**
1414          * Construct an inline script tag with given JS code.
1415          *
1416          * The code will be wrapped in a closure, and it will be executed by ResourceLoader
1417          * only if the client has adequate support for MediaWiki JavaScript code.
1418          *
1419          * @param string $script JavaScript code
1420          * @return string HTML
1421          */
1422         public static function makeInlineScript( $script ) {
1423                 $js = self::makeLoaderConditionalScript( $script );
1424                 return Html::inlineScript( $js );
1425         }
1426
1427         /**
1428          * Returns JS code which will set the MediaWiki configuration array to
1429          * the given value.
1430          *
1431          * @param array $configuration List of configuration values keyed by variable name
1432          * @return string
1433          */
1434         public static function makeConfigSetScript( array $configuration ) {
1435                 return Xml::encodeJsCall(
1436                         'mw.config.set',
1437                         array( $configuration ),
1438                         ResourceLoader::inDebugMode()
1439                 );
1440         }
1441
1442         /**
1443          * Convert an array of module names to a packed query string.
1444          *
1445          * For example, array( 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' )
1446          * becomes 'foo.bar,baz|bar.baz,quux'
1447          * @param array $modules List of module names (strings)
1448          * @return string Packed query string
1449          */
1450         public static function makePackedModulesString( $modules ) {
1451                 $groups = array(); // array( prefix => array( suffixes ) )
1452                 foreach ( $modules as $module ) {
1453                         $pos = strrpos( $module, '.' );
1454                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1455                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1456                         $groups[$prefix][] = $suffix;
1457                 }
1458
1459                 $arr = array();
1460                 foreach ( $groups as $prefix => $suffixes ) {
1461                         $p = $prefix === '' ? '' : $prefix . '.';
1462                         $arr[] = $p . implode( ',', $suffixes );
1463                 }
1464                 $str = implode( '|', $arr );
1465                 return $str;
1466         }
1467
1468         /**
1469          * Determine whether debug mode was requested
1470          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1471          * @return bool
1472          */
1473         public static function inDebugMode() {
1474                 if ( self::$debugMode === null ) {
1475                         global $wgRequest, $wgResourceLoaderDebug;
1476                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1477                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1478                         );
1479                 }
1480                 return self::$debugMode;
1481         }
1482
1483         /**
1484          * Reset static members used for caching.
1485          *
1486          * Global state and $wgRequest are evil, but we're using it right
1487          * now and sometimes we need to be able to force ResourceLoader to
1488          * re-evaluate the context because it has changed (e.g. in the test suite).
1489          */
1490         public static function clearCache() {
1491                 self::$debugMode = null;
1492         }
1493
1494         /**
1495          * Build a load.php URL
1496          *
1497          * @since 1.24
1498          * @param string $source Name of the ResourceLoader source
1499          * @param ResourceLoaderContext $context
1500          * @param array $extraQuery
1501          * @return string URL to load.php. May be protocol-relative (if $wgLoadScript is procol-relative)
1502          */
1503         public function createLoaderURL( $source, ResourceLoaderContext $context,
1504                 $extraQuery = array()
1505         ) {
1506                 $query = self::createLoaderQuery( $context, $extraQuery );
1507                 $script = $this->getLoadScript( $source );
1508
1509                 // Prevent the IE6 extension check from being triggered (bug 28840)
1510                 // by appending a character that's invalid in Windows extensions ('*')
1511                 return wfExpandUrl( wfAppendQuery( $script, $query ) . '&*', PROTO_RELATIVE );
1512         }
1513
1514         /**
1515          * Build a load.php URL
1516          * @deprecated since 1.24 Use createLoaderURL() instead
1517          * @param array $modules Array of module names (strings)
1518          * @param string $lang Language code
1519          * @param string $skin Skin name
1520          * @param string|null $user User name. If null, the &user= parameter is omitted
1521          * @param string|null $version Versioning timestamp
1522          * @param bool $debug Whether the request should be in debug mode
1523          * @param string|null $only &only= parameter
1524          * @param bool $printable Printable mode
1525          * @param bool $handheld Handheld mode
1526          * @param array $extraQuery Extra query parameters to add
1527          * @return string URL to load.php. May be protocol-relative (if $wgLoadScript is procol-relative)
1528          */
1529         public static function makeLoaderURL( $modules, $lang, $skin, $user = null,
1530                 $version = null, $debug = false, $only = null, $printable = false,
1531                 $handheld = false, $extraQuery = array()
1532         ) {
1533                 global $wgLoadScript;
1534
1535                 $query = self::makeLoaderQuery( $modules, $lang, $skin, $user, $version, $debug,
1536                         $only, $printable, $handheld, $extraQuery
1537                 );
1538
1539                 // Prevent the IE6 extension check from being triggered (bug 28840)
1540                 // by appending a character that's invalid in Windows extensions ('*')
1541                 return wfExpandUrl( wfAppendQuery( $wgLoadScript, $query ) . '&*', PROTO_RELATIVE );
1542         }
1543
1544         /**
1545          * Helper for createLoaderURL()
1546          *
1547          * @since 1.24
1548          * @see makeLoaderQuery
1549          * @param ResourceLoaderContext $context
1550          * @param array $extraQuery
1551          * @return array
1552          */
1553         public static function createLoaderQuery( ResourceLoaderContext $context, $extraQuery = array() ) {
1554                 return self::makeLoaderQuery(
1555                         $context->getModules(),
1556                         $context->getLanguage(),
1557                         $context->getSkin(),
1558                         $context->getUser(),
1559                         $context->getVersion(),
1560                         $context->getDebug(),
1561                         $context->getOnly(),
1562                         $context->getRequest()->getBool( 'printable' ),
1563                         $context->getRequest()->getBool( 'handheld' ),
1564                         $extraQuery
1565                 );
1566         }
1567
1568         /**
1569          * Build a query array (array representation of query string) for load.php. Helper
1570          * function for makeLoaderURL().
1571          *
1572          * @param array $modules
1573          * @param string $lang
1574          * @param string $skin
1575          * @param string $user
1576          * @param string $version
1577          * @param bool $debug
1578          * @param string $only
1579          * @param bool $printable
1580          * @param bool $handheld
1581          * @param array $extraQuery
1582          *
1583          * @return array
1584          */
1585         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1586                 $version = null, $debug = false, $only = null, $printable = false,
1587                 $handheld = false, $extraQuery = array()
1588         ) {
1589                 $query = array(
1590                         'modules' => self::makePackedModulesString( $modules ),
1591                         'lang' => $lang,
1592                         'skin' => $skin,
1593                         'debug' => $debug ? 'true' : 'false',
1594                 );
1595                 if ( $user !== null ) {
1596                         $query['user'] = $user;
1597                 }
1598                 if ( $version !== null ) {
1599                         $query['version'] = $version;
1600                 }
1601                 if ( $only !== null ) {
1602                         $query['only'] = $only;
1603                 }
1604                 if ( $printable ) {
1605                         $query['printable'] = 1;
1606                 }
1607                 if ( $handheld ) {
1608                         $query['handheld'] = 1;
1609                 }
1610                 $query += $extraQuery;
1611
1612                 // Make queries uniform in order
1613                 ksort( $query );
1614                 return $query;
1615         }
1616
1617         /**
1618          * Check a module name for validity.
1619          *
1620          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1621          * at most 255 bytes.
1622          *
1623          * @param string $moduleName Module name to check
1624          * @return bool Whether $moduleName is a valid module name
1625          */
1626         public static function isValidModuleName( $moduleName ) {
1627                 return !preg_match( '/[|,!]/', $moduleName ) && strlen( $moduleName ) <= 255;
1628         }
1629
1630         /**
1631          * Returns LESS compiler set up for use with MediaWiki
1632          *
1633          * @param Config $config
1634          * @throws MWException
1635          * @since 1.22
1636          * @return lessc
1637          */
1638         public static function getLessCompiler( Config $config ) {
1639                 // When called from the installer, it is possible that a required PHP extension
1640                 // is missing (at least for now; see bug 47564). If this is the case, throw an
1641                 // exception (caught by the installer) to prevent a fatal error later on.
1642                 if ( !class_exists( 'lessc' ) ) {
1643                         throw new MWException( 'MediaWiki requires the lessphp compiler' );
1644                 }
1645                 if ( !function_exists( 'ctype_digit' ) ) {
1646                         throw new MWException( 'lessc requires the Ctype extension' );
1647                 }
1648
1649                 $less = new lessc();
1650                 $less->setPreserveComments( true );
1651                 $less->setVariables( self::getLessVars( $config ) );
1652                 $less->setImportDir( $config->get( 'ResourceLoaderLESSImportPaths' ) );
1653                 foreach ( $config->get( 'ResourceLoaderLESSFunctions' ) as $name => $func ) {
1654                         $less->registerFunction( $name, $func );
1655                 }
1656                 return $less;
1657         }
1658
1659         /**
1660          * Get global LESS variables.
1661          *
1662          * @param Config $config
1663          * @since 1.22
1664          * @return array Map of variable names to string CSS values.
1665          */
1666         public static function getLessVars( Config $config ) {
1667                 if ( !self::$lessVars ) {
1668                         $lessVars = $config->get( 'ResourceLoaderLESSVars' );
1669                         Hooks::run( 'ResourceLoaderGetLessVars', array( &$lessVars ) );
1670                         // Sort by key to ensure consistent hashing for cache lookups.
1671                         ksort( $lessVars );
1672                         self::$lessVars = $lessVars;
1673                 }
1674                 return self::$lessVars;
1675         }
1676 }