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
 298                 wfProfileOut( __METHOD__ );
 299         }
 300
 301         /**
 302          */
 303         public function registerTestModules() {
 304                 global $IP, $wgEnableJavaScriptTest;
 305
 306                 if ( $wgEnableJavaScriptTest !== true ) {
 307                         throw new MWException( 'Attempt to register JavaScript test modules '
 308                                 . 'but <code>$wgEnableJavaScriptTest</code> is false. '
 309                                 . 'Edit your <code>LocalSettings.php</code> to enable it.' );
 310                 }
 311
 312                 wfProfileIn( __METHOD__ );
 313
 314                 // Get core test suites
 315                 $testModules = array();
 316                 $testModules['qunit'] = array();
 317                 // Get other test suites (e.g. from extensions)
 318                 wfRunHooks( 'ResourceLoaderTestModules', array( &$testModules, &$this ) );
 319
 320                 // Add the testrunner (which configures QUnit) to the dependencies.
 321                 // Since it must be ready before any of the test suites are executed.
 322                 foreach ( $testModules['qunit'] as &$module ) {
 323                         // Make sure all test modules are top-loading so that when QUnit starts
 324                         // on document-ready, it will run once and finish. If some tests arrive
 325                         // later (possibly after QUnit has already finished) they will be ignored.
 326                         $module['position'] = 'top';
 327                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 328                 }
 329
 330                 $testModules['qunit'] =
 331                         ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules['qunit'];
 332
 333                 foreach ( $testModules as $id => $names ) {
 334                         // Register test modules
 335                         $this->register( $testModules[$id] );
 336
 337                         // Keep track of their names so that they can be loaded together
 338                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 339                 }
 340
 341                 wfProfileOut( __METHOD__ );
 342         }
 343
 344         /**
 345          * Add a foreign source of modules.
 346          *
 347          * Source properties:
 348          * 'loadScript': URL (either fully-qualified or protocol-relative) of load.php for this source
 349          *
 350          * @param mixed $id Source ID (string), or array( id1 => props1, id2 => props2, ... )
 351          * @param array $properties Source properties
 352          * @throws MWException
 353          */
 354         public function addSource( $id, $properties = null ) {
 355                 // Allow multiple sources to be registered in one call
 356                 if ( is_array( $id ) ) {
 357                         foreach ( $id as $key => $value ) {
 358                                 $this->addSource( $key, $value );
 359                         }
 360                         return;
 361                 }
 362
 363                 // Disallow duplicates
 364                 if ( isset( $this->sources[$id] ) ) {
 365                         throw new MWException(
 366                                 'ResourceLoader duplicate source addition error. ' .
 367                                 'Another source has already been registered as ' . $id
 368                         );
 369                 }
 370
 371                 // Validate properties
 372                 foreach ( self::$requiredSourceProperties as $prop ) {
 373                         if ( !isset( $properties[$prop] ) ) {
 374                                 throw new MWException( "Required property $prop missing from source ID $id" );
 375                         }
 376                 }
 377
 378                 $this->sources[$id] = $properties;
 379         }
 380
 381         /**
 382          * Get a list of module names.
 383          *
 384          * @return array List of module names
 385          */
 386         public function getModuleNames() {
 387                 return array_keys( $this->moduleInfos );
 388         }
 389
 390         /**
 391          * Get a list of test module names for one (or all) frameworks.
 392          *
 393          * If the given framework id is unknkown, or if the in-object variable is not an array,
 394          * then it will return an empty array.
 395          *
 396          * @param string $framework Get only the test module names for one
 397          *   particular framework (optional)
 398          * @return array
 399          */
 400         public function getTestModuleNames( $framework = 'all' ) {
 401                 /** @todo api siteinfo prop testmodulenames modulenames */
 402                 if ( $framework == 'all' ) {
 403                         return $this->testModuleNames;
 404                 } elseif ( isset( $this->testModuleNames[$framework] )
 405                         && is_array( $this->testModuleNames[$framework] )
 406                 ) {
 407                         return $this->testModuleNames[$framework];
 408                 } else {
 409                         return array();
 410                 }
 411         }
 412
 413         /**
 414          * Get the ResourceLoaderModule object for a given module name.
 415          *
 416          * If an array of module parameters exists but a ResourceLoaderModule object has not
 417          * yet been instantiated, this method will instantiate and cache that object such that
 418          * subsequent calls simply return the same object.
 419          *
 420          * @param string $name Module name
 421          * @return ResourceLoaderModule|null If module has been registered, return a
 422          *  ResourceLoaderModule instance. Otherwise, return null.
 423          */
 424         public function getModule( $name ) {
 425                 if ( !isset( $this->modules[$name] ) ) {
 426                         if ( !isset( $this->moduleInfos[$name] ) ) {
 427                                 // No such module
 428                                 return null;
 429                         }
 430                         // Construct the requested object
 431                         $info = $this->moduleInfos[$name];
 432                         /** @var ResourceLoaderModule $object */
 433                         if ( isset( $info['object'] ) ) {
 434                                 // Object given in info array
 435                                 $object = $info['object'];
 436                         } else {
 437                                 if ( !isset( $info['class'] ) ) {
 438                                         $class = 'ResourceLoaderFileModule';
 439                                 } else {
 440                                         $class = $info['class'];
 441                                 }
 442                                 $object = new $class( $info );
 443                         }
 444                         $object->setName( $name );
 445                         $this->modules[$name] = $object;
 446                 }
 447
 448                 return $this->modules[$name];
 449         }
 450
 451         /**
 452          * Get the list of sources.
 453          *
 454          * @return array Like array( id => array of properties, .. )
 455          */
 456         public function getSources() {
 457                 return $this->sources;
 458         }
 459
 460         /**
 461          * Output a response to a load request, including the content-type header.
 462          *
 463          * @param ResourceLoaderContext $context Context in which a response should be formed
 464          */
 465         public function respond( ResourceLoaderContext $context ) {
 466                 global $wgCacheEpoch, $wgUseFileCache;
 467
 468                 // Use file cache if enabled and available...
 469                 if ( $wgUseFileCache ) {
 470                         $fileCache = ResourceFileCache::newFromContext( $context );
 471                         if ( $this->tryRespondFromFileCache( $fileCache, $context ) ) {
 472                                 return; // output handled
 473                         }
 474                 }
 475
 476                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 477                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 478                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 479                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 480                 // the whole thing in our own output buffer to be sure the active buffer
 481                 // doesn't use ob_gzhandler.
 482                 // See http://bugs.php.net/bug.php?id=36514
 483                 ob_start();
 484
 485                 wfProfileIn( __METHOD__ );
 486                 $errors = '';
 487
 488                 // Find out which modules are missing and instantiate the others
 489                 $modules = array();
 490                 $missing = array();
 491                 foreach ( $context->getModules() as $name ) {
 492                         $module = $this->getModule( $name );
 493                         if ( $module ) {
 494                                 // Do not allow private modules to be loaded from the web.
 495                                 // This is a security issue, see bug 34907.
 496                                 if ( $module->getGroup() === 'private' ) {
 497                                         wfDebugLog( 'resourceloader', __METHOD__ . ": request for private module '$name' denied" );
 498                                         $this->hasErrors = true;
 499                                         // Add exception to the output as a comment
 500                                         $errors .= self::makeComment( "Cannot show private module \"$name\"" );
 501
 502                                         continue;
 503                                 }
 504                                 $modules[$name] = $module;
 505                         } else {
 506                                 $missing[] = $name;
 507                         }
 508                 }
 509
 510                 // Preload information needed to the mtime calculation below
 511                 try {
 512                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 513                 } catch ( Exception $e ) {
 514                         MWExceptionHandler::logException( $e );
 515                         wfDebugLog( 'resourceloader', __METHOD__ . ": preloading module info failed: $e" );
 516                         $this->hasErrors = true;
 517                         // Add exception to the output as a comment
 518                         $errors .= self::formatException( $e );
 519                 }
 520
 521                 wfProfileIn( __METHOD__ . '-getModifiedTime' );
 522
 523                 // To send Last-Modified and support If-Modified-Since, we need to detect
 524                 // the last modified time
 525                 $mtime = wfTimestamp( TS_UNIX, $wgCacheEpoch );
 526                 foreach ( $modules as $module ) {
 527                         /**
 528                          * @var $module ResourceLoaderModule
 529                          */
 530                         try {
 531                                 // Calculate maximum modified time
 532                                 $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 533                         } catch ( Exception $e ) {
 534                                 MWExceptionHandler::logException( $e );
 535                                 wfDebugLog( 'resourceloader', __METHOD__ . ": calculating maximum modified time failed: $e" );
 536                                 $this->hasErrors = true;
 537                                 // Add exception to the output as a comment
 538                                 $errors .= self::formatException( $e );
 539                         }
 540                 }
 541
 542                 wfProfileOut( __METHOD__ . '-getModifiedTime' );
 543
 544                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 545                 if ( $this->tryRespondLastModified( $context, $mtime ) ) {
 546                         wfProfileOut( __METHOD__ );
 547                         return; // output handled (buffers cleared)
 548                 }
 549
 550                 // Generate a response
 551                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 552
 553                 // Prepend comments indicating exceptions
 554                 $response = $errors . $response;
 555
 556                 // Capture any PHP warnings from the output buffer and append them to the
 557                 // response in a comment if we're in debug mode.
 558                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 559                         $response = self::makeComment( $warnings ) . $response;
 560                         $this->hasErrors = true;
 561                 }
 562
 563                 // Save response to file cache unless there are errors
 564                 if ( isset( $fileCache ) && !$errors && !count( $missing ) ) {
 565                         // Cache single modules...and other requests if there are enough hits
 566                         if ( ResourceFileCache::useFileCache( $context ) ) {
 567                                 if ( $fileCache->isCacheWorthy() ) {
 568                                         $fileCache->saveText( $response );
 569                                 } else {
 570                                         $fileCache->incrMissesRecent( $context->getRequest() );
 571                                 }
 572                         }
 573                 }
 574
 575                 // Send content type and cache related headers
 576                 $this->sendResponseHeaders( $context, $mtime, $this->hasErrors );
 577
 578                 // Remove the output buffer and output the response
 579                 ob_end_clean();
 580                 echo $response;
 581
 582                 wfProfileOut( __METHOD__ );
 583         }
 584
 585         /**
 586          * Send content type and last modified headers to the client.
 587          * @param ResourceLoaderContext $context
 588          * @param string $mtime TS_MW timestamp to use for last-modified
 589          * @param bool $errors Whether there are commented-out errors in the response
 590          * @return void
 591          */
 592         protected function sendResponseHeaders( ResourceLoaderContext $context, $mtime, $errors ) {
 593                 global $wgResourceLoaderMaxage;
 594                 // If a version wasn't specified we need a shorter expiry time for updates
 595                 // to propagate to clients quickly
 596                 // If there were errors, we also need a shorter expiry time so we can recover quickly
 597                 if ( is_null( $context->getVersion() ) || $errors ) {
 598                         $maxage = $wgResourceLoaderMaxage['unversioned']['client'];
 599                         $smaxage = $wgResourceLoaderMaxage['unversioned']['server'];
 600                 // If a version was specified we can use a longer expiry time since changing
 601                 // version numbers causes cache misses
 602                 } else {
 603                         $maxage = $wgResourceLoaderMaxage['versioned']['client'];
 604                         $smaxage = $wgResourceLoaderMaxage['versioned']['server'];
 605                 }
 606                 if ( $context->getOnly() === 'styles' ) {
 607                         header( 'Content-Type: text/css; charset=utf-8' );
 608                         header( 'Access-Control-Allow-Origin: *' );
 609                 } else {
 610                         header( 'Content-Type: text/javascript; charset=utf-8' );
 611                 }
 612                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 613                 if ( $context->getDebug() ) {
 614                         // Do not cache debug responses
 615                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 616                         header( 'Pragma: no-cache' );
 617                 } else {
 618                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 619                         $exp = min( $maxage, $smaxage );
 620                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 621                 }
 622         }
 623
 624         /**
 625          * Respond with 304 Last Modified if appropiate.
 626          *
 627          * If there's an If-Modified-Since header, respond with a 304 appropriately
 628          * and clear out the output buffer. If the client cache is too old then do nothing.
 629          *
 630          * @param ResourceLoaderContext $context
 631          * @param string $mtime The TS_MW timestamp to check the header against
 632          * @return bool True if 304 header sent and output handled
 633          */
 634         protected function tryRespondLastModified( ResourceLoaderContext $context, $mtime ) {
 635                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 636                 // Some clients send "timestamp;length=123". Strip the part after the first ';'
 637                 // so we get a valid timestamp.
 638                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 639                 // Never send 304s in debug mode
 640                 if ( $ims !== false && !$context->getDebug() ) {
 641                         $imsTS = strtok( $ims, ';' );
 642                         if ( $mtime <= wfTimestamp( TS_UNIX, $imsTS ) ) {
 643                                 // There's another bug in ob_gzhandler (see also the comment at
 644                                 // the top of this function) that causes it to gzip even empty
 645                                 // responses, meaning it's impossible to produce a truly empty
 646                                 // response (because the gzip header is always there). This is
 647                                 // a problem because 304 responses have to be completely empty
 648                                 // per the HTTP spec, and Firefox behaves buggily when they're not.
 649                                 // See also http://bugs.php.net/bug.php?id=51579
 650                                 // To work around this, we tear down all output buffering before
 651                                 // sending the 304.
 652                                 wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 653
 654                                 header( 'HTTP/1.0 304 Not Modified' );
 655                                 header( 'Status: 304 Not Modified' );
 656                                 return true;
 657                         }
 658                 }
 659                 return false;
 660         }
 661
 662         /**
 663          * Send out code for a response from file cache if possible.
 664          *
 665          * @param ResourceFileCache $fileCache Cache object for this request URL
 666          * @param ResourceLoaderContext $context Context in which to generate a response
 667          * @return bool If this found a cache file and handled the response
 668          */
 669         protected function tryRespondFromFileCache(
 670                 ResourceFileCache $fileCache, ResourceLoaderContext $context
 671         ) {
 672                 global $wgResourceLoaderMaxage;
 673                 // Buffer output to catch warnings.
 674                 ob_start();
 675                 // Get the maximum age the cache can be
 676                 $maxage = is_null( $context->getVersion() )
 677                         ? $wgResourceLoaderMaxage['unversioned']['server']
 678                         : $wgResourceLoaderMaxage['versioned']['server'];
 679                 // Minimum timestamp the cache file must have
 680                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 681                 if ( !$good ) {
 682                         try { // RL always hits the DB on file cache miss...
 683                                 wfGetDB( DB_SLAVE );
 684                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 685                                 $good = $fileCache->isCacheGood(); // cache existence check
 686                         }
 687                 }
 688                 if ( $good ) {
 689                         $ts = $fileCache->cacheTimestamp();
 690                         // Send content type and cache headers
 691                         $this->sendResponseHeaders( $context, $ts, false );
 692                         // If there's an If-Modified-Since header, respond with a 304 appropriately
 693                         if ( $this->tryRespondLastModified( $context, $ts ) ) {
 694                                 return false; // output handled (buffers cleared)
 695                         }
 696                         $response = $fileCache->fetchText();
 697                         // Capture any PHP warnings from the output buffer and append them to the
 698                         // response in a comment if we're in debug mode.
 699                         if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 700                                 $response = "/*\n$warnings\n*/\n" . $response;
 701                         }
 702                         // Remove the output buffer and output the response
 703                         ob_end_clean();
 704                         echo $response . "\n/* Cached {$ts} */";
 705                         return true; // cache hit
 706                 }
 707                 // Clear buffer
 708                 ob_end_clean();
 709
 710                 return false; // cache miss
 711         }
 712
 713         /**
 714          * Generate a CSS or JS comment block.
 715          *
 716          * Only use this for public data, not error message details.
 717          *
 718          * @param string $text
 719          * @return string
 720          */
 721         public static function makeComment( $text ) {
 722                 $encText = str_replace( '*/', '* /', $text );
 723                 return "/*\n$encText\n*/\n";
 724         }
 725
 726         /**
 727          * Handle exception display.
 728          *
 729          * @param Exception $e Exception to be shown to the user
 730          * @return string Sanitized text that can be returned to the user
 731          */
 732         public static function formatException( $e ) {
 733                 global $wgShowExceptionDetails;
 734
 735                 if ( $wgShowExceptionDetails ) {
 736                         return self::makeComment( $e->__toString() );
 737                 } else {
 738                         return self::makeComment( wfMessage( 'internalerror' )->text() );
 739                 }
 740         }
 741
 742         /**
 743          * Generate code for a response.
 744          *
 745          * @param ResourceLoaderContext $context Context in which to generate a response
 746          * @param array $modules List of module objects keyed by module name
 747          * @param array $missing List of requested module names that are unregistered (optional)
 748          * @return string Response data
 749          */
 750         public function makeModuleResponse( ResourceLoaderContext $context,
 751                 array $modules, array $missing = array()
 752         ) {
 753                 $out = '';
 754                 $exceptions = '';
 755                 $states = array();
 756
 757                 if ( !count( $modules ) && !count( $missing ) ) {
 758                         return "/* This file is the Web entry point for MediaWiki's ResourceLoader:
 759    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
 760    no modules were requested. Max made me put this here. */";
 761                 }
 762
 763                 wfProfileIn( __METHOD__ );
 764
 765                 // Pre-fetch blobs
 766                 if ( $context->shouldIncludeMessages() ) {
 767                         try {
 768                                 $blobs = MessageBlobStore::get( $this, $modules, $context->getLanguage() );
 769                         } catch ( Exception $e ) {
 770                                 MWExceptionHandler::logException( $e );
 771                                 wfDebugLog(
 772                                         'resourceloader',
 773                                         __METHOD__ . ": pre-fetching blobs from MessageBlobStore failed: $e"
 774                                 );
 775                                 $this->hasErrors = true;
 776                                 // Add exception to the output as a comment
 777                                 $exceptions .= self::formatException( $e );
 778                         }
 779                 } else {
 780                         $blobs = array();
 781                 }
 782
 783                 foreach ( $missing as $name ) {
 784                         $states[$name] = 'missing';
 785                 }
 786
 787                 // Generate output
 788                 $isRaw = false;
 789                 foreach ( $modules as $name => $module ) {
 790                         /**
 791                          * @var $module ResourceLoaderModule
 792                          */
 793
 794                         wfProfileIn( __METHOD__ . '-' . $name );
 795                         try {
 796                                 $scripts = '';
 797                                 if ( $context->shouldIncludeScripts() ) {
 798                                         // If we are in debug mode, we'll want to return an array of URLs if possible
 799                                         // However, we can't do this if the module doesn't support it
 800                                         // We also can't do this if there is an only= parameter, because we have to give
 801                                         // the module a way to return a load.php URL without causing an infinite loop
 802                                         if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
 803                                                 $scripts = $module->getScriptURLsForDebug( $context );
 804                                         } else {
 805                                                 $scripts = $module->getScript( $context );
 806                                                 // rtrim() because there are usually a few line breaks
 807                                                 // after the last ';'. A new line at EOF, a new line
 808                                                 // added by ResourceLoaderFileModule::readScriptFiles, etc.
 809                                                 if ( is_string( $scripts )
 810                                                         && strlen( $scripts )
 811                                                         && substr( rtrim( $scripts ), -1 ) !== ';'
 812                                                 ) {
 813                                                         // Append semicolon to prevent weird bugs caused by files not
 814                                                         // terminating their statements right (bug 27054)
 815                                                         $scripts .= ";\n";
 816                                                 }
 817                                         }
 818                                 }
 819                                 // Styles
 820                                 $styles = array();
 821                                 if ( $context->shouldIncludeStyles() ) {
 822                                         // Don't create empty stylesheets like array( '' => '' ) for modules
 823                                         // that don't *have* any stylesheets (bug 38024).
 824                                         $stylePairs = $module->getStyles( $context );
 825                                         if ( count( $stylePairs ) ) {
 826                                                 // If we are in debug mode without &only= set, we'll want to return an array of URLs
 827                                                 // See comment near shouldIncludeScripts() for more details
 828                                                 if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
 829                                                         $styles = array(
 830                                                                 'url' => $module->getStyleURLsForDebug( $context )
 831                                                         );
 832                                                 } else {
 833                                                         // Minify CSS before embedding in mw.loader.implement call
 834                                                         // (unless in debug mode)
 835                                                         if ( !$context->getDebug() ) {
 836                                                                 foreach ( $stylePairs as $media => $style ) {
 837                                                                         // Can be either a string or an array of strings.
 838                                                                         if ( is_array( $style ) ) {
 839                                                                                 $stylePairs[$media] = array();
 840                                                                                 foreach ( $style as $cssText ) {
 841                                                                                         if ( is_string( $cssText ) ) {
 842                                                                                                 $stylePairs[$media][] = $this->filter( 'minify-css', $cssText );
 843                                                                                         }
 844                                                                                 }
 845                                                                         } elseif ( is_string( $style ) ) {
 846                                                                                 $stylePairs[$media] = $this->filter( 'minify-css', $style );
 847                                                                         }
 848                                                                 }
 849                                                         }
 850                                                         // Wrap styles into @media groups as needed and flatten into a numerical array
 851                                                         $styles = array(
 852                                                                 'css' => self::makeCombinedStyles( $stylePairs )
 853                                                         );
 854                                                 }
 855                                         }
 856                                 }
 857
 858                                 // Messages
 859                                 $messagesBlob = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 860
 861                                 // Append output
 862                                 switch ( $context->getOnly() ) {
 863                                         case 'scripts':
 864                                                 if ( is_string( $scripts ) ) {
 865                                                         // Load scripts raw...
 866                                                         $out .= $scripts;
 867                                                 } elseif ( is_array( $scripts ) ) {
 868                                                         // ...except when $scripts is an array of URLs
 869                                                         $out .= self::makeLoaderImplementScript( $name, $scripts, array(), array() );
 870                                                 }
 871                                                 break;
 872                                         case 'styles':
 873                                                 // We no longer seperate into media, they are all combined now with
 874                                                 // custom media type groups into @media .. {} sections as part of the css string.
 875                                                 // Module returns either an empty array or a numerical array with css strings.
 876                                                 $out .= isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
 877                                                 break;
 878                                         case 'messages':
 879                                                 $out .= self::makeMessageSetScript( new XmlJsCode( $messagesBlob ) );
 880                                                 break;
 881                                         default:
 882                                                 $out .= self::makeLoaderImplementScript(
 883                                                         $name,
 884                                                         $scripts,
 885                                                         $styles,
 886                                                         new XmlJsCode( $messagesBlob )
 887                                                 );
 888                                                 break;
 889                                 }
 890                         } catch ( Exception $e ) {
 891                                 MWExceptionHandler::logException( $e );
 892                                 wfDebugLog( 'resourceloader', __METHOD__ . ": generating module package failed: $e" );
 893                                 $this->hasErrors = true;
 894                                 // Add exception to the output as a comment
 895                                 $exceptions .= self::formatException( $e );
 896
 897                                 // Respond to client with error-state instead of module implementation
 898                                 $states[$name] = 'error';
 899                                 unset( $modules[$name] );
 900                         }
 901                         $isRaw |= $module->isRaw();
 902                         wfProfileOut( __METHOD__ . '-' . $name );
 903                 }
 904
 905                 // Update module states
 906                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
 907                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
 908                                 // Set the state of modules loaded as only scripts to ready as
 909                                 // they don't have an mw.loader.implement wrapper that sets the state
 910                                 foreach ( $modules as $name => $module ) {
 911                                         $states[$name] = 'ready';
 912                                 }
 913                         }
 914
 915                         // Set the state of modules we didn't respond to with mw.loader.implement
 916                         if ( count( $states ) ) {
 917                                 $out .= self::makeLoaderStateScript( $states );
 918                         }
 919                 } else {
 920                         if ( count( $states ) ) {
 921                                 $exceptions .= self::makeComment(
 922                                         'Problematic modules: ' . FormatJson::encode( $states, ResourceLoader::inDebugMode() )
 923                                 );
 924                         }
 925                 }
 926
 927                 if ( !$context->getDebug() ) {
 928                         if ( $context->getOnly() === 'styles' ) {
 929                                 $out = $this->filter( 'minify-css', $out );
 930                         } else {
 931                                 $out = $this->filter( 'minify-js', $out );
 932                         }
 933                 }
 934
 935                 wfProfileOut( __METHOD__ );
 936                 return $exceptions . $out;
 937         }
 938
 939         /* Static Methods */
 940
 941         /**
 942          * Return JS code that calls mw.loader.implement with given module properties.
 943          *
 944          * @param string $name Module name
 945          * @param mixed $scripts List of URLs to JavaScript files or String of JavaScript code
 946          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
 947          *   to CSS files keyed by media type
 948          * @param mixed $messages List of messages associated with this module. May either be an
 949          *   associative array mapping message key to value, or a JSON-encoded message blob containing
 950          *   the same data, wrapped in an XmlJsCode object.
 951          * @throws MWException
 952          * @return string
 953          */
 954         public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
 955                 if ( is_string( $scripts ) ) {
 956                         $scripts = new XmlJsCode( "function ( $, jQuery ) {\n{$scripts}\n}" );
 957                 } elseif ( !is_array( $scripts ) ) {
 958                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
 959                 }
 960                 return Xml::encodeJsCall(
 961                         'mw.loader.implement',
 962                         array(
 963                                 $name,
 964                                 $scripts,
 965                                 // Force objects. mw.loader.implement requires them to be javascript objects.
 966                                 // Although these variables are associative arrays, which become javascript
 967                                 // objects through json_encode. In many cases they will be empty arrays, and
 968                                 // PHP/json_encode() consider empty arrays to be numerical arrays and
 969                                 // output javascript "[]" instead of "{}". This fixes that.
 970                                 (object)$styles,
 971                                 (object)$messages
 972                         ),
 973                         ResourceLoader::inDebugMode()
 974                 );
 975         }
 976
 977         /**
 978          * Returns JS code which, when called, will register a given list of messages.
 979          *
 980          * @param mixed $messages Either an associative array mapping message key to value, or a
 981          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
 982          * @return string
 983          */
 984         public static function makeMessageSetScript( $messages ) {
 985                 return Xml::encodeJsCall(
 986                         'mw.messages.set',
 987                         array( (object)$messages ),
 988                         ResourceLoader::inDebugMode()
 989                 );
 990         }
 991
 992         /**
 993          * Combines an associative array mapping media type to CSS into a
 994          * single stylesheet with "@media" blocks.
 995          *
 996          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
 997          * @return array
 998          */
 999         public static function makeCombinedStyles( array $stylePairs ) {
1000                 $out = array();
1001                 foreach ( $stylePairs as $media => $styles ) {
1002                         // ResourceLoaderFileModule::getStyle can return the styles
1003                         // as a string or an array of strings. This is to allow separation in
1004                         // the front-end.
1005                         $styles = (array)$styles;
1006                         foreach ( $styles as $style ) {
1007                                 $style = trim( $style );
1008                                 // Don't output an empty "@media print { }" block (bug 40498)
1009                                 if ( $style !== '' ) {
1010                                         // Transform the media type based on request params and config
1011                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
1012                                         $media = OutputPage::transformCssMedia( $media );
1013
1014                                         if ( $media === '' || $media == 'all' ) {
1015                                                 $out[] = $style;
1016                                         } elseif ( is_string( $media ) ) {
1017                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
1018                                         }
1019                                         // else: skip
1020                                 }
1021                         }
1022                 }
1023                 return $out;
1024         }
1025
1026         /**
1027          * Returns a JS call to mw.loader.state, which sets the state of a
1028          * module or modules to a given value. Has two calling conventions:
1029          *
1030          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
1031          *         Set the state of a single module called $name to $state
1032          *
1033          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
1034          *         Set the state of modules with the given names to the given states
1035          *
1036          * @param string $name
1037          * @param string $state
1038          * @return string
1039          */
1040         public static function makeLoaderStateScript( $name, $state = null ) {
1041                 if ( is_array( $name ) ) {
1042                         return Xml::encodeJsCall(
1043                                 'mw.loader.state',
1044                                 array( $name ),
1045                                 ResourceLoader::inDebugMode()
1046                         );
1047                 } else {
1048                         return Xml::encodeJsCall(
1049                                 'mw.loader.state',
1050                                 array( $name, $state ),
1051                                 ResourceLoader::inDebugMode()
1052                         );
1053                 }
1054         }
1055
1056         /**
1057          * Returns JS code which calls the script given by $script. The script will
1058          * be called with local variables name, version, dependencies and group,
1059          * which will have values corresponding to $name, $version, $dependencies
1060          * and $group as supplied.
1061          *
1062          * @param string $name Module name
1063          * @param int $version Module version number as a timestamp
1064          * @param array $dependencies List of module names on which this module depends
1065          * @param string $group Group which the module is in.
1066          * @param string $source Source of the module, or 'local' if not foreign.
1067          * @param string $script JavaScript code
1068          * @return string
1069          */
1070         public static function makeCustomLoaderScript( $name, $version, $dependencies,
1071                 $group, $source, $script
1072         ) {
1073                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1074                 return Xml::encodeJsCall(
1075                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1076                         array( $name, $version, $dependencies, $group, $source ),
1077                         ResourceLoader::inDebugMode()
1078                 );
1079         }
1080
1081         /**
1082          * Returns JS code which calls mw.loader.register with the given
1083          * parameters. Has three calling conventions:
1084          *
1085          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version, $dependencies, $group, $source, $skip ):
1086          *       Register a single module.
1087          *
1088          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
1089          *       Register modules with the given names.
1090          *
1091          *   - ResourceLoader::makeLoaderRegisterScript( array(
1092          *        array( $name1, $version1, $dependencies1, $group1, $source1, $skip1 ),
1093          *        array( $name2, $version2, $dependencies1, $group2, $source2, $skip2 ),
1094          *        ...
1095          *     ) ):
1096          *        Registers modules with the given names and parameters.
1097          *
1098          * @param string $name Module name
1099          * @param int $version Module version number as a timestamp
1100          * @param array $dependencies List of module names on which this module depends
1101          * @param string $group Group which the module is in
1102          * @param string $source Source of the module, or 'local' if not foreign
1103          * @param string $skip Script body of the skip function
1104          * @return string
1105          */
1106         public static function makeLoaderRegisterScript( $name, $version = null,
1107                 $dependencies = null, $group = null, $source = null, $skip = null
1108         ) {
1109                 if ( is_array( $name ) ) {
1110                         return Xml::encodeJsCall(
1111                                 'mw.loader.register',
1112                                 array( $name ),
1113                                 ResourceLoader::inDebugMode()
1114                         );
1115                 } else {
1116                         $version = (int)$version > 1 ? (int)$version : 1;
1117                         return Xml::encodeJsCall(
1118                                 'mw.loader.register',
1119                                 array( $name, $version, $dependencies, $group, $source, $skip ),
1120                                 ResourceLoader::inDebugMode()
1121                         );
1122                 }
1123         }
1124
1125         /**
1126          * Returns JS code which calls mw.loader.addSource() with the given
1127          * parameters. Has two calling conventions:
1128          *
1129          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1130          *       Register a single source
1131          *
1132          *   - ResourceLoader::makeLoaderSourcesScript( array( $id1 => $props1, $id2 => $props2, ... ) );
1133          *       Register sources with the given IDs and properties.
1134          *
1135          * @param string $id Source ID
1136          * @param array $properties Source properties (see addSource())
1137          * @return string
1138          */
1139         public static function makeLoaderSourcesScript( $id, $properties = null ) {
1140                 if ( is_array( $id ) ) {
1141                         return Xml::encodeJsCall(
1142                                 'mw.loader.addSource',
1143                                 array( $id ),
1144                                 ResourceLoader::inDebugMode()
1145                         );
1146                 } else {
1147                         return Xml::encodeJsCall(
1148                                 'mw.loader.addSource',
1149                                 array( $id, $properties ),
1150                                 ResourceLoader::inDebugMode()
1151                         );
1152                 }
1153         }
1154
1155         /**
1156          * Returns JS code which runs given JS code if the client-side framework is
1157          * present.
1158          *
1159          * @param string $script JavaScript code
1160          * @return string
1161          */
1162         public static function makeLoaderConditionalScript( $script ) {
1163                 return "if(window.mw){\n" . trim( $script ) . "\n}";
1164         }
1165
1166         /**
1167          * Returns JS code which will set the MediaWiki configuration array to
1168          * the given value.
1169          *
1170          * @param array $configuration List of configuration values keyed by variable name
1171          * @return string
1172          */
1173         public static function makeConfigSetScript( array $configuration ) {
1174                 return Xml::encodeJsCall(
1175                         'mw.config.set',
1176                         array( $configuration ),
1177                         ResourceLoader::inDebugMode()
1178                 );
1179         }
1180
1181         /**
1182          * Convert an array of module names to a packed query string.
1183          *
1184          * For example, array( 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' )
1185          * becomes 'foo.bar,baz|bar.baz,quux'
1186          * @param array $modules List of module names (strings)
1187          * @return string Packed query string
1188          */
1189         public static function makePackedModulesString( $modules ) {
1190                 $groups = array(); // array( prefix => array( suffixes ) )
1191                 foreach ( $modules as $module ) {
1192                         $pos = strrpos( $module, '.' );
1193                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1194                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1195                         $groups[$prefix][] = $suffix;
1196                 }
1197
1198                 $arr = array();
1199                 foreach ( $groups as $prefix => $suffixes ) {
1200                         $p = $prefix === '' ? '' : $prefix . '.';
1201                         $arr[] = $p . implode( ',', $suffixes );
1202                 }
1203                 $str = implode( '|', $arr );
1204                 return $str;
1205         }
1206
1207         /**
1208          * Determine whether debug mode was requested
1209          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1210          * @return bool
1211          */
1212         public static function inDebugMode() {
1213                 if ( self::$debugMode === null ) {
1214                         global $wgRequest, $wgResourceLoaderDebug;
1215                         self::$debugMode = $wgRequest->getFuzzyBool( 'debug',
1216                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug )
1217                         );
1218                 }
1219                 return self::$debugMode;
1220         }
1221
1222         /**
1223          * Reset static members used for caching.
1224          *
1225          * Global state and $wgRequest are evil, but we're using it right
1226          * now and sometimes we need to be able to force ResourceLoader to
1227          * re-evaluate the context because it has changed (e.g. in the test suite).
1228          */
1229         public static function clearCache() {
1230                 self::$debugMode = null;
1231         }
1232
1233         /**
1234          * Build a load.php URL
1235          * @param array $modules Array of module names (strings)
1236          * @param string $lang Language code
1237          * @param string $skin Skin name
1238          * @param string|null $user User name. If null, the &user= parameter is omitted
1239          * @param string|null $version Versioning timestamp
1240          * @param bool $debug Whether the request should be in debug mode
1241          * @param string|null $only &only= parameter
1242          * @param bool $printable Printable mode
1243          * @param bool $handheld Handheld mode
1244          * @param array $extraQuery Extra query parameters to add
1245          * @return string URL to load.php. May be protocol-relative (if $wgLoadScript is procol-relative)
1246          */
1247         public static function makeLoaderURL( $modules, $lang, $skin, $user = null,
1248                 $version = null, $debug = false, $only = null, $printable = false,
1249                 $handheld = false, $extraQuery = array()
1250         ) {
1251                 global $wgLoadScript;
1252
1253                 $query = self::makeLoaderQuery( $modules, $lang, $skin, $user, $version, $debug,
1254                         $only, $printable, $handheld, $extraQuery
1255                 );
1256
1257                 // Prevent the IE6 extension check from being triggered (bug 28840)
1258                 // by appending a character that's invalid in Windows extensions ('*')
1259                 return wfExpandUrl( wfAppendQuery( $wgLoadScript, $query ) . '&*', PROTO_RELATIVE );
1260         }
1261
1262         /**
1263          * Build a query array (array representation of query string) for load.php. Helper
1264          * function for makeLoaderURL().
1265          *
1266          * @param array $modules
1267          * @param string $lang
1268          * @param string $skin
1269          * @param string $user
1270          * @param string $version
1271          * @param bool $debug
1272          * @param string $only
1273          * @param bool $printable
1274          * @param bool $handheld
1275          * @param array $extraQuery
1276          *
1277          * @return array
1278          */
1279         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null,
1280                 $version = null, $debug = false, $only = null, $printable = false,
1281                 $handheld = false, $extraQuery = array()
1282         ) {
1283                 $query = array(
1284                         'modules' => self::makePackedModulesString( $modules ),
1285                         'lang' => $lang,
1286                         'skin' => $skin,
1287                         'debug' => $debug ? 'true' : 'false',
1288                 );
1289                 if ( $user !== null ) {
1290                         $query['user'] = $user;
1291                 }
1292                 if ( $version !== null ) {
1293                         $query['version'] = $version;
1294                 }
1295                 if ( $only !== null ) {
1296                         $query['only'] = $only;
1297                 }
1298                 if ( $printable ) {
1299                         $query['printable'] = 1;
1300                 }
1301                 if ( $handheld ) {
1302                         $query['handheld'] = 1;
1303                 }
1304                 $query += $extraQuery;
1305
1306                 // Make queries uniform in order
1307                 ksort( $query );
1308                 return $query;
1309         }
1310
1311         /**
1312          * Check a module name for validity.
1313          *
1314          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1315          * at most 255 bytes.
1316          *
1317          * @param string $moduleName Module name to check
1318          * @return bool Whether $moduleName is a valid module name
1319          */
1320         public static function isValidModuleName( $moduleName ) {
1321                 return !preg_match( '/[|,!]/', $moduleName ) && strlen( $moduleName ) <= 255;
1322         }
1323
1324         /**
1325          * Returns LESS compiler set up for use with MediaWiki
1326          *
1327          * @since 1.22
1328          * @return lessc
1329          */
1330         public static function getLessCompiler() {
1331                 global $wgResourceLoaderLESSFunctions, $wgResourceLoaderLESSImportPaths;
1332
1333                 // When called from the installer, it is possible that a required PHP extension
1334                 // is missing (at least for now; see bug 47564). If this is the case, throw an
1335                 // exception (caught by the installer) to prevent a fatal error later on.
1336                 if ( !function_exists( 'ctype_digit' ) ) {
1337                         throw new MWException( 'lessc requires the Ctype extension' );
1338                 }
1339
1340                 $less = new lessc();
1341                 $less->setPreserveComments( true );
1342                 $less->setVariables( self::getLESSVars() );
1343                 $less->setImportDir( $wgResourceLoaderLESSImportPaths );
1344                 foreach ( $wgResourceLoaderLESSFunctions as $name => $func ) {
1345                         $less->registerFunction( $name, $func );
1346                 }
1347                 return $less;
1348         }
1349
1350         /**
1351          * Get global LESS variables.
1352          *
1353          * $since 1.22
1354          * @return array Map of variable names to string CSS values.
1355          */
1356         public static function getLESSVars() {
1357                 global $wgResourceLoaderLESSVars;
1358
1359                 $lessVars = $wgResourceLoaderLESSVars;
1360                 // Sort by key to ensure consistent hashing for cache lookups.
1361                 ksort( $lessVars );
1362                 return $lessVars;
1363         }
1364 }