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 documention is on the MediaWiki documentation wiki starting at:
  29  *    http://www.mediawiki.org/wiki/ResourceLoader
  30  */
  31 class ResourceLoader {
  32
  33         /* Protected Static Members */
  34         protected static $filterCacheVersion = 7;
  35         protected static $requiredSourceProperties = array( 'loadScript' );
  36
  37         /** Array: List of module name/ResourceLoaderModule object pairs */
  38         protected $modules = array();
  39
  40         /** Associative array mapping module name to info associative array */
  41         protected $moduleInfos = array();
  42
  43         /** Associative array mapping framework ids to a list of names of test suite modules */
  44         /** like array( 'qunit' => array( 'mediawiki.tests.qunit.suites', 'ext.foo.tests', .. ), .. ) */
  45         protected $testModuleNames = array();
  46
  47         /** array( 'source-id' => array( 'loadScript' => 'http://.../load.php' ) ) **/
  48         protected $sources = array();
  49
  50         /** @var bool */
  51         protected $hasErrors = false;
  52
  53         /* Protected Methods */
  54
  55         /**
  56          * Loads information stored in the database about modules.
  57          *
  58          * This method grabs modules dependencies from the database and updates modules
  59          * objects.
  60          *
  61          * This is not inside the module code because it is much faster to
  62          * request all of the information at once than it is to have each module
  63          * requests its own information. This sacrifice of modularity yields a substantial
  64          * performance improvement.
  65          *
  66          * @param array $modules List of module names to preload information for
  67          * @param $context ResourceLoaderContext: Context to load the information within
  68          */
  69         public function preloadModuleInfo( array $modules, ResourceLoaderContext $context ) {
  70                 if ( !count( $modules ) ) {
  71                         return; // or else Database*::select() will explode, plus it's cheaper!
  72                 }
  73                 $dbr = wfGetDB( DB_SLAVE );
  74                 $skin = $context->getSkin();
  75                 $lang = $context->getLanguage();
  76
  77                 // Get file dependency information
  78                 $res = $dbr->select( 'module_deps', array( 'md_module', 'md_deps' ), array(
  79                                 'md_module' => $modules,
  80                                 'md_skin' => $skin
  81                         ), __METHOD__
  82                 );
  83
  84                 // Set modules' dependencies
  85                 $modulesWithDeps = array();
  86                 foreach ( $res as $row ) {
  87                         $this->getModule( $row->md_module )->setFileDependencies( $skin,
  88                                 FormatJson::decode( $row->md_deps, true )
  89                         );
  90                         $modulesWithDeps[] = $row->md_module;
  91                 }
  92
  93                 // Register the absence of a dependency row too
  94                 foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
  95                         $this->getModule( $name )->setFileDependencies( $skin, array() );
  96                 }
  97
  98                 // Get message blob mtimes. Only do this for modules with messages
  99                 $modulesWithMessages = array();
 100                 foreach ( $modules as $name ) {
 101                         if ( count( $this->getModule( $name )->getMessages() ) ) {
 102                                 $modulesWithMessages[] = $name;
 103                         }
 104                 }
 105                 $modulesWithoutMessages = array_flip( $modules ); // Will be trimmed down by the loop below
 106                 if ( count( $modulesWithMessages ) ) {
 107                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
 108                                         'mr_resource' => $modulesWithMessages,
 109                                         'mr_lang' => $lang
 110                                 ), __METHOD__
 111                         );
 112                         foreach ( $res as $row ) {
 113                                 $this->getModule( $row->mr_resource )->setMsgBlobMtime( $lang,
 114                                         wfTimestamp( TS_UNIX, $row->mr_timestamp ) );
 115                                 unset( $modulesWithoutMessages[$row->mr_resource] );
 116                         }
 117                 }
 118                 foreach ( array_keys( $modulesWithoutMessages ) as $name ) {
 119                         $this->getModule( $name )->setMsgBlobMtime( $lang, 0 );
 120                 }
 121         }
 122
 123         /**
 124          * Runs JavaScript or CSS data through a filter, caching the filtered result for future calls.
 125          *
 126          * Available filters are:
 127          *  - minify-js \see JavaScriptMinifier::minify
 128          *  - minify-css \see CSSMin::minify
 129          *
 130          * If $data is empty, only contains whitespace or the filter was unknown,
 131          * $data is returned unmodified.
 132          *
 133          * @param string $filter Name of filter to run
 134          * @param string $data Text to filter, such as JavaScript or CSS text
 135          * @return String: Filtered data, or a comment containing an error message
 136          */
 137         protected function filter( $filter, $data ) {
 138                 global $wgResourceLoaderMinifierStatementsOnOwnLine, $wgResourceLoaderMinifierMaxLineLength;
 139                 wfProfileIn( __METHOD__ );
 140
 141                 // For empty/whitespace-only data or for unknown filters, don't perform
 142                 // any caching or processing
 143                 if ( trim( $data ) === ''
 144                         || !in_array( $filter, array( 'minify-js', 'minify-css' ) ) )
 145                 {
 146                         wfProfileOut( __METHOD__ );
 147                         return $data;
 148                 }
 149
 150                 // Try for cache hit
 151                 // Use CACHE_ANYTHING since filtering is very slow compared to DB queries
 152                 $key = wfMemcKey( 'resourceloader', 'filter', $filter, self::$filterCacheVersion, md5( $data ) );
 153                 $cache = wfGetCache( CACHE_ANYTHING );
 154                 $cacheEntry = $cache->get( $key );
 155                 if ( is_string( $cacheEntry ) ) {
 156                         wfIncrStats( "rl-$filter-cache-hits" );
 157                         wfProfileOut( __METHOD__ );
 158                         return $cacheEntry;
 159                 }
 160
 161                 $result = '';
 162                 // Run the filter - we've already verified one of these will work
 163                 try {
 164                         wfIncrStats( "rl-$filter-cache-misses" );
 165                         switch ( $filter ) {
 166                                 case 'minify-js':
 167                                         $result = JavaScriptMinifier::minify( $data,
 168                                                 $wgResourceLoaderMinifierStatementsOnOwnLine,
 169                                                 $wgResourceLoaderMinifierMaxLineLength
 170                                         );
 171                                         $result .= "\n/* cache key: $key */";
 172                                         break;
 173                                 case 'minify-css':
 174                                         $result = CSSMin::minify( $data );
 175                                         $result .= "\n/* cache key: $key */";
 176                                         break;
 177                         }
 178
 179                         // Save filtered text to Memcached
 180                         $cache->set( $key, $result );
 181                 } catch ( Exception $e ) {
 182                         MWExceptionHandler::logException( $e );
 183                         wfDebugLog( 'resourceloader', __METHOD__ . ": minification failed: $e" );
 184                         $this->hasErrors = true;
 185                         // Return exception as a comment
 186                         $result = self::formatException( $e );
 187                 }
 188
 189                 wfProfileOut( __METHOD__ );
 190
 191                 return $result;
 192         }
 193
 194         /* Methods */
 195
 196         /**
 197          * Registers core modules and runs registration hooks.
 198          */
 199         public function __construct() {
 200                 global $IP, $wgResourceModules, $wgResourceLoaderSources, $wgLoadScript, $wgEnableJavaScriptTest;
 201
 202                 wfProfileIn( __METHOD__ );
 203
 204                 // Add 'local' source first
 205                 $this->addSource( 'local', array( 'loadScript' => $wgLoadScript, 'apiScript' => wfScript( 'api' ) ) );
 206
 207                 // Add other sources
 208                 $this->addSource( $wgResourceLoaderSources );
 209
 210                 // Register core modules
 211                 $this->register( include "$IP/resources/Resources.php" );
 212                 // Register extension modules
 213                 wfRunHooks( 'ResourceLoaderRegisterModules', array( &$this ) );
 214                 $this->register( $wgResourceModules );
 215
 216                 if ( $wgEnableJavaScriptTest === true ) {
 217                         $this->registerTestModules();
 218                 }
 219
 220                 wfProfileOut( __METHOD__ );
 221         }
 222
 223         /**
 224          * Registers a module with the ResourceLoader system.
 225          *
 226          * @param $name Mixed: Name of module as a string or List of name/object pairs as an array
 227          * @param array $info Module info array. For backwards compatibility with 1.17alpha,
 228          *   this may also be a ResourceLoaderModule object. Optional when using
 229          *   multiple-registration calling style.
 230          * @throws MWException: If a duplicate module registration is attempted
 231          * @throws MWException: If a module name contains illegal characters (pipes or commas)
 232          * @throws MWException: If something other than a ResourceLoaderModule is being registered
 233          * @return Boolean: False if there were any errors, in which case one or more modules were not
 234          *     registered
 235          */
 236         public function register( $name, $info = null ) {
 237                 wfProfileIn( __METHOD__ );
 238
 239                 // Allow multiple modules to be registered in one call
 240                 $registrations = is_array( $name ) ? $name : array( $name => $info );
 241                 foreach ( $registrations as $name => $info ) {
 242                         // Disallow duplicate registrations
 243                         if ( isset( $this->moduleInfos[$name] ) ) {
 244                                 wfProfileOut( __METHOD__ );
 245                                 // A module has already been registered by this name
 246                                 throw new MWException(
 247                                         'ResourceLoader duplicate registration error. ' .
 248                                         'Another module has already been registered as ' . $name
 249                                 );
 250                         }
 251
 252                         // Check $name for validity
 253                         if ( !self::isValidModuleName( $name ) ) {
 254                                 wfProfileOut( __METHOD__ );
 255                                 throw new MWException( "ResourceLoader module name '$name' is invalid, see ResourceLoader::isValidModuleName()" );
 256                         }
 257
 258                         // Attach module
 259                         if ( is_object( $info ) ) {
 260                                 // Old calling convention
 261                                 // Validate the input
 262                                 if ( !( $info instanceof ResourceLoaderModule ) ) {
 263                                         wfProfileOut( __METHOD__ );
 264                                         throw new MWException( 'ResourceLoader invalid module error. ' .
 265                                                 'Instances of ResourceLoaderModule expected.' );
 266                                 }
 267
 268                                 $this->moduleInfos[$name] = array( 'object' => $info );
 269                                 $info->setName( $name );
 270                                 $this->modules[$name] = $info;
 271                         } else {
 272                                 // New calling convention
 273                                 $this->moduleInfos[$name] = $info;
 274                         }
 275                 }
 276
 277                 wfProfileOut( __METHOD__ );
 278         }
 279
 280         /**
 281          */
 282         public function registerTestModules() {
 283                 global $IP, $wgEnableJavaScriptTest;
 284
 285                 if ( $wgEnableJavaScriptTest !== true ) {
 286                         throw new MWException( 'Attempt to register JavaScript test modules but <code>$wgEnableJavaScriptTest</code> is false. Edit your <code>LocalSettings.php</code> to enable it.' );
 287                 }
 288
 289                 wfProfileIn( __METHOD__ );
 290
 291                 // Get core test suites
 292                 $testModules = array();
 293                 $testModules['qunit'] = include "$IP/tests/qunit/QUnitTestResources.php";
 294                 // Get other test suites (e.g. from extensions)
 295                 wfRunHooks( 'ResourceLoaderTestModules', array( &$testModules, &$this ) );
 296
 297                 // Add the testrunner (which configures QUnit) to the dependencies.
 298                 // Since it must be ready before any of the test suites are executed.
 299                 foreach ( $testModules['qunit'] as &$module ) {
 300                         // Make sure all test modules are top-loading so that when QUnit starts
 301                         // on document-ready, it will run once and finish. If some tests arrive
 302                         // later (possibly after QUnit has already finished) they will be ignored.
 303                         $module['position'] = 'top';
 304                         $module['dependencies'][] = 'mediawiki.tests.qunit.testrunner';
 305                 }
 306
 307                 foreach ( $testModules as $id => $names ) {
 308                         // Register test modules
 309                         $this->register( $testModules[$id] );
 310
 311                         // Keep track of their names so that they can be loaded together
 312                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 313                 }
 314
 315                 wfProfileOut( __METHOD__ );
 316         }
 317
 318         /**
 319          * Add a foreign source of modules.
 320          *
 321          * Source properties:
 322          * 'loadScript': URL (either fully-qualified or protocol-relative) of load.php for this source
 323          *
 324          * @param $id Mixed: source ID (string), or array( id1 => props1, id2 => props2, ... )
 325          * @param array $properties source properties
 326          * @throws MWException
 327          */
 328         public function addSource( $id, $properties = null ) {
 329                 // Allow multiple sources to be registered in one call
 330                 if ( is_array( $id ) ) {
 331                         foreach ( $id as $key => $value ) {
 332                                 $this->addSource( $key, $value );
 333                         }
 334                         return;
 335                 }
 336
 337                 // Disallow duplicates
 338                 if ( isset( $this->sources[$id] ) ) {
 339                         throw new MWException(
 340                                 'ResourceLoader duplicate source addition error. ' .
 341                                 'Another source has already been registered as ' . $id
 342                         );
 343                 }
 344
 345                 // Validate properties
 346                 foreach ( self::$requiredSourceProperties as $prop ) {
 347                         if ( !isset( $properties[$prop] ) ) {
 348                                 throw new MWException( "Required property $prop missing from source ID $id" );
 349                         }
 350                 }
 351
 352                 $this->sources[$id] = $properties;
 353         }
 354
 355         /**
 356          * Get a list of module names
 357          *
 358          * @return Array: List of module names
 359          */
 360         public function getModuleNames() {
 361                 return array_keys( $this->moduleInfos );
 362         }
 363
 364         /**
 365          * Get a list of test module names for one (or all) frameworks.
 366          * If the given framework id is unknkown, or if the in-object variable is not an array,
 367          * then it will return an empty array.
 368          *
 369          * @param string $framework Optional. Get only the test module names for one
 370          * particular framework.
 371          * @return Array
 372          */
 373         public function getTestModuleNames( $framework = 'all' ) {
 374                 /// @todo api siteinfo prop testmodulenames modulenames
 375                 if ( $framework == 'all' ) {
 376                         return $this->testModuleNames;
 377                 } elseif ( isset( $this->testModuleNames[$framework] ) && is_array( $this->testModuleNames[$framework] ) ) {
 378                         return $this->testModuleNames[$framework];
 379                 } else {
 380                         return array();
 381                 }
 382         }
 383
 384         /**
 385          * Get the ResourceLoaderModule object for a given module name.
 386          *
 387          * @param string $name Module name
 388          * @return ResourceLoaderModule if module has been registered, null otherwise
 389          */
 390         public function getModule( $name ) {
 391                 if ( !isset( $this->modules[$name] ) ) {
 392                         if ( !isset( $this->moduleInfos[$name] ) ) {
 393                                 // No such module
 394                                 return null;
 395                         }
 396                         // Construct the requested object
 397                         $info = $this->moduleInfos[$name];
 398                         /** @var ResourceLoaderModule $object */
 399                         if ( isset( $info['object'] ) ) {
 400                                 // Object given in info array
 401                                 $object = $info['object'];
 402                         } else {
 403                                 if ( !isset( $info['class'] ) ) {
 404                                         $class = 'ResourceLoaderFileModule';
 405                                 } else {
 406                                         $class = $info['class'];
 407                                 }
 408                                 $object = new $class( $info );
 409                         }
 410                         $object->setName( $name );
 411                         $this->modules[$name] = $object;
 412                 }
 413
 414                 return $this->modules[$name];
 415         }
 416
 417         /**
 418          * Get the list of sources
 419          *
 420          * @return Array: array( id => array of properties, .. )
 421          */
 422         public function getSources() {
 423                 return $this->sources;
 424         }
 425
 426         /**
 427          * Outputs a response to a resource load-request, including a content-type header.
 428          *
 429          * @param $context ResourceLoaderContext: Context in which a response should be formed
 430          */
 431         public function respond( ResourceLoaderContext $context ) {
 432                 global $wgCacheEpoch, $wgUseFileCache;
 433
 434                 // Use file cache if enabled and available...
 435                 if ( $wgUseFileCache ) {
 436                         $fileCache = ResourceFileCache::newFromContext( $context );
 437                         if ( $this->tryRespondFromFileCache( $fileCache, $context ) ) {
 438                                 return; // output handled
 439                         }
 440                 }
 441
 442                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 443                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 444                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 445                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 446                 // the whole thing in our own output buffer to be sure the active buffer
 447                 // doesn't use ob_gzhandler.
 448                 // See http://bugs.php.net/bug.php?id=36514
 449                 ob_start();
 450
 451                 wfProfileIn( __METHOD__ );
 452                 $errors = '';
 453
 454                 // Split requested modules into two groups, modules and missing
 455                 $modules = array();
 456                 $missing = array();
 457                 foreach ( $context->getModules() as $name ) {
 458                         if ( isset( $this->moduleInfos[$name] ) ) {
 459                                 $module = $this->getModule( $name );
 460                                 // Do not allow private modules to be loaded from the web.
 461                                 // This is a security issue, see bug 34907.
 462                                 if ( $module->getGroup() === 'private' ) {
 463                                         wfDebugLog( 'resourceloader', __METHOD__ . ": request for private module '$name' denied" );
 464                                         $this->hasErrors = true;
 465                                         // Add exception to the output as a comment
 466                                         $errors .= self::makeComment( "Cannot show private module \"$name\"" );
 467
 468                                         continue;
 469                                 }
 470                                 $modules[$name] = $module;
 471                         } else {
 472                                 $missing[] = $name;
 473                         }
 474                 }
 475
 476                 // Preload information needed to the mtime calculation below
 477                 try {
 478                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 479                 } catch ( Exception $e ) {
 480                         MWExceptionHandler::logException( $e );
 481                         wfDebugLog( 'resourceloader', __METHOD__ . ": preloading module info failed: $e" );
 482                         $this->hasErrors = true;
 483                         // Add exception to the output as a comment
 484                         $errors .= self::formatException( $e );
 485                 }
 486
 487                 wfProfileIn( __METHOD__ . '-getModifiedTime' );
 488
 489                 // To send Last-Modified and support If-Modified-Since, we need to detect
 490                 // the last modified time
 491                 $mtime = wfTimestamp( TS_UNIX, $wgCacheEpoch );
 492                 foreach ( $modules as $module ) {
 493                         /**
 494                          * @var $module ResourceLoaderModule
 495                          */
 496                         try {
 497                                 // Calculate maximum modified time
 498                                 $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 499                         } catch ( Exception $e ) {
 500                                 MWExceptionHandler::logException( $e );
 501                                 wfDebugLog( 'resourceloader', __METHOD__ . ": calculating maximum modified time failed: $e" );
 502                                 $this->hasErrors = true;
 503                                 // Add exception to the output as a comment
 504                                 $errors .= self::formatException( $e );
 505                         }
 506                 }
 507
 508                 wfProfileOut( __METHOD__ . '-getModifiedTime' );
 509
 510                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 511                 if ( $this->tryRespondLastModified( $context, $mtime ) ) {
 512                         wfProfileOut( __METHOD__ );
 513                         return; // output handled (buffers cleared)
 514                 }
 515
 516                 // Generate a response
 517                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 518
 519                 // Prepend comments indicating exceptions
 520                 $response = $errors . $response;
 521
 522                 // Capture any PHP warnings from the output buffer and append them to the
 523                 // response in a comment if we're in debug mode.
 524                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 525                         $response = self::makeComment( $warnings ) . $response;
 526                         $this->hasErrors = true;
 527                 }
 528
 529                 // Save response to file cache unless there are errors
 530                 if ( isset( $fileCache ) && !$errors && !$missing ) {
 531                         // Cache single modules...and other requests if there are enough hits
 532                         if ( ResourceFileCache::useFileCache( $context ) ) {
 533                                 if ( $fileCache->isCacheWorthy() ) {
 534                                         $fileCache->saveText( $response );
 535                                 } else {
 536                                         $fileCache->incrMissesRecent( $context->getRequest() );
 537                                 }
 538                         }
 539                 }
 540
 541                 // Send content type and cache related headers
 542                 $this->sendResponseHeaders( $context, $mtime, $this->hasErrors );
 543
 544                 // Remove the output buffer and output the response
 545                 ob_end_clean();
 546                 echo $response;
 547
 548                 wfProfileOut( __METHOD__ );
 549         }
 550
 551         /**
 552          * Send content type and last modified headers to the client.
 553          * @param $context ResourceLoaderContext
 554          * @param string $mtime TS_MW timestamp to use for last-modified
 555          * @param bool $errors Whether there are commented-out errors in the response
 556          * @return void
 557          */
 558         protected function sendResponseHeaders( ResourceLoaderContext $context, $mtime, $errors ) {
 559                 global $wgResourceLoaderMaxage;
 560                 // If a version wasn't specified we need a shorter expiry time for updates
 561                 // to propagate to clients quickly
 562                 // If there were errors, we also need a shorter expiry time so we can recover quickly
 563                 if ( is_null( $context->getVersion() ) || $errors ) {
 564                         $maxage = $wgResourceLoaderMaxage['unversioned']['client'];
 565                         $smaxage = $wgResourceLoaderMaxage['unversioned']['server'];
 566                 // If a version was specified we can use a longer expiry time since changing
 567                 // version numbers causes cache misses
 568                 } else {
 569                         $maxage = $wgResourceLoaderMaxage['versioned']['client'];
 570                         $smaxage = $wgResourceLoaderMaxage['versioned']['server'];
 571                 }
 572                 if ( $context->getOnly() === 'styles' ) {
 573                         header( 'Content-Type: text/css; charset=utf-8' );
 574                         header( 'Access-Control-Allow-Origin: *' );
 575                 } else {
 576                         header( 'Content-Type: text/javascript; charset=utf-8' );
 577                 }
 578                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 579                 if ( $context->getDebug() ) {
 580                         // Do not cache debug responses
 581                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 582                         header( 'Pragma: no-cache' );
 583                 } else {
 584                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 585                         $exp = min( $maxage, $smaxage );
 586                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 587                 }
 588         }
 589
 590         /**
 591          * If there's an If-Modified-Since header, respond with a 304 appropriately
 592          * and clear out the output buffer. If the client cache is too old then do nothing.
 593          * @param $context ResourceLoaderContext
 594          * @param string $mtime The TS_MW timestamp to check the header against
 595          * @return bool True iff 304 header sent and output handled
 596          */
 597         protected function tryRespondLastModified( ResourceLoaderContext $context, $mtime ) {
 598                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 599                 // Some clients send "timestamp;length=123". Strip the part after the first ';'
 600                 // so we get a valid timestamp.
 601                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 602                 // Never send 304s in debug mode
 603                 if ( $ims !== false && !$context->getDebug() ) {
 604                         $imsTS = strtok( $ims, ';' );
 605                         if ( $mtime <= wfTimestamp( TS_UNIX, $imsTS ) ) {
 606                                 // There's another bug in ob_gzhandler (see also the comment at
 607                                 // the top of this function) that causes it to gzip even empty
 608                                 // responses, meaning it's impossible to produce a truly empty
 609                                 // response (because the gzip header is always there). This is
 610                                 // a problem because 304 responses have to be completely empty
 611                                 // per the HTTP spec, and Firefox behaves buggily when they're not.
 612                                 // See also http://bugs.php.net/bug.php?id=51579
 613                                 // To work around this, we tear down all output buffering before
 614                                 // sending the 304.
 615                                 wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 616
 617                                 header( 'HTTP/1.0 304 Not Modified' );
 618                                 header( 'Status: 304 Not Modified' );
 619                                 return true;
 620                         }
 621                 }
 622                 return false;
 623         }
 624
 625         /**
 626          * Send out code for a response from file cache if possible
 627          *
 628          * @param $fileCache ResourceFileCache: Cache object for this request URL
 629          * @param $context ResourceLoaderContext: Context in which to generate a response
 630          * @return bool If this found a cache file and handled the response
 631          */
 632         protected function tryRespondFromFileCache(
 633                 ResourceFileCache $fileCache, ResourceLoaderContext $context
 634         ) {
 635                 global $wgResourceLoaderMaxage;
 636                 // Buffer output to catch warnings.
 637                 ob_start();
 638                 // Get the maximum age the cache can be
 639                 $maxage = is_null( $context->getVersion() )
 640                         ? $wgResourceLoaderMaxage['unversioned']['server']
 641                         : $wgResourceLoaderMaxage['versioned']['server'];
 642                 // Minimum timestamp the cache file must have
 643                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 644                 if ( !$good ) {
 645                         try { // RL always hits the DB on file cache miss...
 646                                 wfGetDB( DB_SLAVE );
 647                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 648                                 $good = $fileCache->isCacheGood(); // cache existence check
 649                         }
 650                 }
 651                 if ( $good ) {
 652                         $ts = $fileCache->cacheTimestamp();
 653                         // Send content type and cache headers
 654                         $this->sendResponseHeaders( $context, $ts, false );
 655                         // If there's an If-Modified-Since header, respond with a 304 appropriately
 656                         if ( $this->tryRespondLastModified( $context, $ts ) ) {
 657                                 return false; // output handled (buffers cleared)
 658                         }
 659                         $response = $fileCache->fetchText();
 660                         // Capture any PHP warnings from the output buffer and append them to the
 661                         // response in a comment if we're in debug mode.
 662                         if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 663                                 $response = "/*\n$warnings\n*/\n" . $response;
 664                         }
 665                         // Remove the output buffer and output the response
 666                         ob_end_clean();
 667                         echo $response . "\n/* Cached {$ts} */";
 668                         return true; // cache hit
 669                 }
 670                 // Clear buffer
 671                 ob_end_clean();
 672
 673                 return false; // cache miss
 674         }
 675
 676         /**
 677          * Generate a CSS or JS comment block. Only use this for public data,
 678          * not error message details.
 679          *
 680          * @param $text string
 681          * @return string
 682          */
 683         public static function makeComment( $text ) {
 684                 $encText = str_replace( '*/', '* /', $text );
 685                 return "/*\n$encText\n*/\n";
 686         }
 687
 688         /**
 689          * Handle exception display
 690          *
 691          * @param Exception $e to be shown to the user
 692          * @return string sanitized text that can be returned to the user
 693          */
 694         public static function formatException( $e ) {
 695                 global $wgShowExceptionDetails;
 696
 697                 if ( $wgShowExceptionDetails ) {
 698                         return self::makeComment( $e->__toString() );
 699                 } else {
 700                         return self::makeComment( wfMessage( 'internalerror' )->text() );
 701                 }
 702         }
 703
 704         /**
 705          * Generates code for a response
 706          *
 707          * @param $context ResourceLoaderContext: Context in which to generate a response
 708          * @param array $modules List of module objects keyed by module name
 709          * @param array $missing List of unavailable modules (optional)
 710          * @return String: Response data
 711          */
 712         public function makeModuleResponse( ResourceLoaderContext $context,
 713                 array $modules, $missing = array()
 714         ) {
 715                 $out = '';
 716                 $exceptions = '';
 717                 if ( $modules === array() && $missing === array() ) {
 718                         return '/* No modules requested. Max made me put this here */';
 719                 }
 720
 721                 wfProfileIn( __METHOD__ );
 722                 // Pre-fetch blobs
 723                 if ( $context->shouldIncludeMessages() ) {
 724                         try {
 725                                 $blobs = MessageBlobStore::get( $this, $modules, $context->getLanguage() );
 726                         } catch ( Exception $e ) {
 727                                 MWExceptionHandler::logException( $e );
 728                                 wfDebugLog( 'resourceloader', __METHOD__ . ": pre-fetching blobs from MessageBlobStore failed: $e" );
 729                                 $this->hasErrors = true;
 730                                 // Add exception to the output as a comment
 731                                 $exceptions .= self::formatException( $e );
 732                         }
 733                 } else {
 734                         $blobs = array();
 735                 }
 736
 737                 // Generate output
 738                 $isRaw = false;
 739                 foreach ( $modules as $name => $module ) {
 740                         /**
 741                          * @var $module ResourceLoaderModule
 742                          */
 743
 744                         wfProfileIn( __METHOD__ . '-' . $name );
 745                         try {
 746                                 $scripts = '';
 747                                 if ( $context->shouldIncludeScripts() ) {
 748                                         // If we are in debug mode, we'll want to return an array of URLs if possible
 749                                         // However, we can't do this if the module doesn't support it
 750                                         // We also can't do this if there is an only= parameter, because we have to give
 751                                         // the module a way to return a load.php URL without causing an infinite loop
 752                                         if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
 753                                                 $scripts = $module->getScriptURLsForDebug( $context );
 754                                         } else {
 755                                                 $scripts = $module->getScript( $context );
 756                                                 if ( is_string( $scripts ) && strlen( $scripts ) && substr( $scripts, -1 ) !== ';' ) {
 757                                                         // bug 27054: Append semicolon to prevent weird bugs
 758                                                         // caused by files not terminating their statements right
 759                                                         $scripts .= ";\n";
 760                                                 }
 761                                         }
 762                                 }
 763                                 // Styles
 764                                 $styles = array();
 765                                 if ( $context->shouldIncludeStyles() ) {
 766                                         // Don't create empty stylesheets like array( '' => '' ) for modules
 767                                         // that don't *have* any stylesheets (bug 38024).
 768                                         $stylePairs = $module->getStyles( $context );
 769                                         if ( count ( $stylePairs ) ) {
 770                                                 // If we are in debug mode without &only= set, we'll want to return an array of URLs
 771                                                 // See comment near shouldIncludeScripts() for more details
 772                                                 if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
 773                                                         $styles = array(
 774                                                                 'url' => $module->getStyleURLsForDebug( $context )
 775                                                         );
 776                                                 } else {
 777                                                         // Minify CSS before embedding in mw.loader.implement call
 778                                                         // (unless in debug mode)
 779                                                         if ( !$context->getDebug() ) {
 780                                                                 foreach ( $stylePairs as $media => $style ) {
 781                                                                         // Can be either a string or an array of strings.
 782                                                                         if ( is_array( $style ) ) {
 783                                                                                 $stylePairs[$media] = array();
 784                                                                                 foreach ( $style as $cssText ) {
 785                                                                                         if ( is_string( $cssText ) ) {
 786                                                                                                 $stylePairs[$media][] = $this->filter( 'minify-css', $cssText );
 787                                                                                         }
 788                                                                                 }
 789                                                                         } elseif ( is_string( $style ) ) {
 790                                                                                 $stylePairs[$media] = $this->filter( 'minify-css', $style );
 791                                                                         }
 792                                                                 }
 793                                                         }
 794                                                         // Wrap styles into @media groups as needed and flatten into a numerical array
 795                                                         $styles = array(
 796                                                                 'css' => self::makeCombinedStyles( $stylePairs )
 797                                                         );
 798                                                 }
 799                                         }
 800                                 }
 801
 802                                 // Messages
 803                                 $messagesBlob = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 804
 805                                 // Append output
 806                                 switch ( $context->getOnly() ) {
 807                                         case 'scripts':
 808                                                 if ( is_string( $scripts ) ) {
 809                                                         // Load scripts raw...
 810                                                         $out .= $scripts;
 811                                                 } elseif ( is_array( $scripts ) ) {
 812                                                         // ...except when $scripts is an array of URLs
 813                                                         $out .= self::makeLoaderImplementScript( $name, $scripts, array(), array() );
 814                                                 }
 815                                                 break;
 816                                         case 'styles':
 817                                                 // We no longer seperate into media, they are all combined now with
 818                                                 // custom media type groups into @media .. {} sections as part of the css string.
 819                                                 // Module returns either an empty array or a numerical array with css strings.
 820                                                 $out .= isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
 821                                                 break;
 822                                         case 'messages':
 823                                                 $out .= self::makeMessageSetScript( new XmlJsCode( $messagesBlob ) );
 824                                                 break;
 825                                         default:
 826                                                 $out .= self::makeLoaderImplementScript(
 827                                                         $name,
 828                                                         $scripts,
 829                                                         $styles,
 830                                                         new XmlJsCode( $messagesBlob )
 831                                                 );
 832                                                 break;
 833                                 }
 834                         } catch ( Exception $e ) {
 835                                 MWExceptionHandler::logException( $e );
 836                                 wfDebugLog( 'resourceloader', __METHOD__ . ": generating module package failed: $e" );
 837                                 $this->hasErrors = true;
 838                                 // Add exception to the output as a comment
 839                                 $exceptions .= self::formatException( $e );
 840
 841                                 // Register module as missing
 842                                 $missing[] = $name;
 843                                 unset( $modules[$name] );
 844                         }
 845                         $isRaw |= $module->isRaw();
 846                         wfProfileOut( __METHOD__ . '-' . $name );
 847                 }
 848
 849                 // Update module states
 850                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
 851                         // Set the state of modules loaded as only scripts to ready
 852                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
 853                                 $out .= self::makeLoaderStateScript(
 854                                         array_fill_keys( array_keys( $modules ), 'ready' ) );
 855                         }
 856                         // Set the state of modules which were requested but unavailable as missing
 857                         if ( is_array( $missing ) && count( $missing ) ) {
 858                                 $out .= self::makeLoaderStateScript( array_fill_keys( $missing, 'missing' ) );
 859                         }
 860                 }
 861
 862                 if ( !$context->getDebug() ) {
 863                         if ( $context->getOnly() === 'styles' ) {
 864                                 $out = $this->filter( 'minify-css', $out );
 865                         } else {
 866                                 $out = $this->filter( 'minify-js', $out );
 867                         }
 868                 }
 869
 870                 wfProfileOut( __METHOD__ );
 871                 return $exceptions . $out;
 872         }
 873
 874         /* Static Methods */
 875
 876         /**
 877          * Returns JS code to call to mw.loader.implement for a module with
 878          * given properties.
 879          *
 880          * @param string $name Module name
 881          * @param $scripts Mixed: List of URLs to JavaScript files or String of JavaScript code
 882          * @param $styles Mixed: Array of CSS strings keyed by media type, or an array of lists of URLs to
 883          * CSS files keyed by media type
 884          * @param $messages Mixed: List of messages associated with this module. May either be an
 885          *     associative array mapping message key to value, or a JSON-encoded message blob containing
 886          *     the same data, wrapped in an XmlJsCode object.
 887          *
 888          * @throws MWException
 889          * @return string
 890          */
 891         public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
 892                 if ( is_string( $scripts ) ) {
 893                         $scripts = new XmlJsCode( "function () {\n{$scripts}\n}" );
 894                 } elseif ( !is_array( $scripts ) ) {
 895                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
 896                 }
 897                 return Xml::encodeJsCall(
 898                         'mw.loader.implement',
 899                         array(
 900                                 $name,
 901                                 $scripts,
 902                                 // Force objects. mw.loader.implement requires them to be javascript objects.
 903                                 // Although these variables are associative arrays, which become javascript
 904                                 // objects through json_encode. In many cases they will be empty arrays, and
 905                                 // PHP/json_encode() consider empty arrays to be numerical arrays and
 906                                 // output javascript "[]" instead of "{}". This fixes that.
 907                                 (object)$styles,
 908                                 (object)$messages
 909                         ),
 910                         ResourceLoader::inDebugMode()
 911                 );
 912         }
 913
 914         /**
 915          * Returns JS code which, when called, will register a given list of messages.
 916          *
 917          * @param $messages Mixed: Either an associative array mapping message key to value, or a
 918          *     JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
 919          *
 920          * @return string
 921          */
 922         public static function makeMessageSetScript( $messages ) {
 923                 return Xml::encodeJsCall( 'mw.messages.set', array( (object)$messages ) );
 924         }
 925
 926         /**
 927          * Combines an associative array mapping media type to CSS into a
 928          * single stylesheet with "@media" blocks.
 929          *
 930          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings.
 931          *
 932          * @return Array
 933          */
 934         private static function makeCombinedStyles( array $stylePairs ) {
 935                 $out = array();
 936                 foreach ( $stylePairs as $media => $styles ) {
 937                         // ResourceLoaderFileModule::getStyle can return the styles
 938                         // as a string or an array of strings. This is to allow separation in
 939                         // the front-end.
 940                         $styles = (array)$styles;
 941                         foreach ( $styles as $style ) {
 942                                 $style = trim( $style );
 943                                 // Don't output an empty "@media print { }" block (bug 40498)
 944                                 if ( $style !== '' ) {
 945                                         // Transform the media type based on request params and config
 946                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
 947                                         $media = OutputPage::transformCssMedia( $media );
 948
 949                                         if ( $media === '' || $media == 'all' ) {
 950                                                 $out[] = $style;
 951                                         } elseif ( is_string( $media ) ) {
 952                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
 953                                         }
 954                                         // else: skip
 955                                 }
 956                         }
 957                 }
 958                 return $out;
 959         }
 960
 961         /**
 962          * Returns a JS call to mw.loader.state, which sets the state of a
 963          * module or modules to a given value. Has two calling conventions:
 964          *
 965          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
 966          *         Set the state of a single module called $name to $state
 967          *
 968          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
 969          *         Set the state of modules with the given names to the given states
 970          *
 971          * @param $name string
 972          * @param $state
 973          *
 974          * @return string
 975          */
 976         public static function makeLoaderStateScript( $name, $state = null ) {
 977                 if ( is_array( $name ) ) {
 978                         return Xml::encodeJsCall( 'mw.loader.state', array( $name ) );
 979                 } else {
 980                         return Xml::encodeJsCall( 'mw.loader.state', array( $name, $state ) );
 981                 }
 982         }
 983
 984         /**
 985          * Returns JS code which calls the script given by $script. The script will
 986          * be called with local variables name, version, dependencies and group,
 987          * which will have values corresponding to $name, $version, $dependencies
 988          * and $group as supplied.
 989          *
 990          * @param string $name Module name
 991          * @param $version Integer: Module version number as a timestamp
 992          * @param array $dependencies List of module names on which this module depends
 993          * @param string $group Group which the module is in.
 994          * @param string $source Source of the module, or 'local' if not foreign.
 995          * @param string $script JavaScript code
 996          *
 997          * @return string
 998          */
 999         public static function makeCustomLoaderScript( $name, $version, $dependencies, $group, $source, $script ) {
1000                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1001                 return Xml::encodeJsCall(
1002                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1003                         array( $name, $version, $dependencies, $group, $source ) );
1004         }
1005
1006         /**
1007          * Returns JS code which calls mw.loader.register with the given
1008          * parameters. Has three calling conventions:
1009          *
1010          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version, $dependencies, $group, $source ):
1011          *       Register a single module.
1012          *
1013          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
1014          *       Register modules with the given names.
1015          *
1016          *   - ResourceLoader::makeLoaderRegisterScript( array(
1017          *        array( $name1, $version1, $dependencies1, $group1, $source1 ),
1018          *        array( $name2, $version2, $dependencies1, $group2, $source2 ),
1019          *        ...
1020          *     ) ):
1021          *        Registers modules with the given names and parameters.
1022          *
1023          * @param string $name Module name
1024          * @param $version Integer: Module version number as a timestamp
1025          * @param array $dependencies List of module names on which this module depends
1026          * @param string $group group which the module is in.
1027          * @param string $source source of the module, or 'local' if not foreign
1028          *
1029          * @return string
1030          */
1031         public static function makeLoaderRegisterScript( $name, $version = null,
1032                 $dependencies = null, $group = null, $source = null
1033         ) {
1034                 if ( is_array( $name ) ) {
1035                         return Xml::encodeJsCall( 'mw.loader.register', array( $name ) );
1036                 } else {
1037                         $version = (int)$version > 1 ? (int)$version : 1;
1038                         return Xml::encodeJsCall( 'mw.loader.register',
1039                                 array( $name, $version, $dependencies, $group, $source ) );
1040                 }
1041         }
1042
1043         /**
1044          * Returns JS code which calls mw.loader.addSource() with the given
1045          * parameters. Has two calling conventions:
1046          *
1047          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1048          *       Register a single source
1049          *
1050          *   - ResourceLoader::makeLoaderSourcesScript( array( $id1 => $props1, $id2 => $props2, ... ) );
1051          *       Register sources with the given IDs and properties.
1052          *
1053          * @param string $id source ID
1054          * @param array $properties source properties (see addSource())
1055          *
1056          * @return string
1057          */
1058         public static function makeLoaderSourcesScript( $id, $properties = null ) {
1059                 if ( is_array( $id ) ) {
1060                         return Xml::encodeJsCall( 'mw.loader.addSource', array( $id ) );
1061                 } else {
1062                         return Xml::encodeJsCall( 'mw.loader.addSource', array( $id, $properties ) );
1063                 }
1064         }
1065
1066         /**
1067          * Returns JS code which runs given JS code if the client-side framework is
1068          * present.
1069          *
1070          * @param string $script JavaScript code
1071          *
1072          * @return string
1073          */
1074         public static function makeLoaderConditionalScript( $script ) {
1075                 return "if(window.mw){\n" . trim( $script ) . "\n}";
1076         }
1077
1078         /**
1079          * Returns JS code which will set the MediaWiki configuration array to
1080          * the given value.
1081          *
1082          * @param array $configuration List of configuration values keyed by variable name
1083          *
1084          * @return string
1085          */
1086         public static function makeConfigSetScript( array $configuration ) {
1087                 return Xml::encodeJsCall( 'mw.config.set', array( $configuration ), ResourceLoader::inDebugMode() );
1088         }
1089
1090         /**
1091          * Convert an array of module names to a packed query string.
1092          *
1093          * For example, array( 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' )
1094          * becomes 'foo.bar,baz|bar.baz,quux'
1095          * @param array $modules of module names (strings)
1096          * @return string Packed query string
1097          */
1098         public static function makePackedModulesString( $modules ) {
1099                 $groups = array(); // array( prefix => array( suffixes ) )
1100                 foreach ( $modules as $module ) {
1101                         $pos = strrpos( $module, '.' );
1102                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1103                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1104                         $groups[$prefix][] = $suffix;
1105                 }
1106
1107                 $arr = array();
1108                 foreach ( $groups as $prefix => $suffixes ) {
1109                         $p = $prefix === '' ? '' : $prefix . '.';
1110                         $arr[] = $p . implode( ',', $suffixes );
1111                 }
1112                 $str = implode( '|', $arr );
1113                 return $str;
1114         }
1115
1116         /**
1117          * Determine whether debug mode was requested
1118          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1119          * @return bool
1120          */
1121         public static function inDebugMode() {
1122                 global $wgRequest, $wgResourceLoaderDebug;
1123                 static $retval = null;
1124                 if ( !is_null( $retval ) ) {
1125                         return $retval;
1126                 }
1127                 return $retval = $wgRequest->getFuzzyBool( 'debug',
1128                         $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug ) );
1129         }
1130
1131         /**
1132          * Build a load.php URL
1133          * @param array $modules of module names (strings)
1134          * @param string $lang Language code
1135          * @param string $skin Skin name
1136          * @param string|null $user User name. If null, the &user= parameter is omitted
1137          * @param string|null $version Versioning timestamp
1138          * @param bool $debug Whether the request should be in debug mode
1139          * @param string|null $only &only= parameter
1140          * @param bool $printable Printable mode
1141          * @param bool $handheld Handheld mode
1142          * @param array $extraQuery Extra query parameters to add
1143          * @return string URL to load.php. May be protocol-relative (if $wgLoadScript is procol-relative)
1144          */
1145         public static function makeLoaderURL( $modules, $lang, $skin, $user = null, $version = null, $debug = false, $only = null,
1146                         $printable = false, $handheld = false, $extraQuery = array() ) {
1147                 global $wgLoadScript;
1148                 $query = self::makeLoaderQuery( $modules, $lang, $skin, $user, $version, $debug,
1149                         $only, $printable, $handheld, $extraQuery
1150                 );
1151
1152                 // Prevent the IE6 extension check from being triggered (bug 28840)
1153                 // by appending a character that's invalid in Windows extensions ('*')
1154                 return wfExpandUrl( wfAppendQuery( $wgLoadScript, $query ) . '&*', PROTO_RELATIVE );
1155         }
1156
1157         /**
1158          * Build a query array (array representation of query string) for load.php. Helper
1159          * function for makeLoaderURL().
1160          *
1161          * @param array $modules
1162          * @param string $lang
1163          * @param string $skin
1164          * @param string $user
1165          * @param string $version
1166          * @param bool $debug
1167          * @param string $only
1168          * @param bool $printable
1169          * @param bool $handheld
1170          * @param array $extraQuery
1171          *
1172          * @return array
1173          */
1174         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null, $version = null, $debug = false, $only = null,
1175                         $printable = false, $handheld = false, $extraQuery = array() ) {
1176                 $query = array(
1177                         'modules' => self::makePackedModulesString( $modules ),
1178                         'lang' => $lang,
1179                         'skin' => $skin,
1180                         'debug' => $debug ? 'true' : 'false',
1181                 );
1182                 if ( $user !== null ) {
1183                         $query['user'] = $user;
1184                 }
1185                 if ( $version !== null ) {
1186                         $query['version'] = $version;
1187                 }
1188                 if ( $only !== null ) {
1189                         $query['only'] = $only;
1190                 }
1191                 if ( $printable ) {
1192                         $query['printable'] = 1;
1193                 }
1194                 if ( $handheld ) {
1195                         $query['handheld'] = 1;
1196                 }
1197                 $query += $extraQuery;
1198
1199                 // Make queries uniform in order
1200                 ksort( $query );
1201                 return $query;
1202         }
1203
1204         /**
1205          * Check a module name for validity.
1206          *
1207          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1208          * at most 255 bytes.
1209          *
1210          * @param string $moduleName Module name to check
1211          * @return bool Whether $moduleName is a valid module name
1212          */
1213         public static function isValidModuleName( $moduleName ) {
1214                 return !preg_match( '/[|,!]/', $moduleName ) && strlen( $moduleName ) <= 255;
1215         }
1216
1217         /**
1218          * Returns LESS compiler set up for use with MediaWiki
1219          *
1220          * @since 1.22
1221          * @return lessc
1222          */
1223         public static function getLessCompiler() {
1224                 global $wgResourceLoaderLESSFunctions, $wgResourceLoaderLESSImportPaths;
1225
1226                 $less = new lessc();
1227                 $less->setPreserveComments( true );
1228                 $less->setVariables( self::getLESSVars() );
1229                 $less->setImportDir( $wgResourceLoaderLESSImportPaths );
1230                 foreach ( $wgResourceLoaderLESSFunctions as $name => $func ) {
1231                         $less->registerFunction( $name, $func );
1232                 }
1233                 return $less;
1234         }
1235
1236         /**
1237          * Get global LESS variables.
1238          *
1239          * $since 1.22
1240          * @return array: Map of variable names to string CSS values.
1241          */
1242         public static function getLESSVars() {
1243                 global $wgResourceLoaderLESSVars;
1244
1245                 static $lessVars = null;
1246                 if ( $lessVars === null ) {
1247                         $lessVars = $wgResourceLoaderLESSVars;
1248                         // Sort by key to ensure consistent hashing for cache lookups.
1249                         ksort( $lessVars );
1250                 }
1251                 return $lessVars;
1252         }
1253 }