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  *    https://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          * Load 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 ResourceLoaderContext $context Context to load the information within
  68          */
  69         public function preloadModuleInfo( array $modules, ResourceLoaderContext $context ) {
  70                 if ( !count( $modules ) ) {
  71                         // Or else Database*::select() will explode, plus it's cheaper!
  72                         return;
  73                 }
  74                 $dbr = wfGetDB( DB_SLAVE );
  75                 $skin = $context->getSkin();
  76                 $lang = $context->getLanguage();
  77
  78                 // Get file dependency information
  79                 $res = $dbr->select( 'module_deps', array( 'md_module', 'md_deps' ), array(
  80                                 'md_module' => $modules,
  81                                 'md_skin' => $skin
  82                         ), __METHOD__
  83                 );
  84
  85                 // Set modules' dependencies
  86                 $modulesWithDeps = array();
  87                 foreach ( $res as $row ) {
  88                         $this->getModule( $row->md_module )->setFileDependencies( $skin,
  89                                 FormatJson::decode( $row->md_deps, true )
  90                         );
  91                         $modulesWithDeps[] = $row->md_module;
  92                 }
  93
  94                 // Register the absence of a dependency row too
  95                 foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
  96                         $this->getModule( $name )->setFileDependencies( $skin, array() );
  97                 }
  98
  99                 // Get message blob mtimes. Only do this for modules with messages
 100                 $modulesWithMessages = array();
 101                 foreach ( $modules as $name ) {
 102                         if ( count( $this->getModule( $name )->getMessages() ) ) {
 103                                 $modulesWithMessages[] = $name;
 104                         }
 105                 }
 106                 $modulesWithoutMessages = array_flip( $modules ); // Will be trimmed down by the loop below
 107                 if ( count( $modulesWithMessages ) ) {
 108                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
 109                                         'mr_resource' => $modulesWithMessages,
 110                                         'mr_lang' => $lang
 111                                 ), __METHOD__
 112                         );
 113                         foreach ( $res as $row ) {
 114                                 $this->getModule( $row->mr_resource )->setMsgBlobMtime( $lang,
 115                                         wfTimestamp( TS_UNIX, $row->mr_timestamp ) );
 116                                 unset( $modulesWithoutMessages[$row->mr_resource] );
 117                         }
 118                 }
 119                 foreach ( array_keys( $modulesWithoutMessages ) as $name ) {
 120                         $this->getModule( $name )->setMsgBlobMtime( $lang, 0 );
 121                 }
 122         }
 123
 124         /**
 125          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 126          *
 127          * Available filters are:
 128          *
 129          *    - minify-js \see JavaScriptMinifier::minify
 130          *    - minify-css \see CSSMin::minify
 131          *
 132          * If $data is empty, only contains whitespace or the filter was unknown,
 133          * $data is returned unmodified.
 134          *
 135          * @param string $filter Name of filter to run
 136          * @param string $data Text to filter, such as JavaScript or CSS text
 137          * @return string Filtered data, or a comment containing an error message
 138          */
 139         protected function filter( $filter, $data ) {
 140                 global $wgResourceLoaderMinifierStatementsOnOwnLine, $wgResourceLoaderMinifierMaxLineLength;
 141                 wfProfileIn( __METHOD__ );
 142
 143                 // For empty/whitespace-only data or for unknown filters, don't perform
 144                 // any caching or processing
 145                 if ( trim( $data ) === '' || !in_array( $filter, array( 'minify-js', 'minify-css' ) ) ) {
 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          * Register 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          * Register a module with the ResourceLoader system.
 225          *
 226          * @param mixed $name 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
 234          *   not 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                 $testModules['qunit'] = array();
 294                 // Get other test suites (e.g. from extensions)
 295                 wfRunHooks( 'ResourceLoaderTestModules', array( &$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'][] = 'test.mediawiki.qunit.testrunner';
 305                 }
 306
 307                 $testModules['qunit'] = ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules['qunit'];
 308
 309                 foreach ( $testModules as $id => $names ) {
 310                         // Register test modules
 311                         $this->register( $testModules[$id] );
 312
 313                         // Keep track of their names so that they can be loaded together
 314                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 315                 }
 316
 317                 wfProfileOut( __METHOD__ );
 318         }
 319
 320         /**
 321          * Add a foreign source of modules.
 322          *
 323          * Source properties:
 324          * 'loadScript': URL (either fully-qualified or protocol-relative) of load.php for this source
 325          *
 326          * @param mixed $id Source ID (string), or array( id1 => props1, id2 => props2, ... )
 327          * @param array $properties Source properties
 328          * @throws MWException
 329          */
 330         public function addSource( $id, $properties = null ) {
 331                 // Allow multiple sources to be registered in one call
 332                 if ( is_array( $id ) ) {
 333                         foreach ( $id as $key => $value ) {
 334                                 $this->addSource( $key, $value );
 335                         }
 336                         return;
 337                 }
 338
 339                 // Disallow duplicates
 340                 if ( isset( $this->sources[$id] ) ) {
 341                         throw new MWException(
 342                                 'ResourceLoader duplicate source addition error. ' .
 343                                 'Another source has already been registered as ' . $id
 344                         );
 345                 }
 346
 347                 // Validate properties
 348                 foreach ( self::$requiredSourceProperties as $prop ) {
 349                         if ( !isset( $properties[$prop] ) ) {
 350                                 throw new MWException( "Required property $prop missing from source ID $id" );
 351                         }
 352                 }
 353
 354                 $this->sources[$id] = $properties;
 355         }
 356
 357         /**
 358          * Get a list of module names.
 359          *
 360          * @return array List of module names
 361          */
 362         public function getModuleNames() {
 363                 return array_keys( $this->moduleInfos );
 364         }
 365
 366         /**
 367          * Get a list of test module names for one (or all) frameworks.
 368          *
 369          * If the given framework id is unknkown, or if the in-object variable is not an array,
 370          * then it will return an empty array.
 371          *
 372          * @param string $framework Get only the test module names for one
 373          *   particular framework (optional)
 374          * @return Array
 375          */
 376         public function getTestModuleNames( $framework = 'all' ) {
 377                 /// @todo api siteinfo prop testmodulenames modulenames
 378                 if ( $framework == 'all' ) {
 379                         return $this->testModuleNames;
 380                 } elseif ( isset( $this->testModuleNames[$framework] ) && is_array( $this->testModuleNames[$framework] ) ) {
 381                         return $this->testModuleNames[$framework];
 382                 } else {
 383                         return array();
 384                 }
 385         }
 386
 387         /**
 388          * Get the ResourceLoaderModule object for a given module name.
 389          *
 390          * @param string $name Module name
 391          * @return ResourceLoaderModule if module has been registered, null otherwise
 392          */
 393         public function getModule( $name ) {
 394                 if ( !isset( $this->modules[$name] ) ) {
 395                         if ( !isset( $this->moduleInfos[$name] ) ) {
 396                                 // No such module
 397                                 return null;
 398                         }
 399                         // Construct the requested object
 400                         $info = $this->moduleInfos[$name];
 401                         /** @var ResourceLoaderModule $object */
 402                         if ( isset( $info['object'] ) ) {
 403                                 // Object given in info array
 404                                 $object = $info['object'];
 405                         } else {
 406                                 if ( !isset( $info['class'] ) ) {
 407                                         $class = 'ResourceLoaderFileModule';
 408                                 } else {
 409                                         $class = $info['class'];
 410                                 }
 411                                 $object = new $class( $info );
 412                         }
 413                         $object->setName( $name );
 414                         $this->modules[$name] = $object;
 415                 }
 416
 417                 return $this->modules[$name];
 418         }
 419
 420         /**
 421          * Get the list of sources.
 422          *
 423          * @return array Like array( id => array of properties, .. )
 424          */
 425         public function getSources() {
 426                 return $this->sources;
 427         }
 428
 429         /**
 430          * Output a response to a load request, including the content-type header.
 431          *
 432          * @param ResourceLoaderContext $context Context in which a response should be formed
 433          */
 434         public function respond( ResourceLoaderContext $context ) {
 435                 global $wgCacheEpoch, $wgUseFileCache;
 436
 437                 // Use file cache if enabled and available...
 438                 if ( $wgUseFileCache ) {
 439                         $fileCache = ResourceFileCache::newFromContext( $context );
 440                         if ( $this->tryRespondFromFileCache( $fileCache, $context ) ) {
 441                                 return; // output handled
 442                         }
 443                 }
 444
 445                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 446                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 447                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 448                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 449                 // the whole thing in our own output buffer to be sure the active buffer
 450                 // doesn't use ob_gzhandler.
 451                 // See http://bugs.php.net/bug.php?id=36514
 452                 ob_start();
 453
 454                 wfProfileIn( __METHOD__ );
 455                 $errors = '';
 456
 457                 // Find out which modules are missing and instantiate the others
 458                 $modules = array();
 459                 $missing = array();
 460                 foreach ( $context->getModules() as $name ) {
 461                         if ( isset( $this->moduleInfos[$name] ) ) {
 462                                 $module = $this->getModule( $name );
 463                                 // Do not allow private modules to be loaded from the web.
 464                                 // This is a security issue, see bug 34907.
 465                                 if ( $module->getGroup() === 'private' ) {
 466                                         wfDebugLog( 'resourceloader', __METHOD__ . ": request for private module '$name' denied" );
 467                                         $this->hasErrors = true;
 468                                         // Add exception to the output as a comment
 469                                         $errors .= self::makeComment( "Cannot show private module \"$name\"" );
 470
 471                                         continue;
 472                                 }
 473                                 $modules[$name] = $module;
 474                         } else {
 475                                 $missing[] = $name;
 476                         }
 477                 }
 478
 479                 // Preload information needed to the mtime calculation below
 480                 try {
 481                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 482                 } catch ( Exception $e ) {
 483                         MWExceptionHandler::logException( $e );
 484                         wfDebugLog( 'resourceloader', __METHOD__ . ": preloading module info failed: $e" );
 485                         $this->hasErrors = true;
 486                         // Add exception to the output as a comment
 487                         $errors .= self::formatException( $e );
 488                 }
 489
 490                 wfProfileIn( __METHOD__ . '-getModifiedTime' );
 491
 492                 // To send Last-Modified and support If-Modified-Since, we need to detect
 493                 // the last modified time
 494                 $mtime = wfTimestamp( TS_UNIX, $wgCacheEpoch );
 495                 foreach ( $modules as $module ) {
 496                         /**
 497                          * @var $module ResourceLoaderModule
 498                          */
 499                         try {
 500                                 // Calculate maximum modified time
 501                                 $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 502                         } catch ( Exception $e ) {
 503                                 MWExceptionHandler::logException( $e );
 504                                 wfDebugLog( 'resourceloader', __METHOD__ . ": calculating maximum modified time failed: $e" );
 505                                 $this->hasErrors = true;
 506                                 // Add exception to the output as a comment
 507                                 $errors .= self::formatException( $e );
 508                         }
 509                 }
 510
 511                 wfProfileOut( __METHOD__ . '-getModifiedTime' );
 512
 513                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 514                 if ( $this->tryRespondLastModified( $context, $mtime ) ) {
 515                         wfProfileOut( __METHOD__ );
 516                         return; // output handled (buffers cleared)
 517                 }
 518
 519                 // Generate a response
 520                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 521
 522                 // Prepend comments indicating exceptions
 523                 $response = $errors . $response;
 524
 525                 // Capture any PHP warnings from the output buffer and append them to the
 526                 // response in a comment if we're in debug mode.
 527                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 528                         $response = self::makeComment( $warnings ) . $response;
 529                         $this->hasErrors = true;
 530                 }
 531
 532                 // Save response to file cache unless there are errors
 533                 if ( isset( $fileCache ) && !$errors && !count( $missing ) ) {
 534                         // Cache single modules...and other requests if there are enough hits
 535                         if ( ResourceFileCache::useFileCache( $context ) ) {
 536                                 if ( $fileCache->isCacheWorthy() ) {
 537                                         $fileCache->saveText( $response );
 538                                 } else {
 539                                         $fileCache->incrMissesRecent( $context->getRequest() );
 540                                 }
 541                         }
 542                 }
 543
 544                 // Send content type and cache related headers
 545                 $this->sendResponseHeaders( $context, $mtime, $this->hasErrors );
 546
 547                 // Remove the output buffer and output the response
 548                 ob_end_clean();
 549                 echo $response;
 550
 551                 wfProfileOut( __METHOD__ );
 552         }
 553
 554         /**
 555          * Send content type and last modified headers to the client.
 556          * @param ResourceLoaderContext $context
 557          * @param string $mtime TS_MW timestamp to use for last-modified
 558          * @param bool $errors Whether there are commented-out errors in the response
 559          * @return void
 560          */
 561         protected function sendResponseHeaders( ResourceLoaderContext $context, $mtime, $errors ) {
 562                 global $wgResourceLoaderMaxage;
 563                 // If a version wasn't specified we need a shorter expiry time for updates
 564                 // to propagate to clients quickly
 565                 // If there were errors, we also need a shorter expiry time so we can recover quickly
 566                 if ( is_null( $context->getVersion() ) || $errors ) {
 567                         $maxage = $wgResourceLoaderMaxage['unversioned']['client'];
 568                         $smaxage = $wgResourceLoaderMaxage['unversioned']['server'];
 569                 // If a version was specified we can use a longer expiry time since changing
 570                 // version numbers causes cache misses
 571                 } else {
 572                         $maxage = $wgResourceLoaderMaxage['versioned']['client'];
 573                         $smaxage = $wgResourceLoaderMaxage['versioned']['server'];
 574                 }
 575                 if ( $context->getOnly() === 'styles' ) {
 576                         header( 'Content-Type: text/css; charset=utf-8' );
 577                         header( 'Access-Control-Allow-Origin: *' );
 578                 } else {
 579                         header( 'Content-Type: text/javascript; charset=utf-8' );
 580                 }
 581                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 582                 if ( $context->getDebug() ) {
 583                         // Do not cache debug responses
 584                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 585                         header( 'Pragma: no-cache' );
 586                 } else {
 587                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 588                         $exp = min( $maxage, $smaxage );
 589                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 590                 }
 591         }
 592
 593         /**
 594          * Respond with 304 Last Modified if appropiate.
 595          *
 596          * If there's an If-Modified-Since header, respond with a 304 appropriately
 597          * and clear out the output buffer. If the client cache is too old then do nothing.
 598          *
 599          * @param $context ResourceLoaderContext
 600          * @param string $mtime The TS_MW timestamp to check the header against
 601          * @return bool True if 304 header sent and output handled
 602          */
 603         protected function tryRespondLastModified( ResourceLoaderContext $context, $mtime ) {
 604                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 605                 // Some clients send "timestamp;length=123". Strip the part after the first ';'
 606                 // so we get a valid timestamp.
 607                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 608                 // Never send 304s in debug mode
 609                 if ( $ims !== false && !$context->getDebug() ) {
 610                         $imsTS = strtok( $ims, ';' );
 611                         if ( $mtime <= wfTimestamp( TS_UNIX, $imsTS ) ) {
 612                                 // There's another bug in ob_gzhandler (see also the comment at
 613                                 // the top of this function) that causes it to gzip even empty
 614                                 // responses, meaning it's impossible to produce a truly empty
 615                                 // response (because the gzip header is always there). This is
 616                                 // a problem because 304 responses have to be completely empty
 617                                 // per the HTTP spec, and Firefox behaves buggily when they're not.
 618                                 // See also http://bugs.php.net/bug.php?id=51579
 619                                 // To work around this, we tear down all output buffering before
 620                                 // sending the 304.
 621                                 wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 622
 623                                 header( 'HTTP/1.0 304 Not Modified' );
 624                                 header( 'Status: 304 Not Modified' );
 625                                 return true;
 626                         }
 627                 }
 628                 return false;
 629         }
 630
 631         /**
 632          * Send out code for a response from file cache if possible.
 633          *
 634          * @param ResourceFileCache $fileCache Cache object for this request URL
 635          * @param ResourceLoaderContext $context Context in which to generate a response
 636          * @return bool If this found a cache file and handled the response
 637          */
 638         protected function tryRespondFromFileCache(
 639                 ResourceFileCache $fileCache, ResourceLoaderContext $context
 640         ) {
 641                 global $wgResourceLoaderMaxage;
 642                 // Buffer output to catch warnings.
 643                 ob_start();
 644                 // Get the maximum age the cache can be
 645                 $maxage = is_null( $context->getVersion() )
 646                         ? $wgResourceLoaderMaxage['unversioned']['server']
 647                         : $wgResourceLoaderMaxage['versioned']['server'];
 648                 // Minimum timestamp the cache file must have
 649                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 650                 if ( !$good ) {
 651                         try { // RL always hits the DB on file cache miss...
 652                                 wfGetDB( DB_SLAVE );
 653                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 654                                 $good = $fileCache->isCacheGood(); // cache existence check
 655                         }
 656                 }
 657                 if ( $good ) {
 658                         $ts = $fileCache->cacheTimestamp();
 659                         // Send content type and cache headers
 660                         $this->sendResponseHeaders( $context, $ts, false );
 661                         // If there's an If-Modified-Since header, respond with a 304 appropriately
 662                         if ( $this->tryRespondLastModified( $context, $ts ) ) {
 663                                 return false; // output handled (buffers cleared)
 664                         }
 665                         $response = $fileCache->fetchText();
 666                         // Capture any PHP warnings from the output buffer and append them to the
 667                         // response in a comment if we're in debug mode.
 668                         if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 669                                 $response = "/*\n$warnings\n*/\n" . $response;
 670                         }
 671                         // Remove the output buffer and output the response
 672                         ob_end_clean();
 673                         echo $response . "\n/* Cached {$ts} */";
 674                         return true; // cache hit
 675                 }
 676                 // Clear buffer
 677                 ob_end_clean();
 678
 679                 return false; // cache miss
 680         }
 681
 682         /**
 683          * Generate a CSS or JS comment block.
 684          *
 685          * Only use this for public data, not error message details.
 686          *
 687          * @param string $text
 688          * @return string
 689          */
 690         public static function makeComment( $text ) {
 691                 $encText = str_replace( '*/', '* /', $text );
 692                 return "/*\n$encText\n*/\n";
 693         }
 694
 695         /**
 696          * Handle exception display.
 697          *
 698          * @param Exception $e to be shown to the user
 699          * @return string sanitized text that can be returned to the user
 700          */
 701         public static function formatException( $e ) {
 702                 global $wgShowExceptionDetails;
 703
 704                 if ( $wgShowExceptionDetails ) {
 705                         return self::makeComment( $e->__toString() );
 706                 } else {
 707                         return self::makeComment( wfMessage( 'internalerror' )->text() );
 708                 }
 709         }
 710
 711         /**
 712          * Generate code for a response.
 713          *
 714          * @param $context ResourceLoaderContext Context in which to generate a response
 715          * @param array $modules List of module objects keyed by module name
 716          * @param array $missing List of requested module names that are unregistered (optional)
 717          * @return string Response data
 718          */
 719         public function makeModuleResponse( ResourceLoaderContext $context,
 720                 array $modules, array $missing = array()
 721         ) {
 722                 $out = '';
 723                 $exceptions = '';
 724                 $states = array();
 725
 726                 if ( !count( $modules ) && !count( $missing ) ) {
 727                         return "/* This file is the Web entry point for MediaWiki's ResourceLoader:
 728    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
 729    no modules were requested. Max made me put this here. */";
 730                 }
 731
 732                 wfProfileIn( __METHOD__ );
 733
 734                 // Pre-fetch blobs
 735                 if ( $context->shouldIncludeMessages() ) {
 736                         try {
 737                                 $blobs = MessageBlobStore::get( $this, $modules, $context->getLanguage() );
 738                         } catch ( Exception $e ) {
 739                                 MWExceptionHandler::logException( $e );
 740                                 wfDebugLog( 'resourceloader', __METHOD__ . ": pre-fetching blobs from MessageBlobStore failed: $e" );
 741                                 $this->hasErrors = true;
 742                                 // Add exception to the output as a comment
 743                                 $exceptions .= self::formatException( $e );
 744                         }
 745                 } else {
 746                         $blobs = array();
 747                 }
 748
 749                 foreach ( $missing as $name ) {
 750                         $states[$name] = 'missing';
 751                 }
 752
 753                 // Generate output
 754                 $isRaw = false;
 755                 foreach ( $modules as $name => $module ) {
 756                         /**
 757                          * @var $module ResourceLoaderModule
 758                          */
 759
 760                         wfProfileIn( __METHOD__ . '-' . $name );
 761                         try {
 762                                 $scripts = '';
 763                                 if ( $context->shouldIncludeScripts() ) {
 764                                         // If we are in debug mode, we'll want to return an array of URLs if possible
 765                                         // However, we can't do this if the module doesn't support it
 766                                         // We also can't do this if there is an only= parameter, because we have to give
 767                                         // the module a way to return a load.php URL without causing an infinite loop
 768                                         if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
 769                                                 $scripts = $module->getScriptURLsForDebug( $context );
 770                                         } else {
 771                                                 $scripts = $module->getScript( $context );
 772                                                 if ( is_string( $scripts ) && strlen( $scripts ) && substr( $scripts, -1 ) !== ';' ) {
 773                                                         // bug 27054: Append semicolon to prevent weird bugs
 774                                                         // caused by files not terminating their statements right
 775                                                         $scripts .= ";\n";
 776                                                 }
 777                                         }
 778                                 }
 779                                 // Styles
 780                                 $styles = array();
 781                                 if ( $context->shouldIncludeStyles() ) {
 782                                         // Don't create empty stylesheets like array( '' => '' ) for modules
 783                                         // that don't *have* any stylesheets (bug 38024).
 784                                         $stylePairs = $module->getStyles( $context );
 785                                         if ( count ( $stylePairs ) ) {
 786                                                 // If we are in debug mode without &only= set, we'll want to return an array of URLs
 787                                                 // See comment near shouldIncludeScripts() for more details
 788                                                 if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
 789                                                         $styles = array(
 790                                                                 'url' => $module->getStyleURLsForDebug( $context )
 791                                                         );
 792                                                 } else {
 793                                                         // Minify CSS before embedding in mw.loader.implement call
 794                                                         // (unless in debug mode)
 795                                                         if ( !$context->getDebug() ) {
 796                                                                 foreach ( $stylePairs as $media => $style ) {
 797                                                                         // Can be either a string or an array of strings.
 798                                                                         if ( is_array( $style ) ) {
 799                                                                                 $stylePairs[$media] = array();
 800                                                                                 foreach ( $style as $cssText ) {
 801                                                                                         if ( is_string( $cssText ) ) {
 802                                                                                                 $stylePairs[$media][] = $this->filter( 'minify-css', $cssText );
 803                                                                                         }
 804                                                                                 }
 805                                                                         } elseif ( is_string( $style ) ) {
 806                                                                                 $stylePairs[$media] = $this->filter( 'minify-css', $style );
 807                                                                         }
 808                                                                 }
 809                                                         }
 810                                                         // Wrap styles into @media groups as needed and flatten into a numerical array
 811                                                         $styles = array(
 812                                                                 'css' => self::makeCombinedStyles( $stylePairs )
 813                                                         );
 814                                                 }
 815                                         }
 816                                 }
 817
 818                                 // Messages
 819                                 $messagesBlob = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 820
 821                                 // Append output
 822                                 switch ( $context->getOnly() ) {
 823                                         case 'scripts':
 824                                                 if ( is_string( $scripts ) ) {
 825                                                         // Load scripts raw...
 826                                                         $out .= $scripts;
 827                                                 } elseif ( is_array( $scripts ) ) {
 828                                                         // ...except when $scripts is an array of URLs
 829                                                         $out .= self::makeLoaderImplementScript( $name, $scripts, array(), array() );
 830                                                 }
 831                                                 break;
 832                                         case 'styles':
 833                                                 // We no longer seperate into media, they are all combined now with
 834                                                 // custom media type groups into @media .. {} sections as part of the css string.
 835                                                 // Module returns either an empty array or a numerical array with css strings.
 836                                                 $out .= isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
 837                                                 break;
 838                                         case 'messages':
 839                                                 $out .= self::makeMessageSetScript( new XmlJsCode( $messagesBlob ) );
 840                                                 break;
 841                                         default:
 842                                                 $out .= self::makeLoaderImplementScript(
 843                                                         $name,
 844                                                         $scripts,
 845                                                         $styles,
 846                                                         new XmlJsCode( $messagesBlob )
 847                                                 );
 848                                                 break;
 849                                 }
 850                         } catch ( Exception $e ) {
 851                                 MWExceptionHandler::logException( $e );
 852                                 wfDebugLog( 'resourceloader', __METHOD__ . ": generating module package failed: $e" );
 853                                 $this->hasErrors = true;
 854                                 // Add exception to the output as a comment
 855                                 $exceptions .= self::formatException( $e );
 856
 857                                 // Respond to client with error-state instead of module implementation
 858                                 $states[$name] = 'error';
 859                                 unset( $modules[$name] );
 860                         }
 861                         $isRaw |= $module->isRaw();
 862                         wfProfileOut( __METHOD__ . '-' . $name );
 863                 }
 864
 865                 // Update module states
 866                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
 867                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
 868                                 // Set the state of modules loaded as only scripts to ready as
 869                                 // they don't have an mw.loader.implement wrapper that sets the state
 870                                 foreach ( $modules as $name => $module ) {
 871                                         $states[$name] = 'ready';
 872                                 }
 873                         }
 874
 875                         // Set the state of modules we didn't respond to with mw.loader.implement
 876                         if ( count( $states ) ) {
 877                                 $out .= self::makeLoaderStateScript( $states );
 878                         }
 879                 }
 880
 881                 if ( !$context->getDebug() ) {
 882                         if ( $context->getOnly() === 'styles' ) {
 883                                 $out = $this->filter( 'minify-css', $out );
 884                         } else {
 885                                 $out = $this->filter( 'minify-js', $out );
 886                         }
 887                 }
 888
 889                 wfProfileOut( __METHOD__ );
 890                 return $exceptions . $out;
 891         }
 892
 893         /* Static Methods */
 894
 895         /**
 896          * Return JS code that calls mw.loader.implement with given module properties.
 897          *
 898          * @param string $name Module name
 899          * @param mixed $scripts List of URLs to JavaScript files or String of JavaScript code
 900          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
 901          *   to CSS files keyed by media type
 902          * @param mixed $messages List of messages associated with this module. May either be an
 903          *   associative array mapping message key to value, or a JSON-encoded message blob containing
 904          *   the same data, wrapped in an XmlJsCode object.
 905          * @throws MWException
 906          * @return string
 907          */
 908         public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
 909                 if ( is_string( $scripts ) ) {
 910                         $scripts = new XmlJsCode( "function () {\n{$scripts}\n}" );
 911                 } elseif ( !is_array( $scripts ) ) {
 912                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
 913                 }
 914                 return Xml::encodeJsCall(
 915                         'mw.loader.implement',
 916                         array(
 917                                 $name,
 918                                 $scripts,
 919                                 // Force objects. mw.loader.implement requires them to be javascript objects.
 920                                 // Although these variables are associative arrays, which become javascript
 921                                 // objects through json_encode. In many cases they will be empty arrays, and
 922                                 // PHP/json_encode() consider empty arrays to be numerical arrays and
 923                                 // output javascript "[]" instead of "{}". This fixes that.
 924                                 (object)$styles,
 925                                 (object)$messages
 926                         ),
 927                         ResourceLoader::inDebugMode()
 928                 );
 929         }
 930
 931         /**
 932          * Returns JS code which, when called, will register a given list of messages.
 933          *
 934          * @param mixed $messages Either an associative array mapping message key to value, or a
 935          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
 936          * @return string
 937          */
 938         public static function makeMessageSetScript( $messages ) {
 939                 return Xml::encodeJsCall( 'mw.messages.set', array( (object)$messages ) );
 940         }
 941
 942         /**
 943          * Combines an associative array mapping media type to CSS into a
 944          * single stylesheet with "@media" blocks.
 945          *
 946          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
 947          * @return array
 948          */
 949         private static function makeCombinedStyles( array $stylePairs ) {
 950                 $out = array();
 951                 foreach ( $stylePairs as $media => $styles ) {
 952                         // ResourceLoaderFileModule::getStyle can return the styles
 953                         // as a string or an array of strings. This is to allow separation in
 954                         // the front-end.
 955                         $styles = (array)$styles;
 956                         foreach ( $styles as $style ) {
 957                                 $style = trim( $style );
 958                                 // Don't output an empty "@media print { }" block (bug 40498)
 959                                 if ( $style !== '' ) {
 960                                         // Transform the media type based on request params and config
 961                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
 962                                         $media = OutputPage::transformCssMedia( $media );
 963
 964                                         if ( $media === '' || $media == 'all' ) {
 965                                                 $out[] = $style;
 966                                         } elseif ( is_string( $media ) ) {
 967                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
 968                                         }
 969                                         // else: skip
 970                                 }
 971                         }
 972                 }
 973                 return $out;
 974         }
 975
 976         /**
 977          * Returns a JS call to mw.loader.state, which sets the state of a
 978          * module or modules to a given value. Has two calling conventions:
 979          *
 980          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
 981          *         Set the state of a single module called $name to $state
 982          *
 983          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
 984          *         Set the state of modules with the given names to the given states
 985          *
 986          * @param string $name
 987          * @param $state
 988          * @return string
 989          */
 990         public static function makeLoaderStateScript( $name, $state = null ) {
 991                 if ( is_array( $name ) ) {
 992                         return Xml::encodeJsCall( 'mw.loader.state', array( $name ) );
 993                 } else {
 994                         return Xml::encodeJsCall( 'mw.loader.state', array( $name, $state ) );
 995                 }
 996         }
 997
 998         /**
 999          * Returns JS code which calls the script given by $script. The script will
1000          * be called with local variables name, version, dependencies and group,
1001          * which will have values corresponding to $name, $version, $dependencies
1002          * and $group as supplied.
1003          *
1004          * @param string $name Module name
1005          * @param int $version Module version number as a timestamp
1006          * @param array $dependencies List of module names on which this module depends
1007          * @param string $group Group which the module is in.
1008          * @param string $source Source of the module, or 'local' if not foreign.
1009          * @param string $script JavaScript code
1010          * @return string
1011          */
1012         public static function makeCustomLoaderScript( $name, $version, $dependencies, $group, $source, $script ) {
1013                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1014                 return Xml::encodeJsCall(
1015                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1016                         array( $name, $version, $dependencies, $group, $source ) );
1017         }
1018
1019         /**
1020          * Returns JS code which calls mw.loader.register with the given
1021          * parameters. Has three calling conventions:
1022          *
1023          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version, $dependencies, $group, $source ):
1024          *       Register a single module.
1025          *
1026          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
1027          *       Register modules with the given names.
1028          *
1029          *   - ResourceLoader::makeLoaderRegisterScript( array(
1030          *        array( $name1, $version1, $dependencies1, $group1, $source1 ),
1031          *        array( $name2, $version2, $dependencies1, $group2, $source2 ),
1032          *        ...
1033          *     ) ):
1034          *        Registers modules with the given names and parameters.
1035          *
1036          * @param string $name Module name
1037          * @param int $version Module version number as a timestamp
1038          * @param array $dependencies List of module names on which this module depends
1039          * @param string $group Group which the module is in
1040          * @param string $source Source of the module, or 'local' if not foreign
1041          * @return string
1042          */
1043         public static function makeLoaderRegisterScript( $name, $version = null,
1044                 $dependencies = null, $group = null, $source = null
1045         ) {
1046                 if ( is_array( $name ) ) {
1047                         return Xml::encodeJsCall( 'mw.loader.register', array( $name ) );
1048                 } else {
1049                         $version = (int)$version > 1 ? (int)$version : 1;
1050                         return Xml::encodeJsCall( 'mw.loader.register',
1051                                 array( $name, $version, $dependencies, $group, $source ) );
1052                 }
1053         }
1054
1055         /**
1056          * Returns JS code which calls mw.loader.addSource() with the given
1057          * parameters. Has two calling conventions:
1058          *
1059          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1060          *       Register a single source
1061          *
1062          *   - ResourceLoader::makeLoaderSourcesScript( array( $id1 => $props1, $id2 => $props2, ... ) );
1063          *       Register sources with the given IDs and properties.
1064          *
1065          * @param string $id source ID
1066          * @param array $properties source properties (see addSource())
1067          * @return string
1068          */
1069         public static function makeLoaderSourcesScript( $id, $properties = null ) {
1070                 if ( is_array( $id ) ) {
1071                         return Xml::encodeJsCall( 'mw.loader.addSource', array( $id ) );
1072                 } else {
1073                         return Xml::encodeJsCall( 'mw.loader.addSource', array( $id, $properties ) );
1074                 }
1075         }
1076
1077         /**
1078          * Returns JS code which runs given JS code if the client-side framework is
1079          * present.
1080          *
1081          * @param string $script JavaScript code
1082          * @return string
1083          */
1084         public static function makeLoaderConditionalScript( $script ) {
1085                 return "if(window.mw){\n" . trim( $script ) . "\n}";
1086         }
1087
1088         /**
1089          * Returns JS code which will set the MediaWiki configuration array to
1090          * the given value.
1091          *
1092          * @param array $configuration List of configuration values keyed by variable name
1093          * @return string
1094          */
1095         public static function makeConfigSetScript( array $configuration ) {
1096                 return Xml::encodeJsCall( 'mw.config.set', array( $configuration ), ResourceLoader::inDebugMode() );
1097         }
1098
1099         /**
1100          * Convert an array of module names to a packed query string.
1101          *
1102          * For example, array( 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' )
1103          * becomes 'foo.bar,baz|bar.baz,quux'
1104          * @param array $modules List of module names (strings)
1105          * @return string Packed query string
1106          */
1107         public static function makePackedModulesString( $modules ) {
1108                 $groups = array(); // array( prefix => array( suffixes ) )
1109                 foreach ( $modules as $module ) {
1110                         $pos = strrpos( $module, '.' );
1111                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1112                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1113                         $groups[$prefix][] = $suffix;
1114                 }
1115
1116                 $arr = array();
1117                 foreach ( $groups as $prefix => $suffixes ) {
1118                         $p = $prefix === '' ? '' : $prefix . '.';
1119                         $arr[] = $p . implode( ',', $suffixes );
1120                 }
1121                 $str = implode( '|', $arr );
1122                 return $str;
1123         }
1124
1125         /**
1126          * Determine whether debug mode was requested
1127          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1128          * @return bool
1129          */
1130         public static function inDebugMode() {
1131                 global $wgRequest, $wgResourceLoaderDebug;
1132                 static $retval = null;
1133                 if ( is_null( $retval ) ) {
1134                         $retval = $wgRequest->getFuzzyBool( 'debug',
1135                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug ) );
1136                 }
1137                 return $retval;
1138         }
1139
1140         /**
1141          * Build a load.php URL
1142          * @param array $modules of module names (strings)
1143          * @param string $lang Language code
1144          * @param string $skin Skin name
1145          * @param string|null $user User name. If null, the &user= parameter is omitted
1146          * @param string|null $version Versioning timestamp
1147          * @param bool $debug Whether the request should be in debug mode
1148          * @param string|null $only &only= parameter
1149          * @param bool $printable Printable mode
1150          * @param bool $handheld Handheld mode
1151          * @param array $extraQuery Extra query parameters to add
1152          * @return string URL to load.php. May be protocol-relative (if $wgLoadScript is procol-relative)
1153          */
1154         public static function makeLoaderURL( $modules, $lang, $skin, $user = null, $version = null, $debug = false, $only = null,
1155                         $printable = false, $handheld = false, $extraQuery = array() ) {
1156                 global $wgLoadScript;
1157                 $query = self::makeLoaderQuery( $modules, $lang, $skin, $user, $version, $debug,
1158                         $only, $printable, $handheld, $extraQuery
1159                 );
1160
1161                 // Prevent the IE6 extension check from being triggered (bug 28840)
1162                 // by appending a character that's invalid in Windows extensions ('*')
1163                 return wfExpandUrl( wfAppendQuery( $wgLoadScript, $query ) . '&*', PROTO_RELATIVE );
1164         }
1165
1166         /**
1167          * Build a query array (array representation of query string) for load.php. Helper
1168          * function for makeLoaderURL().
1169          *
1170          * @param array $modules
1171          * @param string $lang
1172          * @param string $skin
1173          * @param string $user
1174          * @param string $version
1175          * @param bool $debug
1176          * @param string $only
1177          * @param bool $printable
1178          * @param bool $handheld
1179          * @param array $extraQuery
1180          *
1181          * @return array
1182          */
1183         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null, $version = null, $debug = false, $only = null,
1184                         $printable = false, $handheld = false, $extraQuery = array() ) {
1185                 $query = array(
1186                         'modules' => self::makePackedModulesString( $modules ),
1187                         'lang' => $lang,
1188                         'skin' => $skin,
1189                         'debug' => $debug ? 'true' : 'false',
1190                 );
1191                 if ( $user !== null ) {
1192                         $query['user'] = $user;
1193                 }
1194                 if ( $version !== null ) {
1195                         $query['version'] = $version;
1196                 }
1197                 if ( $only !== null ) {
1198                         $query['only'] = $only;
1199                 }
1200                 if ( $printable ) {
1201                         $query['printable'] = 1;
1202                 }
1203                 if ( $handheld ) {
1204                         $query['handheld'] = 1;
1205                 }
1206                 $query += $extraQuery;
1207
1208                 // Make queries uniform in order
1209                 ksort( $query );
1210                 return $query;
1211         }
1212
1213         /**
1214          * Check a module name for validity.
1215          *
1216          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1217          * at most 255 bytes.
1218          *
1219          * @param string $moduleName Module name to check
1220          * @return bool Whether $moduleName is a valid module name
1221          */
1222         public static function isValidModuleName( $moduleName ) {
1223                 return !preg_match( '/[|,!]/', $moduleName ) && strlen( $moduleName ) <= 255;
1224         }
1225
1226         /**
1227          * Returns LESS compiler set up for use with MediaWiki
1228          *
1229          * @since 1.22
1230          * @return lessc
1231          */
1232         public static function getLessCompiler() {
1233                 global $wgResourceLoaderLESSFunctions, $wgResourceLoaderLESSImportPaths;
1234
1235                 // When called from the installer, it is possible that a required PHP extension
1236                 // is missing (at least for now; see bug 47564). If this is the case, throw an
1237                 // exception (caught by the installer) to prevent a fatal error later on.
1238                 if ( !function_exists( 'ctype_digit' ) ) {
1239                         throw new MWException( 'lessc requires the Ctype extension' );
1240                 }
1241
1242                 $less = new lessc();
1243                 $less->setPreserveComments( true );
1244                 $less->setVariables( self::getLESSVars() );
1245                 $less->setImportDir( $wgResourceLoaderLESSImportPaths );
1246                 foreach ( $wgResourceLoaderLESSFunctions as $name => $func ) {
1247                         $less->registerFunction( $name, $func );
1248                 }
1249                 return $less;
1250         }
1251
1252         /**
1253          * Get global LESS variables.
1254          *
1255          * $since 1.22
1256          * @return array: Map of variable names to string CSS values.
1257          */
1258         public static function getLESSVars() {
1259                 global $wgResourceLoaderLESSVars;
1260
1261                 static $lessVars = null;
1262                 if ( $lessVars === null ) {
1263                         $lessVars = $wgResourceLoaderLESSVars;
1264                         // Sort by key to ensure consistent hashing for cache lookups.
1265                         ksort( $lessVars );
1266                 }
1267                 return $lessVars;
1268         }
1269 }