includes/resourceloader/ResourceLoader.php

   1 <?php
   2 /**
   3  * Base class for resource loading system.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @author Roan Kattouw
  22  * @author Trevor Parscal
  23  */
  24
  25 /**
  26  * Dynamic JavaScript and CSS resource loading system.
  27  *
  28  * Most of the documentation is on the MediaWiki documentation wiki starting at:
  29  *    https://www.mediawiki.org/wiki/ResourceLoader
  30  */
  31 class ResourceLoader {
  32
  33         /**
  34          * @var int
  35          */
  36         protected static $filterCacheVersion = 7;
  37         /**
  38          * @var array
  39          */
  40         protected static $requiredSourceProperties = array( 'loadScript' );
  41
  42         /**
  43          * @var array Module name/ResourceLoaderModule object pairs
  44          */
  45         protected $modules = array();
  46
  47         /**
  48          * @var array Associative array mapping module name to info associative array
  49          */
  50         protected $moduleInfos = array();
  51
  52         /**
  53          * @var array Associative array mapping framework ids to a list of names of test suite modules
  54          *      like array( 'qunit' => array( 'mediawiki.tests.qunit.suites', 'ext.foo.tests', .. ), .. )
  55          */
  56         protected $testModuleNames = array();
  57
  58         /**
  59          * @var array e.g. array( 'source-id' => array( 'loadScript' => 'http://.../load.php' ) )
  60          */
  61         protected $sources = array();
  62
  63         /**
  64          * @var bool
  65          */
  66         protected $hasErrors = false;
  67
  68         /**
  69          * Load information stored in the database about modules.
  70          *
  71          * This method grabs modules dependencies from the database and updates modules
  72          * objects.
  73          *
  74          * This is not inside the module code because it is much faster to
  75          * request all of the information at once than it is to have each module
  76          * requests its own information. This sacrifice of modularity yields a substantial
  77          * performance improvement.
  78          *
  79          * @param array $modules List of module names to preload information for
  80          * @param ResourceLoaderContext $context Context to load the information within
  81          */
  82         public function preloadModuleInfo( array $modules, ResourceLoaderContext $context ) {
  83                 if ( !count( $modules ) ) {
  84                         // Or else Database*::select() will explode, plus it's cheaper!
  85                         return;
  86                 }
  87                 $dbr = wfGetDB( DB_SLAVE );
  88                 $skin = $context->getSkin();
  89                 $lang = $context->getLanguage();
  90
  91                 // Get file dependency information
  92                 $res = $dbr->select( 'module_deps', array( 'md_module', 'md_deps' ), array(
  93                                 'md_module' => $modules,
  94                                 'md_skin' => $skin
  95                         ), __METHOD__
  96                 );
  97
  98                 // Set modules' dependencies
  99                 $modulesWithDeps = array();
 100                 foreach ( $res as $row ) {
 101                         $this->getModule( $row->md_module )->setFileDependencies( $skin,
 102                                 FormatJson::decode( $row->md_deps, true )
 103                         );
 104                         $modulesWithDeps[] = $row->md_module;
 105                 }
 106
 107                 // Register the absence of a dependency row too
 108                 foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
 109                         $this->getModule( $name )->setFileDependencies( $skin, array() );
 110                 }
 111
 112                 // Get message blob mtimes. Only do this for modules with messages
 113                 $modulesWithMessages = array();
 114                 foreach ( $modules as $name ) {
 115                         if ( count( $this->getModule( $name )->getMessages() ) ) {
 116                                 $modulesWithMessages[] = $name;
 117                         }
 118                 }
 119                 $modulesWithoutMessages = array_flip( $modules ); // Will be trimmed down by the loop below
 120                 if ( count( $modulesWithMessages ) ) {
 121                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
 122                                         'mr_resource' => $modulesWithMessages,
 123                                         'mr_lang' => $lang
 124                                 ), __METHOD__
 125                         );
 126                         foreach ( $res as $row ) {
 127                                 $this->getModule( $row->mr_resource )->setMsgBlobMtime( $lang,
 128                                         wfTimestamp( TS_UNIX, $row->mr_timestamp ) );
 129                                 unset( $modulesWithoutMessages[$row->mr_resource] );
 130                         }
 131                 }
 132                 foreach ( array_keys( $modulesWithoutMessages ) as $name ) {
 133                         $this->getModule( $name )->setMsgBlobMtime( $lang, 0 );
 134                 }
 135         }
 136
 137         /**
 138          * Run JavaScript or CSS data through a filter, caching the filtered result for future calls.
 139          *
 140          * Available filters are:
 141          *
 142          *    - minify-js \see JavaScriptMinifier::minify
 143          *    - minify-css \see CSSMin::minify
 144          *
 145          * If $data is empty, only contains whitespace or the filter was unknown,
 146          * $data is returned unmodified.
 147          *
 148          * @param string $filter Name of filter to run
 149          * @param string $data Text to filter, such as JavaScript or CSS text
 150          * @return string Filtered data, or a comment containing an error message
 151          */
 152         protected function filter( $filter, $data ) {
 153                 global $wgResourceLoaderMinifierStatementsOnOwnLine, $wgResourceLoaderMinifierMaxLineLength;
 154                 wfProfileIn( __METHOD__ );
 155
 156                 // For empty/whitespace-only data or for unknown filters, don't perform
 157                 // any caching or processing
 158                 if ( trim( $data ) === '' || !in_array( $filter, array( 'minify-js', 'minify-css' ) ) ) {
 159                         wfProfileOut( __METHOD__ );
 160                         return $data;
 161                 }
 162
 163                 // Try for cache hit
 164                 // Use CACHE_ANYTHING since filtering is very slow compared to DB queries
 165                 $key = wfMemcKey( 'resourceloader', 'filter', $filter, self::$filterCacheVersion, md5( $data ) );
 166                 $cache = wfGetCache( CACHE_ANYTHING );
 167                 $cacheEntry = $cache->get( $key );
 168                 if ( is_string( $cacheEntry ) ) {
 169                         wfIncrStats( "rl-$filter-cache-hits" );
 170                         wfProfileOut( __METHOD__ );
 171                         return $cacheEntry;
 172                 }
 173
 174                 $result = '';
 175                 // Run the filter - we've already verified one of these will work
 176                 try {
 177                         wfIncrStats( "rl-$filter-cache-misses" );
 178                         switch ( $filter ) {
 179                                 case 'minify-js':
 180                                         $result = JavaScriptMinifier::minify( $data,
 181                                                 $wgResourceLoaderMinifierStatementsOnOwnLine,
 182                                                 $wgResourceLoaderMinifierMaxLineLength
 183                                         );
 184                                         $result .= "\n/* cache key: $key */";
 185                                         break;
 186                                 case 'minify-css':
 187                                         $result = CSSMin::minify( $data );
 188                                         $result .= "\n/* cache key: $key */";
 189                                         break;
 190                         }
 191
 192                         // Save filtered text to Memcached
 193                         $cache->set( $key, $result );
 194                 } catch ( Exception $e ) {
 195                         MWExceptionHandler::logException( $e );
 196                         wfDebugLog( 'resourceloader', __METHOD__ . ": minification failed: $e" );
 197                         $this->hasErrors = true;
 198                         // Return exception as a comment
 199                         $result = self::formatException( $e );
 200                 }
 201
 202                 wfProfileOut( __METHOD__ );
 203
 204                 return $result;
 205         }
 206
 207         /* Methods */
 208
 209         /**
 210          * Register core modules and runs registration hooks.
 211          */
 212         public function __construct() {
 213                 global $IP, $wgResourceModules, $wgResourceLoaderSources, $wgLoadScript, $wgEnableJavaScriptTest;
 214
 215                 wfProfileIn( __METHOD__ );
 216
 217                 // Add 'local' source first
 218                 $this->addSource( 'local', array( 'loadScript' => $wgLoadScript, 'apiScript' => wfScript( 'api' ) ) );
 219
 220                 // Add other sources
 221                 $this->addSource( $wgResourceLoaderSources );
 222
 223                 // Register core modules
 224                 $this->register( include "$IP/resources/Resources.php" );
 225                 // Register extension modules
 226                 wfRunHooks( 'ResourceLoaderRegisterModules', array( &$this ) );
 227                 $this->register( $wgResourceModules );
 228
 229                 if ( $wgEnableJavaScriptTest === true ) {
 230                         $this->registerTestModules();
 231                 }
 232
 233                 wfProfileOut( __METHOD__ );
 234         }
 235
 236         /**
 237          * Register a module with the ResourceLoader system.
 238          *
 239          * @param mixed $name Name of module as a string or List of name/object pairs as an array
 240          * @param array $info Module info array. For backwards compatibility with 1.17alpha,
 241          *   this may also be a ResourceLoaderModule object. Optional when using
 242          *   multiple-registration calling style.
 243          * @throws MWException: If a duplicate module registration is attempted
 244          * @throws MWException: If a module name contains illegal characters (pipes or commas)
 245          * @throws MWException: If something other than a ResourceLoaderModule is being registered
 246          * @return boolean False if there were any errors, in which case one or more modules were
 247          *   not registered
 248          */
 249         public function register( $name, $info = null ) {
 250                 wfProfileIn( __METHOD__ );
 251
 252                 // Allow multiple modules to be registered in one call
 253                 $registrations = is_array( $name ) ? $name : array( $name => $info );
 254                 foreach ( $registrations as $name => $info ) {
 255                         // Disallow duplicate registrations
 256                         if ( isset( $this->moduleInfos[$name] ) ) {
 257                                 wfProfileOut( __METHOD__ );
 258                                 // A module has already been registered by this name
 259                                 throw new MWException(
 260                                         'ResourceLoader duplicate registration error. ' .
 261                                         'Another module has already been registered as ' . $name
 262                                 );
 263                         }
 264
 265                         // Check $name for validity
 266                         if ( !self::isValidModuleName( $name ) ) {
 267                                 wfProfileOut( __METHOD__ );
 268                                 throw new MWException( "ResourceLoader module name '$name' is invalid, see ResourceLoader::isValidModuleName()" );
 269                         }
 270
 271                         // Attach module
 272                         if ( is_object( $info ) ) {
 273                                 // Old calling convention
 274                                 // Validate the input
 275                                 if ( !( $info instanceof ResourceLoaderModule ) ) {
 276                                         wfProfileOut( __METHOD__ );
 277                                         throw new MWException( 'ResourceLoader invalid module error. ' .
 278                                                 'Instances of ResourceLoaderModule expected.' );
 279                                 }
 280
 281                                 $this->moduleInfos[$name] = array( 'object' => $info );
 282                                 $info->setName( $name );
 283                                 $this->modules[$name] = $info;
 284                         } else {
 285                                 // New calling convention
 286                                 $this->moduleInfos[$name] = $info;
 287                         }
 288                 }
 289
 290                 wfProfileOut( __METHOD__ );
 291         }
 292
 293         /**
 294          */
 295         public function registerTestModules() {
 296                 global $IP, $wgEnableJavaScriptTest;
 297
 298                 if ( $wgEnableJavaScriptTest !== true ) {
 299                         throw new MWException( 'Attempt to register JavaScript test modules but <code>$wgEnableJavaScriptTest</code> is false. Edit your <code>LocalSettings.php</code> to enable it.' );
 300                 }
 301
 302                 wfProfileIn( __METHOD__ );
 303
 304                 // Get core test suites
 305                 $testModules = array();
 306                 $testModules['qunit'] = array();
 307                 // Get other test suites (e.g. from extensions)
 308                 wfRunHooks( 'ResourceLoaderTestModules', array( &$testModules, &$this ) );
 309
 310                 // Add the testrunner (which configures QUnit) to the dependencies.
 311                 // Since it must be ready before any of the test suites are executed.
 312                 foreach ( $testModules['qunit'] as &$module ) {
 313                         // Make sure all test modules are top-loading so that when QUnit starts
 314                         // on document-ready, it will run once and finish. If some tests arrive
 315                         // later (possibly after QUnit has already finished) they will be ignored.
 316                         $module['position'] = 'top';
 317                         $module['dependencies'][] = 'test.mediawiki.qunit.testrunner';
 318                 }
 319
 320                 $testModules['qunit'] = ( include "$IP/tests/qunit/QUnitTestResources.php" ) + $testModules['qunit'];
 321
 322                 foreach ( $testModules as $id => $names ) {
 323                         // Register test modules
 324                         $this->register( $testModules[$id] );
 325
 326                         // Keep track of their names so that they can be loaded together
 327                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 328                 }
 329
 330                 wfProfileOut( __METHOD__ );
 331         }
 332
 333         /**
 334          * Add a foreign source of modules.
 335          *
 336          * Source properties:
 337          * 'loadScript': URL (either fully-qualified or protocol-relative) of load.php for this source
 338          *
 339          * @param mixed $id Source ID (string), or array( id1 => props1, id2 => props2, ... )
 340          * @param array $properties Source properties
 341          * @throws MWException
 342          */
 343         public function addSource( $id, $properties = null ) {
 344                 // Allow multiple sources to be registered in one call
 345                 if ( is_array( $id ) ) {
 346                         foreach ( $id as $key => $value ) {
 347                                 $this->addSource( $key, $value );
 348                         }
 349                         return;
 350                 }
 351
 352                 // Disallow duplicates
 353                 if ( isset( $this->sources[$id] ) ) {
 354                         throw new MWException(
 355                                 'ResourceLoader duplicate source addition error. ' .
 356                                 'Another source has already been registered as ' . $id
 357                         );
 358                 }
 359
 360                 // Validate properties
 361                 foreach ( self::$requiredSourceProperties as $prop ) {
 362                         if ( !isset( $properties[$prop] ) ) {
 363                                 throw new MWException( "Required property $prop missing from source ID $id" );
 364                         }
 365                 }
 366
 367                 $this->sources[$id] = $properties;
 368         }
 369
 370         /**
 371          * Get a list of module names.
 372          *
 373          * @return array List of module names
 374          */
 375         public function getModuleNames() {
 376                 return array_keys( $this->moduleInfos );
 377         }
 378
 379         /**
 380          * Get a list of test module names for one (or all) frameworks.
 381          *
 382          * If the given framework id is unknkown, or if the in-object variable is not an array,
 383          * then it will return an empty array.
 384          *
 385          * @param string $framework Get only the test module names for one
 386          *   particular framework (optional)
 387          * @return Array
 388          */
 389         public function getTestModuleNames( $framework = 'all' ) {
 390                 /// @todo api siteinfo prop testmodulenames modulenames
 391                 if ( $framework == 'all' ) {
 392                         return $this->testModuleNames;
 393                 } elseif ( isset( $this->testModuleNames[$framework] ) && is_array( $this->testModuleNames[$framework] ) ) {
 394                         return $this->testModuleNames[$framework];
 395                 } else {
 396                         return array();
 397                 }
 398         }
 399
 400         /**
 401          * Get the ResourceLoaderModule object for a given module name.
 402          *
 403          * @param string $name Module name
 404          * @return ResourceLoaderModule if module has been registered, null otherwise
 405          */
 406         public function getModule( $name ) {
 407                 if ( !isset( $this->modules[$name] ) ) {
 408                         if ( !isset( $this->moduleInfos[$name] ) ) {
 409                                 // No such module
 410                                 return null;
 411                         }
 412                         // Construct the requested object
 413                         $info = $this->moduleInfos[$name];
 414                         /** @var ResourceLoaderModule $object */
 415                         if ( isset( $info['object'] ) ) {
 416                                 // Object given in info array
 417                                 $object = $info['object'];
 418                         } else {
 419                                 if ( !isset( $info['class'] ) ) {
 420                                         $class = 'ResourceLoaderFileModule';
 421                                 } else {
 422                                         $class = $info['class'];
 423                                 }
 424                                 $object = new $class( $info );
 425                         }
 426                         $object->setName( $name );
 427                         $this->modules[$name] = $object;
 428                 }
 429
 430                 return $this->modules[$name];
 431         }
 432
 433         /**
 434          * Get the list of sources.
 435          *
 436          * @return array Like array( id => array of properties, .. )
 437          */
 438         public function getSources() {
 439                 return $this->sources;
 440         }
 441
 442         /**
 443          * Output a response to a load request, including the content-type header.
 444          *
 445          * @param ResourceLoaderContext $context Context in which a response should be formed
 446          */
 447         public function respond( ResourceLoaderContext $context ) {
 448                 global $wgCacheEpoch, $wgUseFileCache;
 449
 450                 // Use file cache if enabled and available...
 451                 if ( $wgUseFileCache ) {
 452                         $fileCache = ResourceFileCache::newFromContext( $context );
 453                         if ( $this->tryRespondFromFileCache( $fileCache, $context ) ) {
 454                                 return; // output handled
 455                         }
 456                 }
 457
 458                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 459                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 460                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 461                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 462                 // the whole thing in our own output buffer to be sure the active buffer
 463                 // doesn't use ob_gzhandler.
 464                 // See http://bugs.php.net/bug.php?id=36514
 465                 ob_start();
 466
 467                 wfProfileIn( __METHOD__ );
 468                 $errors = '';
 469
 470                 // Find out which modules are missing and instantiate the others
 471                 $modules = array();
 472                 $missing = array();
 473                 foreach ( $context->getModules() as $name ) {
 474                         if ( isset( $this->moduleInfos[$name] ) ) {
 475                                 $module = $this->getModule( $name );
 476                                 // Do not allow private modules to be loaded from the web.
 477                                 // This is a security issue, see bug 34907.
 478                                 if ( $module->getGroup() === 'private' ) {
 479                                         wfDebugLog( 'resourceloader', __METHOD__ . ": request for private module '$name' denied" );
 480                                         $this->hasErrors = true;
 481                                         // Add exception to the output as a comment
 482                                         $errors .= self::makeComment( "Cannot show private module \"$name\"" );
 483
 484                                         continue;
 485                                 }
 486                                 $modules[$name] = $module;
 487                         } else {
 488                                 $missing[] = $name;
 489                         }
 490                 }
 491
 492                 // Preload information needed to the mtime calculation below
 493                 try {
 494                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 495                 } catch ( Exception $e ) {
 496                         MWExceptionHandler::logException( $e );
 497                         wfDebugLog( 'resourceloader', __METHOD__ . ": preloading module info failed: $e" );
 498                         $this->hasErrors = true;
 499                         // Add exception to the output as a comment
 500                         $errors .= self::formatException( $e );
 501                 }
 502
 503                 wfProfileIn( __METHOD__ . '-getModifiedTime' );
 504
 505                 // To send Last-Modified and support If-Modified-Since, we need to detect
 506                 // the last modified time
 507                 $mtime = wfTimestamp( TS_UNIX, $wgCacheEpoch );
 508                 foreach ( $modules as $module ) {
 509                         /**
 510                          * @var $module ResourceLoaderModule
 511                          */
 512                         try {
 513                                 // Calculate maximum modified time
 514                                 $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 515                         } catch ( Exception $e ) {
 516                                 MWExceptionHandler::logException( $e );
 517                                 wfDebugLog( 'resourceloader', __METHOD__ . ": calculating maximum modified time failed: $e" );
 518                                 $this->hasErrors = true;
 519                                 // Add exception to the output as a comment
 520                                 $errors .= self::formatException( $e );
 521                         }
 522                 }
 523
 524                 wfProfileOut( __METHOD__ . '-getModifiedTime' );
 525
 526                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 527                 if ( $this->tryRespondLastModified( $context, $mtime ) ) {
 528                         wfProfileOut( __METHOD__ );
 529                         return; // output handled (buffers cleared)
 530                 }
 531
 532                 // Generate a response
 533                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 534
 535                 // Prepend comments indicating exceptions
 536                 $response = $errors . $response;
 537
 538                 // Capture any PHP warnings from the output buffer and append them to the
 539                 // response in a comment if we're in debug mode.
 540                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 541                         $response = self::makeComment( $warnings ) . $response;
 542                         $this->hasErrors = true;
 543                 }
 544
 545                 // Save response to file cache unless there are errors
 546                 if ( isset( $fileCache ) && !$errors && !count( $missing ) ) {
 547                         // Cache single modules...and other requests if there are enough hits
 548                         if ( ResourceFileCache::useFileCache( $context ) ) {
 549                                 if ( $fileCache->isCacheWorthy() ) {
 550                                         $fileCache->saveText( $response );
 551                                 } else {
 552                                         $fileCache->incrMissesRecent( $context->getRequest() );
 553                                 }
 554                         }
 555                 }
 556
 557                 // Send content type and cache related headers
 558                 $this->sendResponseHeaders( $context, $mtime, $this->hasErrors );
 559
 560                 // Remove the output buffer and output the response
 561                 ob_end_clean();
 562                 echo $response;
 563
 564                 wfProfileOut( __METHOD__ );
 565         }
 566
 567         /**
 568          * Send content type and last modified headers to the client.
 569          * @param ResourceLoaderContext $context
 570          * @param string $mtime TS_MW timestamp to use for last-modified
 571          * @param bool $errors Whether there are commented-out errors in the response
 572          * @return void
 573          */
 574         protected function sendResponseHeaders( ResourceLoaderContext $context, $mtime, $errors ) {
 575                 global $wgResourceLoaderMaxage;
 576                 // If a version wasn't specified we need a shorter expiry time for updates
 577                 // to propagate to clients quickly
 578                 // If there were errors, we also need a shorter expiry time so we can recover quickly
 579                 if ( is_null( $context->getVersion() ) || $errors ) {
 580                         $maxage = $wgResourceLoaderMaxage['unversioned']['client'];
 581                         $smaxage = $wgResourceLoaderMaxage['unversioned']['server'];
 582                 // If a version was specified we can use a longer expiry time since changing
 583                 // version numbers causes cache misses
 584                 } else {
 585                         $maxage = $wgResourceLoaderMaxage['versioned']['client'];
 586                         $smaxage = $wgResourceLoaderMaxage['versioned']['server'];
 587                 }
 588                 if ( $context->getOnly() === 'styles' ) {
 589                         header( 'Content-Type: text/css; charset=utf-8' );
 590                         header( 'Access-Control-Allow-Origin: *' );
 591                 } else {
 592                         header( 'Content-Type: text/javascript; charset=utf-8' );
 593                 }
 594                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 595                 if ( $context->getDebug() ) {
 596                         // Do not cache debug responses
 597                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 598                         header( 'Pragma: no-cache' );
 599                 } else {
 600                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 601                         $exp = min( $maxage, $smaxage );
 602                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 603                 }
 604         }
 605
 606         /**
 607          * Respond with 304 Last Modified if appropiate.
 608          *
 609          * If there's an If-Modified-Since header, respond with a 304 appropriately
 610          * and clear out the output buffer. If the client cache is too old then do nothing.
 611          *
 612          * @param $context ResourceLoaderContext
 613          * @param string $mtime The TS_MW timestamp to check the header against
 614          * @return bool True if 304 header sent and output handled
 615          */
 616         protected function tryRespondLastModified( ResourceLoaderContext $context, $mtime ) {
 617                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 618                 // Some clients send "timestamp;length=123". Strip the part after the first ';'
 619                 // so we get a valid timestamp.
 620                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 621                 // Never send 304s in debug mode
 622                 if ( $ims !== false && !$context->getDebug() ) {
 623                         $imsTS = strtok( $ims, ';' );
 624                         if ( $mtime <= wfTimestamp( TS_UNIX, $imsTS ) ) {
 625                                 // There's another bug in ob_gzhandler (see also the comment at
 626                                 // the top of this function) that causes it to gzip even empty
 627                                 // responses, meaning it's impossible to produce a truly empty
 628                                 // response (because the gzip header is always there). This is
 629                                 // a problem because 304 responses have to be completely empty
 630                                 // per the HTTP spec, and Firefox behaves buggily when they're not.
 631                                 // See also http://bugs.php.net/bug.php?id=51579
 632                                 // To work around this, we tear down all output buffering before
 633                                 // sending the 304.
 634                                 wfResetOutputBuffers( /* $resetGzipEncoding = */ true );
 635
 636                                 header( 'HTTP/1.0 304 Not Modified' );
 637                                 header( 'Status: 304 Not Modified' );
 638                                 return true;
 639                         }
 640                 }
 641                 return false;
 642         }
 643
 644         /**
 645          * Send out code for a response from file cache if possible.
 646          *
 647          * @param ResourceFileCache $fileCache Cache object for this request URL
 648          * @param ResourceLoaderContext $context Context in which to generate a response
 649          * @return bool If this found a cache file and handled the response
 650          */
 651         protected function tryRespondFromFileCache(
 652                 ResourceFileCache $fileCache, ResourceLoaderContext $context
 653         ) {
 654                 global $wgResourceLoaderMaxage;
 655                 // Buffer output to catch warnings.
 656                 ob_start();
 657                 // Get the maximum age the cache can be
 658                 $maxage = is_null( $context->getVersion() )
 659                         ? $wgResourceLoaderMaxage['unversioned']['server']
 660                         : $wgResourceLoaderMaxage['versioned']['server'];
 661                 // Minimum timestamp the cache file must have
 662                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 663                 if ( !$good ) {
 664                         try { // RL always hits the DB on file cache miss...
 665                                 wfGetDB( DB_SLAVE );
 666                         } catch ( DBConnectionError $e ) { // ...check if we need to fallback to cache
 667                                 $good = $fileCache->isCacheGood(); // cache existence check
 668                         }
 669                 }
 670                 if ( $good ) {
 671                         $ts = $fileCache->cacheTimestamp();
 672                         // Send content type and cache headers
 673                         $this->sendResponseHeaders( $context, $ts, false );
 674                         // If there's an If-Modified-Since header, respond with a 304 appropriately
 675                         if ( $this->tryRespondLastModified( $context, $ts ) ) {
 676                                 return false; // output handled (buffers cleared)
 677                         }
 678                         $response = $fileCache->fetchText();
 679                         // Capture any PHP warnings from the output buffer and append them to the
 680                         // response in a comment if we're in debug mode.
 681                         if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 682                                 $response = "/*\n$warnings\n*/\n" . $response;
 683                         }
 684                         // Remove the output buffer and output the response
 685                         ob_end_clean();
 686                         echo $response . "\n/* Cached {$ts} */";
 687                         return true; // cache hit
 688                 }
 689                 // Clear buffer
 690                 ob_end_clean();
 691
 692                 return false; // cache miss
 693         }
 694
 695         /**
 696          * Generate a CSS or JS comment block.
 697          *
 698          * Only use this for public data, not error message details.
 699          *
 700          * @param string $text
 701          * @return string
 702          */
 703         public static function makeComment( $text ) {
 704                 $encText = str_replace( '*/', '* /', $text );
 705                 return "/*\n$encText\n*/\n";
 706         }
 707
 708         /**
 709          * Handle exception display.
 710          *
 711          * @param Exception $e to be shown to the user
 712          * @return string sanitized text that can be returned to the user
 713          */
 714         public static function formatException( $e ) {
 715                 global $wgShowExceptionDetails;
 716
 717                 if ( $wgShowExceptionDetails ) {
 718                         return self::makeComment( $e->__toString() );
 719                 } else {
 720                         return self::makeComment( wfMessage( 'internalerror' )->text() );
 721                 }
 722         }
 723
 724         /**
 725          * Generate code for a response.
 726          *
 727          * @param $context ResourceLoaderContext Context in which to generate a response
 728          * @param array $modules List of module objects keyed by module name
 729          * @param array $missing List of requested module names that are unregistered (optional)
 730          * @return string Response data
 731          */
 732         public function makeModuleResponse( ResourceLoaderContext $context,
 733                 array $modules, array $missing = array()
 734         ) {
 735                 $out = '';
 736                 $exceptions = '';
 737                 $states = array();
 738
 739                 if ( !count( $modules ) && !count( $missing ) ) {
 740                         return "/* This file is the Web entry point for MediaWiki's ResourceLoader:
 741    <https://www.mediawiki.org/wiki/ResourceLoader>. In this request,
 742    no modules were requested. Max made me put this here. */";
 743                 }
 744
 745                 wfProfileIn( __METHOD__ );
 746
 747                 // Pre-fetch blobs
 748                 if ( $context->shouldIncludeMessages() ) {
 749                         try {
 750                                 $blobs = MessageBlobStore::get( $this, $modules, $context->getLanguage() );
 751                         } catch ( Exception $e ) {
 752                                 MWExceptionHandler::logException( $e );
 753                                 wfDebugLog( 'resourceloader', __METHOD__ . ": pre-fetching blobs from MessageBlobStore failed: $e" );
 754                                 $this->hasErrors = true;
 755                                 // Add exception to the output as a comment
 756                                 $exceptions .= self::formatException( $e );
 757                         }
 758                 } else {
 759                         $blobs = array();
 760                 }
 761
 762                 foreach ( $missing as $name ) {
 763                         $states[$name] = 'missing';
 764                 }
 765
 766                 // Generate output
 767                 $isRaw = false;
 768                 foreach ( $modules as $name => $module ) {
 769                         /**
 770                          * @var $module ResourceLoaderModule
 771                          */
 772
 773                         wfProfileIn( __METHOD__ . '-' . $name );
 774                         try {
 775                                 $scripts = '';
 776                                 if ( $context->shouldIncludeScripts() ) {
 777                                         // If we are in debug mode, we'll want to return an array of URLs if possible
 778                                         // However, we can't do this if the module doesn't support it
 779                                         // We also can't do this if there is an only= parameter, because we have to give
 780                                         // the module a way to return a load.php URL without causing an infinite loop
 781                                         if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
 782                                                 $scripts = $module->getScriptURLsForDebug( $context );
 783                                         } else {
 784                                                 $scripts = $module->getScript( $context );
 785                                                 if ( is_string( $scripts ) && strlen( $scripts ) && substr( $scripts, -1 ) !== ';' ) {
 786                                                         // bug 27054: Append semicolon to prevent weird bugs
 787                                                         // caused by files not terminating their statements right
 788                                                         $scripts .= ";\n";
 789                                                 }
 790                                         }
 791                                 }
 792                                 // Styles
 793                                 $styles = array();
 794                                 if ( $context->shouldIncludeStyles() ) {
 795                                         // Don't create empty stylesheets like array( '' => '' ) for modules
 796                                         // that don't *have* any stylesheets (bug 38024).
 797                                         $stylePairs = $module->getStyles( $context );
 798                                         if ( count ( $stylePairs ) ) {
 799                                                 // If we are in debug mode without &only= set, we'll want to return an array of URLs
 800                                                 // See comment near shouldIncludeScripts() for more details
 801                                                 if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
 802                                                         $styles = array(
 803                                                                 'url' => $module->getStyleURLsForDebug( $context )
 804                                                         );
 805                                                 } else {
 806                                                         // Minify CSS before embedding in mw.loader.implement call
 807                                                         // (unless in debug mode)
 808                                                         if ( !$context->getDebug() ) {
 809                                                                 foreach ( $stylePairs as $media => $style ) {
 810                                                                         // Can be either a string or an array of strings.
 811                                                                         if ( is_array( $style ) ) {
 812                                                                                 $stylePairs[$media] = array();
 813                                                                                 foreach ( $style as $cssText ) {
 814                                                                                         if ( is_string( $cssText ) ) {
 815                                                                                                 $stylePairs[$media][] = $this->filter( 'minify-css', $cssText );
 816                                                                                         }
 817                                                                                 }
 818                                                                         } elseif ( is_string( $style ) ) {
 819                                                                                 $stylePairs[$media] = $this->filter( 'minify-css', $style );
 820                                                                         }
 821                                                                 }
 822                                                         }
 823                                                         // Wrap styles into @media groups as needed and flatten into a numerical array
 824                                                         $styles = array(
 825                                                                 'css' => self::makeCombinedStyles( $stylePairs )
 826                                                         );
 827                                                 }
 828                                         }
 829                                 }
 830
 831                                 // Messages
 832                                 $messagesBlob = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 833
 834                                 // Append output
 835                                 switch ( $context->getOnly() ) {
 836                                         case 'scripts':
 837                                                 if ( is_string( $scripts ) ) {
 838                                                         // Load scripts raw...
 839                                                         $out .= $scripts;
 840                                                 } elseif ( is_array( $scripts ) ) {
 841                                                         // ...except when $scripts is an array of URLs
 842                                                         $out .= self::makeLoaderImplementScript( $name, $scripts, array(), array() );
 843                                                 }
 844                                                 break;
 845                                         case 'styles':
 846                                                 // We no longer seperate into media, they are all combined now with
 847                                                 // custom media type groups into @media .. {} sections as part of the css string.
 848                                                 // Module returns either an empty array or a numerical array with css strings.
 849                                                 $out .= isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
 850                                                 break;
 851                                         case 'messages':
 852                                                 $out .= self::makeMessageSetScript( new XmlJsCode( $messagesBlob ) );
 853                                                 break;
 854                                         default:
 855                                                 $out .= self::makeLoaderImplementScript(
 856                                                         $name,
 857                                                         $scripts,
 858                                                         $styles,
 859                                                         new XmlJsCode( $messagesBlob )
 860                                                 );
 861                                                 break;
 862                                 }
 863                         } catch ( Exception $e ) {
 864                                 MWExceptionHandler::logException( $e );
 865                                 wfDebugLog( 'resourceloader', __METHOD__ . ": generating module package failed: $e" );
 866                                 $this->hasErrors = true;
 867                                 // Add exception to the output as a comment
 868                                 $exceptions .= self::formatException( $e );
 869
 870                                 // Respond to client with error-state instead of module implementation
 871                                 $states[$name] = 'error';
 872                                 unset( $modules[$name] );
 873                         }
 874                         $isRaw |= $module->isRaw();
 875                         wfProfileOut( __METHOD__ . '-' . $name );
 876                 }
 877
 878                 // Update module states
 879                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
 880                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
 881                                 // Set the state of modules loaded as only scripts to ready as
 882                                 // they don't have an mw.loader.implement wrapper that sets the state
 883                                 foreach ( $modules as $name => $module ) {
 884                                         $states[$name] = 'ready';
 885                                 }
 886                         }
 887
 888                         // Set the state of modules we didn't respond to with mw.loader.implement
 889                         if ( count( $states ) ) {
 890                                 $out .= self::makeLoaderStateScript( $states );
 891                         }
 892                 }
 893
 894                 if ( !$context->getDebug() ) {
 895                         if ( $context->getOnly() === 'styles' ) {
 896                                 $out = $this->filter( 'minify-css', $out );
 897                         } else {
 898                                 $out = $this->filter( 'minify-js', $out );
 899                         }
 900                 }
 901
 902                 wfProfileOut( __METHOD__ );
 903                 return $exceptions . $out;
 904         }
 905
 906         /* Static Methods */
 907
 908         /**
 909          * Return JS code that calls mw.loader.implement with given module properties.
 910          *
 911          * @param string $name Module name
 912          * @param mixed $scripts List of URLs to JavaScript files or String of JavaScript code
 913          * @param mixed $styles Array of CSS strings keyed by media type, or an array of lists of URLs
 914          *   to CSS files keyed by media type
 915          * @param mixed $messages List of messages associated with this module. May either be an
 916          *   associative array mapping message key to value, or a JSON-encoded message blob containing
 917          *   the same data, wrapped in an XmlJsCode object.
 918          * @throws MWException
 919          * @return string
 920          */
 921         public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
 922                 if ( is_string( $scripts ) ) {
 923                         $scripts = new XmlJsCode( "function () {\n{$scripts}\n}" );
 924                 } elseif ( !is_array( $scripts ) ) {
 925                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
 926                 }
 927                 return Xml::encodeJsCall(
 928                         'mw.loader.implement',
 929                         array(
 930                                 $name,
 931                                 $scripts,
 932                                 // Force objects. mw.loader.implement requires them to be javascript objects.
 933                                 // Although these variables are associative arrays, which become javascript
 934                                 // objects through json_encode. In many cases they will be empty arrays, and
 935                                 // PHP/json_encode() consider empty arrays to be numerical arrays and
 936                                 // output javascript "[]" instead of "{}". This fixes that.
 937                                 (object)$styles,
 938                                 (object)$messages
 939                         ),
 940                         ResourceLoader::inDebugMode()
 941                 );
 942         }
 943
 944         /**
 945          * Returns JS code which, when called, will register a given list of messages.
 946          *
 947          * @param mixed $messages Either an associative array mapping message key to value, or a
 948          *   JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
 949          * @return string
 950          */
 951         public static function makeMessageSetScript( $messages ) {
 952                 return Xml::encodeJsCall(
 953                         'mw.messages.set',
 954                         array( (object)$messages ),
 955                         ResourceLoader::inDebugMode()
 956                 );
 957         }
 958
 959         /**
 960          * Combines an associative array mapping media type to CSS into a
 961          * single stylesheet with "@media" blocks.
 962          *
 963          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings
 964          * @return array
 965          */
 966         private static function makeCombinedStyles( array $stylePairs ) {
 967                 $out = array();
 968                 foreach ( $stylePairs as $media => $styles ) {
 969                         // ResourceLoaderFileModule::getStyle can return the styles
 970                         // as a string or an array of strings. This is to allow separation in
 971                         // the front-end.
 972                         $styles = (array)$styles;
 973                         foreach ( $styles as $style ) {
 974                                 $style = trim( $style );
 975                                 // Don't output an empty "@media print { }" block (bug 40498)
 976                                 if ( $style !== '' ) {
 977                                         // Transform the media type based on request params and config
 978                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
 979                                         $media = OutputPage::transformCssMedia( $media );
 980
 981                                         if ( $media === '' || $media == 'all' ) {
 982                                                 $out[] = $style;
 983                                         } elseif ( is_string( $media ) ) {
 984                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
 985                                         }
 986                                         // else: skip
 987                                 }
 988                         }
 989                 }
 990                 return $out;
 991         }
 992
 993         /**
 994          * Returns a JS call to mw.loader.state, which sets the state of a
 995          * module or modules to a given value. Has two calling conventions:
 996          *
 997          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
 998          *         Set the state of a single module called $name to $state
 999          *
1000          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
1001          *         Set the state of modules with the given names to the given states
1002          *
1003          * @param string $name
1004          * @param $state
1005          * @return string
1006          */
1007         public static function makeLoaderStateScript( $name, $state = null ) {
1008                 if ( is_array( $name ) ) {
1009                         return Xml::encodeJsCall(
1010                                 'mw.loader.state',
1011                                 array( $name ),
1012                                 ResourceLoader::inDebugMode()
1013                         );
1014                 } else {
1015                         return Xml::encodeJsCall(
1016                                 'mw.loader.state',
1017                                 array( $name, $state ),
1018                                 ResourceLoader::inDebugMode()
1019                         );
1020                 }
1021         }
1022
1023         /**
1024          * Returns JS code which calls the script given by $script. The script will
1025          * be called with local variables name, version, dependencies and group,
1026          * which will have values corresponding to $name, $version, $dependencies
1027          * and $group as supplied.
1028          *
1029          * @param string $name Module name
1030          * @param int $version Module version number as a timestamp
1031          * @param array $dependencies List of module names on which this module depends
1032          * @param string $group Group which the module is in.
1033          * @param string $source Source of the module, or 'local' if not foreign.
1034          * @param string $script JavaScript code
1035          * @return string
1036          */
1037         public static function makeCustomLoaderScript( $name, $version, $dependencies, $group, $source, $script ) {
1038                 $script = str_replace( "\n", "\n\t", trim( $script ) );
1039                 return Xml::encodeJsCall(
1040                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
1041                         array( $name, $version, $dependencies, $group, $source ),
1042                         ResourceLoader::inDebugMode()
1043                 );
1044         }
1045
1046         /**
1047          * Returns JS code which calls mw.loader.register with the given
1048          * parameters. Has three calling conventions:
1049          *
1050          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version, $dependencies, $group, $source ):
1051          *       Register a single module.
1052          *
1053          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
1054          *       Register modules with the given names.
1055          *
1056          *   - ResourceLoader::makeLoaderRegisterScript( array(
1057          *        array( $name1, $version1, $dependencies1, $group1, $source1 ),
1058          *        array( $name2, $version2, $dependencies1, $group2, $source2 ),
1059          *        ...
1060          *     ) ):
1061          *        Registers modules with the given names and parameters.
1062          *
1063          * @param string $name Module name
1064          * @param int $version Module version number as a timestamp
1065          * @param array $dependencies List of module names on which this module depends
1066          * @param string $group Group which the module is in
1067          * @param string $source Source of the module, or 'local' if not foreign
1068          * @return string
1069          */
1070         public static function makeLoaderRegisterScript( $name, $version = null,
1071                 $dependencies = null, $group = null, $source = null
1072         ) {
1073                 if ( is_array( $name ) ) {
1074                         return Xml::encodeJsCall(
1075                                 'mw.loader.register',
1076                                 array( $name ),
1077                                 ResourceLoader::inDebugMode()
1078                         );
1079                 } else {
1080                         $version = (int)$version > 1 ? (int)$version : 1;
1081                         return Xml::encodeJsCall(
1082                                 'mw.loader.register',
1083                                 array( $name, $version, $dependencies, $group, $source ),
1084                                 ResourceLoader::inDebugMode()
1085                         );
1086                 }
1087         }
1088
1089         /**
1090          * Returns JS code which calls mw.loader.addSource() with the given
1091          * parameters. Has two calling conventions:
1092          *
1093          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1094          *       Register a single source
1095          *
1096          *   - ResourceLoader::makeLoaderSourcesScript( array( $id1 => $props1, $id2 => $props2, ... ) );
1097          *       Register sources with the given IDs and properties.
1098          *
1099          * @param string $id source ID
1100          * @param array $properties source properties (see addSource())
1101          * @return string
1102          */
1103         public static function makeLoaderSourcesScript( $id, $properties = null ) {
1104                 if ( is_array( $id ) ) {
1105                         return Xml::encodeJsCall(
1106                                 'mw.loader.addSource',
1107                                 array( $id ),
1108                                 ResourceLoader::inDebugMode()
1109                         );
1110                 } else {
1111                         return Xml::encodeJsCall(
1112                                 'mw.loader.addSource',
1113                                 array( $id, $properties ),
1114                                 ResourceLoader::inDebugMode()
1115                         );
1116                 }
1117         }
1118
1119         /**
1120          * Returns JS code which runs given JS code if the client-side framework is
1121          * present.
1122          *
1123          * @param string $script JavaScript code
1124          * @return string
1125          */
1126         public static function makeLoaderConditionalScript( $script ) {
1127                 return "if(window.mw){\n" . trim( $script ) . "\n}";
1128         }
1129
1130         /**
1131          * Returns JS code which will set the MediaWiki configuration array to
1132          * the given value.
1133          *
1134          * @param array $configuration List of configuration values keyed by variable name
1135          * @return string
1136          */
1137         public static function makeConfigSetScript( array $configuration ) {
1138                 return Xml::encodeJsCall(
1139                         'mw.config.set',
1140                         array( $configuration ),
1141                         ResourceLoader::inDebugMode()
1142                 );
1143         }
1144
1145         /**
1146          * Convert an array of module names to a packed query string.
1147          *
1148          * For example, array( 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' )
1149          * becomes 'foo.bar,baz|bar.baz,quux'
1150          * @param array $modules List of module names (strings)
1151          * @return string Packed query string
1152          */
1153         public static function makePackedModulesString( $modules ) {
1154                 $groups = array(); // array( prefix => array( suffixes ) )
1155                 foreach ( $modules as $module ) {
1156                         $pos = strrpos( $module, '.' );
1157                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1158                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1159                         $groups[$prefix][] = $suffix;
1160                 }
1161
1162                 $arr = array();
1163                 foreach ( $groups as $prefix => $suffixes ) {
1164                         $p = $prefix === '' ? '' : $prefix . '.';
1165                         $arr[] = $p . implode( ',', $suffixes );
1166                 }
1167                 $str = implode( '|', $arr );
1168                 return $str;
1169         }
1170
1171         /**
1172          * Determine whether debug mode was requested
1173          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1174          * @return bool
1175          */
1176         public static function inDebugMode() {
1177                 global $wgRequest, $wgResourceLoaderDebug;
1178                 static $retval = null;
1179                 if ( is_null( $retval ) ) {
1180                         $retval = $wgRequest->getFuzzyBool( 'debug',
1181                                 $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug ) );
1182                 }
1183                 return $retval;
1184         }
1185
1186         /**
1187          * Build a load.php URL
1188          * @param array $modules of module names (strings)
1189          * @param string $lang Language code
1190          * @param string $skin Skin name
1191          * @param string|null $user User name. If null, the &user= parameter is omitted
1192          * @param string|null $version Versioning timestamp
1193          * @param bool $debug Whether the request should be in debug mode
1194          * @param string|null $only &only= parameter
1195          * @param bool $printable Printable mode
1196          * @param bool $handheld Handheld mode
1197          * @param array $extraQuery Extra query parameters to add
1198          * @return string URL to load.php. May be protocol-relative (if $wgLoadScript is procol-relative)
1199          */
1200         public static function makeLoaderURL( $modules, $lang, $skin, $user = null, $version = null, $debug = false, $only = null,
1201                         $printable = false, $handheld = false, $extraQuery = array() ) {
1202                 global $wgLoadScript;
1203                 $query = self::makeLoaderQuery( $modules, $lang, $skin, $user, $version, $debug,
1204                         $only, $printable, $handheld, $extraQuery
1205                 );
1206
1207                 // Prevent the IE6 extension check from being triggered (bug 28840)
1208                 // by appending a character that's invalid in Windows extensions ('*')
1209                 return wfExpandUrl( wfAppendQuery( $wgLoadScript, $query ) . '&*', PROTO_RELATIVE );
1210         }
1211
1212         /**
1213          * Build a query array (array representation of query string) for load.php. Helper
1214          * function for makeLoaderURL().
1215          *
1216          * @param array $modules
1217          * @param string $lang
1218          * @param string $skin
1219          * @param string $user
1220          * @param string $version
1221          * @param bool $debug
1222          * @param string $only
1223          * @param bool $printable
1224          * @param bool $handheld
1225          * @param array $extraQuery
1226          *
1227          * @return array
1228          */
1229         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null, $version = null, $debug = false, $only = null,
1230                         $printable = false, $handheld = false, $extraQuery = array() ) {
1231                 $query = array(
1232                         'modules' => self::makePackedModulesString( $modules ),
1233                         'lang' => $lang,
1234                         'skin' => $skin,
1235                         'debug' => $debug ? 'true' : 'false',
1236                 );
1237                 if ( $user !== null ) {
1238                         $query['user'] = $user;
1239                 }
1240                 if ( $version !== null ) {
1241                         $query['version'] = $version;
1242                 }
1243                 if ( $only !== null ) {
1244                         $query['only'] = $only;
1245                 }
1246                 if ( $printable ) {
1247                         $query['printable'] = 1;
1248                 }
1249                 if ( $handheld ) {
1250                         $query['handheld'] = 1;
1251                 }
1252                 $query += $extraQuery;
1253
1254                 // Make queries uniform in order
1255                 ksort( $query );
1256                 return $query;
1257         }
1258
1259         /**
1260          * Check a module name for validity.
1261          *
1262          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1263          * at most 255 bytes.
1264          *
1265          * @param string $moduleName Module name to check
1266          * @return bool Whether $moduleName is a valid module name
1267          */
1268         public static function isValidModuleName( $moduleName ) {
1269                 return !preg_match( '/[|,!]/', $moduleName ) && strlen( $moduleName ) <= 255;
1270         }
1271
1272         /**
1273          * Returns LESS compiler set up for use with MediaWiki
1274          *
1275          * @since 1.22
1276          * @return lessc
1277          */
1278         public static function getLessCompiler() {
1279                 global $wgResourceLoaderLESSFunctions, $wgResourceLoaderLESSImportPaths;
1280
1281                 // When called from the installer, it is possible that a required PHP extension
1282                 // is missing (at least for now; see bug 47564). If this is the case, throw an
1283                 // exception (caught by the installer) to prevent a fatal error later on.
1284                 if ( !function_exists( 'ctype_digit' ) ) {
1285                         throw new MWException( 'lessc requires the Ctype extension' );
1286                 }
1287
1288                 $less = new lessc();
1289                 $less->setPreserveComments( true );
1290                 $less->setVariables( self::getLESSVars() );
1291                 $less->setImportDir( $wgResourceLoaderLESSImportPaths );
1292                 foreach ( $wgResourceLoaderLESSFunctions as $name => $func ) {
1293                         $less->registerFunction( $name, $func );
1294                 }
1295                 return $less;
1296         }
1297
1298         /**
1299          * Get global LESS variables.
1300          *
1301          * $since 1.22
1302          * @return array: Map of variable names to string CSS values.
1303          */
1304         public static function getLESSVars() {
1305                 global $wgResourceLoaderLESSVars;
1306
1307                 static $lessVars = null;
1308                 if ( $lessVars === null ) {
1309                         $lessVars = $wgResourceLoaderLESSVars;
1310                         // Sort by key to ensure consistent hashing for cache lookups.
1311                         ksort( $lessVars );
1312                 }
1313                 return $lessVars;
1314         }
1315 }