includes/resourceloader/ResourceLoader.php

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