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 array $modules 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 string $filter Name of filter to run
 131          * @param string $data 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/* cache key: $key */";
 167                                         break;
 168                                 case 'minify-css':
 169                                         $result = CSSMin::minify( $data );
 170                                         $result .= "\n/* cache key: $key */";
 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                         $this->hasErrors = true;
 180                 }
 181
 182                 wfProfileOut( __METHOD__ );
 183
 184                 return $result;
 185         }
 186
 187         /* Methods */
 188
 189         /**
 190          * Registers core modules and runs registration hooks.
 191          */
 192         public function __construct() {
 193                 global $IP, $wgResourceModules, $wgResourceLoaderSources, $wgLoadScript, $wgEnableJavaScriptTest;
 194
 195                 wfProfileIn( __METHOD__ );
 196
 197                 // Add 'local' source first
 198                 $this->addSource( 'local', array( 'loadScript' => $wgLoadScript, 'apiScript' => wfScript( 'api' ) ) );
 199
 200                 // Add other sources
 201                 $this->addSource( $wgResourceLoaderSources );
 202
 203                 // Register core modules
 204                 $this->register( include( "$IP/resources/Resources.php" ) );
 205                 // Register extension modules
 206                 wfRunHooks( 'ResourceLoaderRegisterModules', array( &$this ) );
 207                 $this->register( $wgResourceModules );
 208
 209                 if ( $wgEnableJavaScriptTest === true ) {
 210                         $this->registerTestModules();
 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 array $info 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( $testModules['qunit'] as &$module ) {
 290                         // Make sure all test modules are top-loading so that when QUnit starts
 291                         // on document-ready, it will run once and finish. If some tests arrive
 292                         // later (possibly after QUnit has already finished) they will be ignored.
 293                         $module['position'] = 'top';
 294                         $module['dependencies'][] = 'mediawiki.tests.qunit.testrunner';
 295                 }
 296
 297                 foreach( $testModules as $id => $names ) {
 298                         // Register test modules
 299                         $this->register( $testModules[$id] );
 300
 301                         // Keep track of their names so that they can be loaded together
 302                         $this->testModuleNames[$id] = array_keys( $testModules[$id] );
 303                 }
 304
 305                 wfProfileOut( __METHOD__ );
 306         }
 307
 308         /**
 309          * Add a foreign source of modules.
 310          *
 311          * Source properties:
 312          * 'loadScript': URL (either fully-qualified or protocol-relative) of load.php for this source
 313          *
 314          * @param $id Mixed: source ID (string), or array( id1 => props1, id2 => props2, ... )
 315          * @param array $properties source properties
 316          * @throws MWException
 317          */
 318         public function addSource( $id, $properties = null) {
 319                 // Allow multiple sources to be registered in one call
 320                 if ( is_array( $id ) ) {
 321                         foreach ( $id as $key => $value ) {
 322                                 $this->addSource( $key, $value );
 323                         }
 324                         return;
 325                 }
 326
 327                 // Disallow duplicates
 328                 if ( isset( $this->sources[$id] ) ) {
 329                         throw new MWException(
 330                                 'ResourceLoader duplicate source addition error. ' .
 331                                 'Another source has already been registered as ' . $id
 332                         );
 333                 }
 334
 335                 // Validate properties
 336                 foreach ( self::$requiredSourceProperties as $prop ) {
 337                         if ( !isset( $properties[$prop] ) ) {
 338                                 throw new MWException( "Required property $prop missing from source ID $id" );
 339                         }
 340                 }
 341
 342                 $this->sources[$id] = $properties;
 343         }
 344
 345         /**
 346          * Get a list of module names
 347          *
 348          * @return Array: List of module names
 349          */
 350         public function getModuleNames() {
 351                 return array_keys( $this->moduleInfos );
 352         }
 353
 354         /**
 355          * Get a list of test module names for one (or all) frameworks.
 356          * If the given framework id is unknkown, or if the in-object variable is not an array,
 357          * then it will return an empty array.
 358          *
 359          * @param string $framework Optional. Get only the test module names for one
 360          * particular framework.
 361          * @return Array
 362          */
 363         public function getTestModuleNames( $framework = 'all' ) {
 364                 /// @TODO: api siteinfo prop testmodulenames modulenames
 365                 if ( $framework == 'all' ) {
 366                         return $this->testModuleNames;
 367                 } elseif ( isset( $this->testModuleNames[$framework] ) && is_array( $this->testModuleNames[$framework] ) ) {
 368                         return $this->testModuleNames[$framework];
 369                 } else {
 370                         return array();
 371                 }
 372         }
 373
 374         /**
 375          * Get the ResourceLoaderModule object for a given module name.
 376          *
 377          * @param string $name Module name
 378          * @return ResourceLoaderModule if module has been registered, null otherwise
 379          */
 380         public function getModule( $name ) {
 381                 if ( !isset( $this->modules[$name] ) ) {
 382                         if ( !isset( $this->moduleInfos[$name] ) ) {
 383                                 // No such module
 384                                 return null;
 385                         }
 386                         // Construct the requested object
 387                         $info = $this->moduleInfos[$name];
 388                         if ( isset( $info['object'] ) ) {
 389                                 // Object given in info array
 390                                 $object = $info['object'];
 391                         } else {
 392                                 if ( !isset( $info['class'] ) ) {
 393                                         $class = 'ResourceLoaderFileModule';
 394                                 } else {
 395                                         $class = $info['class'];
 396                                 }
 397                                 $object = new $class( $info );
 398                         }
 399                         $object->setName( $name );
 400                         $this->modules[$name] = $object;
 401                 }
 402
 403                 return $this->modules[$name];
 404         }
 405
 406         /**
 407          * Get the list of sources
 408          *
 409          * @return Array: array( id => array of properties, .. )
 410          */
 411         public function getSources() {
 412                 return $this->sources;
 413         }
 414
 415         /**
 416          * Outputs a response to a resource load-request, including a content-type header.
 417          *
 418          * @param $context ResourceLoaderContext: Context in which a response should be formed
 419          */
 420         public function respond( ResourceLoaderContext $context ) {
 421                 global $wgCacheEpoch, $wgUseFileCache;
 422
 423                 // Use file cache if enabled and available...
 424                 if ( $wgUseFileCache ) {
 425                         $fileCache = ResourceFileCache::newFromContext( $context );
 426                         if ( $this->tryRespondFromFileCache( $fileCache, $context ) ) {
 427                                 return; // output handled
 428                         }
 429                 }
 430
 431                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 432                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 433                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 434                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 435                 // the whole thing in our own output buffer to be sure the active buffer
 436                 // doesn't use ob_gzhandler.
 437                 // See http://bugs.php.net/bug.php?id=36514
 438                 ob_start();
 439
 440                 wfProfileIn( __METHOD__ );
 441                 $errors = '';
 442                 $this->hasErrors = false;
 443
 444                 // Split requested modules into two groups, modules and missing
 445                 $modules = array();
 446                 $missing = array();
 447                 foreach ( $context->getModules() as $name ) {
 448                         if ( isset( $this->moduleInfos[$name] ) ) {
 449                                 $module = $this->getModule( $name );
 450                                 // Do not allow private modules to be loaded from the web.
 451                                 // This is a security issue, see bug 34907.
 452                                 if ( $module->getGroup() === 'private' ) {
 453                                         $errors .= $this->makeComment( "Cannot show private module \"$name\"" );
 454                                         $this->hasErrors = true;
 455                                         continue;
 456                                 }
 457                                 $modules[$name] = $module;
 458                         } else {
 459                                 $missing[] = $name;
 460                         }
 461                 }
 462
 463                 // Preload information needed to the mtime calculation below
 464                 try {
 465                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 466                 } catch( Exception $e ) {
 467                         // Add exception to the output as a comment
 468                         $errors .= $this->makeComment( $e->__toString() );
 469                         $this->hasErrors = true;
 470                 }
 471
 472                 wfProfileIn( __METHOD__.'-getModifiedTime' );
 473
 474                 // To send Last-Modified and support If-Modified-Since, we need to detect
 475                 // the last modified time
 476                 $mtime = wfTimestamp( TS_UNIX, $wgCacheEpoch );
 477                 foreach ( $modules as $module ) {
 478                         /**
 479                          * @var $module ResourceLoaderModule
 480                          */
 481                         try {
 482                                 // Calculate maximum modified time
 483                                 $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 484                         } catch ( Exception $e ) {
 485                                 // Add exception to the output as a comment
 486                                 $errors .= $this->makeComment( $e->__toString() );
 487                                 $this->hasErrors = true;
 488                         }
 489                 }
 490
 491                 wfProfileOut( __METHOD__.'-getModifiedTime' );
 492
 493                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 494                 if ( $this->tryRespondLastModified( $context, $mtime ) ) {
 495                         wfProfileOut( __METHOD__ );
 496                         return; // output handled (buffers cleared)
 497                 }
 498
 499                 // Generate a response
 500                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 501
 502                 // Prepend comments indicating exceptions
 503                 $response = $errors . $response;
 504
 505                 // Capture any PHP warnings from the output buffer and append them to the
 506                 // response in a comment if we're in debug mode.
 507                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 508                         $response = $this->makeComment( $warnings ) . $response;
 509                         $this->hasErrors = true;
 510                 }
 511
 512                 // Save response to file cache unless there are errors
 513                 if ( isset( $fileCache ) && !$errors && !$missing ) {
 514                         // Cache single modules...and other requests if there are enough hits
 515                         if ( ResourceFileCache::useFileCache( $context ) ) {
 516                                 if ( $fileCache->isCacheWorthy() ) {
 517                                         $fileCache->saveText( $response );
 518                                 } else {
 519                                         $fileCache->incrMissesRecent( $context->getRequest() );
 520                                 }
 521                         }
 522                 }
 523
 524                 // Send content type and cache related headers
 525                 $this->sendResponseHeaders( $context, $mtime, $this->hasErrors );
 526
 527                 // Remove the output buffer and output the response
 528                 ob_end_clean();
 529                 echo $response;
 530
 531                 wfProfileOut( __METHOD__ );
 532         }
 533
 534         /**
 535          * Send content type and last modified headers to the client.
 536          * @param $context ResourceLoaderContext
 537          * @param string $mtime TS_MW timestamp to use for last-modified
 538          * @param bool $error Whether there are commented-out errors in the response
 539          * @return void
 540          */
 541         protected function sendResponseHeaders( ResourceLoaderContext $context, $mtime, $errors ) {
 542                 global $wgResourceLoaderMaxage;
 543                 // If a version wasn't specified we need a shorter expiry time for updates
 544                 // to propagate to clients quickly
 545                 // If there were errors, we also need a shorter expiry time so we can recover quickly
 546                 if ( is_null( $context->getVersion() ) || $errors ) {
 547                         $maxage = $wgResourceLoaderMaxage['unversioned']['client'];
 548                         $smaxage = $wgResourceLoaderMaxage['unversioned']['server'];
 549                 // If a version was specified we can use a longer expiry time since changing
 550                 // version numbers causes cache misses
 551                 } else {
 552                         $maxage = $wgResourceLoaderMaxage['versioned']['client'];
 553                         $smaxage = $wgResourceLoaderMaxage['versioned']['server'];
 554                 }
 555                 if ( $context->getOnly() === 'styles' ) {
 556                         header( 'Content-Type: text/css; charset=utf-8' );
 557                 } else {
 558                         header( 'Content-Type: text/javascript; charset=utf-8' );
 559                 }
 560                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 561                 if ( $context->getDebug() ) {
 562                         // Do not cache debug responses
 563                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 564                         header( 'Pragma: no-cache' );
 565                 } else {
 566                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 567                         $exp = min( $maxage, $smaxage );
 568                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 569                 }
 570         }
 571
 572         /**
 573          * If there's an If-Modified-Since header, respond with a 304 appropriately
 574          * and clear out the output buffer. If the client cache is too old then do nothing.
 575          * @param $context ResourceLoaderContext
 576          * @param string $mtime The TS_MW timestamp to check the header against
 577          * @return bool True iff 304 header sent and output handled
 578          */
 579         protected function tryRespondLastModified( ResourceLoaderContext $context, $mtime ) {
 580                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 581                 // Some clients send "timestamp;length=123". Strip the part after the first ';'
 582                 // so we get a valid timestamp.
 583                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 584                 // Never send 304s in debug mode
 585                 if ( $ims !== false && !$context->getDebug() ) {
 586                         $imsTS = strtok( $ims, ';' );
 587                         if ( $mtime <= wfTimestamp( TS_UNIX, $imsTS ) ) {
 588                                 // There's another bug in ob_gzhandler (see also the comment at
 589                                 // the top of this function) that causes it to gzip even empty
 590                                 // responses, meaning it's impossible to produce a truly empty
 591                                 // response (because the gzip header is always there). This is
 592                                 // a problem because 304 responses have to be completely empty
 593                                 // per the HTTP spec, and Firefox behaves buggily when they're not.
 594                                 // See also http://bugs.php.net/bug.php?id=51579
 595                                 // To work around this, we tear down all output buffering before
 596                                 // sending the 304.
 597                                 // On some setups, ob_get_level() doesn't seem to go down to zero
 598                                 // no matter how often we call ob_get_clean(), so instead of doing
 599                                 // the more intuitive while ( ob_get_level() > 0 ) ob_get_clean();
 600                                 // we have to be safe here and avoid an infinite loop.
 601                                 for ( $i = 0, $len = ob_get_level(); $i < $len; $i++ ) {
 602                                         ob_end_clean();
 603                                 }
 604
 605                                 header( 'HTTP/1.0 304 Not Modified' );
 606                                 header( 'Status: 304 Not Modified' );
 607                                 return true;
 608                         }
 609                 }
 610                 return false;
 611         }
 612
 613         /**
 614          * Send out code for a response from file cache if possible
 615          *
 616          * @param $fileCache ResourceFileCache: Cache object for this request URL
 617          * @param $context ResourceLoaderContext: Context in which to generate a response
 618          * @return bool If this found a cache file and handled the response
 619          */
 620         protected function tryRespondFromFileCache(
 621                 ResourceFileCache $fileCache, ResourceLoaderContext $context
 622         ) {
 623                 global $wgResourceLoaderMaxage;
 624                 // Buffer output to catch warnings.
 625                 ob_start();
 626                 // Get the maximum age the cache can be
 627                 $maxage = is_null( $context->getVersion() )
 628                         ? $wgResourceLoaderMaxage['unversioned']['server']
 629                         : $wgResourceLoaderMaxage['versioned']['server'];
 630                 // Minimum timestamp the cache file must have
 631                 $good = $fileCache->isCacheGood( wfTimestamp( TS_MW, time() - $maxage ) );
 632                 if ( !$good ) {
 633                         try { // RL always hits the DB on file cache miss...
 634                                 wfGetDB( DB_SLAVE );
 635                         } catch( DBConnectionError $e ) { // ...check if we need to fallback to cache
 636                                 $good = $fileCache->isCacheGood(); // cache existence check
 637                         }
 638                 }
 639                 if ( $good ) {
 640                         $ts = $fileCache->cacheTimestamp();
 641                         // Send content type and cache headers
 642                         $this->sendResponseHeaders( $context, $ts, false );
 643                         // If there's an If-Modified-Since header, respond with a 304 appropriately
 644                         if ( $this->tryRespondLastModified( $context, $ts ) ) {
 645                                 return false; // output handled (buffers cleared)
 646                         }
 647                         $response = $fileCache->fetchText();
 648                         // Capture any PHP warnings from the output buffer and append them to the
 649                         // response in a comment if we're in debug mode.
 650                         if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 651                                 $response = "/*\n$warnings\n*/\n" . $response;
 652                         }
 653                         // Remove the output buffer and output the response
 654                         ob_end_clean();
 655                         echo $response . "\n/* Cached {$ts} */";
 656                         return true; // cache hit
 657                 }
 658                 // Clear buffer
 659                 ob_end_clean();
 660
 661                 return false; // cache miss
 662         }
 663
 664         protected function makeComment( $text ) {
 665                 $encText = str_replace( '*/', '* /', $text );
 666                 return "/*\n$encText\n*/\n";
 667         }
 668
 669         /**
 670          * Generates code for a response
 671          *
 672          * @param $context ResourceLoaderContext: Context in which to generate a response
 673          * @param array $modules List of module objects keyed by module name
 674          * @param array $missing List of unavailable modules (optional)
 675          * @return String: Response data
 676          */
 677         public function makeModuleResponse( ResourceLoaderContext $context,
 678                 array $modules, $missing = array()
 679         ) {
 680                 $out = '';
 681                 $exceptions = '';
 682                 if ( $modules === array() && $missing === array() ) {
 683                         return '/* No modules requested. Max made me put this here */';
 684                 }
 685
 686                 wfProfileIn( __METHOD__ );
 687                 // Pre-fetch blobs
 688                 if ( $context->shouldIncludeMessages() ) {
 689                         try {
 690                                 $blobs = MessageBlobStore::get( $this, $modules, $context->getLanguage() );
 691                         } catch ( Exception $e ) {
 692                                 // Add exception to the output as a comment
 693                                 $exceptions .= $this->makeComment( $e->__toString() );
 694                                 $this->hasErrors = true;
 695                         }
 696                 } else {
 697                         $blobs = array();
 698                 }
 699
 700                 // Generate output
 701                 $isRaw = false;
 702                 foreach ( $modules as $name => $module ) {
 703                         /**
 704                          * @var $module ResourceLoaderModule
 705                          */
 706
 707                         wfProfileIn( __METHOD__ . '-' . $name );
 708                         try {
 709                                 $scripts = '';
 710                                 if ( $context->shouldIncludeScripts() ) {
 711                                         // If we are in debug mode, we'll want to return an array of URLs if possible
 712                                         // However, we can't do this if the module doesn't support it
 713                                         // We also can't do this if there is an only= parameter, because we have to give
 714                                         // the module a way to return a load.php URL without causing an infinite loop
 715                                         if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
 716                                                 $scripts = $module->getScriptURLsForDebug( $context );
 717                                         } else {
 718                                                 $scripts = $module->getScript( $context );
 719                                                 if ( is_string( $scripts ) && strlen( $scripts ) && substr( $scripts, -1 ) !== ';' ) {
 720                                                         // bug 27054: Append semicolon to prevent weird bugs
 721                                                         // caused by files not terminating their statements right
 722                                                         $scripts .= ";\n";
 723                                                 }
 724                                         }
 725                                 }
 726                                 // Styles
 727                                 $styles = array();
 728                                 if ( $context->shouldIncludeStyles() ) {
 729                                         // Don't create empty stylesheets like array( '' => '' ) for modules
 730                                         // that don't *have* any stylesheets (bug 38024).
 731                                         $stylePairs = $module->getStyles( $context );
 732                                         if ( count ( $stylePairs ) ) {
 733                                                 // If we are in debug mode without &only= set, we'll want to return an array of URLs
 734                                                 // See comment near shouldIncludeScripts() for more details
 735                                                 if ( $context->getDebug() && !$context->getOnly() && $module->supportsURLLoading() ) {
 736                                                         $styles = array(
 737                                                                 'url' => $module->getStyleURLsForDebug( $context )
 738                                                         );
 739                                                 } else {
 740                                                         // Minify CSS before embedding in mw.loader.implement call
 741                                                         // (unless in debug mode)
 742                                                         if ( !$context->getDebug() ) {
 743                                                                 foreach ( $stylePairs as $media => $style ) {
 744                                                                         // Can be either a string or an array of strings.
 745                                                                         if ( is_array( $style ) ) {
 746                                                                                 $stylePairs[$media] = array();
 747                                                                                 foreach ( $style as $cssText ) {
 748                                                                                         if ( is_string( $cssText ) ) {
 749                                                                                                 $stylePairs[$media][] = $this->filter( 'minify-css', $cssText );
 750                                                                                         }
 751                                                                                 }
 752                                                                         } elseif ( is_string( $style ) ) {
 753                                                                                 $stylePairs[$media] = $this->filter( 'minify-css', $style );
 754                                                                         }
 755                                                                 }
 756                                                         }
 757                                                         // Wrap styles into @media groups as needed and flatten into a numerical array
 758                                                         $styles = array(
 759                                                                 'css' => self::makeCombinedStyles( $stylePairs )
 760                                                         );
 761                                                 }
 762                                         }
 763                                 }
 764
 765                                 // Messages
 766                                 $messagesBlob = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 767
 768                                 // Append output
 769                                 switch ( $context->getOnly() ) {
 770                                         case 'scripts':
 771                                                 if ( is_string( $scripts ) ) {
 772                                                         // Load scripts raw...
 773                                                         $out .= $scripts;
 774                                                 } elseif ( is_array( $scripts ) ) {
 775                                                         // ...except when $scripts is an array of URLs
 776                                                         $out .= self::makeLoaderImplementScript( $name, $scripts, array(), array() );
 777                                                 }
 778                                                 break;
 779                                         case 'styles':
 780                                                 // We no longer seperate into media, they are all combined now with
 781                                                 // custom media type groups into @media .. {} sections as part of the css string.
 782                                                 // Module returns either an empty array or a numerical array with css strings.
 783                                                 $out .= isset( $styles['css'] ) ? implode( '', $styles['css'] ) : '';
 784                                                 break;
 785                                         case 'messages':
 786                                                 $out .= self::makeMessageSetScript( new XmlJsCode( $messagesBlob ) );
 787                                                 break;
 788                                         default:
 789                                                 $out .= self::makeLoaderImplementScript(
 790                                                         $name,
 791                                                         $scripts,
 792                                                         $styles,
 793                                                         new XmlJsCode( $messagesBlob )
 794                                                 );
 795                                                 break;
 796                                 }
 797                         } catch ( Exception $e ) {
 798                                 // Add exception to the output as a comment
 799                                 $exceptions .= $this->makeComment( $e->__toString() );
 800                                 $this->hasErrors = true;
 801
 802                                 // Register module as missing
 803                                 $missing[] = $name;
 804                                 unset( $modules[$name] );
 805                         }
 806                         $isRaw |= $module->isRaw();
 807                         wfProfileOut( __METHOD__ . '-' . $name );
 808                 }
 809
 810                 // Update module states
 811                 if ( $context->shouldIncludeScripts() && !$context->getRaw() && !$isRaw ) {
 812                         // Set the state of modules loaded as only scripts to ready
 813                         if ( count( $modules ) && $context->getOnly() === 'scripts' ) {
 814                                 $out .= self::makeLoaderStateScript(
 815                                         array_fill_keys( array_keys( $modules ), 'ready' ) );
 816                         }
 817                         // Set the state of modules which were requested but unavailable as missing
 818                         if ( is_array( $missing ) && count( $missing ) ) {
 819                                 $out .= self::makeLoaderStateScript( array_fill_keys( $missing, 'missing' ) );
 820                         }
 821                 }
 822
 823                 if ( !$context->getDebug() ) {
 824                         if ( $context->getOnly() === 'styles' ) {
 825                                 $out = $this->filter( 'minify-css', $out );
 826                         } else {
 827                                 $out = $this->filter( 'minify-js', $out );
 828                         }
 829                 }
 830
 831                 wfProfileOut( __METHOD__ );
 832                 return $exceptions . $out;
 833         }
 834
 835         /* Static Methods */
 836
 837         /**
 838          * Returns JS code to call to mw.loader.implement for a module with
 839          * given properties.
 840          *
 841          * @param string $name Module name
 842          * @param $scripts Mixed: List of URLs to JavaScript files or String of JavaScript code
 843          * @param $styles Mixed: Array of CSS strings keyed by media type, or an array of lists of URLs to
 844          * CSS files keyed by media type
 845          * @param $messages Mixed: List of messages associated with this module. May either be an
 846          *     associative array mapping message key to value, or a JSON-encoded message blob containing
 847          *     the same data, wrapped in an XmlJsCode object.
 848          *
 849          * @throws MWException
 850          * @return string
 851          */
 852         public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
 853                 if ( is_string( $scripts ) ) {
 854                         $scripts = new XmlJsCode( "function () {\n{$scripts}\n}" );
 855                 } elseif ( !is_array( $scripts ) ) {
 856                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
 857                 }
 858                 return Xml::encodeJsCall(
 859                         'mw.loader.implement',
 860                         array(
 861                                 $name,
 862                                 $scripts,
 863                                 // Force objects. mw.loader.implement requires them to be javascript objects.
 864                                 // Although these variables are associative arrays, which become javascript
 865                                 // objects through json_encode. In many cases they will be empty arrays, and
 866                                 // PHP/json_encode() consider empty arrays to be numerical arrays and
 867                                 // output javascript "[]" instead of "{}". This fixes that.
 868                                 (object)$styles,
 869                                 (object)$messages
 870                         ),
 871                         ResourceLoader::inDebugMode()
 872                 );
 873         }
 874
 875         /**
 876          * Returns JS code which, when called, will register a given list of messages.
 877          *
 878          * @param $messages Mixed: Either an associative array mapping message key to value, or a
 879          *     JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
 880          *
 881          * @return string
 882          */
 883         public static function makeMessageSetScript( $messages ) {
 884                 return Xml::encodeJsCall( 'mw.messages.set', array( (object)$messages ) );
 885         }
 886
 887         /**
 888          * Combines an associative array mapping media type to CSS into a
 889          * single stylesheet with "@media" blocks.
 890          *
 891          * @param array $stylePairs Array keyed by media type containing (arrays of) CSS strings.
 892          *
 893          * @return Array
 894          */
 895         private static function makeCombinedStyles( array $stylePairs ) {
 896                 $out = array();
 897                 foreach ( $stylePairs as $media => $styles ) {
 898                         // ResourceLoaderFileModule::getStyle can return the styles
 899                         // as a string or an array of strings. This is to allow separation in
 900                         // the front-end.
 901                         $styles = (array)$styles;
 902                         foreach ( $styles as $style ) {
 903                                 $style = trim( $style );
 904                                 // Don't output an empty "@media print { }" block (bug 40498)
 905                                 if ( $style !== '' ) {
 906                                         // Transform the media type based on request params and config
 907                                         // The way that this relies on $wgRequest to propagate request params is slightly evil
 908                                         $media = OutputPage::transformCssMedia( $media );
 909
 910                                         if ( $media === '' || $media == 'all' ) {
 911                                                 $out[] = $style;
 912                                         } else if ( is_string( $media ) ) {
 913                                                 $out[] = "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "}";
 914                                         }
 915                                         // else: skip
 916                                 }
 917                         }
 918                 }
 919                 return $out;
 920         }
 921
 922         /**
 923          * Returns a JS call to mw.loader.state, which sets the state of a
 924          * module or modules to a given value. Has two calling conventions:
 925          *
 926          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
 927          *         Set the state of a single module called $name to $state
 928          *
 929          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
 930          *         Set the state of modules with the given names to the given states
 931          *
 932          * @param $name string
 933          * @param $state
 934          *
 935          * @return string
 936          */
 937         public static function makeLoaderStateScript( $name, $state = null ) {
 938                 if ( is_array( $name ) ) {
 939                         return Xml::encodeJsCall( 'mw.loader.state', array( $name ) );
 940                 } else {
 941                         return Xml::encodeJsCall( 'mw.loader.state', array( $name, $state ) );
 942                 }
 943         }
 944
 945         /**
 946          * Returns JS code which calls the script given by $script. The script will
 947          * be called with local variables name, version, dependencies and group,
 948          * which will have values corresponding to $name, $version, $dependencies
 949          * and $group as supplied.
 950          *
 951          * @param string $name Module name
 952          * @param $version Integer: Module version number as a timestamp
 953          * @param array $dependencies List of module names on which this module depends
 954          * @param string $group Group which the module is in.
 955          * @param string $source Source of the module, or 'local' if not foreign.
 956          * @param string $script JavaScript code
 957          *
 958          * @return string
 959          */
 960         public static function makeCustomLoaderScript( $name, $version, $dependencies, $group, $source, $script ) {
 961                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 962                 return Xml::encodeJsCall(
 963                         "( function ( name, version, dependencies, group, source ) {\n\t$script\n} )",
 964                         array( $name, $version, $dependencies, $group, $source ) );
 965         }
 966
 967         /**
 968          * Returns JS code which calls mw.loader.register with the given
 969          * parameters. Has three calling conventions:
 970          *
 971          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version, $dependencies, $group, $source ):
 972          *       Register a single module.
 973          *
 974          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
 975          *       Register modules with the given names.
 976          *
 977          *   - ResourceLoader::makeLoaderRegisterScript( array(
 978          *        array( $name1, $version1, $dependencies1, $group1, $source1 ),
 979          *        array( $name2, $version2, $dependencies1, $group2, $source2 ),
 980          *        ...
 981          *     ) ):
 982          *        Registers modules with the given names and parameters.
 983          *
 984          * @param string $name Module name
 985          * @param $version Integer: Module version number as a timestamp
 986          * @param array $dependencies List of module names on which this module depends
 987          * @param string $group group which the module is in.
 988          * @param string $source source of the module, or 'local' if not foreign
 989          *
 990          * @return string
 991          */
 992         public static function makeLoaderRegisterScript( $name, $version = null,
 993                 $dependencies = null, $group = null, $source = null
 994         ) {
 995                 if ( is_array( $name ) ) {
 996                         return Xml::encodeJsCall( 'mw.loader.register', array( $name ) );
 997                 } else {
 998                         $version = (int)$version > 1 ? (int)$version : 1;
 999                         return Xml::encodeJsCall( 'mw.loader.register',
1000                                 array( $name, $version, $dependencies, $group, $source ) );
1001                 }
1002         }
1003
1004         /**
1005          * Returns JS code which calls mw.loader.addSource() with the given
1006          * parameters. Has two calling conventions:
1007          *
1008          *   - ResourceLoader::makeLoaderSourcesScript( $id, $properties ):
1009          *       Register a single source
1010          *
1011          *   - ResourceLoader::makeLoaderSourcesScript( array( $id1 => $props1, $id2 => $props2, ... ) );
1012          *       Register sources with the given IDs and properties.
1013          *
1014          * @param string $id source ID
1015          * @param array $properties source properties (see addSource())
1016          *
1017          * @return string
1018          */
1019         public static function makeLoaderSourcesScript( $id, $properties = null ) {
1020                 if ( is_array( $id ) ) {
1021                         return Xml::encodeJsCall( 'mw.loader.addSource', array( $id ) );
1022                 } else {
1023                         return Xml::encodeJsCall( 'mw.loader.addSource', array( $id, $properties ) );
1024                 }
1025         }
1026
1027         /**
1028          * Returns JS code which runs given JS code if the client-side framework is
1029          * present.
1030          *
1031          * @param string $script JavaScript code
1032          *
1033          * @return string
1034          */
1035         public static function makeLoaderConditionalScript( $script ) {
1036                 return "if(window.mw){\n" . trim( $script ) . "\n}";
1037         }
1038
1039         /**
1040          * Returns JS code which will set the MediaWiki configuration array to
1041          * the given value.
1042          *
1043          * @param array $configuration List of configuration values keyed by variable name
1044          *
1045          * @return string
1046          */
1047         public static function makeConfigSetScript( array $configuration ) {
1048                 return Xml::encodeJsCall( 'mw.config.set', array( $configuration ), ResourceLoader::inDebugMode() );
1049         }
1050
1051         /**
1052          * Convert an array of module names to a packed query string.
1053          *
1054          * For example, array( 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' )
1055          * becomes 'foo.bar,baz|bar.baz,quux'
1056          * @param array $modules of module names (strings)
1057          * @return string Packed query string
1058          */
1059         public static function makePackedModulesString( $modules ) {
1060                 $groups = array(); // array( prefix => array( suffixes ) )
1061                 foreach ( $modules as $module ) {
1062                         $pos = strrpos( $module, '.' );
1063                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
1064                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
1065                         $groups[$prefix][] = $suffix;
1066                 }
1067
1068                 $arr = array();
1069                 foreach ( $groups as $prefix => $suffixes ) {
1070                         $p = $prefix === '' ? '' : $prefix . '.';
1071                         $arr[] = $p . implode( ',', $suffixes );
1072                 }
1073                 $str = implode( '|', $arr );
1074                 return $str;
1075         }
1076
1077         /**
1078          * Determine whether debug mode was requested
1079          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
1080          * @return bool
1081          */
1082         public static function inDebugMode() {
1083                 global $wgRequest, $wgResourceLoaderDebug;
1084                 static $retval = null;
1085                 if ( !is_null( $retval ) ) {
1086                         return $retval;
1087                 }
1088                 return $retval = $wgRequest->getFuzzyBool( 'debug',
1089                         $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug ) );
1090         }
1091
1092         /**
1093          * Build a load.php URL
1094          * @param array $modules of module names (strings)
1095          * @param string $lang Language code
1096          * @param string $skin Skin name
1097          * @param string|null $user User name. If null, the &user= parameter is omitted
1098          * @param string|null $version Versioning timestamp
1099          * @param bool $debug Whether the request should be in debug mode
1100          * @param string|null $only &only= parameter
1101          * @param bool $printable Printable mode
1102          * @param bool $handheld Handheld mode
1103          * @param array $extraQuery Extra query parameters to add
1104          * @return string URL to load.php. May be protocol-relative (if $wgLoadScript is procol-relative)
1105          */
1106         public static function makeLoaderURL( $modules, $lang, $skin, $user = null, $version = null, $debug = false, $only = null,
1107                         $printable = false, $handheld = false, $extraQuery = array() ) {
1108                 global $wgLoadScript;
1109                 $query = self::makeLoaderQuery( $modules, $lang, $skin, $user, $version, $debug,
1110                         $only, $printable, $handheld, $extraQuery
1111                 );
1112
1113                 // Prevent the IE6 extension check from being triggered (bug 28840)
1114                 // by appending a character that's invalid in Windows extensions ('*')
1115                 return wfExpandUrl( wfAppendQuery( $wgLoadScript, $query ) . '&*', PROTO_RELATIVE );
1116         }
1117
1118         /**
1119          * Build a query array (array representation of query string) for load.php. Helper
1120          * function for makeLoaderURL().
1121          * @return array
1122          */
1123         public static function makeLoaderQuery( $modules, $lang, $skin, $user = null, $version = null, $debug = false, $only = null,
1124                         $printable = false, $handheld = false, $extraQuery = array() ) {
1125                 $query = array(
1126                         'modules' => self::makePackedModulesString( $modules ),
1127                         'lang' => $lang,
1128                         'skin' => $skin,
1129                         'debug' => $debug ? 'true' : 'false',
1130                 );
1131                 if ( $user !== null ) {
1132                         $query['user'] = $user;
1133                 }
1134                 if ( $version !== null ) {
1135                         $query['version'] = $version;
1136                 }
1137                 if ( $only !== null ) {
1138                         $query['only'] = $only;
1139                 }
1140                 if ( $printable ) {
1141                         $query['printable'] = 1;
1142                 }
1143                 if ( $handheld ) {
1144                         $query['handheld'] = 1;
1145                 }
1146                 $query += $extraQuery;
1147
1148                 // Make queries uniform in order
1149                 ksort( $query );
1150                 return $query;
1151         }
1152
1153         /**
1154          * Check a module name for validity.
1155          *
1156          * Module names may not contain pipes (|), commas (,) or exclamation marks (!) and can be
1157          * at most 255 bytes.
1158          *
1159          * @param string $moduleName Module name to check
1160          * @return bool Whether $moduleName is a valid module name
1161          */
1162         public static function isValidModuleName( $moduleName ) {
1163                 return !preg_match( '/[|,!]/', $moduleName ) && strlen( $moduleName ) <= 255;
1164         }
1165 }