includes/resourceloader/ResourceLoader.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  * @author Roan Kattouw
  20  * @author Trevor Parscal
  21  */
  22
  23 /**
  24  * Dynamic JavaScript and CSS resource loading system.
  25  *
  26  * Most of the documention is on the MediaWiki documentation wiki starting at:
  27  *    http://www.mediawiki.org/wiki/ResourceLoader
  28  */
  29 class ResourceLoader {
  30
  31         /* Protected Static Members */
  32
  33         /** Array: List of module name/ResourceLoaderModule object pairs */
  34         protected $modules = array();
  35         /** Associative array mapping module name to info associative array */
  36         protected $moduleInfos = array();
  37
  38         /* Protected Methods */
  39
  40         /**
  41          * Loads information stored in the database about modules.
  42          *
  43          * This method grabs modules dependencies from the database and updates modules
  44          * objects.
  45          *
  46          * This is not inside the module code because it is much faster to
  47          * request all of the information at once than it is to have each module
  48          * requests its own information. This sacrifice of modularity yields a substantial
  49          * performance improvement.
  50          *
  51          * @param $modules Array: List of module names to preload information for
  52          * @param $context ResourceLoaderContext: Context to load the information within
  53          */
  54         protected function preloadModuleInfo( array $modules, ResourceLoaderContext $context ) {
  55                 if ( !count( $modules ) ) {
  56                         return; // or else Database*::select() will explode, plus it's cheaper!
  57                 }
  58                 $dbr = wfGetDB( DB_SLAVE );
  59                 $skin = $context->getSkin();
  60                 $lang = $context->getLanguage();
  61
  62                 // Get file dependency information
  63                 $res = $dbr->select( 'module_deps', array( 'md_module', 'md_deps' ), array(
  64                                 'md_module' => $modules,
  65                                 'md_skin' => $context->getSkin()
  66                         ), __METHOD__
  67                 );
  68
  69                 // Set modules' dependecies
  70                 $modulesWithDeps = array();
  71                 foreach ( $res as $row ) {
  72                         $this->getModule( $row->md_module )->setFileDependencies( $skin,
  73                                 FormatJson::decode( $row->md_deps, true )
  74                         );
  75                         $modulesWithDeps[] = $row->md_module;
  76                 }
  77
  78                 // Register the absence of a dependency row too
  79                 foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
  80                         $this->getModule( $name )->setFileDependencies( $skin, array() );
  81                 }
  82
  83                 // Get message blob mtimes. Only do this for modules with messages
  84                 $modulesWithMessages = array();
  85                 $modulesWithoutMessages = array();
  86                 foreach ( $modules as $name ) {
  87                         if ( count( $this->getModule( $name )->getMessages() ) ) {
  88                                 $modulesWithMessages[] = $name;
  89                         } else {
  90                                 $modulesWithoutMessages[] = $name;
  91                         }
  92                 }
  93                 if ( count( $modulesWithMessages ) ) {
  94                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
  95                                         'mr_resource' => $modulesWithMessages,
  96                                         'mr_lang' => $lang
  97                                 ), __METHOD__
  98                         );
  99                         foreach ( $res as $row ) {
 100                                 $this->getModule( $row->mr_resource )->setMsgBlobMtime( $lang, $row->mr_timestamp );
 101                         }
 102                 }
 103                 foreach ( $modulesWithoutMessages as $name ) {
 104                         $this->getModule( $name )->setMsgBlobMtime( $lang, 0 );
 105                 }
 106         }
 107
 108         /**
 109          * Runs JavaScript or CSS data through a filter, caching the filtered result for future calls.
 110          *
 111          * Available filters are:
 112          *  - minify-js \see JSMin::minify
 113          *  - minify-css \see CSSMin::minify
 114          *  - flip-css \see CSSJanus::transform
 115          *
 116          * If $data is empty, only contains whitespace or the filter was unknown,
 117          * $data is returned unmodified.
 118          *
 119          * @param $filter String: Name of filter to run
 120          * @param $data String: Text to filter, such as JavaScript or CSS text
 121          * @return String: Filtered data
 122          */
 123         protected function filter( $filter, $data ) {
 124                 wfProfileIn( __METHOD__ );
 125
 126                 // For empty/whitespace-only data or for unknown filters, don't perform
 127                 // any caching or processing
 128                 if ( trim( $data ) === ''
 129                         || !in_array( $filter, array( 'minify-js', 'minify-css', 'flip-css' ) ) )
 130                 {
 131                         wfProfileOut( __METHOD__ );
 132                         return $data;
 133                 }
 134
 135                 // Try for cache hit
 136                 // Use CACHE_ANYTHING since filtering is very slow compared to DB queries
 137                 $key = wfMemcKey( 'resourceloader', 'filter', $filter, md5( $data ) );
 138                 $cache = wfGetCache( CACHE_ANYTHING );
 139                 $cacheEntry = $cache->get( $key );
 140                 if ( is_string( $cacheEntry ) ) {
 141                         wfProfileOut( __METHOD__ );
 142                         return $cacheEntry;
 143                 }
 144
 145                 // Run the filter - we've already verified one of these will work
 146                 try {
 147                         switch ( $filter ) {
 148                                 case 'minify-js':
 149                                         $result = JSMin::minify( $data );
 150                                         break;
 151                                 case 'minify-css':
 152                                         $result = CSSMin::minify( $data );
 153                                         break;
 154                                 case 'flip-css':
 155                                         $result = CSSJanus::transform( $data, true, false );
 156                                         break;
 157                         }
 158                 } catch ( Exception $exception ) {
 159                         throw new MWException( 'ResourceLoader filter error. ' .
 160                                 'Exception was thrown: ' . $exception->getMessage() );
 161                 }
 162
 163                 // Save filtered text to Memcached
 164                 $cache->set( $key, $result );
 165
 166                 wfProfileOut( __METHOD__ );
 167
 168                 return $result;
 169         }
 170
 171         /* Methods */
 172
 173         /**
 174          * Registers core modules and runs registration hooks.
 175          */
 176         public function __construct() {
 177                 global $IP, $wgResourceModules;
 178
 179                 wfProfileIn( __METHOD__ );
 180
 181                 // Register core modules
 182                 $this->register( include( "$IP/resources/Resources.php" ) );
 183                 // Register extension modules
 184                 wfRunHooks( 'ResourceLoaderRegisterModules', array( &$this ) );
 185                 $this->register( $wgResourceModules );
 186
 187                 wfProfileOut( __METHOD__ );
 188         }
 189
 190         /**
 191          * Registers a module with the ResourceLoader system.
 192          *
 193          * @param $name Mixed: Name of module as a string or List of name/object pairs as an array
 194          * @param $info Module info array. For backwards compatibility with 1.17alpha,
 195          *   this may also be a ResourceLoaderModule object. Optional when using
 196          *   multiple-registration calling style.
 197          * @throws MWException: If a duplicate module registration is attempted
 198          * @throws MWException: If something other than a ResourceLoaderModule is being registered
 199          * @return Boolean: False if there were any errors, in which case one or more modules were not
 200          *     registered
 201          */
 202         public function register( $name, $info = null ) {
 203                 wfProfileIn( __METHOD__ );
 204
 205                 // Allow multiple modules to be registered in one call
 206                 if ( is_array( $name ) ) {
 207                         foreach ( $name as $key => $value ) {
 208                                 $this->register( $key, $value );
 209                         }
 210                         return;
 211                 }
 212
 213                 // Disallow duplicate registrations
 214                 if ( isset( $this->moduleInfos[$name] ) ) {
 215                         // A module has already been registered by this name
 216                         throw new MWException(
 217                                 'ResourceLoader duplicate registration error. ' .
 218                                 'Another module has already been registered as ' . $name
 219                         );
 220                 }
 221
 222                 // Attach module
 223                 if ( is_object( $info ) ) {
 224                         // Old calling convention
 225                         // Validate the input
 226                         if ( !( $info instanceof ResourceLoaderModule ) ) {
 227                                 throw new MWException( 'ResourceLoader invalid module error. ' .
 228                                         'Instances of ResourceLoaderModule expected.' );
 229                         }
 230
 231                         $this->moduleInfos[$name] = array( 'object' => $info );
 232                         $this->modules[$name] = $info;
 233                 } else {
 234                         // New calling convention
 235                         $this->moduleInfos[$name] = $info;
 236                 }
 237
 238                 wfProfileOut( __METHOD__ );
 239         }
 240
 241         /**
 242          * Get a list of module names
 243          *
 244          * @return Array: List of module names
 245          */
 246         public function getModuleNames() {
 247                 return array_keys( $this->moduleInfos );
 248         }
 249
 250         /**
 251          * Get the ResourceLoaderModule object for a given module name.
 252          *
 253          * @param $name String: Module name
 254          * @return Mixed: ResourceLoaderModule if module has been registered, null otherwise
 255          */
 256         public function getModule( $name ) {
 257                 if ( !isset( $this->modules[$name] ) ) {
 258                         if ( !isset( $this->moduleInfos[$name] ) ) {
 259                                 // No such module
 260                                 return null;
 261                         }
 262                         // Construct the requested object
 263                         $info = $this->moduleInfos[$name];
 264                         if ( isset( $info['object'] ) ) {
 265                                 // Object given in info array
 266                                 $object = $info['object'];
 267                         } else {
 268                                 if ( !isset( $info['class'] ) ) {
 269                                         $class = 'ResourceLoaderFileModule';
 270                                 } else {
 271                                         $class = $info['class'];
 272                                 }
 273                                 $object = new $class( $info );
 274                         }
 275                         $object->setName( $name );
 276                         $this->modules[$name] = $object;
 277                 }
 278
 279                 return $this->modules[$name];
 280         }
 281
 282         /**
 283          * Outputs a response to a resource load-request, including a content-type header.
 284          *
 285          * @param $context ResourceLoaderContext: Context in which a response should be formed
 286          */
 287         public function respond( ResourceLoaderContext $context ) {
 288                 global $wgResourceLoaderMaxage, $wgCacheEpoch;
 289
 290                 wfProfileIn( __METHOD__ );
 291
 292                 // Split requested modules into two groups, modules and missing
 293                 $modules = array();
 294                 $missing = array();
 295                 foreach ( $context->getModules() as $name ) {
 296                         if ( isset( $this->moduleInfos[$name] ) ) {
 297                                 $modules[$name] = $this->getModule( $name );
 298                         } else {
 299                                 $missing[] = $name;
 300                         }
 301                 }
 302
 303                 // If a version wasn't specified we need a shorter expiry time for updates
 304                 // to propagate to clients quickly
 305                 if ( is_null( $context->getVersion() ) ) {
 306                         $maxage  = $wgResourceLoaderMaxage['unversioned']['client'];
 307                         $smaxage = $wgResourceLoaderMaxage['unversioned']['server'];
 308                 }
 309                 // If a version was specified we can use a longer expiry time since changing
 310                 // version numbers causes cache misses
 311                 else {
 312                         $maxage  = $wgResourceLoaderMaxage['versioned']['client'];
 313                         $smaxage = $wgResourceLoaderMaxage['versioned']['server'];
 314                 }
 315
 316                 // Preload information needed to the mtime calculation below
 317                 $this->preloadModuleInfo( array_keys( $modules ), $context );
 318
 319                 wfProfileIn( __METHOD__.'-getModifiedTime' );
 320
 321                 // To send Last-Modified and support If-Modified-Since, we need to detect
 322                 // the last modified time
 323                 $mtime = wfTimestamp( TS_UNIX, $wgCacheEpoch );
 324                 foreach ( $modules as $module ) {
 325                         // Bypass squid cache if the request includes any private modules
 326                         if ( $module->getGroup() === 'private' ) {
 327                                 $smaxage = 0;
 328                         }
 329                         // Calculate maximum modified time
 330                         $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 331                 }
 332
 333                 wfProfileOut( __METHOD__.'-getModifiedTime' );
 334
 335                 if ( $context->getOnly() === 'styles' ) {
 336                         header( 'Content-Type: text/css' );
 337                 } else {
 338                         header( 'Content-Type: text/javascript' );
 339                 }
 340                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 341                 if ( $context->getDebug() ) {
 342                         header( 'Cache-Control: must-revalidate' );
 343                 } else {
 344                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 345                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, min( $maxage, $smaxage ) + time() ) );
 346                 }
 347
 348                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 349                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 350                 if ( $ims !== false && $mtime <= wfTimestamp( TS_UNIX, $ims ) ) {
 351                         header( 'HTTP/1.0 304 Not Modified' );
 352                         header( 'Status: 304 Not Modified' );
 353                         wfProfileOut( __METHOD__ );
 354                         return;
 355                 }
 356
 357                 // Generate a response
 358                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 359
 360                 // Tack on PHP warnings as a comment in debug mode
 361                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 362                         $response .= "/*\n$warnings\n*/";
 363                 }
 364
 365                 // Clear any warnings from the buffer
 366                 ob_clean();
 367                 echo $response;
 368
 369                 wfProfileOut( __METHOD__ );
 370         }
 371
 372         /**
 373          * Generates code for a response
 374          *
 375          * @param $context ResourceLoaderContext: Context in which to generate a response
 376          * @param $modules Array: List of module objects keyed by module name
 377          * @param $missing Array: List of unavailable modules (optional)
 378          * @return String: Response data
 379          */
 380         public function makeModuleResponse( ResourceLoaderContext $context,
 381                 array $modules, $missing = array() )
 382         {
 383                 // Pre-fetch blobs
 384                 if ( $context->shouldIncludeMessages() ) {
 385                         $blobs = MessageBlobStore::get( $this, $modules, $context->getLanguage() );
 386                 } else {
 387                         $blobs = array();
 388                 }
 389
 390                 // Generate output
 391                 $out = '';
 392                 foreach ( $modules as $name => $module ) {
 393
 394                         wfProfileIn( __METHOD__ . '-' . $name );
 395
 396                         // Scripts
 397                         $scripts = '';
 398                         if ( $context->shouldIncludeScripts() ) {
 399                                 $scripts .= $module->getScript( $context ) . "\n";
 400                         }
 401
 402                         // Styles
 403                         $styles = array();
 404                         if ( $context->shouldIncludeStyles() ) {
 405                                 $styles = $module->getStyles( $context );
 406                                 // Flip CSS on a per-module basis
 407                                 if ( $styles && $module->getFlip( $context ) ) {
 408                                         foreach ( $styles as $media => $style ) {
 409                                                 $styles[$media] = $this->filter( 'flip-css', $style );
 410                                         }
 411                                 }
 412                         }
 413
 414                         // Messages
 415                         $messagesBlob = isset( $blobs[$name] ) ? $blobs[$name] : array();
 416
 417                         // Append output
 418                         switch ( $context->getOnly() ) {
 419                                 case 'scripts':
 420                                         $out .= $scripts;
 421                                         break;
 422                                 case 'styles':
 423                                         $out .= self::makeCombinedStyles( $styles );
 424                                         break;
 425                                 case 'messages':
 426                                         $out .= self::makeMessageSetScript( new XmlJsCode( $messagesBlob ) );
 427                                         break;
 428                                 default:
 429                                         // Minify CSS before embedding in mediaWiki.loader.implement call
 430                                         // (unless in debug mode)
 431                                         if ( !$context->getDebug() ) {
 432                                                 foreach ( $styles as $media => $style ) {
 433                                                         $styles[$media] = $this->filter( 'minify-css', $style );
 434                                                 }
 435                                         }
 436                                         $out .= self::makeLoaderImplementScript( $name, $scripts, $styles,
 437                                                 new XmlJsCode( $messagesBlob ) );
 438                                         break;
 439                         }
 440
 441                         wfProfileOut( __METHOD__ . '-' . $name );
 442                 }
 443
 444                 // Update module states
 445                 if ( $context->shouldIncludeScripts() ) {
 446                         // Set the state of modules loaded as only scripts to ready
 447                         if ( count( $modules ) && $context->getOnly() === 'scripts'
 448                                 && !isset( $modules['startup'] ) )
 449                         {
 450                                 $out .= self::makeLoaderStateScript(
 451                                         array_fill_keys( array_keys( $modules ), 'ready' ) );
 452                         }
 453                         // Set the state of modules which were requested but unavailable as missing
 454                         if ( is_array( $missing ) && count( $missing ) ) {
 455                                 $out .= self::makeLoaderStateScript( array_fill_keys( $missing, 'missing' ) );
 456                         }
 457                 }
 458
 459                 if ( $context->getDebug() ) {
 460                         return $out;
 461                 } else {
 462                         if ( $context->getOnly() === 'styles' ) {
 463                                 return $this->filter( 'minify-css', $out );
 464                         } else {
 465                                 return $this->filter( 'minify-js', $out );
 466                         }
 467                 }
 468         }
 469
 470         /* Static Methods */
 471
 472         /**
 473          * Returns JS code to call to mediaWiki.loader.implement for a module with
 474          * given properties.
 475          *
 476          * @param $name Module name
 477          * @param $scripts Array: List of JavaScript code snippets to be executed after the
 478          *     module is loaded
 479          * @param $styles Array: List of CSS strings keyed by media type
 480          * @param $messages Mixed: List of messages associated with this module. May either be an
 481          *     associative array mapping message key to value, or a JSON-encoded message blob containing
 482          *     the same data, wrapped in an XmlJsCode object.
 483          */
 484         public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
 485                 if ( is_array( $scripts ) ) {
 486                         $scripts = implode( $scripts, "\n" );
 487                 }
 488                 return Xml::encodeJsCall(
 489                         'mediaWiki.loader.implement',
 490                         array(
 491                                 $name,
 492                                 new XmlJsCode( "function() {{$scripts}}" ),
 493                                 (object)$styles,
 494                                 (object)$messages
 495                         ) );
 496         }
 497
 498         /**
 499          * Returns JS code which, when called, will register a given list of messages.
 500          *
 501          * @param $messages Mixed: Either an associative array mapping message key to value, or a
 502          *     JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
 503          */
 504         public static function makeMessageSetScript( $messages ) {
 505                 return Xml::encodeJsCall( 'mediaWiki.messages.set', array( (object)$messages ) );
 506         }
 507
 508         /**
 509          * Combines an associative array mapping media type to CSS into a
 510          * single stylesheet with @media blocks.
 511          *
 512          * @param $styles Array: List of CSS strings keyed by media type
 513          */
 514         public static function makeCombinedStyles( array $styles ) {
 515                 $out = '';
 516                 foreach ( $styles as $media => $style ) {
 517                         $out .= "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "\n}\n";
 518                 }
 519                 return $out;
 520         }
 521
 522         /**
 523          * Returns a JS call to mediaWiki.loader.state, which sets the state of a
 524          * module or modules to a given value. Has two calling conventions:
 525          *
 526          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
 527          *         Set the state of a single module called $name to $state
 528          *
 529          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
 530          *         Set the state of modules with the given names to the given states
 531          */
 532         public static function makeLoaderStateScript( $name, $state = null ) {
 533                 if ( is_array( $name ) ) {
 534                         return Xml::encodeJsCall( 'mediaWiki.loader.state', array( $name ) );
 535                 } else {
 536                         return Xml::encodeJsCall( 'mediaWiki.loader.state', array( $name, $state ) );
 537                 }
 538         }
 539
 540         /**
 541          * Returns JS code which calls the script given by $script. The script will
 542          * be called with local variables name, version, dependencies and group,
 543          * which will have values corresponding to $name, $version, $dependencies
 544          * and $group as supplied.
 545          *
 546          * @param $name String: Module name
 547          * @param $version Integer: Module version number as a timestamp
 548          * @param $dependencies Array: List of module names on which this module depends
 549          * @param $group String: Group which the module is in.
 550          * @param $script String: JavaScript code
 551          */
 552         public static function makeCustomLoaderScript( $name, $version, $dependencies, $group, $script ) {
 553                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 554                 return Xml::encodeJsCall(
 555                         "( function( name, version, dependencies, group ) {\n\t$script\n} )",
 556                         array( $name, $version, $dependencies, $group ) );
 557         }
 558
 559         /**
 560          * Returns JS code which calls mediaWiki.loader.register with the given
 561          * parameters. Has three calling conventions:
 562          *
 563          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version, $dependencies, $group ):
 564          *       Register a single module.
 565          *
 566          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
 567          *       Register modules with the given names.
 568          *
 569          *   - ResourceLoader::makeLoaderRegisterScript( array(
 570          *        array( $name1, $version1, $dependencies1, $group1 ),
 571          *        array( $name2, $version2, $dependencies1, $group2 ),
 572          *        ...
 573          *     ) ):
 574          *        Registers modules with the given names and parameters.
 575          *
 576          * @param $name String: Module name
 577          * @param $version Integer: Module version number as a timestamp
 578          * @param $dependencies Array: List of module names on which this module depends
 579          * @param $group String: group which the module is in.
 580          */
 581         public static function makeLoaderRegisterScript( $name, $version = null,
 582                 $dependencies = null, $group = null )
 583         {
 584                 if ( is_array( $name ) ) {
 585                         return Xml::encodeJsCall( 'mediaWiki.loader.register', array( $name ) );
 586                 } else {
 587                         $version = (int) $version > 1 ? (int) $version : 1;
 588                         return Xml::encodeJsCall( 'mediaWiki.loader.register',
 589                                 array( $name, $version, $dependencies, $group ) );
 590                 }
 591         }
 592
 593         /**
 594          * Returns JS code which runs given JS code if the client-side framework is
 595          * present.
 596          *
 597          * @param $script String: JavaScript code
 598          */
 599         public static function makeLoaderConditionalScript( $script ) {
 600                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 601                 return "if ( window.mediaWiki ) {\n\t$script\n}\n";
 602         }
 603
 604         /**
 605          * Returns JS code which will set the MediaWiki configuration array to
 606          * the given value.
 607          *
 608          * @param $configuration Array: List of configuration values keyed by variable name
 609          */
 610         public static function makeConfigSetScript( array $configuration ) {
 611                 return Xml::encodeJsCall( 'mediaWiki.config.set', array( $configuration ) );
 612         }
 613
 614         /**
 615          * Determine whether debug mode was requested
 616          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
 617          * @return bool
 618          */
 619         public static function inDebugMode() {
 620                 global $wgRequest, $wgResourceLoaderDebug;
 621                 static $retval = null;
 622                 if ( !is_null( $retval ) )
 623                         return $retval;
 624                 return $retval = $wgRequest->getFuzzyBool( 'debug',
 625                         $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug ) );
 626         }
 627 }