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