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         /** @var {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                 global $wgMemc;
 123
 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 Memcached hit
 136                 $key = wfMemcKey( 'resourceloader', 'filter', $filter, md5( $data ) );
 137                 $cacheEntry = $wgMemc->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                 $wgMemc->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: string of name of module or array of name/object pairs
 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
 195          *   registered
 196          * @return Boolean: false if there were any errors, in which case one or more
 197          *   modules were not registered
 198          */
 199         public function register( $name, ResourceLoaderModule $object = null ) {
 200
 201                 wfProfileIn( __METHOD__ );
 202
 203                 // Allow multiple modules to be registered in one call
 204                 if ( is_array( $name ) && !isset( $object ) ) {
 205                         foreach ( $name as $key => $value ) {
 206                                 $this->register( $key, $value );
 207                         }
 208
 209                         wfProfileOut( __METHOD__ );
 210
 211                         return;
 212                 }
 213
 214                 // Disallow duplicate registrations
 215                 if ( isset( $this->modules[$name] ) ) {
 216                         // A module has already been registered by this name
 217                         throw new MWException(
 218                                 'ResourceLoader duplicate registration error. ' .
 219                                 'Another module has already been registered as ' . $name
 220                         );
 221                 }
 222
 223                 // Validate the input (type hinting lets null through)
 224                 if ( !( $object instanceof ResourceLoaderModule ) ) {
 225                         throw new MWException( 'ResourceLoader invalid module error. ' .
 226                                 'Instances of ResourceLoaderModule expected.' );
 227                 }
 228
 229                 // Attach module
 230                 $this->modules[$name] = $object;
 231                 $object->setName( $name );
 232
 233                 wfProfileOut( __METHOD__ );
 234         }
 235
 236         /**
 237          * Gets a map of all modules and their options
 238          *
 239          * @return Array: array( modulename => ResourceLoaderModule )
 240          */
 241         public function getModules() {
 242                 return $this->modules;
 243         }
 244
 245         /**
 246          * Get the ResourceLoaderModule object for a given module name.
 247          *
 248          * @param $name String: module name
 249          * @return Mixed: ResourceLoaderModule if module has been registered, null otherwise
 250          */
 251         public function getModule( $name ) {
 252                 return isset( $this->modules[$name] ) ? $this->modules[$name] : null;
 253         }
 254
 255         /**
 256          * Outputs a response to a resource load-request, including a content-type header.
 257          *
 258          * @param $context ResourceLoaderContext: context in which a response should be formed
 259          */
 260         public function respond( ResourceLoaderContext $context ) {
 261                 global $wgResourceLoaderMaxage, $wgCacheEpoch;
 262
 263                 wfProfileIn( __METHOD__ );
 264
 265                 // Split requested modules into two groups, modules and missing
 266                 $modules = array();
 267                 $missing = array();
 268                 foreach ( $context->getModules() as $name ) {
 269                         if ( isset( $this->modules[$name] ) ) {
 270                                 $modules[$name] = $this->modules[$name];
 271                         } else {
 272                                 $missing[] = $name;
 273                         }
 274                 }
 275
 276                 // If a version wasn't specified we need a shorter expiry time for updates
 277                 // to propagate to clients quickly
 278                 if ( is_null( $context->getVersion() ) ) {
 279                         $maxage  = $wgResourceLoaderMaxage['unversioned']['client'];
 280                         $smaxage = $wgResourceLoaderMaxage['unversioned']['server'];
 281                 }
 282                 // If a version was specified we can use a longer expiry time since changing
 283                 // version numbers causes cache misses
 284                 else {
 285                         $maxage  = $wgResourceLoaderMaxage['versioned']['client'];
 286                         $smaxage = $wgResourceLoaderMaxage['versioned']['server'];
 287                 }
 288
 289                 // Preload information needed to the mtime calculation below
 290                 $this->preloadModuleInfo( array_keys( $modules ), $context );
 291
 292                 wfProfileIn( __METHOD__.'-getModifiedTime' );
 293
 294                 // To send Last-Modified and support If-Modified-Since, we need to detect
 295                 // the last modified time
 296                 $mtime = wfTimestamp( TS_UNIX, $wgCacheEpoch );
 297                 foreach ( $modules as $module ) {
 298                         // Bypass squid cache if the request includes any private modules
 299                         if ( $module->getGroup() === 'private' ) {
 300                                 $smaxage = 0;
 301                         }
 302                         // Calculate maximum modified time
 303                         $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 304                 }
 305
 306                 wfProfileOut( __METHOD__.'-getModifiedTime' );
 307
 308                 if ( $context->getOnly() === 'styles' ) {
 309                         header( 'Content-Type: text/css' );
 310                 } else {
 311                         header( 'Content-Type: text/javascript' );
 312                 }
 313                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 314                 if ( $context->getDebug() ) {
 315                         header( 'Cache-Control: must-revalidate' );
 316                 } else {
 317                         header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 318                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, min( $maxage, $smaxage ) + time() ) );
 319                 }
 320
 321                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 322                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 323                 if ( $ims !== false && $mtime <= wfTimestamp( TS_UNIX, $ims ) ) {
 324                         header( 'HTTP/1.0 304 Not Modified' );
 325                         header( 'Status: 304 Not Modified' );
 326                         wfProfileOut( __METHOD__ );
 327                         return;
 328                 }
 329
 330                 // Generate a response
 331                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 332
 333                 // Tack on PHP warnings as a comment in debug mode
 334                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 335                         $response .= "/*\n$warnings\n*/";
 336                 }
 337
 338                 // Clear any warnings from the buffer
 339                 ob_clean();
 340                 echo $response;
 341
 342                 wfProfileOut( __METHOD__ );
 343         }
 344
 345         /**
 346          * Generates code for a response
 347          *
 348          * @param $context ResourceLoaderContext: context in which to generate a response
 349          * @param $modules Array: list of module objects keyed by module name
 350          * @param $missing Array: list of unavailable modules (optional)
 351          * @return String: response data
 352          */
 353         public function makeModuleResponse( ResourceLoaderContext $context,
 354                 array $modules, $missing = array() )
 355         {
 356                 // Pre-fetch blobs
 357                 if ( $context->shouldIncludeMessages() ) {
 358                         $blobs = MessageBlobStore::get( $this, $modules, $context->getLanguage() );
 359                 } else {
 360                         $blobs = array();
 361                 }
 362
 363                 // Generate output
 364                 $out = '';
 365                 foreach ( $modules as $name => $module ) {
 366
 367                         wfProfileIn( __METHOD__ . '-' . $name );
 368
 369                         // Scripts
 370                         $scripts = '';
 371                         if ( $context->shouldIncludeScripts() ) {
 372                                 $scripts .= $module->getScript( $context ) . "\n";
 373                         }
 374
 375                         // Styles
 376                         $styles = array();
 377                         if ( $context->shouldIncludeStyles() ) {
 378                                 $styles = $module->getStyles( $context );
 379                                 // Flip CSS on a per-module basis
 380                                 if ( $styles && $this->modules[$name]->getFlip( $context ) ) {
 381                                         foreach ( $styles as $media => $style ) {
 382                                                 $styles[$media] = $this->filter( 'flip-css', $style );
 383                                         }
 384                                 }
 385                         }
 386
 387                         // Messages
 388                         $messages = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 389
 390                         // Append output
 391                         switch ( $context->getOnly() ) {
 392                                 case 'scripts':
 393                                         $out .= $scripts;
 394                                         break;
 395                                 case 'styles':
 396                                         $out .= self::makeCombinedStyles( $styles );
 397                                         break;
 398                                 case 'messages':
 399                                         $out .= self::makeMessageSetScript( $messages );
 400                                         break;
 401                                 default:
 402                                         // Minify CSS before embedding in mediaWiki.loader.implement call
 403                                         // (unless in debug mode)
 404                                         if ( !$context->getDebug() ) {
 405                                                 foreach ( $styles as $media => $style ) {
 406                                                         $styles[$media] = $this->filter( 'minify-css', $style );
 407                                                 }
 408                                         }
 409                                         $out .= self::makeLoaderImplementScript( $name, $scripts, $styles, $messages );
 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         public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
 445                 if ( is_array( $scripts ) ) {
 446                         $scripts = implode( $scripts, "\n" );
 447                 }
 448                 if ( is_array( $styles ) ) {
 449                         $styles = count( $styles ) ? FormatJson::encode( $styles ) : 'null';
 450                 }
 451                 if ( is_array( $messages ) ) {
 452                         $messages = count( $messages ) ? FormatJson::encode( $messages ) : 'null';
 453                 }
 454                 return "mediaWiki.loader.implement( '$name', function() {{$scripts}},\n$styles,\n$messages );\n";
 455         }
 456
 457         public static function makeMessageSetScript( $messages ) {
 458                 if ( is_array( $messages ) ) {
 459                         $messages = count( $messages ) ? FormatJson::encode( $messages ) : 'null';
 460                 }
 461                 return "mediaWiki.msg.set( $messages );\n";
 462         }
 463
 464         public static function makeCombinedStyles( array $styles ) {
 465                 $out = '';
 466                 foreach ( $styles as $media => $style ) {
 467                         $out .= "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "\n}\n";
 468                 }
 469                 return $out;
 470         }
 471
 472         public static function makeLoaderStateScript( $name, $state = null ) {
 473                 if ( is_array( $name ) ) {
 474                         $statuses = FormatJson::encode( $name );
 475                         return "mediaWiki.loader.state( $statuses );\n";
 476                 } else {
 477                         $name = Xml::escapeJsString( $name );
 478                         $state = Xml::escapeJsString( $state );
 479                         return "mediaWiki.loader.state( '$name', '$state' );\n";
 480                 }
 481         }
 482
 483         public static function makeCustomLoaderScript( $name, $version, $dependencies, $group, $script ) {
 484                 $name = Xml::escapeJsString( $name );
 485                 $version = (int) $version > 1 ? (int) $version : 1;
 486                 $dependencies = FormatJson::encode( $dependencies );
 487                 $group = FormatJson::encode( $group );
 488                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 489                 return "( function( name, version, dependencies, group ) {\n\t$script\n} )" .
 490                         "( '$name', $version, $dependencies, $group );\n";
 491         }
 492
 493         public static function makeLoaderRegisterScript( $name, $version = null,
 494                 $dependencies = null, $group = null )
 495         {
 496                 if ( is_array( $name ) ) {
 497                         $registrations = FormatJson::encode( $name );
 498                         return "mediaWiki.loader.register( $registrations );\n";
 499                 } else {
 500                         $name = Xml::escapeJsString( $name );
 501                         $version = (int) $version > 1 ? (int) $version : 1;
 502                         $dependencies = FormatJson::encode( $dependencies );
 503                         $group = FormatJson::encode( $group );
 504                         return "mediaWiki.loader.register( '$name', $version, $dependencies, $group );\n";
 505                 }
 506         }
 507
 508         public static function makeLoaderConditionalScript( $script ) {
 509                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 510                 return "if ( window.mediaWiki ) {\n\t$script\n}\n";
 511         }
 512
 513         public static function makeConfigSetScript( array $configuration ) {
 514                 $configuration = FormatJson::encode( $configuration );
 515                 return "mediaWiki.config.set( $configuration );\n";
 516         }
 517 }