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 defined( 'MEDIAWIKI' ) || die( 1 );
  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
  35         // @var array list of module name/ResourceLoaderModule object pairs
  36         protected $modules = array();
  37
  38         /* Protected Methods */
  39
  40         /**
  41          * Loads information stored in the database about modules
  42          *
  43          * This is not inside the module code because it's so much more performant to request all of the information at once
  44          * than it is to have each module requests it's own information.
  45          *
  46          * This method grab modules dependencies from the database and initialize modules object.
  47          * A first pass compute dependencies, a second one the blob mtime.
  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 Database*::select() will explode
  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                 // Register the absence of a dependency row too
  76                 foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
  77                         $this->modules[$name]->setFileDependencies( $skin, array() );
  78                 }
  79
  80                 // Get message blob mtimes. Only do this for modules with messages
  81                 $modulesWithMessages = array();
  82                 $modulesWithoutMessages = array();
  83                 foreach ( $modules as $name ) {
  84                         if ( count( $this->modules[$name]->getMessages() ) ) {
  85                                 $modulesWithMessages[] = $name;
  86                         } else {
  87                                 $modulesWithoutMessages[] = $name;
  88                         }
  89                 }
  90                 if ( count( $modulesWithMessages ) ) {
  91                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
  92                                         'mr_resource' => $modulesWithMessages,
  93                                         'mr_lang' => $lang
  94                                 ), __METHOD__
  95                         );
  96                         foreach ( $res as $row ) {
  97                                 $this->modules[$row->mr_resource]->setMsgBlobMtime( $lang, $row->mr_timestamp );
  98                         }
  99                 }
 100                 foreach ( $modulesWithoutMessages as $name ) {
 101                         $this->modules[$name]->setMsgBlobMtime( $lang, 0 );
 102                 }
 103         }
 104
 105         /**
 106          * Runs text (js,CSS) through a filter, caching the filtered result for future calls.
 107          *
 108          * Availables filters are:
 109          *  - minify-js \see JSMin::minify
 110          *  - minify-css \see CSSMin::minify
 111          *  - flip-css \see CSSJanus::transform
 112          * When the filter names does not exist, text is returned as is.
 113          *
 114          * @param $filter String: name of filter to run
 115          * @param $data String: text to filter, such as JavaScript or CSS text
 116          * @param $file String: path to file being filtered, (optional: only required for CSS to resolve paths)
 117          * @return String: filtered data
 118          */
 119         protected function filter( $filter, $data ) {
 120                 global $wgMemc;
 121                 wfProfileIn( __METHOD__ );
 122
 123                 // For empty or whitespace-only things, don't do any processing
 124                 # FIXME: we should return the data unfiltered if $filter is not supported.
 125                 # that would save up a md5 computation and one memcached get.
 126                 if ( trim( $data ) === '' ) {
 127                         wfProfileOut( __METHOD__ );
 128                         return $data;
 129                 }
 130
 131                 // Try memcached
 132                 $key = wfMemcKey( 'resourceloader', 'filter', $filter, md5( $data ) );
 133                 $cached = $wgMemc->get( $key );
 134
 135                 if ( $cached !== false && $cached !== null ) {
 136                         wfProfileOut( __METHOD__ );
 137                         return $cached;
 138                 }
 139
 140                 // Run the filter
 141                 try {
 142                         switch ( $filter ) {
 143                                 # note: if adding a new filter. Please update method documentation above.
 144                                 case 'minify-js':
 145                                         $result = JSMin::minify( $data );
 146                                         break;
 147                                 case 'minify-css':
 148                                         $result = CSSMin::minify( $data );
 149                                         break;
 150                                 case 'flip-css':
 151                                         $result = CSSJanus::transform( $data, true, false );
 152                                         break;
 153                                 default:
 154                                         // Don't cache anything, just pass right through
 155                                         wfProfileOut( __METHOD__ );
 156                                         return $data;
 157                         }
 158                 } catch ( Exception $exception ) {
 159                         throw new MWException( 'Filter threw an exception: ' . $exception->getMessage() );
 160                 }
 161
 162                 // Save filtered text to memcached
 163                 $wgMemc->set( $key, $result );
 164
 165                 wfProfileOut( __METHOD__ );
 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          * Note that registering the same object under multiple names is not supported
 191          * and may silently fail in all kinds of interesting ways.
 192          *
 193          * @param $name Mixed: string of name of module or array of name/object pairs
 194          * @param $object ResourceLoaderModule: module object (optional when using
 195          *    multiple-registration calling style)
 196          * @return Boolean: false if there were any errors, in which case one or more
 197          *    modules were not registered
 198          *
 199          * @todo We need much more clever error reporting, not just in detailing what
 200          *    happened, but in bringing errors to the client in a way that they can
 201          *    easily see them if they want to, such as by using FireBug
 202          */
 203         public function register( $name, ResourceLoaderModule $object = null ) {
 204                 wfProfileIn( __METHOD__ );
 205
 206                 // Allow multiple modules to be registered in one call
 207                 if ( is_array( $name ) && !isset( $object ) ) {
 208                         foreach ( $name as $key => $value ) {
 209                                 $this->register( $key, $value );
 210                         }
 211
 212                         wfProfileOut( __METHOD__ );
 213                         return;
 214                 }
 215
 216                 // Disallow duplicate registrations
 217                 if ( isset( $this->modules[$name] ) ) {
 218                         // A module has already been registered by this name
 219                         throw new MWException( 'Another module has already been registered as ' . $name );
 220                 }
 221
 222                 // Validate the input (type hinting lets null through)
 223                 if ( !( $object instanceof ResourceLoaderModule ) ) {
 224                         throw new MWException( 'Invalid ResourceLoader module error. Instances of ResourceLoaderModule expected.' );
 225                 }
 226
 227                 // Attach module
 228                 $this->modules[$name] = $object;
 229                 $object->setName( $name );
 230
 231                 wfProfileOut( __METHOD__ );
 232         }
 233
 234         /**
 235          * Gets a map of all modules and their options
 236          *
 237          * @return Array: array( modulename => ResourceLoaderModule )
 238          */
 239         public function getModules() {
 240                 return $this->modules;
 241         }
 242
 243         /**
 244          * Get the ResourceLoaderModule object for a given module name
 245          *
 246          * @param $name String: module name
 247          * @return mixed ResourceLoaderModule or null if not registered
 248          */
 249         public function getModule( $name ) {
 250                 return isset( $this->modules[$name] ) ? $this->modules[$name] : null;
 251         }
 252
 253         /**
 254          * Outputs a response to a resource load-request, including a content-type header
 255          *
 256          * @param $context ResourceLoaderContext object
 257          */
 258         public function respond( ResourceLoaderContext $context ) {
 259                 global $wgResourceLoaderMaxage, $wgCacheEpoch;
 260
 261                 wfProfileIn( __METHOD__ );
 262
 263                 // Split requested modules into two groups, modules and missing
 264                 $modules = array();
 265                 $missing = array();
 266
 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 to
 276                 // 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                 // To send Last-Modified and support If-Modified-Since, we need to detect
 292                 // the last modified time
 293                 wfProfileIn( __METHOD__.'-getModifiedTime' );
 294                 $mtime = wfTimestamp( TS_UNIX, $wgCacheEpoch );
 295                 foreach ( $modules as $module ) {
 296                         // Bypass squid cache if the request includes any private modules
 297                         if ( $module->getGroup() === 'private' ) {
 298                                 $smaxage = 0;
 299                         }
 300                         // Calculate maximum modified time
 301                         $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 302                 }
 303                 wfProfileOut( __METHOD__.'-getModifiedTime' );
 304
 305                 header( 'Content-Type: ' . ( $context->getOnly() === 'styles' ? 'text/css' : 'text/javascript' ) );
 306                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 307                 header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 308                 header( 'Expires: ' . wfTimestamp( TS_RFC2822, min( $maxage, $smaxage ) + time() ) );
 309
 310                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 311                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 312                 if ( $ims !== false && $mtime <= wfTimestamp( TS_UNIX, $ims ) ) {
 313                         header( 'HTTP/1.0 304 Not Modified' );
 314                         header( 'Status: 304 Not Modified' );
 315                         wfProfileOut( __METHOD__ );
 316                         return;
 317                 }
 318
 319                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 320                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 321                         $response .= "/*\n$warnings\n*/";
 322                 }
 323                 // Clear any warnings from the buffer
 324                 ob_clean();
 325                 echo $response;
 326
 327                 wfProfileOut( __METHOD__ );
 328         }
 329
 330         /**
 331          *
 332          * @param $context ResourceLoaderContext
 333          * @param $modules Array array( modulename => ResourceLoaderModule )
 334          * @param $missing Unavailables modules (Default null)
 335          */
 336         public function makeModuleResponse( ResourceLoaderContext $context, array $modules, $missing = null ) {
 337                 // Pre-fetch blobs
 338                 $blobs = $context->shouldIncludeMessages() ?
 339                         MessageBlobStore::get( $this, $modules, $context->getLanguage() ) : array();
 340
 341                 // Generate output
 342                 $out = '';
 343                 foreach ( $modules as $name => $module ) {
 344                         wfProfileIn( __METHOD__ . '-' . $name );
 345
 346                         // Scripts
 347                         $scripts = '';
 348                         if ( $context->shouldIncludeScripts() ) {
 349                                 $scripts .= $module->getScript( $context ) . "\n";
 350                         }
 351
 352                         // Styles
 353                         $styles = array();
 354                         if ( $context->shouldIncludeStyles() && ( count( $styles = $module->getStyles( $context ) ) ) ) {
 355                                 // Flip CSS on a per-module basis
 356                                 if ( $this->modules[$name]->getFlip( $context ) ) {
 357                                         foreach ( $styles as $media => $style ) {
 358                                                 $styles[$media] = $this->filter( 'flip-css', $style );
 359                                         }
 360                                 }
 361                         }
 362
 363                         // Messages
 364                         $messages = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 365
 366                         // Append output
 367                         switch ( $context->getOnly() ) {
 368                                 case 'scripts':
 369                                         $out .= $scripts;
 370                                         break;
 371                                 case 'styles':
 372                                         $out .= self::makeCombinedStyles( $styles );
 373                                         break;
 374                                 case 'messages':
 375                                         $out .= self::makeMessageSetScript( $messages );
 376                                         break;
 377                                 default:
 378                                         // Minify CSS before embedding in mediaWiki.loader.implement call (unless in debug mode)
 379                                         if ( !$context->getDebug() ) {
 380                                                 foreach ( $styles as $media => $style ) {
 381                                                         $styles[$media] = $this->filter( 'minify-css', $style );
 382                                                 }
 383                                         }
 384                                         $out .= self::makeLoaderImplementScript( $name, $scripts, $styles, $messages );
 385                                         break;
 386                         }
 387
 388                         wfProfileOut( __METHOD__ . '-' . $name );
 389                 }
 390
 391                 // Update module states
 392                 if ( $context->shouldIncludeScripts() ) {
 393                         // Set the state of modules loaded as only scripts to ready
 394                         if ( count( $modules ) && $context->getOnly() === 'scripts' && !isset( $modules['startup'] ) ) {
 395                                 $out .= self::makeLoaderStateScript( array_fill_keys( array_keys( $modules ), 'ready' ) );
 396                         }
 397                         // Set the state of modules which were requested but unavailable as missing
 398                         if ( is_array( $missing ) && count( $missing ) ) {
 399                                 $out .= self::makeLoaderStateScript( array_fill_keys( $missing, 'missing' ) );
 400                         }
 401                 }
 402
 403                 if ( $context->getDebug() ) {
 404                         return $out;
 405                 } else {
 406                         if ( $context->getOnly() === 'styles' ) {
 407                                 return $this->filter( 'minify-css', $out );
 408                         } else {
 409                                 return $this->filter( 'minify-js', $out );
 410                         }
 411                 }
 412         }
 413
 414         /* Static Methods */
 415
 416         public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
 417                 if ( is_array( $scripts ) ) {
 418                         $scripts = implode( $scripts, "\n" );
 419                 }
 420                 if ( is_array( $styles ) ) {
 421                         $styles = count( $styles ) ? FormatJson::encode( $styles ) : 'null';
 422                 }
 423                 if ( is_array( $messages ) ) {
 424                         $messages = count( $messages ) ? FormatJson::encode( $messages ) : 'null';
 425                 }
 426                 return "mediaWiki.loader.implement( '$name', function() {{$scripts}},\n$styles,\n$messages );\n";
 427         }
 428
 429         public static function makeMessageSetScript( $messages ) {
 430                 if ( is_array( $messages ) ) {
 431                         $messages = count( $messages ) ? FormatJson::encode( $messages ) : 'null';
 432                 }
 433                 return "mediaWiki.msg.set( $messages );\n";
 434         }
 435
 436         public static function makeCombinedStyles( array $styles ) {
 437                 $out = '';
 438                 foreach ( $styles as $media => $style ) {
 439                         $out .= "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "\n}\n";
 440                 }
 441                 return $out;
 442         }
 443
 444         public static function makeLoaderStateScript( $name, $state = null ) {
 445                 if ( is_array( $name ) ) {
 446                         $statuses = FormatJson::encode( $name );
 447                         return "mediaWiki.loader.state( $statuses );\n";
 448                 } else {
 449                         $name = Xml::escapeJsString( $name );
 450                         $state = Xml::escapeJsString( $state );
 451                         return "mediaWiki.loader.state( '$name', '$state' );\n";
 452                 }
 453         }
 454
 455         public static function makeCustomLoaderScript( $name, $version, $dependencies, $group, $script ) {
 456                 $name = Xml::escapeJsString( $name );
 457                 $version = (int) $version > 1 ? (int) $version : 1;
 458                 $dependencies = FormatJson::encode( $dependencies );
 459                 $group = FormatJson::encode( $group );
 460                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 461                 return "( function( name, version, dependencies, group ) {\n\t$script\n} )" .
 462                         "( '$name', $version, $dependencies, $group );\n";
 463         }
 464
 465         public static function makeLoaderRegisterScript( $name, $version = null, $dependencies = null, $group = null ) {
 466                 if ( is_array( $name ) ) {
 467                         $registrations = FormatJson::encode( $name );
 468                         return "mediaWiki.loader.register( $registrations );\n";
 469                 } else {
 470                         $name = Xml::escapeJsString( $name );
 471                         $version = (int) $version > 1 ? (int) $version : 1;
 472                         $dependencies = FormatJson::encode( $dependencies );
 473                         $group = FormatJson::encode( $group );
 474                         return "mediaWiki.loader.register( '$name', $version, $dependencies, $group );\n";
 475                 }
 476         }
 477
 478         public static function makeLoaderConditionalScript( $script ) {
 479                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 480                 return "if ( window.mediaWiki ) {\n\t$script\n}\n";
 481         }
 482
 483         public static function makeConfigSetScript( array $configuration ) {
 484                 $configuration = FormatJson::encode( $configuration );
 485                 return "mediaWiki.config.set( $configuration );\n";
 486         }
 487 }