includes/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 class ResourceLoader {
  29
  30         /* Protected Static Members */
  31
  32         // @var array list of module name/ResourceLoaderModule object pairs
  33         protected static $modules = array();
  34         protected static $initialized = false;
  35
  36         /* Protected Static Methods */
  37
  38         /**
  39          * Registers core modules and runs registration hooks
  40          */
  41         protected static function initialize() {
  42                 global $IP;
  43
  44                 // Safety check - this should never be called more than once
  45                 if ( !self::$initialized ) {
  46                         wfProfileIn( __METHOD__ );
  47                         // This needs to be first, because hooks might call ResourceLoader
  48                         // public interfaces which will call this
  49                         self::$initialized = true;
  50                         self::register( include( "$IP/resources/Resources.php" ) );
  51                         wfRunHooks( 'ResourceLoaderRegisterModules' );
  52                         wfProfileOut( __METHOD__ );
  53                 }
  54         }
  55
  56         /*
  57          * Loads information stored in the database about modules
  58          *
  59          * This is not inside the module code because it's so much more performant to request all of the information at once
  60          * than it is to have each module requests it's own information.
  61          *
  62          * @param $modules array list of module names to preload information for
  63          * @param $context ResourceLoaderContext context to load the information within
  64          */
  65         protected static function preloadModuleInfo( array $modules, ResourceLoaderContext $context ) {
  66                 $dbr = wfGetDb( DB_SLAVE );
  67                 $skin = $context->getSkin();
  68                 $lang = $context->getLanguage();
  69
  70                 // Get file dependency information
  71                 $res = $dbr->select( 'module_deps', array( 'md_module', 'md_deps' ), array(
  72                                 'md_module' => $modules,
  73                                 'md_skin' => $context->getSkin()
  74                         ), __METHOD__
  75                 );
  76
  77                 $modulesWithDeps = array();
  78                 foreach ( $res as $row ) {
  79                         self::$modules[$row->md_module]->setFileDependencies( $skin,
  80                                 FormatJson::decode( $row->md_deps, true )
  81                         );
  82                         $modulesWithDeps[] = $row->md_module;
  83                 }
  84                 // Register the absence of a dependencies row too
  85                 foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
  86                         self::$modules[$name]->setFileDependencies( $skin, array() );
  87                 }
  88
  89                 // Get message blob mtimes. Only do this for modules with messages
  90                 $modulesWithMessages = array();
  91                 $modulesWithoutMessages = array();
  92                 foreach ( $modules as $name ) {
  93                         if ( count( self::$modules[$name]->getMessages() ) ) {
  94                                 $modulesWithMessages[] = $name;
  95                         } else {
  96                                 $modulesWithoutMessages[] = $name;
  97                         }
  98                 }
  99                 if ( count( $modulesWithMessages ) ) {
 100                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
 101                                         'mr_resource' => $modulesWithMessages,
 102                                         'mr_lang' => $lang
 103                                 ), __METHOD__
 104                         );
 105                         foreach ( $res as $row ) {
 106                                 self::$modules[$row->mr_resource]->setMsgBlobMtime( $lang, $row->mr_timestamp );
 107                         }
 108                 }
 109                 foreach ( $modulesWithoutMessages as $name ) {
 110                         self::$modules[$name]->setMsgBlobMtime( $lang, 0 );
 111                 }
 112         }
 113
 114         /**
 115          * Runs text through a filter, caching the filtered result for future calls
 116          *
 117          * @param $filter String: name of filter to run
 118          * @param $data String: text to filter, such as JavaScript or CSS text
 119          * @param $file String: path to file being filtered, (optional: only required for CSS to resolve paths)
 120          * @return String: filtered data
 121          */
 122         protected static function filter( $filter, $data ) {
 123                 global $wgMemc;
 124                 wfProfileIn( __METHOD__ );
 125
 126                 // For empty or whitespace-only things, don't do any processing
 127                 if ( trim( $data ) === '' ) {
 128                         wfProfileOut( __METHOD__ );
 129                         return $data;
 130                 }
 131
 132                 // Try memcached
 133                 $key = wfMemcKey( 'resourceloader', 'filter', $filter, md5( $data ) );
 134                 $cached = $wgMemc->get( $key );
 135
 136                 if ( $cached !== false && $cached !== null ) {
 137                         wfProfileOut( __METHOD__ );
 138                         return $cached;
 139                 }
 140
 141                 // Run the filter
 142                 try {
 143                         switch ( $filter ) {
 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 to memcached
 163                 $wgMemc->set( $key, $result );
 164
 165                 wfProfileOut( __METHOD__ );
 166                 return $result;
 167         }
 168
 169         /* Static Methods */
 170
 171         /**
 172          * Registers a module with the ResourceLoader system.
 173          *
 174          * Note that registering the same object under multiple names is not supported
 175          * and may silently fail in all kinds of interesting ways.
 176          *
 177          * @param $name Mixed: string of name of module or array of name/object pairs
 178          * @param $object ResourceLoaderModule: module object (optional when using
 179          *    multiple-registration calling style)
 180          * @return Boolean: false if there were any errors, in which case one or more
 181          *    modules were not registered
 182          *
 183          * @todo We need much more clever error reporting, not just in detailing what
 184          *    happened, but in bringing errors to the client in a way that they can
 185          *    easily see them if they want to, such as by using FireBug
 186          */
 187         public static function register( $name, ResourceLoaderModule $object = null ) {
 188                 wfProfileIn( __METHOD__ );
 189                 self::initialize();
 190
 191                 // Allow multiple modules to be registered in one call
 192                 if ( is_array( $name ) && !isset( $object ) ) {
 193                         foreach ( $name as $key => $value ) {
 194                                 self::register( $key, $value );
 195                         }
 196
 197                         wfProfileOut( __METHOD__ );
 198                         return;
 199                 }
 200
 201                 // Disallow duplicate registrations
 202                 if ( isset( self::$modules[$name] ) ) {
 203                         // A module has already been registered by this name
 204                         throw new MWException( 'Another module has already been registered as ' . $name );
 205                 }
 206                 // Attach module
 207                 self::$modules[$name] = $object;
 208                 $object->setName( $name );
 209                 wfProfileOut( __METHOD__ );
 210         }
 211
 212         /**
 213          * Gets a map of all modules and their options
 214          *
 215          * @return Array: array( modulename => ResourceLoaderModule )
 216          */
 217         public static function getModules() {
 218
 219                 self::initialize();
 220
 221                 return self::$modules;
 222         }
 223
 224         /**
 225          * Get the ResourceLoaderModule object for a given module name
 226          *
 227          * @param $name String: module name
 228          * @return mixed ResourceLoaderModule or null if not registered
 229          */
 230         public static function getModule( $name ) {
 231
 232                 self::initialize();
 233
 234                 return isset( self::$modules[$name] ) ? self::$modules[$name] : null;
 235         }
 236
 237         /**
 238          * Get the highest modification time of all modules, based on a given
 239          * combination of language code, skin name and debug mode flag.
 240          *
 241          * @param $context ResourceLoaderContext object
 242          * @return Integer: UNIX timestamp
 243          */
 244         public static function getHighestModifiedTime( ResourceLoaderContext $context ) {
 245
 246                 self::initialize();
 247
 248                 $time = 1; // wfTimestamp() treats 0 as 'now', so that's not a suitable choice
 249
 250                 foreach ( self::$modules as $module ) {
 251                         $time = max( $time, $module->getModifiedTime( $context ) );
 252                 }
 253
 254                 return $time;
 255         }
 256
 257         /**
 258          * Outputs a response to a resource load-request, including a content-type header
 259          *
 260          * @param $context ResourceLoaderContext object
 261          */
 262         public static function respond( ResourceLoaderContext $context ) {
 263                 global $wgResourceLoaderMaxage;
 264
 265                 wfProfileIn( __METHOD__ );
 266                 self::initialize();
 267
 268                 // Split requested modules into two groups, modules and missing
 269                 $modules = array();
 270                 $missing = array();
 271
 272                 foreach ( $context->getModules() as $name ) {
 273                         if ( isset( self::$modules[$name] ) ) {
 274                                 $modules[$name] = self::$modules[$name];
 275                         } else {
 276                                 $missing[] = $name;
 277                         }
 278                 }
 279
 280                 // If a version wasn't specified we need a shorter expiry time for updates to
 281                 // propagate to clients quickly
 282                 if ( is_null( $context->getVersion() ) ) {
 283                         $maxage = $wgResourceLoaderMaxage['unversioned']['client'];
 284                         $smaxage = $wgResourceLoaderMaxage['unversioned']['server'];
 285                 }
 286                 // If a version was specified we can use a longer expiry time since changing
 287                 // version numbers causes cache misses
 288                 else {
 289                         $maxage = $wgResourceLoaderMaxage['versioned']['client'];
 290                         $smaxage = $wgResourceLoaderMaxage['versioned']['server'];
 291                 }
 292
 293                 // Preload information needed to the mtime calculation below
 294                 self::preloadModuleInfo( array_keys( $modules ), $context );
 295
 296                 // To send Last-Modified and support If-Modified-Since, we need to detect
 297                 // the last modified time
 298                 wfProfileIn( __METHOD__.'-getModifiedTime' );
 299                 $mtime = 1;
 300                 foreach ( $modules as $module ) {
 301                         // Bypass squid cache if the request includes any private modules
 302                         if ( $module->getGroup() === 'private' ) {
 303                                 $smaxage = 0;
 304                         }
 305                         // Calculate maximum modified time
 306                         $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 307                 }
 308                 wfProfileOut( __METHOD__.'-getModifiedTime' );
 309
 310                 header( 'Content-Type: ' . ( $context->getOnly() === 'styles' ? 'text/css' : 'text/javascript' ) );
 311                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 312                 header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 313                 header( 'Expires: ' . wfTimestamp( TS_RFC2822, min( $maxage, $smaxage ) + time() ) );
 314
 315                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 316                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 317                 if ( $ims !== false && $mtime >= wfTimestamp( TS_UNIX, $ims ) ) {
 318                         header( 'HTTP/1.0 304 Not Modified' );
 319                         header( 'Status: 304 Not Modified' );
 320                         wfProfileOut( __METHOD__ );
 321                         return;
 322                 }
 323
 324                 echo self::makeModuleResponse( $context, $modules, $missing );
 325
 326                 wfProfileOut( __METHOD__ );
 327         }
 328
 329         public static function makeModuleResponse( ResourceLoaderContext $context, array $modules, $missing = null ) {
 330                 global $wgUser;
 331
 332                 // Pre-fetch blobs
 333                 $blobs = $context->shouldIncludeMessages() ?
 334                         MessageBlobStore::get( array_keys( $modules ), $context->getLanguage() ) : array();
 335
 336                 // Generate output
 337                 $out = '';
 338                 foreach ( $modules as $name => $module ) {
 339                         wfProfileIn( __METHOD__ . '-' . $name );
 340
 341                         // Scripts
 342                         $scripts = '';
 343                         if ( $context->shouldIncludeScripts() ) {
 344                                 $scripts .= $module->getScript( $context ) . "\n";
 345                         }
 346
 347                         // Styles
 348                         $styles = array();
 349                         if (
 350                                 $context->shouldIncludeStyles() &&
 351                                 ( count( $styles = $module->getStyles( $context ) ) )
 352                         ) {
 353                                 // Flip CSS on a per-module basis
 354                                 if ( self::$modules[$name]->getFlip( $context ) ) {
 355                                         foreach ( $styles as $media => $style ) {
 356                                                 $styles[$media] = self::filter( 'flip-css', $style );
 357                                         }
 358                                 }
 359                         }
 360
 361                         // Messages
 362                         $messages = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 363
 364                         // Append output
 365                         switch ( $context->getOnly() ) {
 366                                 case 'scripts':
 367                                         $out .= $scripts;
 368                                         break;
 369                                 case 'styles':
 370                                         $out .= self::makeCombinedStyles( $styles );
 371                                         break;
 372                                 case 'messages':
 373                                         $out .= self::makeMessageSetScript( $messages );
 374                                         break;
 375                                 default:
 376                                         // Minify CSS before embedding in mediaWiki.loader.implement call (unless in debug mode)
 377                                         if ( !$context->getDebug() ) {
 378                                                 foreach ( $styles as $media => $style ) {
 379                                                         $styles[$media] = self::filter( 'minify-css', $style );
 380                                                 }
 381                                         }
 382                                         $out .= self::makeLoaderImplementScript( $name, $scripts, $styles, $messages );
 383                                         break;
 384                         }
 385
 386                         wfProfileOut( __METHOD__ . '-' . $name );
 387                 }
 388
 389                 // Update module states
 390                 if ( $context->shouldIncludeScripts() ) {
 391                         // Set the state of modules loaded as only scripts to ready
 392                         if ( count( $modules ) && $context->getOnly() === 'scripts' && !isset( $modules['startup'] ) ) {
 393                                 $out .= self::makeLoaderStateScript( array_fill_keys( array_keys( $modules ), 'ready' ) );
 394                         }
 395                         // Set the state of modules which were requested but unavailable as missing
 396                         if ( is_array( $missing ) && count( $missing ) ) {
 397                                 $out .= self::makeLoaderStateScript( array_fill_keys( $missing, 'missing' ) );
 398                         }
 399                 }
 400
 401                 if ( $context->getDebug() ) {
 402                         return $out;
 403                 } else {
 404                         if ( $context->getOnly() === 'styles' ) {
 405                                 return self::filter( 'minify-css', $out );
 406                         } else {
 407                                 return self::filter( 'minify-js', $out );
 408                         }
 409                 }
 410         }
 411
 412         // Client code generation methods
 413
 414         public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
 415                 if ( is_array( $scripts ) ) {
 416                         $scripts = implode( $scripts, "\n" );
 417                 }
 418                 if ( is_array( $styles ) ) {
 419                         $styles = count( $styles ) ? FormatJson::encode( $styles ) : 'null';
 420                 }
 421                 if ( is_array( $messages ) ) {
 422                         $messages = count( $messages ) ? FormatJson::encode( $messages ) : 'null';
 423                 }
 424                 return "mediaWiki.loader.implement( '$name', function() {{$scripts}},\n$styles,\n$messages );\n";
 425         }
 426
 427         public static function makeMessageSetScript( $messages ) {
 428                 if ( is_array( $messages ) ) {
 429                         $messages = count( $messages ) ? FormatJson::encode( $messages ) : 'null';
 430                 }
 431                 return "mediaWiki.msg.set( $messages );\n";
 432         }
 433
 434         public static function makeCombinedStyles( array $styles ) {
 435                 $out = '';
 436                 foreach ( $styles as $media => $style ) {
 437                         $out .= "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "\n}\n";
 438                 }
 439                 return $out;
 440         }
 441
 442         public static function makeLoaderStateScript( $name, $state = null ) {
 443                 if ( is_array( $name ) ) {
 444                         $statuses = FormatJson::encode( $name );
 445                         return "mediaWiki.loader.state( $statuses );\n";
 446                 } else {
 447                         $name = Xml::escapeJsString( $name );
 448                         $name = Xml::escapeJsString( $state );
 449                         return "mediaWiki.loader.state( '$name', '$state' );\n";
 450                 }
 451         }
 452
 453         public static function makeCustomLoaderScript( $name, $version, $dependencies, $group, $script ) {
 454                 $name = Xml::escapeJsString( $name );
 455                 $version = (int) $version > 1 ? (int) $version : 1;
 456                 if ( is_array( $dependencies ) ) {
 457                         $dependencies = FormatJson::encode( $dependencies );
 458                 } else if ( is_string( $dependencies ) ) {
 459                         $dependencies = "'" . Xml::escapeJsString( $dependencies ) . "'";
 460                 } else {
 461                         $dependencies = 'null';
 462                 }
 463                 if ( is_string( $group ) ) {
 464                         $group = "'" . Xml::escapeJsString( $group ) . "'";
 465                 } else {
 466                         $group = 'null';
 467                 }
 468                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 469                 return "( function( name, version, dependencies ) {\n\t$script\n} )" .
 470                         "( '$name', $version, $dependencies, $group );\n";
 471         }
 472
 473         public static function makeLoaderRegisterScript( $name, $version = null, $dependencies = null, $group = null ) {
 474                 if ( is_array( $name ) ) {
 475                         $registrations = FormatJson::encode( $name );
 476                         return "mediaWiki.loader.register( $registrations );\n";
 477                 } else {
 478                         $name = Xml::escapeJsString( $name );
 479                         $version = (int) $version > 1 ? (int) $version : 1;
 480                         if ( is_array( $dependencies ) ) {
 481                                 $dependencies = FormatJson::encode( $dependencies );
 482                         } else if ( is_string( $dependencies ) ) {
 483                                 $dependencies = "'" . Xml::escapeJsString( $dependencies ) . "'";
 484                         } else {
 485                                 $dependencies = 'null';
 486                         }
 487                         if ( is_string( $group ) ) {
 488                                 $group = "'" . Xml::escapeJsString( $group ) . "'";
 489                         } else {
 490                                 $group = 'null';
 491                         }
 492                         return "mediaWiki.loader.register( '$name', $version, $dependencies, $group );\n";
 493                 }
 494         }
 495
 496         public static function makeLoaderConditionalScript( $script ) {
 497                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 498                 return "if ( window.mediaWiki ) {\n\t$script\n}\n";
 499         }
 500
 501         public static function makeConfigSetScript( array $configuration ) {
 502                 $configuration = FormatJson::encode( $configuration );
 503                 return "mediaWiki.config.set( $configuration );\n";
 504         }
 505 }