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 $modules = array();
  34
  35         /* Protected Methods */
  36
  37         /**
  38          * Loads information stored in the database about modules
  39          *
  40          * This is not inside the module code because it's so much more performant to request all of the information at once
  41          * than it is to have each module requests it's own information.
  42          *
  43          * @param $modules array list of module names to preload information for
  44          * @param $context ResourceLoaderContext context to load the information within
  45          */
  46         protected function preloadModuleInfo( array $modules, ResourceLoaderContext $context ) {
  47                 if ( !count( $modules ) ) {
  48                         return; # or Database*::select() will explode
  49                 }
  50                 $dbr = wfGetDb( DB_SLAVE );
  51                 $skin = $context->getSkin();
  52                 $lang = $context->getLanguage();
  53
  54                 // Get file dependency information
  55                 $res = $dbr->select( 'module_deps', array( 'md_module', 'md_deps' ), array(
  56                                 'md_module' => $modules,
  57                                 'md_skin' => $context->getSkin()
  58                         ), __METHOD__
  59                 );
  60
  61                 $modulesWithDeps = array();
  62                 foreach ( $res as $row ) {
  63                         $this->modules[$row->md_module]->setFileDependencies( $skin,
  64                                 FormatJson::decode( $row->md_deps, true )
  65                         );
  66                         $modulesWithDeps[] = $row->md_module;
  67                 }
  68                 // Register the absence of a dependencies row too
  69                 foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
  70                         $this->modules[$name]->setFileDependencies( $skin, array() );
  71                 }
  72
  73                 // Get message blob mtimes. Only do this for modules with messages
  74                 $modulesWithMessages = array();
  75                 $modulesWithoutMessages = array();
  76                 foreach ( $modules as $name ) {
  77                         if ( count( $this->modules[$name]->getMessages() ) ) {
  78                                 $modulesWithMessages[] = $name;
  79                         } else {
  80                                 $modulesWithoutMessages[] = $name;
  81                         }
  82                 }
  83                 if ( count( $modulesWithMessages ) ) {
  84                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
  85                                         'mr_resource' => $modulesWithMessages,
  86                                         'mr_lang' => $lang
  87                                 ), __METHOD__
  88                         );
  89                         foreach ( $res as $row ) {
  90                                 $this->modules[$row->mr_resource]->setMsgBlobMtime( $lang, $row->mr_timestamp );
  91                         }
  92                 }
  93                 foreach ( $modulesWithoutMessages as $name ) {
  94                         $this->modules[$name]->setMsgBlobMtime( $lang, 0 );
  95                 }
  96         }
  97
  98         /**
  99          * Runs text through a filter, caching the filtered result for future calls
 100          *
 101          * @param $filter String: name of filter to run
 102          * @param $data String: text to filter, such as JavaScript or CSS text
 103          * @param $file String: path to file being filtered, (optional: only required for CSS to resolve paths)
 104          * @return String: filtered data
 105          */
 106         protected function filter( $filter, $data ) {
 107                 global $wgMemc;
 108                 wfProfileIn( __METHOD__ );
 109
 110                 // For empty or whitespace-only things, don't do any processing
 111                 if ( trim( $data ) === '' ) {
 112                         wfProfileOut( __METHOD__ );
 113                         return $data;
 114                 }
 115
 116                 // Try memcached
 117                 $key = wfMemcKey( 'resourceloader', 'filter', $filter, md5( $data ) );
 118                 $cached = $wgMemc->get( $key );
 119
 120                 if ( $cached !== false && $cached !== null ) {
 121                         wfProfileOut( __METHOD__ );
 122                         return $cached;
 123                 }
 124
 125                 // Run the filter
 126                 try {
 127                         switch ( $filter ) {
 128                                 case 'minify-js':
 129                                         $result = JSMin::minify( $data );
 130                                         break;
 131                                 case 'minify-css':
 132                                         $result = CSSMin::minify( $data );
 133                                         break;
 134                                 case 'flip-css':
 135                                         $result = CSSJanus::transform( $data, true, false );
 136                                         break;
 137                                 default:
 138                                         // Don't cache anything, just pass right through
 139                                         wfProfileOut( __METHOD__ );
 140                                         return $data;
 141                         }
 142                 } catch ( Exception $exception ) {
 143                         throw new MWException( 'Filter threw an exception: ' . $exception->getMessage() );
 144                 }
 145
 146                 // Save to memcached
 147                 $wgMemc->set( $key, $result );
 148
 149                 wfProfileOut( __METHOD__ );
 150                 return $result;
 151         }
 152
 153         /* Methods */
 154
 155         /**
 156          * Registers core modules and runs registration hooks
 157          */
 158         public function __construct() {
 159                 global $IP;
 160
 161                 wfProfileIn( __METHOD__ );
 162
 163                 // Register core modules
 164                 $this->register( include( "$IP/resources/Resources.php" ) );
 165                 // Register extension modules
 166                 wfRunHooks( 'ResourceLoaderRegisterModules', array( &$this ) );
 167
 168                 wfProfileOut( __METHOD__ );
 169         }
 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 function register( $name, ResourceLoaderModule $object = null ) {
 188                 wfProfileIn( __METHOD__ );
 189
 190                 // Allow multiple modules to be registered in one call
 191                 if ( is_array( $name ) && !isset( $object ) ) {
 192                         foreach ( $name as $key => $value ) {
 193                                 $this->register( $key, $value );
 194                         }
 195
 196                         wfProfileOut( __METHOD__ );
 197                         return;
 198                 }
 199
 200                 // Disallow duplicate registrations
 201                 if ( isset( $this->modules[$name] ) ) {
 202                         // A module has already been registered by this name
 203                         throw new MWException( 'Another module has already been registered as ' . $name );
 204                 }
 205
 206                 // Validate the input (type hinting lets null through)
 207                 if ( !( $object instanceof ResourceLoaderModule ) ) {
 208                         throw new MWException( 'Invalid ResourceLoader module error. Instances of ResourceLoaderModule expected.' );
 209                 }
 210
 211                 // Attach module
 212                 $this->modules[$name] = $object;
 213                 $object->setName( $name );
 214
 215                 wfProfileOut( __METHOD__ );
 216         }
 217
 218         /**
 219          * Gets a map of all modules and their options
 220          *
 221          * @return Array: array( modulename => ResourceLoaderModule )
 222          */
 223         public function getModules() {
 224                 return $this->modules;
 225         }
 226
 227         /**
 228          * Get the ResourceLoaderModule object for a given module name
 229          *
 230          * @param $name String: module name
 231          * @return mixed ResourceLoaderModule or null if not registered
 232          */
 233         public function getModule( $name ) {
 234                 return isset( $this->modules[$name] ) ? $this->modules[$name] : null;
 235         }
 236
 237         /**
 238          * Outputs a response to a resource load-request, including a content-type header
 239          *
 240          * @param $context ResourceLoaderContext object
 241          */
 242         public function respond( ResourceLoaderContext $context ) {
 243                 global $wgResourceLoaderMaxage, $wgCacheEpoch;
 244
 245                 wfProfileIn( __METHOD__ );
 246
 247                 // Split requested modules into two groups, modules and missing
 248                 $modules = array();
 249                 $missing = array();
 250
 251                 foreach ( $context->getModules() as $name ) {
 252                         if ( isset( $this->modules[$name] ) ) {
 253                                 $modules[$name] = $this->modules[$name];
 254                         } else {
 255                                 $missing[] = $name;
 256                         }
 257                 }
 258
 259                 // If a version wasn't specified we need a shorter expiry time for updates to
 260                 // propagate to clients quickly
 261                 if ( is_null( $context->getVersion() ) ) {
 262                         $maxage = $wgResourceLoaderMaxage['unversioned']['client'];
 263                         $smaxage = $wgResourceLoaderMaxage['unversioned']['server'];
 264                 }
 265                 // If a version was specified we can use a longer expiry time since changing
 266                 // version numbers causes cache misses
 267                 else {
 268                         $maxage = $wgResourceLoaderMaxage['versioned']['client'];
 269                         $smaxage = $wgResourceLoaderMaxage['versioned']['server'];
 270                 }
 271
 272                 // Preload information needed to the mtime calculation below
 273                 $this->preloadModuleInfo( array_keys( $modules ), $context );
 274
 275                 // To send Last-Modified and support If-Modified-Since, we need to detect
 276                 // the last modified time
 277                 wfProfileIn( __METHOD__.'-getModifiedTime' );
 278                 $mtime = $wgCacheEpoch;
 279                 foreach ( $modules as $module ) {
 280                         // Bypass squid cache if the request includes any private modules
 281                         if ( $module->getGroup() === 'private' ) {
 282                                 $smaxage = 0;
 283                         }
 284                         // Calculate maximum modified time
 285                         $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 286                 }
 287                 wfProfileOut( __METHOD__.'-getModifiedTime' );
 288
 289                 header( 'Content-Type: ' . ( $context->getOnly() === 'styles' ? 'text/css' : 'text/javascript' ) );
 290                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 291                 header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 292                 header( 'Expires: ' . wfTimestamp( TS_RFC2822, min( $maxage, $smaxage ) + time() ) );
 293
 294                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 295                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 296                 if ( $ims !== false && $mtime <= wfTimestamp( TS_UNIX, $ims ) ) {
 297                         header( 'HTTP/1.0 304 Not Modified' );
 298                         header( 'Status: 304 Not Modified' );
 299                         wfProfileOut( __METHOD__ );
 300                         return;
 301                 }
 302
 303                 echo $this->makeModuleResponse( $context, $modules, $missing );
 304
 305                 wfProfileOut( __METHOD__ );
 306         }
 307
 308         public function makeModuleResponse( ResourceLoaderContext $context, array $modules, $missing = null ) {
 309                 // Pre-fetch blobs
 310                 $blobs = $context->shouldIncludeMessages() ?
 311                         MessageBlobStore::get( $this, $modules, $context->getLanguage() ) : array();
 312
 313                 // Generate output
 314                 $out = '';
 315                 foreach ( $modules as $name => $module ) {
 316                         wfProfileIn( __METHOD__ . '-' . $name );
 317
 318                         // Scripts
 319                         $scripts = '';
 320                         if ( $context->shouldIncludeScripts() ) {
 321                                 $scripts .= $module->getScript( $context ) . "\n";
 322                         }
 323
 324                         // Styles
 325                         $styles = array();
 326                         if (
 327                                 $context->shouldIncludeStyles() &&
 328                                 ( count( $styles = $module->getStyles( $context ) ) )
 329                         ) {
 330                                 // Flip CSS on a per-module basis
 331                                 if ( $this->modules[$name]->getFlip( $context ) ) {
 332                                         foreach ( $styles as $media => $style ) {
 333                                                 $styles[$media] = $this->filter( 'flip-css', $style );
 334                                         }
 335                                 }
 336                         }
 337
 338                         // Messages
 339                         $messages = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 340
 341                         // Append output
 342                         switch ( $context->getOnly() ) {
 343                                 case 'scripts':
 344                                         $out .= $scripts;
 345                                         break;
 346                                 case 'styles':
 347                                         $out .= self::makeCombinedStyles( $styles );
 348                                         break;
 349                                 case 'messages':
 350                                         $out .= self::makeMessageSetScript( $messages );
 351                                         break;
 352                                 default:
 353                                         // Minify CSS before embedding in mediaWiki.loader.implement call (unless in debug mode)
 354                                         if ( !$context->getDebug() ) {
 355                                                 foreach ( $styles as $media => $style ) {
 356                                                         $styles[$media] = $this->filter( 'minify-css', $style );
 357                                                 }
 358                                         }
 359                                         $out .= self::makeLoaderImplementScript( $name, $scripts, $styles, $messages );
 360                                         break;
 361                         }
 362
 363                         wfProfileOut( __METHOD__ . '-' . $name );
 364                 }
 365
 366                 // Update module states
 367                 if ( $context->shouldIncludeScripts() ) {
 368                         // Set the state of modules loaded as only scripts to ready
 369                         if ( count( $modules ) && $context->getOnly() === 'scripts' && !isset( $modules['startup'] ) ) {
 370                                 $out .= self::makeLoaderStateScript( array_fill_keys( array_keys( $modules ), 'ready' ) );
 371                         }
 372                         // Set the state of modules which were requested but unavailable as missing
 373                         if ( is_array( $missing ) && count( $missing ) ) {
 374                                 $out .= self::makeLoaderStateScript( array_fill_keys( $missing, 'missing' ) );
 375                         }
 376                 }
 377
 378                 if ( $context->getDebug() ) {
 379                         return $out;
 380                 } else {
 381                         if ( $context->getOnly() === 'styles' ) {
 382                                 return $this->filter( 'minify-css', $out );
 383                         } else {
 384                                 return $this->filter( 'minify-js', $out );
 385                         }
 386                 }
 387         }
 388
 389         /* Static Methods */
 390
 391         public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
 392                 if ( is_array( $scripts ) ) {
 393                         $scripts = implode( $scripts, "\n" );
 394                 }
 395                 if ( is_array( $styles ) ) {
 396                         $styles = count( $styles ) ? FormatJson::encode( $styles ) : 'null';
 397                 }
 398                 if ( is_array( $messages ) ) {
 399                         $messages = count( $messages ) ? FormatJson::encode( $messages ) : 'null';
 400                 }
 401                 return "mediaWiki.loader.implement( '$name', function() {{$scripts}},\n$styles,\n$messages );\n";
 402         }
 403
 404         public static function makeMessageSetScript( $messages ) {
 405                 if ( is_array( $messages ) ) {
 406                         $messages = count( $messages ) ? FormatJson::encode( $messages ) : 'null';
 407                 }
 408                 return "mediaWiki.msg.set( $messages );\n";
 409         }
 410
 411         public static function makeCombinedStyles( array $styles ) {
 412                 $out = '';
 413                 foreach ( $styles as $media => $style ) {
 414                         $out .= "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "\n}\n";
 415                 }
 416                 return $out;
 417         }
 418
 419         public static function makeLoaderStateScript( $name, $state = null ) {
 420                 if ( is_array( $name ) ) {
 421                         $statuses = FormatJson::encode( $name );
 422                         return "mediaWiki.loader.state( $statuses );\n";
 423                 } else {
 424                         $name = Xml::escapeJsString( $name );
 425                         $state = Xml::escapeJsString( $state );
 426                         return "mediaWiki.loader.state( '$name', '$state' );\n";
 427                 }
 428         }
 429
 430         public static function makeCustomLoaderScript( $name, $version, $dependencies, $group, $script ) {
 431                 $name = Xml::escapeJsString( $name );
 432                 $version = (int) $version > 1 ? (int) $version : 1;
 433                 if ( is_array( $dependencies ) ) {
 434                         $dependencies = FormatJson::encode( $dependencies );
 435                 } else if ( is_string( $dependencies ) ) {
 436                         $dependencies = "'" . Xml::escapeJsString( $dependencies ) . "'";
 437                 } else {
 438                         $dependencies = 'null';
 439                 }
 440                 if ( is_string( $group ) ) {
 441                         $group = "'" . Xml::escapeJsString( $group ) . "'";
 442                 } else {
 443                         $group = 'null';
 444                 }
 445                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 446                 return "( function( name, version, dependencies, group ) {\n\t$script\n} )" .
 447                         "( '$name', $version, $dependencies, $group );\n";
 448         }
 449
 450         public static function makeLoaderRegisterScript( $name, $version = null, $dependencies = null, $group = null ) {
 451                 if ( is_array( $name ) ) {
 452                         $registrations = FormatJson::encode( $name );
 453                         return "mediaWiki.loader.register( $registrations );\n";
 454                 } else {
 455                         $name = Xml::escapeJsString( $name );
 456                         $version = (int) $version > 1 ? (int) $version : 1;
 457                         if ( is_array( $dependencies ) ) {
 458                                 $dependencies = FormatJson::encode( $dependencies );
 459                         } else if ( is_string( $dependencies ) ) {
 460                                 $dependencies = "'" . Xml::escapeJsString( $dependencies ) . "'";
 461                         } else {
 462                                 $dependencies = 'null';
 463                         }
 464                         if ( is_string( $group ) ) {
 465                                 $group = "'" . Xml::escapeJsString( $group ) . "'";
 466                         } else {
 467                                 $group = 'null';
 468                         }
 469                         return "mediaWiki.loader.register( '$name', $version, $dependencies, $group );\n";
 470                 }
 471         }
 472
 473         public static function makeLoaderConditionalScript( $script ) {
 474                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 475                 return "if ( window.mediaWiki ) {\n\t$script\n}\n";
 476         }
 477
 478         public static function makeConfigSetScript( array $configuration ) {
 479                 $configuration = FormatJson::encode( $configuration );
 480                 return "mediaWiki.config.set( $configuration );\n";
 481         }
 482 }