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                 $dbr = wfGetDb( DB_SLAVE );
  48                 $skin = $context->getSkin();
  49                 $lang = $context->getLanguage();
  50
  51                 // Get file dependency information
  52                 $res = $dbr->select( 'module_deps', array( 'md_module', 'md_deps' ), array(
  53                                 'md_module' => $modules,
  54                                 'md_skin' => $context->getSkin()
  55                         ), __METHOD__
  56                 );
  57
  58                 $modulesWithDeps = array();
  59                 foreach ( $res as $row ) {
  60                         $this->modules[$row->md_module]->setFileDependencies( $skin,
  61                                 FormatJson::decode( $row->md_deps, true )
  62                         );
  63                         $modulesWithDeps[] = $row->md_module;
  64                 }
  65                 // Register the absence of a dependencies row too
  66                 foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
  67                         $this->modules[$name]->setFileDependencies( $skin, array() );
  68                 }
  69
  70                 // Get message blob mtimes. Only do this for modules with messages
  71                 $modulesWithMessages = array();
  72                 $modulesWithoutMessages = array();
  73                 foreach ( $modules as $name ) {
  74                         if ( count( $this->modules[$name]->getMessages() ) ) {
  75                                 $modulesWithMessages[] = $name;
  76                         } else {
  77                                 $modulesWithoutMessages[] = $name;
  78                         }
  79                 }
  80                 if ( count( $modulesWithMessages ) ) {
  81                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
  82                                         'mr_resource' => $modulesWithMessages,
  83                                         'mr_lang' => $lang
  84                                 ), __METHOD__
  85                         );
  86                         foreach ( $res as $row ) {
  87                                 $this->modules[$row->mr_resource]->setMsgBlobMtime( $lang, $row->mr_timestamp );
  88                         }
  89                 }
  90                 foreach ( $modulesWithoutMessages as $name ) {
  91                         $this->modules[$name]->setMsgBlobMtime( $lang, 0 );
  92                 }
  93         }
  94
  95         /**
  96          * Runs text through a filter, caching the filtered result for future calls
  97          *
  98          * @param $filter String: name of filter to run
  99          * @param $data String: text to filter, such as JavaScript or CSS text
 100          * @param $file String: path to file being filtered, (optional: only required for CSS to resolve paths)
 101          * @return String: filtered data
 102          */
 103         protected function filter( $filter, $data ) {
 104                 global $wgMemc;
 105                 wfProfileIn( __METHOD__ );
 106
 107                 // For empty or whitespace-only things, don't do any processing
 108                 if ( trim( $data ) === '' ) {
 109                         wfProfileOut( __METHOD__ );
 110                         return $data;
 111                 }
 112
 113                 // Try memcached
 114                 $key = wfMemcKey( 'resourceloader', 'filter', $filter, md5( $data ) );
 115                 $cached = $wgMemc->get( $key );
 116
 117                 if ( $cached !== false && $cached !== null ) {
 118                         wfProfileOut( __METHOD__ );
 119                         return $cached;
 120                 }
 121
 122                 // Run the filter
 123                 try {
 124                         switch ( $filter ) {
 125                                 case 'minify-js':
 126                                         $result = JSMin::minify( $data );
 127                                         break;
 128                                 case 'minify-css':
 129                                         $result = CSSMin::minify( $data );
 130                                         break;
 131                                 case 'flip-css':
 132                                         $result = CSSJanus::transform( $data, true, false );
 133                                         break;
 134                                 default:
 135                                         // Don't cache anything, just pass right through
 136                                         wfProfileOut( __METHOD__ );
 137                                         return $data;
 138                         }
 139                 } catch ( Exception $exception ) {
 140                         throw new MWException( 'Filter threw an exception: ' . $exception->getMessage() );
 141                 }
 142
 143                 // Save to memcached
 144                 $wgMemc->set( $key, $result );
 145
 146                 wfProfileOut( __METHOD__ );
 147                 return $result;
 148         }
 149
 150         /* Methods */
 151
 152         /**
 153          * Registers core modules and runs registration hooks
 154          */
 155         public function __construct() {
 156                 global $IP;
 157
 158                 wfProfileIn( __METHOD__ );
 159
 160                 // Register core modules
 161                 $this->register( include( "$IP/resources/Resources.php" ) );
 162                 // Register extension modules
 163                 wfRunHooks( 'ResourceLoaderRegisterModules', array( &$this ) );
 164
 165                 wfProfileOut( __METHOD__ );
 166         }
 167
 168         /**
 169          * Registers a module with the ResourceLoader system.
 170          *
 171          * Note that registering the same object under multiple names is not supported
 172          * and may silently fail in all kinds of interesting ways.
 173          *
 174          * @param $name Mixed: string of name of module or array of name/object pairs
 175          * @param $object ResourceLoaderModule: module object (optional when using
 176          *    multiple-registration calling style)
 177          * @return Boolean: false if there were any errors, in which case one or more
 178          *    modules were not registered
 179          *
 180          * @todo We need much more clever error reporting, not just in detailing what
 181          *    happened, but in bringing errors to the client in a way that they can
 182          *    easily see them if they want to, such as by using FireBug
 183          */
 184         public function register( $name, ResourceLoaderModule $object = null ) {
 185                 wfProfileIn( __METHOD__ );
 186
 187                 // Allow multiple modules to be registered in one call
 188                 if ( is_array( $name ) && !isset( $object ) ) {
 189                         foreach ( $name as $key => $value ) {
 190                                 $this->register( $key, $value );
 191                         }
 192
 193                         wfProfileOut( __METHOD__ );
 194                         return;
 195                 }
 196
 197                 // Disallow duplicate registrations
 198                 if ( isset( $this->modules[$name] ) ) {
 199                         // A module has already been registered by this name
 200                         throw new MWException( 'Another module has already been registered as ' . $name );
 201                 }
 202                 // Attach module
 203                 $this->modules[$name] = $object;
 204                 $object->setName( $name );
 205
 206                 wfProfileOut( __METHOD__ );
 207         }
 208
 209         /**
 210          * Gets a map of all modules and their options
 211          *
 212          * @return Array: array( modulename => ResourceLoaderModule )
 213          */
 214         public function getModules() {
 215                 return $this->modules;
 216         }
 217
 218         /**
 219          * Get the ResourceLoaderModule object for a given module name
 220          *
 221          * @param $name String: module name
 222          * @return mixed ResourceLoaderModule or null if not registered
 223          */
 224         public function getModule( $name ) {
 225                 return isset( $this->modules[$name] ) ? $this->modules[$name] : null;
 226         }
 227
 228         /**
 229          * Outputs a response to a resource load-request, including a content-type header
 230          *
 231          * @param $context ResourceLoaderContext object
 232          */
 233         public function respond( ResourceLoaderContext $context ) {
 234                 global $wgResourceLoaderMaxage;
 235
 236                 wfProfileIn( __METHOD__ );
 237
 238                 // Split requested modules into two groups, modules and missing
 239                 $modules = array();
 240                 $missing = array();
 241
 242                 foreach ( $context->getModules() as $name ) {
 243                         if ( isset( $this->modules[$name] ) ) {
 244                                 $modules[$name] = $this->modules[$name];
 245                         } else {
 246                                 $missing[] = $name;
 247                         }
 248                 }
 249
 250                 // If a version wasn't specified we need a shorter expiry time for updates to
 251                 // propagate to clients quickly
 252                 if ( is_null( $context->getVersion() ) ) {
 253                         $maxage = $wgResourceLoaderMaxage['unversioned']['client'];
 254                         $smaxage = $wgResourceLoaderMaxage['unversioned']['server'];
 255                 }
 256                 // If a version was specified we can use a longer expiry time since changing
 257                 // version numbers causes cache misses
 258                 else {
 259                         $maxage = $wgResourceLoaderMaxage['versioned']['client'];
 260                         $smaxage = $wgResourceLoaderMaxage['versioned']['server'];
 261                 }
 262
 263                 // Preload information needed to the mtime calculation below
 264                 $this->preloadModuleInfo( array_keys( $modules ), $context );
 265
 266                 // To send Last-Modified and support If-Modified-Since, we need to detect
 267                 // the last modified time
 268                 wfProfileIn( __METHOD__.'-getModifiedTime' );
 269                 $mtime = 1;
 270                 foreach ( $modules as $module ) {
 271                         // Bypass squid cache if the request includes any private modules
 272                         if ( $module->getGroup() === 'private' ) {
 273                                 $smaxage = 0;
 274                         }
 275                         // Calculate maximum modified time
 276                         $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 277                 }
 278                 wfProfileOut( __METHOD__.'-getModifiedTime' );
 279
 280                 header( 'Content-Type: ' . ( $context->getOnly() === 'styles' ? 'text/css' : 'text/javascript' ) );
 281                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 282                 header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 283                 header( 'Expires: ' . wfTimestamp( TS_RFC2822, min( $maxage, $smaxage ) + time() ) );
 284
 285                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 286                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 287                 if ( $ims !== false && $mtime >= wfTimestamp( TS_UNIX, $ims ) ) {
 288                         header( 'HTTP/1.0 304 Not Modified' );
 289                         header( 'Status: 304 Not Modified' );
 290                         wfProfileOut( __METHOD__ );
 291                         return;
 292                 }
 293
 294                 echo self::makeModuleResponse( $context, $modules, $missing );
 295
 296                 wfProfileOut( __METHOD__ );
 297         }
 298
 299         public function makeModuleResponse( ResourceLoaderContext $context, array $modules, $missing = null ) {
 300                 // Pre-fetch blobs
 301                 $blobs = $context->shouldIncludeMessages() ?
 302                         MessageBlobStore::get( $this, $modules, $context->getLanguage() ) : array();
 303
 304                 // Generate output
 305                 $out = '';
 306                 foreach ( $modules as $name => $module ) {
 307                         wfProfileIn( __METHOD__ . '-' . $name );
 308
 309                         // Scripts
 310                         $scripts = '';
 311                         if ( $context->shouldIncludeScripts() ) {
 312                                 $scripts .= $module->getScript( $context ) . "\n";
 313                         }
 314
 315                         // Styles
 316                         $styles = array();
 317                         if (
 318                                 $context->shouldIncludeStyles() &&
 319                                 ( count( $styles = $module->getStyles( $context ) ) )
 320                         ) {
 321                                 // Flip CSS on a per-module basis
 322                                 if ( $this->modules[$name]->getFlip( $context ) ) {
 323                                         foreach ( $styles as $media => $style ) {
 324                                                 $styles[$media] = $this->filter( 'flip-css', $style );
 325                                         }
 326                                 }
 327                         }
 328
 329                         // Messages
 330                         $messages = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 331
 332                         // Append output
 333                         switch ( $context->getOnly() ) {
 334                                 case 'scripts':
 335                                         $out .= $scripts;
 336                                         break;
 337                                 case 'styles':
 338                                         $out .= self::makeCombinedStyles( $styles );
 339                                         break;
 340                                 case 'messages':
 341                                         $out .= self::makeMessageSetScript( $messages );
 342                                         break;
 343                                 default:
 344                                         // Minify CSS before embedding in mediaWiki.loader.implement call (unless in debug mode)
 345                                         if ( !$context->getDebug() ) {
 346                                                 foreach ( $styles as $media => $style ) {
 347                                                         $styles[$media] = $this->filter( 'minify-css', $style );
 348                                                 }
 349                                         }
 350                                         $out .= self::makeLoaderImplementScript( $name, $scripts, $styles, $messages );
 351                                         break;
 352                         }
 353
 354                         wfProfileOut( __METHOD__ . '-' . $name );
 355                 }
 356
 357                 // Update module states
 358                 if ( $context->shouldIncludeScripts() ) {
 359                         // Set the state of modules loaded as only scripts to ready
 360                         if ( count( $modules ) && $context->getOnly() === 'scripts' && !isset( $modules['startup'] ) ) {
 361                                 $out .= self::makeLoaderStateScript( array_fill_keys( array_keys( $modules ), 'ready' ) );
 362                         }
 363                         // Set the state of modules which were requested but unavailable as missing
 364                         if ( is_array( $missing ) && count( $missing ) ) {
 365                                 $out .= self::makeLoaderStateScript( array_fill_keys( $missing, 'missing' ) );
 366                         }
 367                 }
 368
 369                 if ( $context->getDebug() ) {
 370                         return $out;
 371                 } else {
 372                         if ( $context->getOnly() === 'styles' ) {
 373                                 return $this->filter( 'minify-css', $out );
 374                         } else {
 375                                 return $this->filter( 'minify-js', $out );
 376                         }
 377                 }
 378         }
 379
 380         /* Static Methods */
 381
 382         public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
 383                 if ( is_array( $scripts ) ) {
 384                         $scripts = implode( $scripts, "\n" );
 385                 }
 386                 if ( is_array( $styles ) ) {
 387                         $styles = count( $styles ) ? FormatJson::encode( $styles ) : 'null';
 388                 }
 389                 if ( is_array( $messages ) ) {
 390                         $messages = count( $messages ) ? FormatJson::encode( $messages ) : 'null';
 391                 }
 392                 return "mediaWiki.loader.implement( '$name', function() {{$scripts}},\n$styles,\n$messages );\n";
 393         }
 394
 395         public static function makeMessageSetScript( $messages ) {
 396                 if ( is_array( $messages ) ) {
 397                         $messages = count( $messages ) ? FormatJson::encode( $messages ) : 'null';
 398                 }
 399                 return "mediaWiki.msg.set( $messages );\n";
 400         }
 401
 402         public static function makeCombinedStyles( array $styles ) {
 403                 $out = '';
 404                 foreach ( $styles as $media => $style ) {
 405                         $out .= "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "\n}\n";
 406                 }
 407                 return $out;
 408         }
 409
 410         public static function makeLoaderStateScript( $name, $state = null ) {
 411                 if ( is_array( $name ) ) {
 412                         $statuses = FormatJson::encode( $name );
 413                         return "mediaWiki.loader.state( $statuses );\n";
 414                 } else {
 415                         $name = Xml::escapeJsString( $name );
 416                         $name = Xml::escapeJsString( $state );
 417                         return "mediaWiki.loader.state( '$name', '$state' );\n";
 418                 }
 419         }
 420
 421         public static function makeCustomLoaderScript( $name, $version, $dependencies, $group, $script ) {
 422                 $name = Xml::escapeJsString( $name );
 423                 $version = (int) $version > 1 ? (int) $version : 1;
 424                 if ( is_array( $dependencies ) ) {
 425                         $dependencies = FormatJson::encode( $dependencies );
 426                 } else if ( is_string( $dependencies ) ) {
 427                         $dependencies = "'" . Xml::escapeJsString( $dependencies ) . "'";
 428                 } else {
 429                         $dependencies = 'null';
 430                 }
 431                 if ( is_string( $group ) ) {
 432                         $group = "'" . Xml::escapeJsString( $group ) . "'";
 433                 } else {
 434                         $group = 'null';
 435                 }
 436                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 437                 return "( function( name, version, dependencies ) {\n\t$script\n} )" .
 438                         "( '$name', $version, $dependencies, $group );\n";
 439         }
 440
 441         public static function makeLoaderRegisterScript( $name, $version = null, $dependencies = null, $group = null ) {
 442                 if ( is_array( $name ) ) {
 443                         $registrations = FormatJson::encode( $name );
 444                         return "mediaWiki.loader.register( $registrations );\n";
 445                 } else {
 446                         $name = Xml::escapeJsString( $name );
 447                         $version = (int) $version > 1 ? (int) $version : 1;
 448                         if ( is_array( $dependencies ) ) {
 449                                 $dependencies = FormatJson::encode( $dependencies );
 450                         } else if ( is_string( $dependencies ) ) {
 451                                 $dependencies = "'" . Xml::escapeJsString( $dependencies ) . "'";
 452                         } else {
 453                                 $dependencies = 'null';
 454                         }
 455                         if ( is_string( $group ) ) {
 456                                 $group = "'" . Xml::escapeJsString( $group ) . "'";
 457                         } else {
 458                                 $group = 'null';
 459                         }
 460                         return "mediaWiki.loader.register( '$name', $version, $dependencies, $group );\n";
 461                 }
 462         }
 463
 464         public static function makeLoaderConditionalScript( $script ) {
 465                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 466                 return "if ( window.mediaWiki ) {\n\t$script\n}\n";
 467         }
 468
 469         public static function makeConfigSetScript( array $configuration ) {
 470                 $configuration = FormatJson::encode( $configuration );
 471                 return "mediaWiki.config.set( $configuration );\n";
 472         }
 473 }