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 /**
  24  * Dynamic JavaScript and CSS resource loading system
  25  */
  26 class ResourceLoader {
  27
  28         /* Protected Static Members */
  29
  30         // @var array list of module name/ResourceLoaderModule object pairs
  31         protected static $modules = array();
  32         protected static $initialized = false;
  33
  34         /* Protected Static Methods */
  35
  36         /*
  37          * Registers core modules and runs registration hooks
  38          */
  39         protected static function initialize() {
  40                 global $IP;
  41
  42                 // Safety check - this should never be called more than once
  43                 if ( !self::$initialized ) {
  44                         // This needs to be first, because hooks might call ResourceLoader public interfaces which will call this
  45                         self::$initialized = true;
  46                         self::register( include( "$IP/resources/Resources.php" ) );
  47                         wfRunHooks( 'ResourceLoaderRegisterModules' );
  48                 }
  49         }
  50
  51         /**
  52          * Runs text through a filter, caching the filtered result for future calls
  53          *
  54          * @param $filter String: name of filter to run
  55          * @param $data String: text to filter, such as JavaScript or CSS text
  56          * @param $file String: path to file being filtered, (optional: only required for CSS to resolve paths)
  57          * @return String: filtered data
  58          */
  59         protected static function filter( $filter, $data ) {
  60                 global $wgMemc;
  61
  62                 // For empty or whitespace-only things, don't do any processing
  63                 if ( trim( $data ) === '' ) {
  64                         return $data;
  65                 }
  66
  67                 // Try memcached
  68                 $key = wfMemcKey( 'resourceloader', 'filter', $filter, md5( $data ) );
  69                 $cached = $wgMemc->get( $key );
  70
  71                 if ( $cached !== false && $cached !== null ) {
  72                         return $cached;
  73                 }
  74
  75                 // Run the filter
  76                 try {
  77                         switch ( $filter ) {
  78                                 case 'minify-js':
  79                                         $result = JSMin::minify( $data );
  80                                         break;
  81                                 case 'minify-css':
  82                                         $result = CSSMin::minify( $data );
  83                                         break;
  84                                 case 'flip-css':
  85                                         $result = CSSJanus::transform( $data, true, false );
  86                                         break;
  87                                 default:
  88                                         // Don't cache anything, just pass right through
  89                                         return $data;
  90                         }
  91                 } catch ( Exception $exception ) {
  92                         throw new MWException( 'Filter threw an exception: ' . $exception->getMessage() );
  93                 }
  94
  95                 // Save to memcached
  96                 $wgMemc->set( $key, $result );
  97
  98                 return $result;
  99         }
 100
 101         /* Static Methods */
 102
 103         /**
 104          * Registers a module with the ResourceLoader system.
 105          *
 106          * Note that registering the same object under multiple names is not supported and may silently fail in all
 107          * kinds of interesting ways.
 108          *
 109          * @param $name Mixed: string of name of module or array of name/object pairs
 110          * @param $object ResourceLoaderModule: module object (optional when using multiple-registration calling style)
 111          * @return Boolean: false if there were any errors, in which case one or more modules were not registered
 112          *
 113          * @todo We need much more clever error reporting, not just in detailing what happened, but in bringing errors to
 114          * the client in a way that they can easily see them if they want to, such as by using FireBug
 115          */
 116         public static function register( $name, ResourceLoaderModule $object = null ) {
 117
 118                 self::initialize();
 119
 120                 // Allow multiple modules to be registered in one call
 121                 if ( is_array( $name ) && !isset( $object ) ) {
 122                         foreach ( $name as $key => $value ) {
 123                                 self::register( $key, $value );
 124                         }
 125
 126                         return;
 127                 }
 128
 129                 // Disallow duplicate registrations
 130                 if ( isset( self::$modules[$name] ) ) {
 131                         // A module has already been registered by this name
 132                         throw new MWException( 'Another module has already been registered as ' . $name );
 133                 }
 134                 // Attach module
 135                 self::$modules[$name] = $object;
 136                 $object->setName( $name );
 137         }
 138
 139         /**
 140          * Gets a map of all modules and their options
 141          *
 142          * @return Array: array( modulename => ResourceLoaderModule )
 143          */
 144         public static function getModules() {
 145
 146                 self::initialize();
 147
 148                 return self::$modules;
 149         }
 150
 151         /**
 152          * Get the ResourceLoaderModule object for a given module name
 153          *
 154          * @param $name String: module name
 155          * @return mixed ResourceLoaderModule or null if not registered
 156          */
 157         public static function getModule( $name ) {
 158
 159                 self::initialize();
 160
 161                 return isset( self::$modules[$name] ) ? self::$modules[$name] : null;
 162         }
 163
 164         /**
 165          * Gets registration code for all modules, except pre-registered ones listed in self::$preRegisteredModules
 166          *
 167          * @param $context ResourceLoaderContext object
 168          * @return String: JavaScript code for registering all modules with the client loader
 169          */
 170         public static function getModuleRegistrations( ResourceLoaderContext $context ) {
 171
 172                 self::initialize();
 173
 174                 $scripts = '';
 175                 $registrations = array();
 176
 177                 foreach ( self::$modules as $name => $module ) {
 178                         // Support module loader scripts
 179                         if ( ( $loader = $module->getLoaderScript() ) !== false ) {
 180                                 $deps = FormatJson::encode( $module->getDependencies() );
 181                                 $version = wfTimestamp( TS_ISO_8601, round( $module->getModifiedTime( $context ), -2 ) );
 182                                 $scripts .= "( function( name, version, dependencies ) { $loader } )( '$name', '$version', $deps );";
 183                         }
 184                         // Automatically register module
 185                         else {
 186                                 // Modules without dependencies pass two arguments (name, timestamp) to mediaWiki.loader.register()
 187                                 if ( !count( $module->getDependencies() ) ) {
 188                                         $registrations[] = array( $name, $module->getModifiedTime( $context ) );
 189                                 }
 190                                 // Modules with dependencies pass three arguments (name, timestamp, dependencies) to mediaWiki.loader.register()
 191                                 else {
 192                                         $registrations[] = array( $name, $module->getModifiedTime( $context ), $module->getDependencies() );
 193                                 }
 194                         }
 195                 }
 196                 return $scripts . "mediaWiki.loader.register( " . FormatJson::encode( $registrations ) . " );";
 197         }
 198
 199         /**
 200          * Get the highest modification time of all modules, based on a given combination of language code,
 201          * skin name and debug mode flag.
 202          *
 203          * @param $context ResourceLoaderContext object
 204          * @return Integer: UNIX timestamp
 205          */
 206         public static function getHighestModifiedTime( ResourceLoaderContext $context ) {
 207
 208                 self::initialize();
 209
 210                 $time = 1; // wfTimestamp() treats 0 as 'now', so that's not a suitable choice
 211
 212                 foreach ( self::$modules as $module ) {
 213                         $time = max( $time, $module->getModifiedTime( $context ) );
 214                 }
 215
 216                 return $time;
 217         }
 218
 219         /**
 220          * Outputs a response to a resource load-request, including a content-type header
 221          *
 222          * @param $context ResourceLoaderContext object
 223          */
 224         public static function respond( ResourceLoaderContext $context ) {
 225                 global $wgResourceLoaderVersionedClientMaxage, $wgResourceLoaderVersionedServerMaxage;
 226                 global $wgResourceLoaderUnversionedServerMaxage, $wgResourceLoaderUnversionedClientMaxage;
 227
 228                 self::initialize();
 229
 230                 // Split requested modules into two groups, modules and missing
 231                 $modules = array();
 232                 $missing = array();
 233
 234                 foreach ( $context->getModules() as $name ) {
 235                         if ( isset( self::$modules[$name] ) ) {
 236                                 $modules[] = $name;
 237                         } else {
 238                                 $missing[] = $name;
 239                         }
 240                 }
 241
 242                 // If a version wasn't specified we need a shorter expiry time for updates to propagate to clients quickly
 243                 if ( is_null( $context->getVersion() ) ) {
 244                         $maxage = $wgResourceLoaderUnversionedClientMaxage;
 245                         $smaxage = $wgResourceLoaderUnversionedServerMaxage;
 246                 }
 247                 // If a version was specified we can use a longer expiry time since changing version numbers causes cache misses
 248                 else {
 249                         $maxage = $wgResourceLoaderVersionedClientMaxage;
 250                         $smaxage = $wgResourceLoaderVersionedServerMaxage;
 251                 }
 252
 253                 // To send Last-Modified and support If-Modified-Since, we need to detect the last modified time
 254                 $mtime = 1;
 255                 foreach ( $modules as $name ) {
 256                         $mtime = max( $mtime, self::$modules[$name]->getModifiedTime( $context ) );
 257                 }
 258
 259                 header( 'Content-Type: ' . ( $context->getOnly() === 'styles' ? 'text/css' : 'text/javascript' ) );
 260                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 261                 header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 262                 header( 'Expires: ' . wfTimestamp( TS_RFC2822, min( $maxage, $smaxage ) + time() ) );
 263
 264                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 265                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 266                 if ( $ims !== false && $mtime >= wfTimestamp( TS_UNIX, $ims ) ) {
 267                         header( 'HTTP/1.0 304 Not Modified' );
 268                         header( 'Status: 304 Not Modified' );
 269                         return;
 270                 }
 271
 272                 // Use output buffering
 273                 ob_start();
 274
 275                 // Pre-fetch blobs
 276                 $blobs = $context->shouldIncludeMessages() ?
 277                 MessageBlobStore::get( $modules, $context->getLanguage() ) : array();
 278
 279                 // Generate output
 280                 foreach ( $modules as $name ) {
 281                         // Scripts
 282                         $scripts = '';
 283
 284                         if ( $context->shouldIncludeScripts() ) {
 285                                 $scripts .= self::$modules[$name]->getScript( $context );
 286                         }
 287
 288                         // Styles
 289                         $styles = array();
 290
 291                         if (
 292                                 $context->shouldIncludeStyles() && ( count( $styles = self::$modules[$name]->getStyles( $context ) ) )
 293                         ) {
 294                                 foreach ( $styles as $media => $style ) {
 295                                         if ( self::$modules[$name]->getFlip( $context ) ) {
 296                                                 $styles[$media] = self::filter( 'flip-css', $style );
 297                                         }
 298                                         if ( !$context->getDebug() ) {
 299                                                 $styles[$media] = self::filter( 'minify-css', $style );
 300                                         }
 301                                 }
 302                         }
 303
 304                         // Messages
 305                         $messages = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 306
 307                         // Output
 308                         if ( $context->getOnly() === 'styles' ) {
 309                                 if ( $context->getDebug() ) {
 310                                         echo "/* $name */\n";
 311                                         foreach ( $styles as $media => $style ) {
 312                                                 echo "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "\n}\n";
 313                                         }
 314                                 } else {
 315                                         foreach ( $styles as $media => $style ) {
 316                                                 if ( strlen( $style ) ) {
 317                                                         echo "@media $media{" . $style . "}";
 318                                                 }
 319                                         }
 320                                 }
 321                         } else if ( $context->getOnly() === 'scripts' ) {
 322                                 echo $scripts;
 323                         } else if ( $context->getOnly() === 'messages' ) {
 324                                 echo "mediaWiki.msg.set( $messages );\n";
 325                         } else {
 326                                 if ( count( $styles ) ) {
 327                                         $styles = FormatJson::encode( $styles );
 328                                 } else {
 329                                         $styles = 'null';
 330                                 }
 331                                 echo "mediaWiki.loader.implement( '$name', function() {{$scripts}},\n$styles,\n$messages );\n";
 332                         }
 333                 }
 334
 335                 // Update the status of script-only modules
 336                 if ( $context->getOnly() === 'scripts' && !in_array( 'startup', $modules ) ) {
 337                         $statuses = array();
 338
 339                         foreach ( $modules as $name ) {
 340                                 $statuses[$name] = 'ready';
 341                         }
 342
 343                         $statuses = FormatJson::encode( $statuses );
 344                         echo "mediaWiki.loader.state( $statuses );\n";
 345                 }
 346
 347                 // Register missing modules
 348                 if ( $context->shouldIncludeScripts() ) {
 349                         foreach ( $missing as $name ) {
 350                                 echo "mediaWiki.loader.register( '$name', null, 'missing' );\n";
 351                         }
 352                 }
 353
 354                 // Output the appropriate header
 355                 if ( $context->getOnly() !== 'styles' ) {
 356                         if ( $context->getDebug() ) {
 357                                 ob_end_flush();
 358                         } else {
 359                                 echo self::filter( 'minify-js', ob_get_clean() );
 360                         }
 361                 }
 362         }
 363 }