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