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                         wfProfileIn( __METHOD__ );
  45                         // This needs to be first, because hooks might call ResourceLoader
  46                         // public interfaces which will call this
  47                         self::$initialized = true;
  48                         self::register( include( "$IP/resources/Resources.php" ) );
  49                         wfRunHooks( 'ResourceLoaderRegisterModules' );
  50                         wfProfileOut( __METHOD__ );
  51                 }
  52         }
  53
  54         /**
  55          * Runs text through a filter, caching the filtered result for future calls
  56          *
  57          * @param $filter String: name of filter to run
  58          * @param $data String: text to filter, such as JavaScript or CSS text
  59          * @param $file String: path to file being filtered, (optional: only required
  60          *     for CSS to resolve paths)
  61          * @return String: filtered data
  62          */
  63         protected static function filter( $filter, $data ) {
  64                 global $wgMemc;
  65                 wfProfileIn( __METHOD__ );
  66
  67                 // For empty or whitespace-only things, don't do any processing
  68                 if ( trim( $data ) === '' ) {
  69                         wfProfileOut( __METHOD__ );
  70                         return $data;
  71                 }
  72
  73                 // Try memcached
  74                 $key = wfMemcKey( 'resourceloader', 'filter', $filter, md5( $data ) );
  75                 $cached = $wgMemc->get( $key );
  76
  77                 if ( $cached !== false && $cached !== null ) {
  78                         wfProfileOut( __METHOD__ );
  79                         return $cached;
  80                 }
  81
  82                 // Run the filter
  83                 try {
  84                         switch ( $filter ) {
  85                                 case 'minify-js':
  86                                         $result = JSMin::minify( $data );
  87                                         break;
  88                                 case 'minify-css':
  89                                         $result = CSSMin::minify( $data );
  90                                         break;
  91                                 case 'flip-css':
  92                                         $result = CSSJanus::transform( $data, true, false );
  93                                         break;
  94                                 default:
  95                                         // Don't cache anything, just pass right through
  96                                         wfProfileOut( __METHOD__ );
  97                                         return $data;
  98                         }
  99                 } catch ( Exception $exception ) {
 100                         throw new MWException( 'Filter threw an exception: ' . $exception->getMessage() );
 101                 }
 102
 103                 // Save to memcached
 104                 $wgMemc->set( $key, $result );
 105
 106                 wfProfileOut( __METHOD__ );
 107                 return $result;
 108         }
 109
 110         /* Static Methods */
 111
 112         /**
 113          * Registers a module with the ResourceLoader system.
 114          *
 115          * Note that registering the same object under multiple names is not supported
 116          * and may silently fail in all kinds of interesting ways.
 117          *
 118          * @param $name Mixed: string of name of module or array of name/object pairs
 119          * @param $object ResourceLoaderModule: module object (optional when using
 120          *    multiple-registration calling style)
 121          * @return Boolean: false if there were any errors, in which case one or more
 122          *    modules were not registered
 123          *
 124          * @todo We need much more clever error reporting, not just in detailing what
 125          *    happened, but in bringing errors to the client in a way that they can
 126          *    easily see them if they want to, such as by using FireBug
 127          */
 128         public static function register( $name, ResourceLoaderModule $object = null ) {
 129                 wfProfileIn( __METHOD__ );
 130                 self::initialize();
 131
 132                 // Allow multiple modules to be registered in one call
 133                 if ( is_array( $name ) && !isset( $object ) ) {
 134                         foreach ( $name as $key => $value ) {
 135                                 self::register( $key, $value );
 136                         }
 137
 138                         wfProfileOut( __METHOD__ );
 139                         return;
 140                 }
 141
 142                 // Disallow duplicate registrations
 143                 if ( isset( self::$modules[$name] ) ) {
 144                         // A module has already been registered by this name
 145                         throw new MWException( 'Another module has already been registered as ' . $name );
 146                 }
 147                 // Attach module
 148                 self::$modules[$name] = $object;
 149                 $object->setName( $name );
 150                 wfProfileOut( __METHOD__ );
 151         }
 152
 153         /**
 154          * Gets a map of all modules and their options
 155          *
 156          * @return Array: array( modulename => ResourceLoaderModule )
 157          */
 158         public static function getModules() {
 159
 160                 self::initialize();
 161
 162                 return self::$modules;
 163         }
 164
 165         /**
 166          * Get the ResourceLoaderModule object for a given module name
 167          *
 168          * @param $name String: module name
 169          * @return mixed ResourceLoaderModule or null if not registered
 170          */
 171         public static function getModule( $name ) {
 172
 173                 self::initialize();
 174
 175                 return isset( self::$modules[$name] ) ? self::$modules[$name] : null;
 176         }
 177
 178         /**
 179          * Gets registration code for all modules, except pre-registered ones listed in
 180          * self::$preRegisteredModules
 181          *
 182          * @param $context ResourceLoaderContext object
 183          * @return String: JavaScript code for registering all modules with the client loader
 184          */
 185         public static function getModuleRegistrations( ResourceLoaderContext $context ) {
 186                 wfProfileIn( __METHOD__ );
 187                 self::initialize();
 188
 189                 $scripts = '';
 190                 $registrations = array();
 191
 192                 foreach ( self::$modules as $name => $module ) {
 193                         // Support module loader scripts
 194                         if ( ( $loader = $module->getLoaderScript() ) !== false ) {
 195                                 $deps = FormatJson::encode( $module->getDependencies() );
 196                                 $version = wfTimestamp( TS_ISO_8601,
 197                                         round( $module->getModifiedTime( $context ), -2 ) );
 198                                 $scripts .= "( function( name, version, dependencies ) { $loader } )\n" .
 199                                         "( '$name', '$version', $deps );\n";
 200                         }
 201                         // Automatically register module
 202                         else {
 203                                 // Modules without dependencies pass two arguments (name, timestamp) to
 204                                 // mediaWiki.loader.register()
 205                                 if ( !count( $module->getDependencies() ) ) {
 206                                         $registrations[] = array( $name, $module->getModifiedTime( $context ) );
 207                                 }
 208                                 // Modules with dependencies pass three arguments (name, timestamp, dependencies)
 209                                 // to mediaWiki.loader.register()
 210                                 else {
 211                                         $registrations[] = array( $name, $module->getModifiedTime( $context ),
 212                                                 $module->getDependencies() );
 213                                 }
 214                         }
 215                 }
 216                 $out = $scripts . "mediaWiki.loader.register( " . FormatJson::encode( $registrations ) . " );\n";
 217                 wfProfileOut( __METHOD__ );
 218                 return $out;
 219         }
 220
 221         /**
 222          * Get the highest modification time of all modules, based on a given
 223          * combination of language code, skin name and debug mode flag.
 224          *
 225          * @param $context ResourceLoaderContext object
 226          * @return Integer: UNIX timestamp
 227          */
 228         public static function getHighestModifiedTime( ResourceLoaderContext $context ) {
 229
 230                 self::initialize();
 231
 232                 $time = 1; // wfTimestamp() treats 0 as 'now', so that's not a suitable choice
 233
 234                 foreach ( self::$modules as $module ) {
 235                         $time = max( $time, $module->getModifiedTime( $context ) );
 236                 }
 237
 238                 return $time;
 239         }
 240
 241         /**
 242          * Outputs a response to a resource load-request, including a content-type header
 243          *
 244          * @param $context ResourceLoaderContext object
 245          */
 246         public static function respond( ResourceLoaderContext $context ) {
 247                 global $wgResourceLoaderVersionedClientMaxage, $wgResourceLoaderVersionedServerMaxage;
 248                 global $wgResourceLoaderUnversionedServerMaxage, $wgResourceLoaderUnversionedClientMaxage;
 249
 250                 wfProfileIn( __METHOD__ );
 251                 self::initialize();
 252
 253                 // Split requested modules into two groups, modules and missing
 254                 $modules = array();
 255                 $missing = array();
 256
 257                 foreach ( $context->getModules() as $name ) {
 258                         if ( isset( self::$modules[$name] ) ) {
 259                                 $modules[] = $name;
 260                         } else {
 261                                 $missing[] = $name;
 262                         }
 263                 }
 264
 265                 // If a version wasn't specified we need a shorter expiry time for updates to
 266                 // propagate to clients quickly
 267                 if ( is_null( $context->getVersion() ) ) {
 268                         $maxage = $wgResourceLoaderUnversionedClientMaxage;
 269                         $smaxage = $wgResourceLoaderUnversionedServerMaxage;
 270                 }
 271                 // If a version was specified we can use a longer expiry time since changing
 272                 // version numbers causes cache misses
 273                 else {
 274                         $maxage = $wgResourceLoaderVersionedClientMaxage;
 275                         $smaxage = $wgResourceLoaderVersionedServerMaxage;
 276                 }
 277
 278                 // To send Last-Modified and support If-Modified-Since, we need to detect
 279                 // the last modified time
 280                 wfProfileIn( __METHOD__.'-getModifiedTime' );
 281                 $mtime = 1;
 282                 foreach ( $modules as $name ) {
 283                         $mtime = max( $mtime, self::$modules[$name]->getModifiedTime( $context ) );
 284                 }
 285                 wfProfileOut( __METHOD__.'-getModifiedTime' );
 286
 287                 header( 'Content-Type: ' . ( $context->getOnly() === 'styles' ? 'text/css' : 'text/javascript' ) );
 288                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 289                 header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 290                 header( 'Expires: ' . wfTimestamp( TS_RFC2822, min( $maxage, $smaxage ) + time() ) );
 291
 292                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 293                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 294                 if ( $ims !== false && $mtime >= wfTimestamp( TS_UNIX, $ims ) ) {
 295                         header( 'HTTP/1.0 304 Not Modified' );
 296                         header( 'Status: 304 Not Modified' );
 297                         wfProfileOut( __METHOD__ );
 298                         return;
 299                 }
 300
 301                 // Use output buffering
 302                 ob_start();
 303
 304                 // Pre-fetch blobs
 305                 $blobs = $context->shouldIncludeMessages() ?
 306                 MessageBlobStore::get( $modules, $context->getLanguage() ) : array();
 307
 308                 // Generate output
 309                 foreach ( $modules as $name ) {
 310                         wfProfileIn( __METHOD__ . '-' . $name );
 311                         // Scripts
 312                         $scripts = '';
 313
 314                         if ( $context->shouldIncludeScripts() ) {
 315                                 $scripts .= self::$modules[$name]->getScript( $context ) . "\n";
 316                         }
 317
 318                         // Styles
 319                         $styles = array();
 320
 321                         if (
 322                                 $context->shouldIncludeStyles()
 323                                 && ( count( $styles = self::$modules[$name]->getStyles( $context ) ) )
 324                         ) {
 325                                 foreach ( $styles as $media => $style ) {
 326                                         if ( self::$modules[$name]->getFlip( $context ) ) {
 327                                                 $styles[$media] = self::filter( 'flip-css', $style );
 328                                         }
 329                                         if ( !$context->getDebug() ) {
 330                                                 $styles[$media] = self::filter( 'minify-css', $style );
 331                                         }
 332                                 }
 333                         }
 334
 335                         // Messages
 336                         $messages = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 337
 338                         // Output
 339                         if ( $context->getOnly() === 'styles' ) {
 340                                 if ( $context->getDebug() ) {
 341                                         echo "/* $name */\n";
 342                                         foreach ( $styles as $media => $style ) {
 343                                                 echo "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "\n}\n";
 344                                         }
 345                                 } else {
 346                                         foreach ( $styles as $media => $style ) {
 347                                                 if ( strlen( $style ) ) {
 348                                                         echo "@media $media{" . $style . "}";
 349                                                 }
 350                                         }
 351                                 }
 352                         } else if ( $context->getOnly() === 'scripts' ) {
 353                                 echo $scripts;
 354                         } else if ( $context->getOnly() === 'messages' ) {
 355                                 echo "mediaWiki.msg.set( $messages );\n";
 356                         } else {
 357                                 if ( count( $styles ) ) {
 358                                         $styles = FormatJson::encode( $styles );
 359                                 } else {
 360                                         $styles = 'null';
 361                                 }
 362                                 echo "mediaWiki.loader.implement( '$name', function() {{$scripts}},\n$styles,\n$messages );\n";
 363                         }
 364                         wfProfileOut( __METHOD__ . '-' . $name );
 365                 }
 366
 367                 // Update the status of script-only modules
 368                 if ( $context->getOnly() === 'scripts' && !in_array( 'startup', $modules ) ) {
 369                         $statuses = array();
 370
 371                         foreach ( $modules as $name ) {
 372                                 $statuses[$name] = 'ready';
 373                         }
 374
 375                         $statuses = FormatJson::encode( $statuses );
 376                         echo "mediaWiki.loader.state( $statuses );\n";
 377                 }
 378
 379                 // Register missing modules
 380                 if ( $context->shouldIncludeScripts() ) {
 381                         foreach ( $missing as $name ) {
 382                                 echo "mediaWiki.loader.register( '$name', null, 'missing' );\n";
 383                         }
 384                 }
 385
 386                 // Output the appropriate header
 387                 if ( $context->getOnly() !== 'styles' ) {
 388                         if ( $context->getDebug() ) {
 389                                 ob_end_flush();
 390                         } else {
 391                                 echo self::filter( 'minify-js', ob_get_clean() );
 392                         }
 393                 }
 394                 wfProfileOut( __METHOD__ );
 395         }
 396 }