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
 180          *
 181          * @param $context ResourceLoaderContext object
 182          * @return String: JavaScript code for registering all modules with the client loader
 183          */
 184         public static function getModuleRegistrations( ResourceLoaderContext $context ) {
 185                 wfProfileIn( __METHOD__ );
 186                 self::initialize();
 187
 188                 $scripts = '';
 189                 $registrations = array();
 190
 191                 foreach ( self::$modules as $name => $module ) {
 192                         // Support module loader scripts
 193                         if ( ( $loader = $module->getLoaderScript() ) !== false ) {
 194                                 $deps = FormatJson::encode( $module->getDependencies() );
 195                                 $group = FormatJson::encode( $module->getGroup() );
 196                                 $version = wfTimestamp( TS_ISO_8601, round( $module->getModifiedTime( $context ), -2 ) );
 197                                 $scripts .= "( function( name, version, dependencies ) { $loader } )\n" .
 198                                         "( '$name', '$version', $deps, $group );\n";
 199                         }
 200                         // Automatically register module
 201                         else {
 202                                 // Modules without dependencies or a group pass two arguments (name, timestamp) to
 203                                 // mediaWiki.loader.register()
 204                                 if ( !count( $module->getDependencies() && $module->getGroup() === null ) ) {
 205                                         $registrations[] = array( $name, $module->getModifiedTime( $context ) );
 206                                 }
 207                                 // Modules with dependencies but no group pass three arguments (name, timestamp, dependencies)
 208                                 // to mediaWiki.loader.register()
 209                                 else if ( $module->getGroup() === null ) {
 210                                         $registrations[] = array(
 211                                                 $name, $module->getModifiedTime( $context ),  $module->getDependencies() );
 212                                 }
 213                                 // Modules with dependencies pass four arguments (name, timestamp, dependencies, group)
 214                                 // to mediaWiki.loader.register()
 215                                 else {
 216                                         $registrations[] = array(
 217                                                 $name, $module->getModifiedTime( $context ),  $module->getDependencies(), $module->getGroup() );
 218                                 }
 219                         }
 220                 }
 221                 $out = $scripts . "mediaWiki.loader.register( " . FormatJson::encode( $registrations ) . " );\n";
 222                 wfProfileOut( __METHOD__ );
 223                 return $out;
 224         }
 225
 226         /**
 227          * Get the highest modification time of all modules, based on a given
 228          * combination of language code, skin name and debug mode flag.
 229          *
 230          * @param $context ResourceLoaderContext object
 231          * @return Integer: UNIX timestamp
 232          */
 233         public static function getHighestModifiedTime( ResourceLoaderContext $context ) {
 234
 235                 self::initialize();
 236
 237                 $time = 1; // wfTimestamp() treats 0 as 'now', so that's not a suitable choice
 238
 239                 foreach ( self::$modules as $module ) {
 240                         $time = max( $time, $module->getModifiedTime( $context ) );
 241                 }
 242
 243                 return $time;
 244         }
 245
 246         /**
 247          * Outputs a response to a resource load-request, including a content-type header
 248          *
 249          * @param $context ResourceLoaderContext object
 250          */
 251         public static function respond( ResourceLoaderContext $context ) {
 252                 global $wgResourceLoaderMaxage;
 253
 254                 wfProfileIn( __METHOD__ );
 255                 self::initialize();
 256
 257                 // Split requested modules into two groups, modules and missing
 258                 $modules = array();
 259                 $missing = array();
 260
 261                 foreach ( $context->getModules() as $name ) {
 262                         if ( isset( self::$modules[$name] ) ) {
 263                                 $modules[] = $name;
 264                         } else {
 265                                 $missing[] = $name;
 266                         }
 267                 }
 268
 269                 // If a version wasn't specified we need a shorter expiry time for updates to
 270                 // propagate to clients quickly
 271                 if ( is_null( $context->getVersion() ) ) {
 272                         $maxage = $wgResourceLoaderMaxage['unversioned']['client'];
 273                         $smaxage = $wgResourceLoaderMaxage['unversioned']['server'];
 274                 }
 275                 // If a version was specified we can use a longer expiry time since changing
 276                 // version numbers causes cache misses
 277                 else {
 278                         $maxage = $wgResourceLoaderMaxage['versioned']['client'];
 279                         $smaxage = $wgResourceLoaderMaxage['versioned']['server'];
 280                 }
 281
 282                 // To send Last-Modified and support If-Modified-Since, we need to detect
 283                 // the last modified time
 284                 wfProfileIn( __METHOD__.'-getModifiedTime' );
 285                 $mtime = 1;
 286                 foreach ( $modules as $name ) {
 287                         $mtime = max( $mtime, self::$modules[$name]->getModifiedTime( $context ) );
 288                 }
 289                 wfProfileOut( __METHOD__.'-getModifiedTime' );
 290
 291                 header( 'Content-Type: ' . ( $context->getOnly() === 'styles' ? 'text/css' : 'text/javascript' ) );
 292                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 293                 header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 294                 header( 'Expires: ' . wfTimestamp( TS_RFC2822, min( $maxage, $smaxage ) + time() ) );
 295
 296                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 297                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 298                 if ( $ims !== false && $mtime >= wfTimestamp( TS_UNIX, $ims ) ) {
 299                         header( 'HTTP/1.0 304 Not Modified' );
 300                         header( 'Status: 304 Not Modified' );
 301                         wfProfileOut( __METHOD__ );
 302                         return;
 303                 }
 304
 305                 // Use output buffering
 306                 ob_start();
 307
 308                 // Pre-fetch blobs
 309                 $blobs = $context->shouldIncludeMessages() ?
 310                 MessageBlobStore::get( $modules, $context->getLanguage() ) : array();
 311
 312                 // Generate output
 313                 foreach ( $modules as $name ) {
 314                         wfProfileIn( __METHOD__ . '-' . $name );
 315                         // Scripts
 316                         $scripts = '';
 317
 318                         if ( $context->shouldIncludeScripts() ) {
 319                                 $scripts .= self::$modules[$name]->getScript( $context ) . "\n";
 320                         }
 321
 322                         // Styles
 323                         $styles = array();
 324
 325                         if (
 326                                 $context->shouldIncludeStyles()
 327                                 && ( count( $styles = self::$modules[$name]->getStyles( $context ) ) )
 328                         ) {
 329                                 foreach ( $styles as $media => $style ) {
 330                                         if ( self::$modules[$name]->getFlip( $context ) ) {
 331                                                 $styles[$media] = self::filter( 'flip-css', $style );
 332                                         }
 333                                         if ( !$context->getDebug() ) {
 334                                                 $styles[$media] = self::filter( 'minify-css', $style );
 335                                         }
 336                                 }
 337                         }
 338
 339                         // Messages
 340                         $messages = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 341
 342                         // Output
 343                         if ( $context->getOnly() === 'styles' ) {
 344                                 if ( $context->getDebug() ) {
 345                                         echo "/* $name */\n";
 346                                         foreach ( $styles as $media => $style ) {
 347                                                 echo "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "\n}\n";
 348                                         }
 349                                 } else {
 350                                         foreach ( $styles as $media => $style ) {
 351                                                 if ( strlen( $style ) ) {
 352                                                         echo "@media $media{" . $style . "}";
 353                                                 }
 354                                         }
 355                                 }
 356                         } else if ( $context->getOnly() === 'scripts' ) {
 357                                 echo $scripts;
 358                         } else if ( $context->getOnly() === 'messages' ) {
 359                                 echo "mediaWiki.msg.set( $messages );\n";
 360                         } else {
 361                                 if ( count( $styles ) ) {
 362                                         $styles = FormatJson::encode( $styles );
 363                                 } else {
 364                                         $styles = 'null';
 365                                 }
 366                                 echo "mediaWiki.loader.implement( '$name', function() {{$scripts}},\n$styles,\n$messages );\n";
 367                         }
 368                         wfProfileOut( __METHOD__ . '-' . $name );
 369                 }
 370
 371                 // Update the status of script-only modules
 372                 if ( $context->getOnly() === 'scripts' && !in_array( 'startup', $modules ) ) {
 373                         $statuses = array();
 374
 375                         foreach ( $modules as $name ) {
 376                                 $statuses[$name] = 'ready';
 377                         }
 378
 379                         $statuses = FormatJson::encode( $statuses );
 380                         echo "mediaWiki.loader.state( $statuses );\n";
 381                 }
 382
 383                 // Register missing modules
 384                 if ( $context->shouldIncludeScripts() ) {
 385                         foreach ( $missing as $name ) {
 386                                 echo "mediaWiki.loader.register( '$name', null, 'missing' );\n";
 387                         }
 388                 }
 389
 390                 // Output the appropriate header
 391                 if ( $context->getOnly() !== 'styles' ) {
 392                         if ( $context->getDebug() ) {
 393                                 ob_end_flush();
 394                         } else {
 395                                 echo self::filter( 'minify-js', ob_get_clean() );
 396                         }
 397                 }
 398                 wfProfileOut( __METHOD__ );
 399         }
 400 }