includes/resourceloader/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  * Most of the documention is on the MediaWiki documentation wiki starting at:
  27  *    http://www.mediawiki.org/wiki/ResourceLoader
  28  */
  29 class ResourceLoader {
  30
  31         /* Protected Static Members */
  32         protected static $filterCacheVersion = 4;
  33
  34         /** Array: List of module name/ResourceLoaderModule object pairs */
  35         protected $modules = array();
  36         /** Associative array mapping module name to info associative array */
  37         protected $moduleInfos = array();
  38
  39         /* Protected Methods */
  40
  41         /**
  42          * Loads information stored in the database about modules.
  43          *
  44          * This method grabs modules dependencies from the database and updates modules
  45          * objects.
  46          *
  47          * This is not inside the module code because it is much faster to
  48          * request all of the information at once than it is to have each module
  49          * requests its own information. This sacrifice of modularity yields a substantial
  50          * performance improvement.
  51          *
  52          * @param $modules Array: List of module names to preload information for
  53          * @param $context ResourceLoaderContext: Context to load the information within
  54          */
  55         public function preloadModuleInfo( array $modules, ResourceLoaderContext $context ) {
  56                 if ( !count( $modules ) ) {
  57                         return; // or else Database*::select() will explode, plus it's cheaper!
  58                 }
  59                 $dbr = wfGetDB( DB_SLAVE );
  60                 $skin = $context->getSkin();
  61                 $lang = $context->getLanguage();
  62
  63                 // Get file dependency information
  64                 $res = $dbr->select( 'module_deps', array( 'md_module', 'md_deps' ), array(
  65                                 'md_module' => $modules,
  66                                 'md_skin' => $skin
  67                         ), __METHOD__
  68                 );
  69
  70                 // Set modules' dependencies
  71                 $modulesWithDeps = array();
  72                 foreach ( $res as $row ) {
  73                         $this->getModule( $row->md_module )->setFileDependencies( $skin,
  74                                 FormatJson::decode( $row->md_deps, true )
  75                         );
  76                         $modulesWithDeps[] = $row->md_module;
  77                 }
  78
  79                 // Register the absence of a dependency row too
  80                 foreach ( array_diff( $modules, $modulesWithDeps ) as $name ) {
  81                         $this->getModule( $name )->setFileDependencies( $skin, array() );
  82                 }
  83
  84                 // Get message blob mtimes. Only do this for modules with messages
  85                 $modulesWithMessages = array();
  86                 foreach ( $modules as $name ) {
  87                         if ( count( $this->getModule( $name )->getMessages() ) ) {
  88                                 $modulesWithMessages[] = $name;
  89                         }
  90                 }
  91                 $modulesWithoutMessages = array_flip( $modules ); // Will be trimmed down by the loop below
  92                 if ( count( $modulesWithMessages ) ) {
  93                         $res = $dbr->select( 'msg_resource', array( 'mr_resource', 'mr_timestamp' ), array(
  94                                         'mr_resource' => $modulesWithMessages,
  95                                         'mr_lang' => $lang
  96                                 ), __METHOD__
  97                         );
  98                         foreach ( $res as $row ) {
  99                                 $this->getModule( $row->mr_resource )->setMsgBlobMtime( $lang,
 100                                         wfTimestamp( TS_UNIX, $row->mr_timestamp ) );
 101                                 unset( $modulesWithoutMessages[$row->mr_resource] );
 102                         }
 103                 }
 104                 foreach ( array_keys( $modulesWithoutMessages ) as $name ) {
 105                         $this->getModule( $name )->setMsgBlobMtime( $lang, 0 );
 106                 }
 107         }
 108
 109         /**
 110          * Runs JavaScript or CSS data through a filter, caching the filtered result for future calls.
 111          *
 112          * Available filters are:
 113          *  - minify-js \see JavaScriptMinifier::minify
 114          *  - minify-css \see CSSMin::minify
 115          *
 116          * If $data is empty, only contains whitespace or the filter was unknown,
 117          * $data is returned unmodified.
 118          *
 119          * @param $filter String: Name of filter to run
 120          * @param $data String: Text to filter, such as JavaScript or CSS text
 121          * @return String: Filtered data, or a comment containing an error message
 122          */
 123         protected function filter( $filter, $data ) {
 124                 global $wgResourceLoaderMinifierStatementsOnOwnLine, $wgResourceLoaderMinifierMaxLineLength;
 125                 wfProfileIn( __METHOD__ );
 126
 127                 // For empty/whitespace-only data or for unknown filters, don't perform
 128                 // any caching or processing
 129                 if ( trim( $data ) === ''
 130                         || !in_array( $filter, array( 'minify-js', 'minify-css' ) ) )
 131                 {
 132                         wfProfileOut( __METHOD__ );
 133                         return $data;
 134                 }
 135
 136                 // Try for cache hit
 137                 // Use CACHE_ANYTHING since filtering is very slow compared to DB queries
 138                 $key = wfMemcKey( 'resourceloader', 'filter', $filter, self::$filterCacheVersion, md5( $data ) );
 139                 $cache = wfGetCache( CACHE_ANYTHING );
 140                 $cacheEntry = $cache->get( $key );
 141                 if ( is_string( $cacheEntry ) ) {
 142                         wfProfileOut( __METHOD__ );
 143                         return $cacheEntry;
 144                 }
 145
 146                 $result = '';
 147                 // Run the filter - we've already verified one of these will work
 148                 try {
 149                         switch ( $filter ) {
 150                                 case 'minify-js':
 151                                         $result = JavaScriptMinifier::minify( $data,
 152                                                 $wgResourceLoaderMinifierStatementsOnOwnLine,
 153                                                 $wgResourceLoaderMinifierMaxLineLength
 154                                         );
 155                                         $result .= "\n\n/* cache key: $key */\n";
 156                                         break;
 157                                 case 'minify-css':
 158                                         $result = CSSMin::minify( $data );
 159                                         $result .= "\n\n/* cache key: $key */\n";
 160                                         break;
 161                         }
 162
 163                         // Save filtered text to Memcached
 164                         $cache->set( $key, $result );
 165                 } catch ( Exception $exception ) {
 166                         // Return exception as a comment
 167                         $result = "/*\n{$exception->__toString()}\n*/\n";
 168                 }
 169
 170                 wfProfileOut( __METHOD__ );
 171
 172                 return $result;
 173         }
 174
 175         /* Methods */
 176
 177         /**
 178          * Registers core modules and runs registration hooks.
 179          */
 180         public function __construct() {
 181                 global $IP, $wgResourceModules;
 182
 183                 wfProfileIn( __METHOD__ );
 184
 185                 // Register core modules
 186                 $this->register( include( "$IP/resources/Resources.php" ) );
 187                 // Register extension modules
 188                 wfRunHooks( 'ResourceLoaderRegisterModules', array( &$this ) );
 189                 $this->register( $wgResourceModules );
 190
 191                 wfProfileOut( __METHOD__ );
 192         }
 193
 194         /**
 195          * Registers a module with the ResourceLoader system.
 196          *
 197          * @param $name Mixed: Name of module as a string or List of name/object pairs as an array
 198          * @param $info Module info array. For backwards compatibility with 1.17alpha,
 199          *   this may also be a ResourceLoaderModule object. Optional when using
 200          *   multiple-registration calling style.
 201          * @throws MWException: If a duplicate module registration is attempted
 202          * @throws MWException: If a module name contains illegal characters (pipes or commas)
 203          * @throws MWException: If something other than a ResourceLoaderModule is being registered
 204          * @return Boolean: False if there were any errors, in which case one or more modules were not
 205          *     registered
 206          */
 207         public function register( $name, $info = null ) {
 208                 wfProfileIn( __METHOD__ );
 209
 210                 // Allow multiple modules to be registered in one call
 211                 if ( is_array( $name ) ) {
 212                         foreach ( $name as $key => $value ) {
 213                                 $this->register( $key, $value );
 214                         }
 215                         wfProfileOut( __METHOD__ );
 216                         return;
 217                 }
 218
 219                 // Disallow duplicate registrations
 220                 if ( isset( $this->moduleInfos[$name] ) ) {
 221                         // A module has already been registered by this name
 222                         throw new MWException(
 223                                 'ResourceLoader duplicate registration error. ' .
 224                                 'Another module has already been registered as ' . $name
 225                         );
 226                 }
 227
 228                 // Check $name for illegal characters
 229                 if ( preg_match( '/[|,!]/', $name ) ) {
 230                         throw new MWException( "ResourceLoader module name '$name' is invalid. Names may not contain pipes (|), commas (,) or exclamation marks (!)" );
 231                 }
 232
 233                 // Attach module
 234                 if ( is_object( $info ) ) {
 235                         // Old calling convention
 236                         // Validate the input
 237                         if ( !( $info instanceof ResourceLoaderModule ) ) {
 238                                 throw new MWException( 'ResourceLoader invalid module error. ' .
 239                                         'Instances of ResourceLoaderModule expected.' );
 240                         }
 241
 242                         $this->moduleInfos[$name] = array( 'object' => $info );
 243                         $info->setName( $name );
 244                         $this->modules[$name] = $info;
 245                 } else {
 246                         // New calling convention
 247                         $this->moduleInfos[$name] = $info;
 248                 }
 249
 250                 wfProfileOut( __METHOD__ );
 251         }
 252
 253         /**
 254          * Get a list of module names
 255          *
 256          * @return Array: List of module names
 257          */
 258         public function getModuleNames() {
 259                 return array_keys( $this->moduleInfos );
 260         }
 261
 262         /**
 263          * Get the ResourceLoaderModule object for a given module name.
 264          *
 265          * @param $name String: Module name
 266          * @return ResourceLoaderModule if module has been registered, null otherwise
 267          */
 268         public function getModule( $name ) {
 269                 if ( !isset( $this->modules[$name] ) ) {
 270                         if ( !isset( $this->moduleInfos[$name] ) ) {
 271                                 // No such module
 272                                 return null;
 273                         }
 274                         // Construct the requested object
 275                         $info = $this->moduleInfos[$name];
 276                         if ( isset( $info['object'] ) ) {
 277                                 // Object given in info array
 278                                 $object = $info['object'];
 279                         } else {
 280                                 if ( !isset( $info['class'] ) ) {
 281                                         $class = 'ResourceLoaderFileModule';
 282                                 } else {
 283                                         $class = $info['class'];
 284                                 }
 285                                 $object = new $class( $info );
 286                         }
 287                         $object->setName( $name );
 288                         $this->modules[$name] = $object;
 289                 }
 290
 291                 return $this->modules[$name];
 292         }
 293
 294         /**
 295          * Outputs a response to a resource load-request, including a content-type header.
 296          *
 297          * @param $context ResourceLoaderContext: Context in which a response should be formed
 298          */
 299         public function respond( ResourceLoaderContext $context ) {
 300                 global $wgResourceLoaderMaxage, $wgCacheEpoch;
 301
 302                 // Buffer output to catch warnings. Normally we'd use ob_clean() on the
 303                 // top-level output buffer to clear warnings, but that breaks when ob_gzhandler
 304                 // is used: ob_clean() will clear the GZIP header in that case and it won't come
 305                 // back for subsequent output, resulting in invalid GZIP. So we have to wrap
 306                 // the whole thing in our own output buffer to be sure the active buffer
 307                 // doesn't use ob_gzhandler.
 308                 // See http://bugs.php.net/bug.php?id=36514
 309                 ob_start();
 310
 311                 wfProfileIn( __METHOD__ );
 312                 $exceptions = '';
 313
 314                 // Split requested modules into two groups, modules and missing
 315                 $modules = array();
 316                 $missing = array();
 317                 foreach ( $context->getModules() as $name ) {
 318                         if ( isset( $this->moduleInfos[$name] ) ) {
 319                                 $modules[$name] = $this->getModule( $name );
 320                         } else {
 321                                 $missing[] = $name;
 322                         }
 323                 }
 324
 325                 // If a version wasn't specified we need a shorter expiry time for updates
 326                 // to propagate to clients quickly
 327                 if ( is_null( $context->getVersion() ) ) {
 328                         $maxage  = $wgResourceLoaderMaxage['unversioned']['client'];
 329                         $smaxage = $wgResourceLoaderMaxage['unversioned']['server'];
 330                 }
 331                 // If a version was specified we can use a longer expiry time since changing
 332                 // version numbers causes cache misses
 333                 else {
 334                         $maxage  = $wgResourceLoaderMaxage['versioned']['client'];
 335                         $smaxage = $wgResourceLoaderMaxage['versioned']['server'];
 336                 }
 337
 338                 // Preload information needed to the mtime calculation below
 339                 try {
 340                         $this->preloadModuleInfo( array_keys( $modules ), $context );
 341                 } catch( Exception $e ) {
 342                         // Add exception to the output as a comment
 343                         $exceptions .= "/*\n{$e->__toString()}\n*/\n";
 344                 }
 345
 346                 wfProfileIn( __METHOD__.'-getModifiedTime' );
 347
 348                 $private = false;
 349                 // To send Last-Modified and support If-Modified-Since, we need to detect
 350                 // the last modified time
 351                 $mtime = wfTimestamp( TS_UNIX, $wgCacheEpoch );
 352                 foreach ( $modules as $module ) {
 353                         try {
 354                                 // Bypass Squid and other shared caches if the request includes any private modules
 355                                 if ( $module->getGroup() === 'private' ) {
 356                                         $private = true;
 357                                 }
 358                                 // Calculate maximum modified time
 359                                 $mtime = max( $mtime, $module->getModifiedTime( $context ) );
 360                         } catch ( Exception $e ) {
 361                                 // Add exception to the output as a comment
 362                                 $exceptions .= "/*\n{$e->__toString()}\n*/\n";
 363                         }
 364                 }
 365
 366                 wfProfileOut( __METHOD__.'-getModifiedTime' );
 367
 368                 if ( $context->getOnly() === 'styles' ) {
 369                         header( 'Content-Type: text/css; charset=utf-8' );
 370                 } else {
 371                         header( 'Content-Type: text/javascript; charset=utf-8' );
 372                 }
 373                 header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $mtime ) );
 374                 if ( $context->getDebug() ) {
 375                         // Do not cache debug responses
 376                         header( 'Cache-Control: private, no-cache, must-revalidate' );
 377                         header( 'Pragma: no-cache' );
 378                 } else {
 379                         if ( $private ) {
 380                                 header( "Cache-Control: private, max-age=$maxage" );
 381                                 $exp = $maxage;
 382                         } else {
 383                                 header( "Cache-Control: public, max-age=$maxage, s-maxage=$smaxage" );
 384                                 $exp = min( $maxage, $smaxage );
 385                         }
 386                         header( 'Expires: ' . wfTimestamp( TS_RFC2822, $exp + time() ) );
 387                 }
 388
 389                 // If there's an If-Modified-Since header, respond with a 304 appropriately
 390                 // Some clients send "timestamp;length=123". Strip the part after the first ';'
 391                 // so we get a valid timestamp.
 392                 $ims = $context->getRequest()->getHeader( 'If-Modified-Since' );
 393                 // Never send 304s in debug mode
 394                 if ( $ims !== false && !$context->getDebug() ) {
 395                         $imsTS = strtok( $ims, ';' );
 396                         if ( $mtime <= wfTimestamp( TS_UNIX, $imsTS ) ) {
 397                                 // There's another bug in ob_gzhandler (see also the comment at
 398                                 // the top of this function) that causes it to gzip even empty
 399                                 // responses, meaning it's impossible to produce a truly empty
 400                                 // response (because the gzip header is always there). This is
 401                                 // a problem because 304 responses have to be completely empty
 402                                 // per the HTTP spec, and Firefox behaves buggily when they're not.
 403                                 // See also http://bugs.php.net/bug.php?id=51579
 404                                 // To work around this, we tear down all output buffering before
 405                                 // sending the 304.
 406                                 // On some setups, ob_get_level() doesn't seem to go down to zero
 407                                 // no matter how often we call ob_get_clean(), so instead of doing
 408                                 // the more intuitive while ( ob_get_level() > 0 ) ob_get_clean();
 409                                 // we have to be safe here and avoid an infinite loop.
 410                                 for ( $i = 0; $i < ob_get_level(); $i++ ) {
 411                                         ob_end_clean();
 412                                 }
 413
 414                                 header( 'HTTP/1.0 304 Not Modified' );
 415                                 header( 'Status: 304 Not Modified' );
 416                                 wfProfileOut( __METHOD__ );
 417                                 return;
 418                         }
 419                 }
 420
 421                 // Generate a response
 422                 $response = $this->makeModuleResponse( $context, $modules, $missing );
 423
 424                 // Prepend comments indicating exceptions
 425                 $response = $exceptions . $response;
 426
 427                 // Capture any PHP warnings from the output buffer and append them to the
 428                 // response in a comment if we're in debug mode.
 429                 if ( $context->getDebug() && strlen( $warnings = ob_get_contents() ) ) {
 430                         $response = "/*\n$warnings\n*/\n" . $response;
 431                 }
 432
 433                 // Remove the output buffer and output the response
 434                 ob_end_clean();
 435                 echo $response;
 436
 437                 wfProfileOut( __METHOD__ );
 438         }
 439
 440         /**
 441          * Generates code for a response
 442          *
 443          * @param $context ResourceLoaderContext: Context in which to generate a response
 444          * @param $modules Array: List of module objects keyed by module name
 445          * @param $missing Array: List of unavailable modules (optional)
 446          * @return String: Response data
 447          */
 448         public function makeModuleResponse( ResourceLoaderContext $context,
 449                 array $modules, $missing = array() )
 450         {
 451                 $out = '';
 452                 $exceptions = '';
 453                 if ( $modules === array() && $missing === array() ) {
 454                         return '/* No modules requested. Max made me put this here */';
 455                 }
 456
 457                 wfProfileIn( __METHOD__ );
 458                 // Pre-fetch blobs
 459                 if ( $context->shouldIncludeMessages() ) {
 460                         try {
 461                                 $blobs = MessageBlobStore::get( $this, $modules, $context->getLanguage() );
 462                         } catch ( Exception $e ) {
 463                                 // Add exception to the output as a comment
 464                                 $exceptions .= "/*\n{$e->__toString()}\n*/\n";
 465                         }
 466                 } else {
 467                         $blobs = array();
 468                 }
 469
 470                 // Generate output
 471                 foreach ( $modules as $name => $module ) {
 472                         wfProfileIn( __METHOD__ . '-' . $name );
 473                         try {
 474                                 $scripts = '';
 475                                 if ( $context->shouldIncludeScripts() ) {
 476                                         $scripts = $module->getScript( $context );
 477                                         if ( is_string( $scripts ) ) {
 478                                                 // bug 27054: Append semicolon to prevent weird bugs
 479                                                 // caused by files not terminating their statements right
 480                                                 $scripts .= ";\n";
 481                                         }
 482                                 }
 483                                 // Styles
 484                                 $styles = array();
 485                                 if ( $context->shouldIncludeStyles() ) {
 486                                         $styles = $module->getStyles( $context );
 487                                 }
 488
 489                                 // Messages
 490                                 $messagesBlob = isset( $blobs[$name] ) ? $blobs[$name] : '{}';
 491
 492                                 // Append output
 493                                 switch ( $context->getOnly() ) {
 494                                         case 'scripts':
 495                                                 if ( is_string( $scripts ) ) {
 496                                                         $out .= $scripts;
 497                                                 } else if ( is_array( $scripts ) ) {
 498                                                         $out .= self::makeLoaderImplementScript( $name, $scripts, array(), array() );
 499                                                 }
 500                                                 break;
 501                                         case 'styles':
 502                                                 $out .= self::makeCombinedStyles( $styles );
 503                                                 break;
 504                                         case 'messages':
 505                                                 $out .= self::makeMessageSetScript( new XmlJsCode( $messagesBlob ) );
 506                                                 break;
 507                                         default:
 508                                                 // Minify CSS before embedding in mw.loader.implement call
 509                                                 // (unless in debug mode)
 510                                                 if ( !$context->getDebug() ) {
 511                                                         foreach ( $styles as $media => $style ) {
 512                                                                 if ( is_string( $style ) ) {
 513                                                                         $styles[$media] = $this->filter( 'minify-css', $style );
 514                                                                 }
 515                                                         }
 516                                                 }
 517                                                 $out .= self::makeLoaderImplementScript( $name, $scripts, $styles,
 518                                                         new XmlJsCode( $messagesBlob ) );
 519                                                 break;
 520                                 }
 521                         } catch ( Exception $e ) {
 522                                 // Add exception to the output as a comment
 523                                 $exceptions .= "/*\n{$e->__toString()}\n*/\n";
 524
 525                                 // Register module as missing
 526                                 $missing[] = $name;
 527                                 unset( $modules[$name] );
 528                         }
 529                         wfProfileOut( __METHOD__ . '-' . $name );
 530                 }
 531
 532                 // Update module states
 533                 if ( $context->shouldIncludeScripts() ) {
 534                         // Set the state of modules loaded as only scripts to ready
 535                         if ( count( $modules ) && $context->getOnly() === 'scripts'
 536                                 && !isset( $modules['startup'] ) )
 537                         {
 538                                 $out .= self::makeLoaderStateScript(
 539                                         array_fill_keys( array_keys( $modules ), 'ready' ) );
 540                         }
 541                         // Set the state of modules which were requested but unavailable as missing
 542                         if ( is_array( $missing ) && count( $missing ) ) {
 543                                 $out .= self::makeLoaderStateScript( array_fill_keys( $missing, 'missing' ) );
 544                         }
 545                 }
 546
 547                 if ( !$context->getDebug() ) {
 548                         if ( $context->getOnly() === 'styles' ) {
 549                                 $out = $this->filter( 'minify-css', $out );
 550                         } else {
 551                                 $out = $this->filter( 'minify-js', $out );
 552                         }
 553                 }
 554
 555                 wfProfileOut( __METHOD__ );
 556                 return $exceptions . $out;
 557         }
 558
 559         /* Static Methods */
 560
 561         /**
 562          * Returns JS code to call to mw.loader.implement for a module with
 563          * given properties.
 564          *
 565          * @param $name Module name
 566          * @param $scripts Mixed: List of URLs to JavaScript files or String of JavaScript code
 567          * @param $styles Mixed: List of CSS strings keyed by media type, or list of lists of URLs to
 568          * CSS files keyed by media type
 569          * @param $messages Mixed: List of messages associated with this module. May either be an
 570          *     associative array mapping message key to value, or a JSON-encoded message blob containing
 571          *     the same data, wrapped in an XmlJsCode object.
 572          *
 573          * @return string
 574          */
 575         public static function makeLoaderImplementScript( $name, $scripts, $styles, $messages ) {
 576                 if ( is_string( $scripts ) ) {
 577                         $scripts = new XmlJsCode( "function( $ ) {{$scripts}}" );
 578                 } else if ( !is_array( $scripts ) ) {
 579                         throw new MWException( 'Invalid scripts error. Array of URLs or string of code expected.' );
 580                 }
 581                 return Xml::encodeJsCall(
 582                         'mw.loader.implement',
 583                         array(
 584                                 $name,
 585                                 $scripts,
 586                                 (object)$styles,
 587                                 (object)$messages
 588                         ) );
 589         }
 590
 591         /**
 592          * Returns JS code which, when called, will register a given list of messages.
 593          *
 594          * @param $messages Mixed: Either an associative array mapping message key to value, or a
 595          *     JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
 596          *
 597          * @return string
 598          */
 599         public static function makeMessageSetScript( $messages ) {
 600                 return Xml::encodeJsCall( 'mw.messages.set', array( (object)$messages ) );
 601         }
 602
 603         /**
 604          * Combines an associative array mapping media type to CSS into a
 605          * single stylesheet with @media blocks.
 606          *
 607          * @param $styles Array: List of CSS strings keyed by media type
 608          *
 609          * @return string
 610          */
 611         public static function makeCombinedStyles( array $styles ) {
 612                 $out = '';
 613                 foreach ( $styles as $media => $style ) {
 614                         // Transform the media type based on request params and config
 615                         // The way that this relies on $wgRequest to propagate request params is slightly evil
 616                         $media = OutputPage::transformCssMedia( $media );
 617
 618                         if ( $media === null ) {
 619                                 // Skip
 620                         } else if ( $media === '' || $media == 'all' ) {
 621                                 // Don't output invalid or frivolous @media statements
 622                                 $out .= "$style\n";
 623                         } else {
 624                                 $out .= "@media $media {\n" . str_replace( "\n", "\n\t", "\t" . $style ) . "\n}\n";
 625                         }
 626                 }
 627                 return $out;
 628         }
 629
 630         /**
 631          * Returns a JS call to mw.loader.state, which sets the state of a
 632          * module or modules to a given value. Has two calling conventions:
 633          *
 634          *    - ResourceLoader::makeLoaderStateScript( $name, $state ):
 635          *         Set the state of a single module called $name to $state
 636          *
 637          *    - ResourceLoader::makeLoaderStateScript( array( $name => $state, ... ) ):
 638          *         Set the state of modules with the given names to the given states
 639          *
 640          * @param $name string
 641          * @param $state
 642          *
 643          * @return string
 644          */
 645         public static function makeLoaderStateScript( $name, $state = null ) {
 646                 if ( is_array( $name ) ) {
 647                         return Xml::encodeJsCall( 'mw.loader.state', array( $name ) );
 648                 } else {
 649                         return Xml::encodeJsCall( 'mw.loader.state', array( $name, $state ) );
 650                 }
 651         }
 652
 653         /**
 654          * Returns JS code which calls the script given by $script. The script will
 655          * be called with local variables name, version, dependencies and group,
 656          * which will have values corresponding to $name, $version, $dependencies
 657          * and $group as supplied.
 658          *
 659          * @param $name String: Module name
 660          * @param $version Integer: Module version number as a timestamp
 661          * @param $dependencies Array: List of module names on which this module depends
 662          * @param $group String: Group which the module is in.
 663          * @param $script String: JavaScript code
 664          *
 665          * @return string
 666          */
 667         public static function makeCustomLoaderScript( $name, $version, $dependencies, $group, $script ) {
 668                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 669                 return Xml::encodeJsCall(
 670                         "( function( name, version, dependencies, group ) {\n\t$script\n} )",
 671                         array( $name, $version, $dependencies, $group ) );
 672         }
 673
 674         /**
 675          * Returns JS code which calls mw.loader.register with the given
 676          * parameters. Has three calling conventions:
 677          *
 678          *   - ResourceLoader::makeLoaderRegisterScript( $name, $version, $dependencies, $group ):
 679          *       Register a single module.
 680          *
 681          *   - ResourceLoader::makeLoaderRegisterScript( array( $name1, $name2 ) ):
 682          *       Register modules with the given names.
 683          *
 684          *   - ResourceLoader::makeLoaderRegisterScript( array(
 685          *        array( $name1, $version1, $dependencies1, $group1 ),
 686          *        array( $name2, $version2, $dependencies1, $group2 ),
 687          *        ...
 688          *     ) ):
 689          *        Registers modules with the given names and parameters.
 690          *
 691          * @param $name String: Module name
 692          * @param $version Integer: Module version number as a timestamp
 693          * @param $dependencies Array: List of module names on which this module depends
 694          * @param $group String: group which the module is in.
 695          *
 696          * @return string
 697          */
 698         public static function makeLoaderRegisterScript( $name, $version = null,
 699                 $dependencies = null, $group = null )
 700         {
 701                 if ( is_array( $name ) ) {
 702                         return Xml::encodeJsCall( 'mw.loader.register', array( $name ) );
 703                 } else {
 704                         $version = (int) $version > 1 ? (int) $version : 1;
 705                         return Xml::encodeJsCall( 'mw.loader.register',
 706                                 array( $name, $version, $dependencies, $group ) );
 707                 }
 708         }
 709
 710         /**
 711          * Returns JS code which runs given JS code if the client-side framework is
 712          * present.
 713          *
 714          * @param $script String: JavaScript code
 715          *
 716          * @return string
 717          */
 718         public static function makeLoaderConditionalScript( $script ) {
 719                 $script = str_replace( "\n", "\n\t", trim( $script ) );
 720                 return "if ( window.mediaWiki ) {\n\t$script\n}\n";
 721         }
 722
 723         /**
 724          * Returns JS code which will set the MediaWiki configuration array to
 725          * the given value.
 726          *
 727          * @param $configuration Array: List of configuration values keyed by variable name
 728          *
 729          * @return string
 730          */
 731         public static function makeConfigSetScript( array $configuration ) {
 732                 return Xml::encodeJsCall( 'mw.config.set', array( $configuration ) );
 733         }
 734
 735         /**
 736          * Convert an array of module names to a packed query string.
 737          *
 738          * For example, array( 'foo.bar', 'foo.baz', 'bar.baz', 'bar.quux' )
 739          * becomes 'foo.bar,baz|bar.baz,quux'
 740          * @param $modules array of module names (strings)
 741          * @return string Packed query string
 742          */
 743         public static function makePackedModulesString( $modules ) {
 744                 $groups = array(); // array( prefix => array( suffixes ) )
 745                 foreach ( $modules as $module ) {
 746                         $pos = strrpos( $module, '.' );
 747                         $prefix = $pos === false ? '' : substr( $module, 0, $pos );
 748                         $suffix = $pos === false ? $module : substr( $module, $pos + 1 );
 749                         $groups[$prefix][] = $suffix;
 750                 }
 751
 752                 $arr = array();
 753                 foreach ( $groups as $prefix => $suffixes ) {
 754                         $p = $prefix === '' ? '' : $prefix . '.';
 755                         $arr[] = $p . implode( ',', $suffixes );
 756                 }
 757                 $str = implode( '|', $arr );
 758                 return $str;
 759         }
 760
 761         /**
 762          * Determine whether debug mode was requested
 763          * Order of priority is 1) request param, 2) cookie, 3) $wg setting
 764          * @return bool
 765          */
 766         public static function inDebugMode() {
 767                 global $wgRequest, $wgResourceLoaderDebug;
 768                 static $retval = null;
 769                 if ( !is_null( $retval ) ) {
 770                         return $retval;
 771                 }
 772                 return $retval = $wgRequest->getFuzzyBool( 'debug',
 773                         $wgRequest->getCookie( 'resourceLoaderDebug', '', $wgResourceLoaderDebug ) );
 774         }
 775 }