resources/mediawiki/mediawiki.js

   1 /*
   2  * JavaScript backwards-compatibility and support
   3  */
   4
   5 // Implementation of string trimming functionality introduced natively in JavaScript 1.8.1
   6 if ( typeof String.prototype.trim === 'undefined' ) {
   7         // Add removing trailing and leading whitespace functionality cross-browser
   8         // See also: http://blog.stevenlevithan.com/archives/faster-trim-javascript
   9         String.prototype.trim = function() {
  10                 return this.replace( /^\s+|\s+$/g, '' );
  11         };
  12 }
  13 if ( typeof String.prototype.trimLeft === 'undefined' ) {
  14         String.prototype.trimLeft = function() {
  15                 return this.replace( /^\s\s*/, "" );
  16         };
  17 }
  18 if ( typeof String.prototype.trimRight === 'undefined' ) {
  19         String.prototype.trimRight = function() {
  20                 return this.replace(/\s\s*$/, "");
  21         };
  22 }
  23
  24 /*
  25  * Prototype enhancements
  26  */
  27
  28 // Capitalize the first character of the given string
  29 if ( typeof String.prototype.ucFirst === 'undefined' ) {
  30         String.prototype.ucFirst = function() {
  31                 return this.substr(0, 1).toUpperCase() + this.substr(1, this.length);
  32         };
  33 }
  34
  35 // Escape all RegExp special characters such that the result can be safely used
  36 // in a RegExp as a literal.
  37 if ( typeof String.prototype.escapeRE === 'undefined' ) {
  38         String.prototype.escapeRE = function() {
  39                 return this.replace (/([\\{}()|.?*+^$\[\]])/g, "\\$1");
  40         };
  41 }
  42
  43 /*
  44  * Core MediaWiki JavaScript Library
  45  */
  46
  47 // Attach to window
  48 window.mediaWiki = new ( function( $ ) {
  49
  50         /* Constants */
  51
  52         // This will not change until we are 100% ready to turn off legacy globals
  53         var LEGACY_GLOBALS = true;
  54
  55         /* Private Members */
  56
  57         // List of messages that have been requested to be loaded
  58         var messageQueue = {};
  59
  60         /* Prototypes */
  61
  62         /**
  63          * An object which allows single and multiple get/set/exists functionality
  64          * on a list of key / value pairs.
  65          *
  66          * @param {boolean} global Whether to get/set/exists values on the window
  67          *   object or a private object
  68          */
  69         function Map( global ) {
  70                 this.values = ( global === true ) ? window : {};
  71         };
  72
  73         /**
  74          * Gets the value of a key, or a list of key/value pairs for an array of keys.
  75          *
  76          * If called with no arguments, all values will be returned.
  77          *
  78          * @param {mixed} selection Key or array of keys to get values for
  79          * @param {mixed} fallback Value to use in case key(s) do not exist (optional)
  80          */
  81         Map.prototype.get = function( selection, fallback ) {
  82                 if ( typeof selection === 'object' ) {
  83                         selection = $.makeArray( selection );
  84                         var results = {};
  85                         for ( var i = 0; i < selection.length; i++ ) {
  86                                 results[selection[i]] = this.get( selection[i], fallback );
  87                         }
  88                         return results;
  89                 } else if ( typeof selection === 'string' ) {
  90                         if ( typeof this.values[selection] === 'undefined' ) {
  91                                 if ( typeof fallback !== 'undefined' ) {
  92                                         return fallback;
  93                                 }
  94                                 return null;
  95                         }
  96                         return this.values[selection];
  97                 }
  98                 return this.values;
  99         };
 100
 101         /**
 102          * Sets one or multiple key/value pairs.
 103          *
 104          * @param {mixed} selection Key or object of key/value pairs to set
 105          * @param {mixed} value Value to set (optional, only in use when key is a string)
 106          */
 107         Map.prototype.set = function( selection, value ) {
 108                 if ( typeof selection === 'object' ) {
 109                         for ( var s in selection ) {
 110                                 this.values[s] = selection[s];
 111                         }
 112                 } else if ( typeof selection === 'string' && typeof value !== 'undefined' ) {
 113                         this.values[selection] = value;
 114                 }
 115         };
 116
 117         /**
 118          * Checks if one or multiple keys exist.
 119          *
 120          * @param {mixed} key Key or array of keys to check
 121          * @return {boolean} Existence of key(s)
 122          */
 123         Map.prototype.exists = function( selection ) {
 124                 if ( typeof keys === 'object' ) {
 125                         for ( var s = 0; s < selection.length; s++ ) {
 126                                 if ( !( selection[s] in this.values ) ) {
 127                                         return false;
 128                                 }
 129                         }
 130                         return true;
 131                 } else {
 132                         return selection in this.values;
 133                 }
 134         };
 135
 136         /**
 137          * Message object, similar to Message in PHP
 138          */
 139         function Message( map, key, parameters ) {
 140                 this.format = 'parse';
 141                 this.map = map;
 142                 this.key = key;
 143                 this.parameters = typeof parameters === 'undefined' ? [] : $.makeArray( parameters );
 144         };
 145
 146         /**
 147          * Appends parameters for replacement
 148          *
 149          * @param {mixed} args First in a list of variadic arguments to append as message parameters
 150          */
 151         Message.prototype.params = function( parameters ) {
 152                 for ( var i = 0; i < parameters.length; i++ ) {
 153                         this.parameters[this.parameters.length] = parameters[i];
 154                 }
 155                 return this;
 156         };
 157
 158         /**
 159          * Converts message object to it's string form based on the state of format
 160          *
 161          * @return {string} String form of message
 162          */
 163         Message.prototype.toString = function() {
 164                 if ( !this.map.exists( this.key ) ) {
 165                         // Return <key> if key does not exist
 166                         return '<' + this.key + '>';
 167                 }
 168                 var text = this.map.get( this.key );
 169                 var parameters = this.parameters;
 170                 text = text.replace( /\$(\d+)/g, function( string, match ) {
 171                         var index = parseInt( match, 10 ) - 1;
 172                         return index in parameters ? parameters[index] : '$' + match;
 173                 } );
 174                 /* This should be fixed up when we have a parser
 175                 if ( this.format === 'parse' && 'language' in mediaWiki ) {
 176                         text = mediaWiki.language.parse( text );
 177                 }
 178                 */
 179                 return text;
 180         };
 181
 182         /**
 183          * Changes format to parse and converts message to string
 184          *
 185          * @return {string} String form of parsed message
 186          */
 187         Message.prototype.parse = function() {
 188                 this.format = 'parse';
 189                 return this.toString();
 190         };
 191
 192         /**
 193          * Changes format to plain and converts message to string
 194          *
 195          * @return {string} String form of plain message
 196          */
 197         Message.prototype.plain = function() {
 198                 this.format = 'plain';
 199                 return this.toString();
 200         };
 201
 202         /**
 203          * Checks if message exists
 204          *
 205          * @return {string} String form of parsed message
 206          */
 207         Message.prototype.exists = function() {
 208                 return this.map.exists( this.key );
 209         };
 210
 211         /**
 212          * User object
 213          */
 214         function User() {
 215                 this.options = new Map();
 216         }
 217
 218         /* Public Members */
 219
 220         /*
 221          * Dummy function which in debug mode can be replaced with a function that
 222          * does something clever
 223          */
 224         this.log = function() { };
 225
 226         /*
 227          * List of configuration values
 228          *
 229          * In legacy mode the values this object wraps will be in the global space
 230          */
 231         this.config = new Map( LEGACY_GLOBALS );
 232
 233         /*
 234          * Information about the current user
 235          */
 236         this.user = new User();
 237
 238         /*
 239          * Localization system
 240          */
 241         this.messages = new Map();
 242
 243         /* Public Methods */
 244
 245         /**
 246          * Gets a message object, similar to wfMessage()
 247          *
 248          * @param {string} key Key of message to get
 249          * @param {mixed} params First argument in a list of variadic arguments, each a parameter for $
 250          * replacement
 251          */
 252         this.message = function( key, parameters ) {
 253                 // Support variadic arguments
 254                 if ( typeof parameters !== 'undefined' ) {
 255                         parameters = $.makeArray( arguments );
 256                         parameters.shift();
 257                 } else {
 258                         parameters = [];
 259                 }
 260                 return new Message( mediaWiki.messages, key, parameters );
 261         };
 262
 263         /**
 264          * Gets a message string, similar to wfMsg()
 265          *
 266          * @param {string} key Key of message to get
 267          * @param {mixed} params First argument in a list of variadic arguments, each a parameter for $
 268          * replacement
 269          */
 270         this.msg = function( key, parameters ) {
 271                 return mediaWiki.message.apply( mediaWiki.message, arguments ).toString();
 272         };
 273
 274         /**
 275          * Client-side module loader which integrates with the MediaWiki ResourceLoader
 276          */
 277         this.loader = new ( function() {
 278
 279                 /* Private Members */
 280
 281                 /**
 282                  * Mapping of registered modules
 283                  *
 284                  * The jquery module is pre-registered, because it must have already
 285                  * been provided for this object to have been built, and in debug mode
 286                  * jquery would have been provided through a unique loader request,
 287                  * making it impossible to hold back registration of jquery until after
 288                  * mediawiki.
 289                  *
 290                  * Format:
 291                  *      {
 292                  *              'moduleName': {
 293                  *                      'dependencies': ['required module', 'required module', ...], (or) function() {}
 294                  *                      'state': 'registered', 'loading', 'loaded', 'ready', or 'error'
 295                  *                      'script': function() {},
 296                  *                      'style': 'css code string',
 297                  *                      'messages': { 'key': 'value' },
 298                  *                      'version': ############## (unix timestamp)
 299                  *              }
 300                  *      }
 301                  */
 302                 var registry = {};
 303                 // List of modules which will be loaded as when ready
 304                 var batch = [];
 305                 // List of modules to be loaded
 306                 var queue = [];
 307                 // List of callback functions waiting for modules to be ready to be called
 308                 var jobs = [];
 309                 // Flag indicating that requests should be suspended
 310                 var suspended = true;
 311                 // Flag inidicating that document ready has occured
 312                 var ready = false;
 313
 314                 /* Private Methods */
 315
 316                 function compare( a, b ) {
 317                         if ( a.length != b.length ) {
 318                                 return false;
 319                         }
 320                         for ( var i = 0; i < b.length; i++ ) {
 321                                 if ( $.isArray( a[i] ) ) {
 322                                         if ( !compare( a[i], b[i] ) ) {
 323                                                 return false;
 324                                         }
 325                                 }
 326                                 if ( a[i] !== b[i] ) {
 327                                         return false;
 328                                 }
 329                         }
 330                         return true;
 331                 };
 332
 333                 /**
 334                  * Generates an ISO8601 "basic" string from a UNIX timestamp
 335                  */
 336                 function formatVersionNumber( timestamp ) {
 337                         function pad( a, b, c ) {
 338                                 return [a < 10 ? '0' + a : a, b < 10 ? '0' + b : b, c < 10 ? '0' + c : c].join( '' );
 339                         }
 340                         var d = new Date()
 341                         d.setTime( timestamp * 1000 );
 342                         return [
 343                                 pad( d.getUTCFullYear(), d.getUTCMonth() + 1, d.getUTCDate() ), 'T',
 344                                 pad( d.getUTCHours(), d.getUTCMinutes(), d.getUTCSeconds() ), 'Z'
 345                         ].join( '' );
 346                 }
 347
 348                 /**
 349                  * Recursively resolves dependencies and detects circular references
 350                  */
 351                 function recurse( module, resolved, unresolved ) {
 352                         if ( typeof registry[module] === 'undefined' ) {
 353                                 throw new Error( 'Unknown dependency: ' + module );
 354                         }
 355                         // Resolves dynamic loader function and replaces it with its own results
 356                         if ( typeof registry[module].dependencies === 'function' ) {
 357                                 registry[module].dependencies = registry[module].dependencies();
 358                                 // Ensures the module's dependencies are always in an array
 359                                 if ( typeof registry[module].dependencies !== 'object' ) {
 360                                         registry[module].dependencies = [registry[module].dependencies];
 361                                 }
 362                         }
 363                         // Tracks down dependencies
 364                         for ( var n = 0; n < registry[module].dependencies.length; n++ ) {
 365                                 if ( $.inArray( registry[module].dependencies[n], resolved ) === -1 ) {
 366                                         if ( $.inArray( registry[module].dependencies[n], unresolved ) !== -1 ) {
 367                                                 throw new Error(
 368                                                         'Circular reference detected: ' + module +
 369                                                         ' -> ' + registry[module].dependencies[n]
 370                                                 );
 371                                         }
 372                                         recurse( registry[module].dependencies[n], resolved, unresolved );
 373                                 }
 374                         }
 375                         resolved[resolved.length] = module;
 376                         unresolved.splice( $.inArray( module, unresolved ), 1 );
 377                 }
 378
 379                 /**
 380                  * Gets a list of module names that a module depends on in their proper dependency order
 381                  *
 382                  * @param mixed string module name or array of string module names
 383                  * @return list of dependencies
 384                  * @throws Error if circular reference is detected
 385                  */
 386                 function resolve( module, resolved, unresolved ) {
 387                         // Allow calling with an array of module names
 388                         if ( typeof module === 'object' ) {
 389                                 var modules = [];
 390                                 for ( var m = 0; m < module.length; m++ ) {
 391                                         var dependencies = resolve( module[m] );
 392                                         for ( var n = 0; n < dependencies.length; n++ ) {
 393                                                 modules[modules.length] = dependencies[n];
 394                                         }
 395                                 }
 396                                 return modules;
 397                         } else if ( typeof module === 'string' ) {
 398                                 // Undefined modules have no dependencies
 399                                 if ( !( module in registry ) ) {
 400                                         return [];
 401                                 }
 402                                 var resolved = [];
 403                                 recurse( module, resolved, [] );
 404                                 return resolved;
 405                         }
 406                         throw new Error( 'Invalid module argument: ' + module );
 407                 };
 408
 409                 /**
 410                  * Narrows a list of module names down to those matching a specific
 411                  * state. Possible states are 'undefined', 'registered', 'loading',
 412                  * 'loaded', or 'ready'
 413                  *
 414                  * @param mixed string or array of strings of module states to filter by
 415                  * @param array list of module names to filter (optional, all modules
 416                  *   will be used by default)
 417                  * @return array list of filtered module names
 418                  */
 419                 function filter( states, modules ) {
 420                         // Allow states to be given as a string
 421                         if ( typeof states === 'string' ) {
 422                                 states = [states];
 423                         }
 424                         // If called without a list of modules, build and use a list of all modules
 425                         var list = [];
 426                         if ( typeof modules === 'undefined' ) {
 427                                 modules = [];
 428                                 for ( module in registry ) {
 429                                         modules[modules.length] = module;
 430                                 }
 431                         }
 432                         // Build a list of modules which are in one of the specified states
 433                         for ( var s = 0; s < states.length; s++ ) {
 434                                 for ( var m = 0; m < modules.length; m++ ) {
 435                                         if ( typeof registry[modules[m]] === 'undefined' ) {
 436                                                 // Module does not exist
 437                                                 if ( states[s] == 'undefined' ) {
 438                                                         // OK, undefined
 439                                                         list[list.length] = modules[m];
 440                                                 }
 441                                         } else {
 442                                                 // Module exists, check state
 443                                                 if ( registry[modules[m]].state === states[s] ) {
 444                                                         // OK, correct state
 445                                                         list[list.length] = modules[m];
 446                                                 }
 447                                         }
 448                                 }
 449                         }
 450                         return list;
 451                 }
 452
 453                 /**
 454                  * Executes a loaded module, making it ready to use
 455                  *
 456                  * @param string module name to execute
 457                  */
 458                 function execute( module ) {
 459                         if ( typeof registry[module] === 'undefined' ) {
 460                                 throw new Error( 'Module has not been registered yet: ' + module );
 461                         } else if ( registry[module].state === 'registered' ) {
 462                                 throw new Error( 'Module has not been requested from the server yet: ' + module );
 463                         } else if ( registry[module].state === 'loading' ) {
 464                                 throw new Error( 'Module has not completed loading yet: ' + module );
 465                         } else if ( registry[module].state === 'ready' ) {
 466                                 throw new Error( 'Module has already been loaded: ' + module );
 467                         }
 468                         // Add style sheet to document
 469                         if ( typeof registry[module].style === 'string' && registry[module].style.length ) {
 470                                 $( 'head' )
 471                                         .append( '<style type="text/css">' + registry[module].style + '</style>' );
 472                         } else if ( typeof registry[module].style === 'object'
 473                                 && !( registry[module].style instanceof Array ) )
 474                         {
 475                                 for ( var media in registry[module].style ) {
 476                                         $( 'head' ).append(
 477                                                 '<style type="text/css" media="' + media + '">' +
 478                                                 registry[module].style[media] +
 479                                                 '</style>'
 480                                         );
 481                                 }
 482                         }
 483                         // Add localizations to message system
 484                         if ( typeof registry[module].messages === 'object' ) {
 485                                 mediaWiki.messages.set( registry[module].messages );
 486                         }
 487                         // Execute script
 488                         try {
 489                                 registry[module].script();
 490                                 registry[module].state = 'ready';
 491                                 // Run jobs who's dependencies have just been met
 492                                 for ( var j = 0; j < jobs.length; j++ ) {
 493                                         if ( compare(
 494                                                 filter( 'ready', jobs[j].dependencies ),
 495                                                 jobs[j].dependencies ) )
 496                                         {
 497                                                 if ( typeof jobs[j].ready === 'function' ) {
 498                                                         jobs[j].ready();
 499                                                 }
 500                                                 jobs.splice( j, 1 );
 501                                                 j--;
 502                                         }
 503                                 }
 504                                 // Execute modules who's dependencies have just been met
 505                                 for ( r in registry ) {
 506                                         if ( registry[r].state == 'loaded' ) {
 507                                                 if ( compare(
 508                                                         filter( ['ready'], registry[r].dependencies ),
 509                                                         registry[r].dependencies ) )
 510                                                 {
 511                                                         execute( r );
 512                                                 }
 513                                         }
 514                                 }
 515                         } catch ( e ) {
 516                                 mediaWiki.log( 'Exception thrown by ' + module + ': ' + e.message );
 517                                 mediaWiki.log( e );
 518                                 registry[module].state = 'error';
 519                                 // Run error callbacks of jobs affected by this condition
 520                                 for ( var j = 0; j < jobs.length; j++ ) {
 521                                         if ( $.inArray( module, jobs[j].dependencies ) !== -1 ) {
 522                                                 if ( typeof jobs[j].error === 'function' ) {
 523                                                         jobs[j].error();
 524                                                 }
 525                                                 jobs.splice( j, 1 );
 526                                                 j--;
 527                                         }
 528                                 }
 529                         }
 530                 }
 531
 532                 /**
 533                  * Adds a dependencies to the queue with optional callbacks to be run
 534                  * when the dependencies are ready or fail
 535                  *
 536                  * @param mixed string moulde name or array of string module names
 537                  * @param function ready callback to execute when all dependencies are ready
 538                  * @param function error callback to execute when any dependency fails
 539                  */
 540                 function request( dependencies, ready, error ) {
 541                         // Allow calling by single module name
 542                         if ( typeof dependencies === 'string' ) {
 543                                 dependencies = [dependencies];
 544                                 if ( dependencies[0] in registry ) {
 545                                         for ( var n = 0; n < registry[dependencies[0]].dependencies.length; n++ ) {
 546                                                 dependencies[dependencies.length] =
 547                                                         registry[dependencies[0]].dependencies[n];
 548                                         }
 549                                 }
 550                         }
 551                         // Add ready and error callbacks if they were given
 552                         if ( arguments.length > 1 ) {
 553                                 jobs[jobs.length] = {
 554                                         'dependencies': filter(
 555                                                 ['undefined', 'registered', 'loading', 'loaded'],
 556                                                 dependencies ),
 557                                         'ready': ready,
 558                                         'error': error
 559                                 };
 560                         }
 561                         // Queue up any dependencies that are undefined or registered
 562                         dependencies = filter( ['undefined', 'registered'], dependencies );
 563                         for ( var n = 0; n < dependencies.length; n++ ) {
 564                                 if ( $.inArray( dependencies[n], queue ) === -1 ) {
 565                                         queue[queue.length] = dependencies[n];
 566                                 }
 567                         }
 568                         // Work the queue
 569                         mediaWiki.loader.work();
 570                 }
 571
 572                 function sortQuery(o) {
 573                         var sorted = {}, key, a = [];
 574                         for ( key in o ) {
 575                                 if ( o.hasOwnProperty( key ) ) {
 576                                         a.push( key );
 577                                 }
 578                         }
 579                         a.sort();
 580                         for ( key = 0; key < a.length; key++ ) {
 581                                 sorted[a[key]] = o[a[key]];
 582                         }
 583                         return sorted;
 584                 }
 585
 586                 /* Public Methods */
 587
 588                 /**
 589                  * Requests dependencies from server, loading and executing when things when ready.
 590                  */
 591                 this.work = function() {
 592                         // Appends a list of modules to the batch
 593                         for ( var q = 0; q < queue.length; q++ ) {
 594                                 // Only request modules which are undefined or registered
 595                                 if ( !( queue[q] in registry ) || registry[queue[q]].state == 'registered' ) {
 596                                         // Prevent duplicate entries
 597                                         if ( $.inArray( queue[q], batch ) === -1 ) {
 598                                                 batch[batch.length] = queue[q];
 599                                                 // Mark registered modules as loading
 600                                                 if ( queue[q] in registry ) {
 601                                                         registry[queue[q]].state = 'loading';
 602                                                 }
 603                                         }
 604                                 }
 605                         }
 606                         // Clean up the queue
 607                         queue = [];
 608                         // After document ready, handle the batch
 609                         if ( !suspended && batch.length ) {
 610                                 // Always order modules alphabetically to help reduce cache
 611                                 // misses for otherwise identical content
 612                                 batch.sort();
 613                                 // Build a list of request parameters
 614                                 var base = {
 615                                         'skin': mediaWiki.config.get( 'skin' ),
 616                                         'lang': mediaWiki.config.get( 'wgUserLanguage' ),
 617                                         'debug': mediaWiki.config.get( 'debug' )
 618                                 };
 619                                 // Extend request parameters with a list of modules in the batch
 620                                 var requests = [];
 621                                 // Split into groups
 622                                 var groups = {};
 623                                 for ( var b = 0; b < batch.length; b++ ) {
 624                                         var group = registry[batch[b]].group;
 625                                         if ( !( group in groups ) ) {
 626                                                 groups[group] = [];
 627                                         }
 628                                         groups[group][groups[group].length] = batch[b];
 629                                 }
 630                                 for ( var group in groups ) {
 631                                         // Calculate the highest timestamp
 632                                         var version = 0;
 633                                         for ( var g = 0; g < groups[group].length; g++ ) {
 634                                                 if ( registry[groups[group][g]].version > version ) {
 635                                                         version = registry[groups[group][g]].version;
 636                                                 }
 637                                         }
 638                                         requests[requests.length] = $.extend(
 639                                                 { 'modules': groups[group].join( '|' ), 'version': formatVersionNumber( version ) }, base
 640                                         );
 641                                 }
 642                                 // Clear the batch - this MUST happen before we append the
 643                                 // script element to the body or it's possible that the script
 644                                 // will be locally cached, instantly load, and work the batch
 645                                 // again, all before we've cleared it causing each request to
 646                                 // include modules which are already loaded
 647                                 batch = [];
 648                                 // Asynchronously append a script tag to the end of the body
 649                                 function request() {
 650                                         var html = '';
 651                                         for ( var r = 0; r < requests.length; r++ ) {
 652                                                 requests[r] = sortQuery( requests[r] );
 653                                                 // Build out the HTML
 654                                                 var src = mediaWiki.config.get( 'wgLoadScript' ) + '?' + $.param( requests[r] );
 655                                                 html += '<script type="text/javascript" src="' + src + '"></script>';
 656                                         }
 657                                         return html;
 658                                 }
 659                                 // Load asynchronously after doumument ready
 660                                 if ( ready ) {
 661                                         setTimeout( function() { $( 'body' ).append( request() ); }, 0 )
 662                                 } else {
 663                                         document.write( request() );
 664                                 }
 665                         }
 666                 };
 667
 668                 /**
 669                  * Registers a module, letting the system know about it and its
 670                  * dependencies. loader.js files contain calls to this function.
 671                  */
 672                 this.register = function( module, version, dependencies, group ) {
 673                         // Allow multiple registration
 674                         if ( typeof module === 'object' ) {
 675                                 for ( var m = 0; m < module.length; m++ ) {
 676                                         if ( typeof module[m] === 'string' ) {
 677                                                 mediaWiki.loader.register( module[m] );
 678                                         } else if ( typeof module[m] === 'object' ) {
 679                                                 mediaWiki.loader.register.apply( mediaWiki.loader, module[m] );
 680                                         }
 681                                 }
 682                                 return;
 683                         }
 684                         // Validate input
 685                         if ( typeof module !== 'string' ) {
 686                                 throw new Error( 'module must be a string, not a ' + typeof module );
 687                         }
 688                         if ( typeof registry[module] !== 'undefined' ) {
 689                                 throw new Error( 'module already implemeneted: ' + module );
 690                         }
 691                         // List the module as registered
 692                         registry[module] = {
 693                                 'state': 'registered',
 694                                 'group': typeof group === 'string' ? group : null,
 695                                 'dependencies': [],
 696                                 'version': typeof version !== 'undefined' ? parseInt( version ) : 0
 697                         };
 698                         if ( typeof dependencies === 'string' ) {
 699                                 // Allow dependencies to be given as a single module name
 700                                 registry[module].dependencies = [dependencies];
 701                         } else if ( typeof dependencies === 'object' || typeof dependencies === 'function' ) {
 702                                 // Allow dependencies to be given as an array of module names
 703                                 // or a function which returns an array
 704                                 registry[module].dependencies = dependencies;
 705                         }
 706                 };
 707
 708                 /**
 709                  * Implements a module, giving the system a course of action to take
 710                  * upon loading. Results of a request for one or more modules contain
 711                  * calls to this function.
 712                  */
 713                 this.implement = function( module, script, style, localization ) {
 714                         // Automaically register module
 715                         if ( typeof registry[module] === 'undefined' ) {
 716                                 mediaWiki.loader.register( module );
 717                         }
 718                         // Validate input
 719                         if ( typeof script !== 'function' ) {
 720                                 throw new Error( 'script must be a function, not a ' + typeof script );
 721                         }
 722                         if ( typeof style !== 'undefined'
 723                                 && typeof style !== 'string'
 724                                 && typeof style !== 'object' )
 725                         {
 726                                 throw new Error( 'style must be a string or object, not a ' + typeof style );
 727                         }
 728                         if ( typeof localization !== 'undefined'
 729                                 && typeof localization !== 'object' )
 730                         {
 731                                 throw new Error( 'localization must be an object, not a ' + typeof localization );
 732                         }
 733                         if ( typeof registry[module] !== 'undefined'
 734                                 && typeof registry[module].script !== 'undefined' )
 735                         {
 736                                 throw new Error( 'module already implemeneted: ' + module );
 737                         }
 738                         // Mark module as loaded
 739                         registry[module].state = 'loaded';
 740                         // Attach components
 741                         registry[module].script = script;
 742                         if ( typeof style === 'string'
 743                                 || typeof style === 'object' && !( style instanceof Array ) )
 744                         {
 745                                 registry[module].style = style;
 746                         }
 747                         if ( typeof localization === 'object' ) {
 748                                 registry[module].messages = localization;
 749                         }
 750                         // Execute or queue callback
 751                         if ( compare(
 752                                 filter( ['ready'], registry[module].dependencies ),
 753                                 registry[module].dependencies ) )
 754                         {
 755                                 execute( module );
 756                         } else {
 757                                 request( module );
 758                         }
 759                 };
 760
 761                 /**
 762                  * Executes a function as soon as one or more required modules are ready
 763                  *
 764                  * @param mixed string or array of strings of modules names the callback
 765                  *   dependencies to be ready before
 766                  * executing
 767                  * @param function callback to execute when all dependencies are ready (optional)
 768                  * @param function callback to execute when if dependencies have a errors (optional)
 769                  */
 770                 this.using = function( dependencies, ready, error ) {
 771                         // Validate input
 772                         if ( typeof dependencies !== 'object' && typeof dependencies !== 'string' ) {
 773                                 throw new Error( 'dependencies must be a string or an array, not a ' +
 774                                         typeof dependencies )
 775                         }
 776                         // Allow calling with a single dependency as a string
 777                         if ( typeof dependencies === 'string' ) {
 778                                 dependencies = [dependencies];
 779                         }
 780                         // Resolve entire dependency map
 781                         dependencies = resolve( dependencies );
 782                         // If all dependencies are met, execute ready immediately
 783                         if ( compare( filter( ['ready'], dependencies ), dependencies ) ) {
 784                                 if ( typeof ready === 'function' ) {
 785                                         ready();
 786                                 }
 787                         }
 788                         // If any dependencies have errors execute error immediately
 789                         else if ( filter( ['error'], dependencies ).length ) {
 790                                 if ( typeof error === 'function' ) {
 791                                         error();
 792                                 }
 793                         }
 794                         // Since some dependencies are not yet ready, queue up a request
 795                         else {
 796                                 request( dependencies, ready, error );
 797                         }
 798                 };
 799
 800                 /**
 801                  * Loads an external script or one or more modules for future use
 802                  *
 803                  * @param {mixed} modules either the name of a module, array of modules,
 804                  *   or a URL of an external script or style
 805                  * @param {string} type mime-type to use if calling with a URL of an
 806                  *   external script or style; acceptable values are "text/css" and
 807                  *   "text/javascript"; if no type is provided, text/javascript is
 808                  *   assumed
 809                  */
 810                 this.load = function( modules, type ) {
 811                         // Validate input
 812                         if ( typeof modules !== 'object' && typeof modules !== 'string' ) {
 813                                 throw new Error( 'dependencies must be a string or an array, not a ' +
 814                                         typeof dependencies )
 815                         }
 816                         // Allow calling with an external script or single dependency as a string
 817                         if ( typeof modules === 'string' ) {
 818                                 // Support adding arbitrary external scripts
 819                                 if ( modules.substr( 0, 7 ) == 'http://'
 820                                         || modules.substr( 0, 8 ) == 'https://' )
 821                                 {
 822                                         if ( type === 'text/css' ) {
 823                                                 $( 'head' )
 824                                                         .append( $( '<link rel="stylesheet" type="text/css" />' )
 825                                                         .attr( 'href', modules ) );
 826                                                 return true;
 827                                         } else if ( type === 'text/javascript' || typeof type === 'undefined' ) {
 828                                                 var script = '<script type="text/javascript" src="' + modules + '"></script>';
 829                                                 if ( ready ) {
 830                                                         $( 'body' ).append( script );
 831                                                 } else {
 832                                                         document.write( script );
 833                                                 }
 834                                                 return true;
 835                                         }
 836                                         // Unknown type
 837                                         return false;
 838                                 }
 839                                 // Called with single module
 840                                 modules = [modules];
 841                         }
 842                         // Resolve entire dependency map
 843                         modules = resolve( modules );
 844                         // If all modules are ready, nothing dependency be done
 845                         if ( compare( filter( ['ready'], modules ), modules ) ) {
 846                                 return true;
 847                         }
 848                         // If any modules have errors return false
 849                         else if ( filter( ['error'], modules ).length ) {
 850                                 return false;
 851                         }
 852                         // Since some modules are not yet ready, queue up a request
 853                         else {
 854                                 request( modules );
 855                                 return true;
 856                         }
 857                 };
 858
 859                 /**
 860                  * Flushes the request queue and begin executing load requests on demand
 861                  */
 862                 this.go = function() {
 863                         suspended = false;
 864                         mediaWiki.loader.work();
 865                 };
 866
 867                 /**
 868                  * Changes the state of a module
 869                  *
 870                  * @param mixed module string module name or object of module name/state pairs
 871                  * @param string state string state name
 872                  */
 873                 this.state = function( module, state ) {
 874                         if ( typeof module === 'object' ) {
 875                                 for ( var m in module ) {
 876                                         mediaWiki.loader.state( m, module[m] );
 877                                 }
 878                                 return;
 879                         }
 880                         if ( !( module in registry ) ) {
 881                                 mediaWiki.loader.register( module );
 882                         }
 883                         registry[module].state = state;
 884                 };
 885
 886                 /**
 887                  * Gets the version of a module
 888                  *
 889                  * @param string module name of module to get version for
 890                  */
 891                 this.version = function( module ) {
 892                         if ( module in registry && 'version' in registry[module] ) {
 893                                 return formatVersionNumber( registry[module].version );
 894                         }
 895                         return null;
 896                 }
 897
 898                 /* Cache document ready status */
 899
 900                 $(document).ready( function() { ready = true; } );
 901         } )();
 902
 903         /* Extension points */
 904
 905         this.legacy = {};
 906
 907 } )( jQuery );
 908
 909 /* Auto-register from pre-loaded startup scripts */
 910
 911 if ( typeof startUp === 'function' ) {
 912         startUp();
 913         delete startUp;
 914 }
 915
 916 // Alias $j to jQuery for backwards compatibility
 917 window.$j = jQuery;
 918 window.mw = mediaWiki;