resources/mediawiki/mediawiki.js

   1 /*
   2  * Core MediaWiki JavaScript Library
   3  */
   4
   5 var mw = ( function ( $, undefined ) {
   6         'use strict';
   7
   8         /* Private Members */
   9
  10         var hasOwn = Object.prototype.hasOwnProperty,
  11                 slice = Array.prototype.slice;
  12
  13         /* Object constructors */
  14
  15         /**
  16          * Creates an object that can be read from or written to from prototype functions
  17          * that allow both single and multiple variables at once.
  18          * @class mw.Map
  19          *
  20          * @constructor
  21          * @param {boolean} global Whether to store the values in the global window
  22          *  object or a exclusively in the object property 'values'.
  23          */
  24         function Map( global ) {
  25                 this.values = global === true ? window : {};
  26                 return this;
  27         }
  28
  29         Map.prototype = {
  30                 /**
  31                  * Get the value of one or multiple a keys.
  32                  *
  33                  * If called with no arguments, all values will be returned.
  34                  *
  35                  * @param {string|Array} selection String key or array of keys to get values for.
  36                  * @param {Mixed} [fallback] Value to use in case key(s) do not exist.
  37                  * @return mixed If selection was a string returns the value or null,
  38                  *  If selection was an array, returns an object of key/values (value is null if not found),
  39                  *  If selection was not passed or invalid, will return the 'values' object member (be careful as
  40                  *  objects are always passed by reference in JavaScript!).
  41                  * @return {string|Object|null} Values as a string or object, null if invalid/inexistant.
  42                  */
  43                 get: function ( selection, fallback ) {
  44                         var results, i;
  45                         // If we only do this in the `return` block, it'll fail for the
  46                         // call to get() from the mutli-selection block.
  47                         fallback = arguments.length > 1 ? fallback : null;
  48
  49                         if ( $.isArray( selection ) ) {
  50                                 selection = slice.call( selection );
  51                                 results = {};
  52                                 for ( i = 0; i < selection.length; i++ ) {
  53                                         results[selection[i]] = this.get( selection[i], fallback );
  54                                 }
  55                                 return results;
  56                         }
  57
  58                         if ( typeof selection === 'string' ) {
  59                                 if ( !hasOwn.call( this.values, selection ) ) {
  60                                         return fallback;
  61                                 }
  62                                 return this.values[selection];
  63                         }
  64
  65                         if ( selection === undefined ) {
  66                                 return this.values;
  67                         }
  68
  69                         // invalid selection key
  70                         return null;
  71                 },
  72
  73                 /**
  74                  * Sets one or multiple key/value pairs.
  75                  *
  76                  * @param {string|Object} selection String key to set value for, or object mapping keys to values.
  77                  * @param {Mixed} [value] Value to set (optional, only in use when key is a string)
  78                  * @return {Boolean} This returns true on success, false on failure.
  79                  */
  80                 set: function ( selection, value ) {
  81                         var s;
  82
  83                         if ( $.isPlainObject( selection ) ) {
  84                                 for ( s in selection ) {
  85                                         this.values[s] = selection[s];
  86                                 }
  87                                 return true;
  88                         }
  89                         if ( typeof selection === 'string' && arguments.length > 1 ) {
  90                                 this.values[selection] = value;
  91                                 return true;
  92                         }
  93                         return false;
  94                 },
  95
  96                 /**
  97                  * Checks if one or multiple keys exist.
  98                  *
  99                  * @param {Mixed} selection String key or array of keys to check
 100                  * @return {boolean} Existence of key(s)
 101                  */
 102                 exists: function ( selection ) {
 103                         var s;
 104
 105                         if ( $.isArray( selection ) ) {
 106                                 for ( s = 0; s < selection.length; s++ ) {
 107                                         if ( typeof selection[s] !== 'string' || !hasOwn.call( this.values, selection[s] ) ) {
 108                                                 return false;
 109                                         }
 110                                 }
 111                                 return true;
 112                         }
 113                         return typeof selection === 'string' && hasOwn.call( this.values, selection );
 114                 }
 115         };
 116
 117         /**
 118          * Object constructor for messages,
 119          * similar to the Message class in MediaWiki PHP.
 120          * @class mw.Message
 121          *
 122          * @constructor
 123          * @param {mw.Map} map Message storage
 124          * @param {string} key
 125          * @param {Array} [parameters]
 126          */
 127         function Message( map, key, parameters ) {
 128                 this.format = 'text';
 129                 this.map = map;
 130                 this.key = key;
 131                 this.parameters = parameters === undefined ? [] : slice.call( parameters );
 132                 return this;
 133         }
 134
 135         Message.prototype = {
 136                 /**
 137                  * Simple message parser, does $N replacement and nothing else.
 138                  *
 139                  * This may be overridden to provide a more complex message parser.
 140                  *
 141                  * The primary override is in mediawiki.jqueryMsg.
 142                  *
 143                  * This function will not be called for nonexistent messages.
 144                  */
 145                 parser: function () {
 146                         var parameters = this.parameters;
 147                         return this.map.get( this.key ).replace( /\$(\d+)/g, function ( str, match ) {
 148                                 var index = parseInt( match, 10 ) - 1;
 149                                 return parameters[index] !== undefined ? parameters[index] : '$' + match;
 150                         } );
 151                 },
 152
 153                 /**
 154                  * Appends (does not replace) parameters for replacement to the .parameters property.
 155                  *
 156                  * @param {Array} parameters
 157                  * @chainable
 158                  */
 159                 params: function ( parameters ) {
 160                         var i;
 161                         for ( i = 0; i < parameters.length; i += 1 ) {
 162                                 this.parameters.push( parameters[i] );
 163                         }
 164                         return this;
 165                 },
 166
 167                 /**
 168                  * Converts message object to it's string form based on the state of format.
 169                  *
 170                  * @return {string} Message as a string in the current form or `<key>` if key does not exist.
 171                  */
 172                 toString: function () {
 173                         var text;
 174
 175                         if ( !this.exists() ) {
 176                                 // Use <key> as text if key does not exist
 177                                 if ( this.format === 'escaped' || this.format === 'parse' ) {
 178                                         // format 'escaped' and 'parse' need to have the brackets and key html escaped
 179                                         return mw.html.escape( '<' + this.key + '>' );
 180                                 }
 181                                 return '<' + this.key + '>';
 182                         }
 183
 184                         if ( this.format === 'plain' || this.format === 'text' || this.format === 'parse' ) {
 185                                 text = this.parser();
 186                         }
 187
 188                         if ( this.format === 'escaped' ) {
 189                                 text = this.parser();
 190                                 text = mw.html.escape( text );
 191                         }
 192
 193                         return text;
 194                 },
 195
 196                 /**
 197                  * Changes format to 'parse' and converts message to string
 198                  *
 199                  * If jqueryMsg is loaded, this parses the message text from wikitext
 200                  * (where supported) to HTML
 201                  *
 202                  * Otherwise, it is equivalent to plain.
 203                  *
 204                  * @return {string} String form of parsed message
 205                  */
 206                 parse: function () {
 207                         this.format = 'parse';
 208                         return this.toString();
 209                 },
 210
 211                 /**
 212                  * Changes format to 'plain' and converts message to string
 213                  *
 214                  * This substitutes parameters, but otherwise does not change the
 215                  * message text.
 216                  *
 217                  * @return {string} String form of plain message
 218                  */
 219                 plain: function () {
 220                         this.format = 'plain';
 221                         return this.toString();
 222                 },
 223
 224                 /**
 225                  * Changes format to 'text' and converts message to string
 226                  *
 227                  * If jqueryMsg is loaded, {{-transformation is done where supported
 228                  * (such as {{plural:}}, {{gender:}}, {{int:}}).
 229                  *
 230                  * Otherwise, it is equivalent to plain.
 231                  */
 232                 text: function () {
 233                         this.format = 'text';
 234                         return this.toString();
 235                 },
 236
 237                 /**
 238                  * Changes the format to 'escaped' and converts message to string
 239                  *
 240                  * This is equivalent to using the 'text' format (see text method), then
 241                  * HTML-escaping the output.
 242                  *
 243                  * @return {string} String form of html escaped message
 244                  */
 245                 escaped: function () {
 246                         this.format = 'escaped';
 247                         return this.toString();
 248                 },
 249
 250                 /**
 251                  * Checks if message exists
 252                  *
 253                  * @see mw.Map#exists
 254                  * @return {boolean}
 255                  */
 256                 exists: function () {
 257                         return this.map.exists( this.key );
 258                 }
 259         };
 260
 261         /**
 262          * @class mw
 263          * @alternateClassName mediaWiki
 264          * @singleton
 265          */
 266         return {
 267                 /* Public Members */
 268
 269                 /**
 270                  * Dummy placeholder for {@link mw.log}
 271                  * @method
 272                  */
 273                 log: ( function () {
 274                         var log = function () {};
 275                         log.warn = function () {};
 276                         log.deprecate = function ( obj, key, val ) {
 277                                 obj[key] = val;
 278                         };
 279                         return log;
 280                 }() ),
 281
 282                 // Make the Map constructor publicly available.
 283                 Map: Map,
 284
 285                 // Make the Message constructor publicly available.
 286                 Message: Message,
 287
 288                 /**
 289                  * List of configuration values
 290                  *
 291                  * Dummy placeholder. Initiated in startUp module as a new instance of mw.Map().
 292                  * If `$wgLegacyJavaScriptGlobals` is true, this Map will have its values
 293                  * in the global window object.
 294                  * @property
 295                  */
 296                 config: null,
 297
 298                 /**
 299                  * Empty object that plugins can be installed in.
 300                  * @property
 301                  */
 302                 libs: {},
 303
 304                 /**
 305                  * @property
 306                  */
 307                 legacy: {},
 308
 309                 /**
 310                  * Localization system
 311                  * @property {mw.Map}
 312                  */
 313                 messages: new Map(),
 314
 315                 /* Public Methods */
 316
 317                 /**
 318                  * Gets a message object, similar to wfMessage().
 319                  *
 320                  * @param {string} key Key of message to get
 321                  * @param {Mixed...} parameters Parameters for the $N replacements in messages.
 322                  * @return {mw.Message}
 323                  */
 324                 message: function ( key ) {
 325                         // Variadic arguments
 326                         var parameters = slice.call( arguments, 1 );
 327                         return new Message( mw.messages, key, parameters );
 328                 },
 329
 330                 /**
 331                  * Gets a message string, similar to wfMessage()
 332                  *
 333                  * @see mw.Message#toString
 334                  * @param {string} key Key of message to get
 335                  * @param {Mixed...} parameters Parameters for the $N replacements in messages.
 336                  * @return {string}
 337                  */
 338                 msg: function ( /* key, parameters... */ ) {
 339                         return mw.message.apply( mw.message, arguments ).toString();
 340                 },
 341
 342                 /**
 343                  * Client-side module loader which integrates with the MediaWiki ResourceLoader
 344                  * @class mw.loader
 345                  * @singleton
 346                  */
 347                 loader: ( function () {
 348
 349                         /* Private Members */
 350
 351                         /**
 352                          * Mapping of registered modules
 353                          *
 354                          * The jquery module is pre-registered, because it must have already
 355                          * been provided for this object to have been built, and in debug mode
 356                          * jquery would have been provided through a unique loader request,
 357                          * making it impossible to hold back registration of jquery until after
 358                          * mediawiki.
 359                          *
 360                          * For exact details on support for script, style and messages, look at
 361                          * mw.loader.implement.
 362                          *
 363                          * Format:
 364                          *     {
 365                          *         'moduleName': {
 366                          *             'version': ############## (unix timestamp),
 367                          *             'dependencies': ['required.foo', 'bar.also', ...], (or) function () {}
 368                          *             'group': 'somegroup', (or) null,
 369                          *             'source': 'local', 'someforeignwiki', (or) null
 370                          *             'state': 'registered', 'loaded', 'loading', 'ready', 'error' or 'missing'
 371                          *             'script': ...,
 372                          *             'style': ...,
 373                          *             'messages': { 'key': 'value' },
 374                          *         }
 375                          *     }
 376                          *
 377                          * @property
 378                          * @private
 379                          */
 380                         var registry = {},
 381                                 //
 382                                 // Mapping of sources, keyed by source-id, values are objects.
 383                                 // Format:
 384                                 //      {
 385                                 //              'sourceId': {
 386                                 //                      'loadScript': 'http://foo.bar/w/load.php'
 387                                 //              }
 388                                 //      }
 389                                 //
 390                                 sources = {},
 391                                 // List of modules which will be loaded as when ready
 392                                 batch = [],
 393                                 // List of modules to be loaded
 394                                 queue = [],
 395                                 // List of callback functions waiting for modules to be ready to be called
 396                                 jobs = [],
 397                                 // Selector cache for the marker element. Use getMarker() to get/use the marker!
 398                                 $marker = null,
 399                                 // Buffer for addEmbeddedCSS.
 400                                 cssBuffer = '',
 401                                 // Callbacks for addEmbeddedCSS.
 402                                 cssCallbacks = $.Callbacks();
 403
 404                         /* Private methods */
 405
 406                         function getMarker() {
 407                                 // Cached ?
 408                                 if ( $marker ) {
 409                                         return $marker;
 410                                 }
 411
 412                                 $marker = $( 'meta[name="ResourceLoaderDynamicStyles"]' );
 413                                 if ( $marker.length ) {
 414                                         return $marker;
 415                                 }
 416                                 mw.log( 'getMarker> No <meta name="ResourceLoaderDynamicStyles"> found, inserting dynamically.' );
 417                                 $marker = $( '<meta>' ).attr( 'name', 'ResourceLoaderDynamicStyles' ).appendTo( 'head' );
 418
 419                                 return $marker;
 420                         }
 421
 422                         /**
 423                          * Create a new style tag and add it to the DOM.
 424                          *
 425                          * @private
 426                          * @param {string} text CSS text
 427                          * @param {Mixed} [nextnode] An Element or jQuery object for an element where
 428                          * the style tag should be inserted before. Otherwise appended to the `<head>`.
 429                          * @return {HTMLElement} Node reference to the created `<style>` tag.
 430                          */
 431                         function addStyleTag( text, nextnode ) {
 432                                 var s = document.createElement( 'style' );
 433                                 // Insert into document before setting cssText (bug 33305)
 434                                 if ( nextnode ) {
 435                                         // Must be inserted with native insertBefore, not $.fn.before.
 436                                         // When using jQuery to insert it, like $nextnode.before( s ),
 437                                         // then IE6 will throw "Access is denied" when trying to append
 438                                         // to .cssText later. Some kind of weird security measure.
 439                                         // http://stackoverflow.com/q/12586482/319266
 440                                         // Works: jsfiddle.net/zJzMy/1
 441                                         // Fails: jsfiddle.net/uJTQz
 442                                         // Works again: http://jsfiddle.net/Azr4w/ (diff: the next 3 lines)
 443                                         if ( nextnode.jquery ) {
 444                                                 nextnode = nextnode.get( 0 );
 445                                         }
 446                                         nextnode.parentNode.insertBefore( s, nextnode );
 447                                 } else {
 448                                         document.getElementsByTagName( 'head' )[0].appendChild( s );
 449                                 }
 450                                 if ( s.styleSheet ) {
 451                                         // IE
 452                                         s.styleSheet.cssText = text;
 453                                 } else {
 454                                         // Other browsers.
 455                                         // (Safari sometimes borks on non-string values,
 456                                         // play safe by casting to a string, just in case.)
 457                                         s.appendChild( document.createTextNode( String( text ) ) );
 458                                 }
 459                                 return s;
 460                         }
 461
 462                         /**
 463                          * Checks whether it is safe to add this css to a stylesheet.
 464                          *
 465                          * @private
 466                          * @param {string} cssText
 467                          * @return {boolean} False if a new one must be created.
 468                          */
 469                         function canExpandStylesheetWith( cssText ) {
 470                                 // Makes sure that cssText containing `@import`
 471                                 // rules will end up in a new stylesheet (as those only work when
 472                                 // placed at the start of a stylesheet; bug 35562).
 473                                 return cssText.indexOf( '@import' ) === -1;
 474                         }
 475
 476                         /**
 477                          * @param {string} [cssText=cssBuffer] If called without cssText,
 478                          * the internal buffer will be inserted instead.
 479                          * @param {Function} [callback]
 480                          */
 481                         function addEmbeddedCSS( cssText, callback ) {
 482                                 var $style, styleEl;
 483
 484                                 if ( callback ) {
 485                                         cssCallbacks.add( callback );
 486                                 }
 487
 488                                 // Yield once before inserting the <style> tag. There are likely
 489                                 // more calls coming up which we can combine this way.
 490                                 // Appending a stylesheet and waiting for the browser to repaint
 491                                 // is fairly expensive, this reduces it (bug 45810)
 492                                 if ( cssText ) {
 493                                         // Be careful not to extend the buffer with css that needs a new stylesheet
 494                                         if ( !cssBuffer || canExpandStylesheetWith( cssText ) ) {
 495                                                 // Linebreak for somewhat distinguishable sections
 496                                                 // (the rl-cachekey comment separating each)
 497                                                 cssBuffer += '\n' + cssText;
 498                                                 // TODO: Use requestAnimationFrame in the future which will
 499                                                 // perform even better by not injecting styles while the browser
 500                                                 // is paiting.
 501                                                 setTimeout( function () {
 502                                                         // Can't pass addEmbeddedCSS to setTimeout directly because Firefox
 503                                                         // (below version 13) has the non-standard behaviour of passing a
 504                                                         // numerical "lateness" value as first argument to this callback
 505                                                         // http://benalman.com/news/2009/07/the-mysterious-firefox-settime/
 506                                                         addEmbeddedCSS();
 507                                                 } );
 508                                                 return;
 509                                         }
 510
 511                                 // This is a delayed call and we got a buffer still
 512                                 } else if ( cssBuffer ) {
 513                                         cssText = cssBuffer;
 514                                         cssBuffer = '';
 515                                 } else {
 516                                         // This is a delayed call, but buffer is already cleared by
 517                                         // another delayed call.
 518                                         return;
 519                                 }
 520
 521                                 // By default, always create a new <style>. Appending text
 522                                 // to a <style> tag means the contents have to be re-parsed (bug 45810).
 523                                 // Except, of course, in IE below 9, in there we default to
 524                                 // re-using and appending to a <style> tag due to the
 525                                 // IE stylesheet limit (bug 31676).
 526                                 if ( 'documentMode' in document && document.documentMode <= 9 ) {
 527
 528                                         $style = getMarker().prev();
 529                                         // Verify that the the element before Marker actually is a
 530                                         // <style> tag and one that came from ResourceLoader
 531                                         // (not some other style tag or even a `<meta>` or `<script>`).
 532                                         if ( $style.data( 'ResourceLoaderDynamicStyleTag' ) === true ) {
 533                                                 // There's already a dynamic <style> tag present and
 534                                                 // canExpandStylesheetWith() gave a green light to append more to it.
 535                                                 styleEl = $style.get( 0 );
 536                                                 if ( styleEl.styleSheet ) {
 537                                                         try {
 538                                                                 styleEl.styleSheet.cssText += cssText; // IE
 539                                                         } catch ( e ) {
 540                                                                 log( 'addEmbeddedCSS fail\ne.message: ' + e.message, e );
 541                                                         }
 542                                                 } else {
 543                                                         styleEl.appendChild( document.createTextNode( String( cssText ) ) );
 544                                                 }
 545                                                 cssCallbacks.fire().empty();
 546                                                 return;
 547                                         }
 548                                 }
 549
 550                                 $( addStyleTag( cssText, getMarker() ) ).data( 'ResourceLoaderDynamicStyleTag', true );
 551
 552                                 cssCallbacks.fire().empty();
 553                         }
 554
 555                         /**
 556                          * Generates an ISO8601 "basic" string from a UNIX timestamp
 557                          * @private
 558                          */
 559                         function formatVersionNumber( timestamp ) {
 560                                 var     d = new Date();
 561                                 function pad( a, b, c ) {
 562                                         return [a < 10 ? '0' + a : a, b < 10 ? '0' + b : b, c < 10 ? '0' + c : c].join( '' );
 563                                 }
 564                                 d.setTime( timestamp * 1000 );
 565                                 return [
 566                                         pad( d.getUTCFullYear(), d.getUTCMonth() + 1, d.getUTCDate() ), 'T',
 567                                         pad( d.getUTCHours(), d.getUTCMinutes(), d.getUTCSeconds() ), 'Z'
 568                                 ].join( '' );
 569                         }
 570
 571                         /**
 572                          * Resolves dependencies and detects circular references.
 573                          *
 574                          * @private
 575                          * @param {string} module Name of the top-level module whose dependencies shall be
 576                          *   resolved and sorted.
 577                          * @param {Array} resolved Returns a topological sort of the given module and its
 578                          *   dependencies, such that later modules depend on earlier modules. The array
 579                          *   contains the module names. If the array contains already some module names,
 580                          *   this function appends its result to the pre-existing array.
 581                          * @param {Object} [unresolved] Hash used to track the current dependency
 582                          *   chain; used to report loops in the dependency graph.
 583                          * @throws {Error} If any unregistered module or a dependency loop is encountered
 584                          */
 585                         function sortDependencies( module, resolved, unresolved ) {
 586                                 var n, deps, len;
 587
 588                                 if ( registry[module] === undefined ) {
 589                                         throw new Error( 'Unknown dependency: ' + module );
 590                                 }
 591                                 // Resolves dynamic loader function and replaces it with its own results
 592                                 if ( $.isFunction( registry[module].dependencies ) ) {
 593                                         registry[module].dependencies = registry[module].dependencies();
 594                                         // Ensures the module's dependencies are always in an array
 595                                         if ( typeof registry[module].dependencies !== 'object' ) {
 596                                                 registry[module].dependencies = [registry[module].dependencies];
 597                                         }
 598                                 }
 599                                 if ( $.inArray( module, resolved ) !== -1 ) {
 600                                         // Module already resolved; nothing to do.
 601                                         return;
 602                                 }
 603                                 // unresolved is optional, supply it if not passed in
 604                                 if ( !unresolved ) {
 605                                         unresolved = {};
 606                                 }
 607                                 // Tracks down dependencies
 608                                 deps = registry[module].dependencies;
 609                                 len = deps.length;
 610                                 for ( n = 0; n < len; n += 1 ) {
 611                                         if ( $.inArray( deps[n], resolved ) === -1 ) {
 612                                                 if ( unresolved[deps[n]] ) {
 613                                                         throw new Error(
 614                                                                 'Circular reference detected: ' + module +
 615                                                                 ' -> ' + deps[n]
 616                                                         );
 617                                                 }
 618
 619                                                 // Add to unresolved
 620                                                 unresolved[module] = true;
 621                                                 sortDependencies( deps[n], resolved, unresolved );
 622                                                 delete unresolved[module];
 623                                         }
 624                                 }
 625                                 resolved[resolved.length] = module;
 626                         }
 627
 628                         /**
 629                          * Gets a list of module names that a module depends on in their proper dependency
 630                          * order.
 631                          *
 632                          * @private
 633                          * @param {string} module Module name or array of string module names
 634                          * @return {Array} list of dependencies, including 'module'.
 635                          * @throws {Error} If circular reference is detected
 636                          */
 637                         function resolve( module ) {
 638                                 var m, resolved;
 639
 640                                 // Allow calling with an array of module names
 641                                 if ( $.isArray( module ) ) {
 642                                         resolved = [];
 643                                         for ( m = 0; m < module.length; m += 1 ) {
 644                                                 sortDependencies( module[m], resolved );
 645                                         }
 646                                         return resolved;
 647                                 }
 648
 649                                 if ( typeof module === 'string' ) {
 650                                         resolved = [];
 651                                         sortDependencies( module, resolved );
 652                                         return resolved;
 653                                 }
 654
 655                                 throw new Error( 'Invalid module argument: ' + module );
 656                         }
 657
 658                         /**
 659                          * Narrows a list of module names down to those matching a specific
 660                          * state (see comment on top of this scope for a list of valid states).
 661                          * One can also filter for 'unregistered', which will return the
 662                          * modules names that don't have a registry entry.
 663                          *
 664                          * @private
 665                          * @param {string|string[]} states Module states to filter by
 666                          * @param {Array} [modules] List of module names to filter (optional, by default the entire
 667                          * registry is used)
 668                          * @return {Array} List of filtered module names
 669                          */
 670                         function filter( states, modules ) {
 671                                 var list, module, s, m;
 672
 673                                 // Allow states to be given as a string
 674                                 if ( typeof states === 'string' ) {
 675                                         states = [states];
 676                                 }
 677                                 // If called without a list of modules, build and use a list of all modules
 678                                 list = [];
 679                                 if ( modules === undefined ) {
 680                                         modules = [];
 681                                         for ( module in registry ) {
 682                                                 modules[modules.length] = module;
 683                                         }
 684                                 }
 685                                 // Build a list of modules which are in one of the specified states
 686                                 for ( s = 0; s < states.length; s += 1 ) {
 687                                         for ( m = 0; m < modules.length; m += 1 ) {
 688                                                 if ( registry[modules[m]] === undefined ) {
 689                                                         // Module does not exist
 690                                                         if ( states[s] === 'unregistered' ) {
 691                                                                 // OK, undefined
 692                                                                 list[list.length] = modules[m];
 693                                                         }
 694                                                 } else {
 695                                                         // Module exists, check state
 696                                                         if ( registry[modules[m]].state === states[s] ) {
 697                                                                 // OK, correct state
 698                                                                 list[list.length] = modules[m];
 699                                                         }
 700                                                 }
 701                                         }
 702                                 }
 703                                 return list;
 704                         }
 705
 706                         /**
 707                          * Determine whether all dependencies are in state 'ready', which means we may
 708                          * execute the module or job now.
 709                          *
 710                          * @private
 711                          * @param {Array} dependencies Dependencies (module names) to be checked.
 712                          * @return {boolean} True if all dependencies are in state 'ready', false otherwise
 713                          */
 714                         function allReady( dependencies ) {
 715                                 return filter( 'ready', dependencies ).length === dependencies.length;
 716                         }
 717
 718                         /**
 719                          * Log a message to window.console, if possible. Useful to force logging of some
 720                          * errors that are otherwise hard to detect (I.e., this logs also in production mode).
 721                          * Gets console references in each invocation, so that delayed debugging tools work
 722                          * fine. No need for optimization here, which would only result in losing logs.
 723                          *
 724                          * @private
 725                          * @param {string} msg text for the log entry.
 726                          * @param {Error} [e]
 727                          */
 728                         function log( msg, e ) {
 729                                 var console = window.console;
 730                                 if ( console && console.log ) {
 731                                         console.log( msg );
 732                                         // If we have an exception object, log it through .error() to trigger
 733                                         // proper stacktraces in browsers that support it. There are no (known)
 734                                         // browsers that don't support .error(), that do support .log() and
 735                                         // have useful exception handling through .log().
 736                                         if ( e && console.error ) {
 737                                                 console.error( e );
 738                                         }
 739                                 }
 740                         }
 741
 742                         /**
 743                          * A module has entered state 'ready', 'error', or 'missing'. Automatically update pending jobs
 744                          * and modules that depend upon this module. if the given module failed, propagate the 'error'
 745                          * state up the dependency tree; otherwise, execute all jobs/modules that now have all their
 746                          * dependencies satisfied. On jobs depending on a failed module, run the error callback, if any.
 747                          *
 748                          * @private
 749                          * @param {string} module Name of module that entered one of the states 'ready', 'error', or 'missing'.
 750                          */
 751                         function handlePending( module ) {
 752                                 var j, job, hasErrors, m, stateChange;
 753
 754                                 // Modules.
 755                                 if ( $.inArray( registry[module].state, ['error', 'missing'] ) !== -1 ) {
 756                                         // If the current module failed, mark all dependent modules also as failed.
 757                                         // Iterate until steady-state to propagate the error state upwards in the
 758                                         // dependency tree.
 759                                         do {
 760                                                 stateChange = false;
 761                                                 for ( m in registry ) {
 762                                                         if ( $.inArray( registry[m].state, ['error', 'missing'] ) === -1 ) {
 763                                                                 if ( filter( ['error', 'missing'], registry[m].dependencies ).length > 0 ) {
 764                                                                         registry[m].state = 'error';
 765                                                                         stateChange = true;
 766                                                                 }
 767                                                         }
 768                                                 }
 769                                         } while ( stateChange );
 770                                 }
 771
 772                                 // Execute all jobs whose dependencies are either all satisfied or contain at least one failed module.
 773                                 for ( j = 0; j < jobs.length; j += 1 ) {
 774                                         hasErrors = filter( ['error', 'missing'], jobs[j].dependencies ).length > 0;
 775                                         if ( hasErrors || allReady( jobs[j].dependencies ) ) {
 776                                                 // All dependencies satisfied, or some have errors
 777                                                 job = jobs[j];
 778                                                 jobs.splice( j, 1 );
 779                                                 j -= 1;
 780                                                 try {
 781                                                         if ( hasErrors ) {
 782                                                                 throw new Error( 'Module ' + module + ' failed.');
 783                                                         } else {
 784                                                                 if ( $.isFunction( job.ready ) ) {
 785                                                                         job.ready();
 786                                                                 }
 787                                                         }
 788                                                 } catch ( e ) {
 789                                                         if ( $.isFunction( job.error ) ) {
 790                                                                 try {
 791                                                                         job.error( e, [module] );
 792                                                                 } catch ( ex ) {
 793                                                                         // A user-defined operation raised an exception. Swallow to protect
 794                                                                         // our state machine!
 795                                                                         log( 'Exception thrown by job.error()', ex );
 796                                                                 }
 797                                                         }
 798                                                 }
 799                                         }
 800                                 }
 801
 802                                 if ( registry[module].state === 'ready' ) {
 803                                         // The current module became 'ready'. Recursively execute all dependent modules that are loaded
 804                                         // and now have all dependencies satisfied.
 805                                         for ( m in registry ) {
 806                                                 if ( registry[m].state === 'loaded' && allReady( registry[m].dependencies ) ) {
 807                                                         execute( m );
 808                                                 }
 809                                         }
 810                                 }
 811                         }
 812
 813                         /**
 814                          * Adds a script tag to the DOM, either using document.write or low-level DOM manipulation,
 815                          * depending on whether document-ready has occurred yet and whether we are in async mode.
 816                          *
 817                          * @private
 818                          * @param {string} src URL to script, will be used as the src attribute in the script tag
 819                          * @param {Function} [callback] Callback which will be run when the script is done
 820                          */
 821                         function addScript( src, callback, async ) {
 822                                 /*jshint evil:true */
 823                                 var script, head,
 824                                         done = false;
 825
 826                                 // Using isReady directly instead of storing it locally from
 827                                 // a $.fn.ready callback (bug 31895).
 828                                 if ( $.isReady || async ) {
 829                                         // Can't use jQuery.getScript because that only uses <script> for cross-domain,
 830                                         // it uses XHR and eval for same-domain scripts, which we don't want because it
 831                                         // messes up line numbers.
 832                                         // The below is based on jQuery ([jquery@1.8.2]/src/ajax/script.js)
 833
 834                                         // IE-safe way of getting the <head>. document.head isn't supported
 835                                         // in old IE, and doesn't work when in the <head>.
 836                                         head = document.getElementsByTagName( 'head' )[0] || document.body;
 837
 838                                         script = document.createElement( 'script' );
 839                                         script.async = true;
 840                                         script.src = src;
 841                                         if ( $.isFunction( callback ) ) {
 842                                                 script.onload = script.onreadystatechange = function () {
 843                                                         if (
 844                                                                 !done
 845                                                                 && (
 846                                                                         !script.readyState
 847                                                                         || /loaded|complete/.test( script.readyState )
 848                                                                 )
 849                                                         ) {
 850                                                                 done = true;
 851
 852                                                                 // Handle memory leak in IE
 853                                                                 script.onload = script.onreadystatechange = null;
 854
 855                                                                 // Remove the script
 856                                                                 if ( script.parentNode ) {
 857                                                                         script.parentNode.removeChild( script );
 858                                                                 }
 859
 860                                                                 // Dereference the script
 861                                                                 script = undefined;
 862
 863                                                                 callback();
 864                                                         }
 865                                                 };
 866                                         }
 867
 868                                         if ( window.opera ) {
 869                                                 // Appending to the <head> blocks rendering completely in Opera,
 870                                                 // so append to the <body> after document ready. This means the
 871                                                 // scripts only start loading after the document has been rendered,
 872                                                 // but so be it. Opera users don't deserve faster web pages if their
 873                                                 // browser makes it impossible.
 874                                                 $( function () {
 875                                                         document.body.appendChild( script );
 876                                                 } );
 877                                         } else {
 878                                                 head.appendChild( script );
 879                                         }
 880                                 } else {
 881                                         document.write( mw.html.element( 'script', { 'src': src }, '' ) );
 882                                         if ( $.isFunction( callback ) ) {
 883                                                 // Document.write is synchronous, so this is called when it's done
 884                                                 // FIXME: that's a lie. doc.write isn't actually synchronous
 885                                                 callback();
 886                                         }
 887                                 }
 888                         }
 889
 890                         /**
 891                          * Executes a loaded module, making it ready to use
 892                          *
 893                          * @private
 894                          * @param {string} module Module name to execute
 895                          */
 896                         function execute( module ) {
 897                                 var key, value, media, i, urls, cssHandle, checkCssHandles,
 898                                         cssHandlesRegistered = false;
 899
 900                                 if ( registry[module] === undefined ) {
 901                                         throw new Error( 'Module has not been registered yet: ' + module );
 902                                 } else if ( registry[module].state === 'registered' ) {
 903                                         throw new Error( 'Module has not been requested from the server yet: ' + module );
 904                                 } else if ( registry[module].state === 'loading' ) {
 905                                         throw new Error( 'Module has not completed loading yet: ' + module );
 906                                 } else if ( registry[module].state === 'ready' ) {
 907                                         throw new Error( 'Module has already been executed: ' + module );
 908                                 }
 909
 910                                 /**
 911                                  * Define loop-function here for efficiency
 912                                  * and to avoid re-using badly scoped variables.
 913                                  * @ignore
 914                                  */
 915                                 function addLink( media, url ) {
 916                                         var el = document.createElement( 'link' );
 917                                         getMarker().before( el ); // IE: Insert in dom before setting href
 918                                         el.rel = 'stylesheet';
 919                                         if ( media && media !== 'all' ) {
 920                                                 el.media = media;
 921                                         }
 922                                         el.href = url;
 923                                 }
 924
 925                                 function runScript() {
 926                                         var script, markModuleReady, nestedAddScript;
 927                                         try {
 928                                                 script = registry[module].script;
 929                                                 markModuleReady = function () {
 930                                                         registry[module].state = 'ready';
 931                                                         handlePending( module );
 932                                                 };
 933                                                 nestedAddScript = function ( arr, callback, async, i ) {
 934                                                         // Recursively call addScript() in its own callback
 935                                                         // for each element of arr.
 936                                                         if ( i >= arr.length ) {
 937                                                                 // We're at the end of the array
 938                                                                 callback();
 939                                                                 return;
 940                                                         }
 941
 942                                                         addScript( arr[i], function () {
 943                                                                 nestedAddScript( arr, callback, async, i + 1 );
 944                                                         }, async );
 945                                                 };
 946
 947                                                 if ( $.isArray( script ) ) {
 948                                                         nestedAddScript( script, markModuleReady, registry[module].async, 0 );
 949                                                 } else if ( $.isFunction( script ) ) {
 950                                                         registry[module].state = 'ready';
 951                                                         script( $ );
 952                                                         handlePending( module );
 953                                                 }
 954                                         } catch ( e ) {
 955                                                 // This needs to NOT use mw.log because these errors are common in production mode
 956                                                 // and not in debug mode, such as when a symbol that should be global isn't exported
 957                                                 log( 'Exception thrown by ' + module + ': ' + e.message, e );
 958                                                 registry[module].state = 'error';
 959                                                 handlePending( module );
 960                                         }
 961                                 }
 962
 963                                 // This used to be inside runScript, but since that is now fired asychronously
 964                                 // (after CSS is loaded) we need to set it here right away. It is crucial that
 965                                 // when execute() is called this is set synchronously, otherwise modules will get
 966                                 // executed multiple times as the registry will state that it isn't loading yet.
 967                                 registry[module].state = 'loading';
 968
 969                                 // Add localizations to message system
 970                                 if ( $.isPlainObject( registry[module].messages ) ) {
 971                                         mw.messages.set( registry[module].messages );
 972                                 }
 973
 974                                 // Make sure we don't run the scripts until all (potentially asynchronous)
 975                                 // stylesheet insertions have completed.
 976                                 ( function () {
 977                                         var pending = 0;
 978                                         checkCssHandles = function () {
 979                                                 // cssHandlesRegistered ensures we don't take off too soon, e.g. when
 980                                                 // one of the cssHandles is fired while we're still creating more handles.
 981                                                 if ( cssHandlesRegistered && pending === 0 && runScript ) {
 982                                                         runScript();
 983                                                         runScript = undefined; // Revoke
 984                                                 }
 985                                         };
 986                                         cssHandle = function () {
 987                                                 var check = checkCssHandles;
 988                                                 pending++;
 989                                                 return function () {
 990                                                         if (check) {
 991                                                                 pending--;
 992                                                                 check();
 993                                                                 check = undefined; // Revoke
 994                                                         }
 995                                                 };
 996                                         };
 997                                 }() );
 998
 999                                 // Process styles (see also mw.loader.implement)
1000                                 // * back-compat: { <media>: css }
1001                                 // * back-compat: { <media>: [url, ..] }
1002                                 // * { "css": [css, ..] }
1003                                 // * { "url": { <media>: [url, ..] } }
1004                                 if ( $.isPlainObject( registry[module].style ) ) {
1005                                         for ( key in registry[module].style ) {
1006                                                 value = registry[module].style[key];
1007                                                 media = undefined;
1008
1009                                                 if ( key !== 'url' && key !== 'css' ) {
1010                                                         // Backwards compatibility, key is a media-type
1011                                                         if ( typeof value === 'string' ) {
1012                                                                 // back-compat: { <media>: css }
1013                                                                 // Ignore 'media' because it isn't supported (nor was it used).
1014                                                                 // Strings are pre-wrapped in "@media". The media-type was just ""
1015                                                                 // (because it had to be set to something).
1016                                                                 // This is one of the reasons why this format is no longer used.
1017                                                                 addEmbeddedCSS( value, cssHandle() );
1018                                                         } else {
1019                                                                 // back-compat: { <media>: [url, ..] }
1020                                                                 media = key;
1021                                                                 key = 'bc-url';
1022                                                         }
1023                                                 }
1024
1025                                                 // Array of css strings in key 'css',
1026                                                 // or back-compat array of urls from media-type
1027                                                 if ( $.isArray( value ) ) {
1028                                                         for ( i = 0; i < value.length; i += 1 ) {
1029                                                                 if ( key === 'bc-url' ) {
1030                                                                         // back-compat: { <media>: [url, ..] }
1031                                                                         addLink( media, value[i] );
1032                                                                 } else if ( key === 'css' ) {
1033                                                                         // { "css": [css, ..] }
1034                                                                         addEmbeddedCSS( value[i], cssHandle() );
1035                                                                 }
1036                                                         }
1037                                                 // Not an array, but a regular object
1038                                                 // Array of urls inside media-type key
1039                                                 } else if ( typeof value === 'object' ) {
1040                                                         // { "url": { <media>: [url, ..] } }
1041                                                         for ( media in value ) {
1042                                                                 urls = value[media];
1043                                                                 for ( i = 0; i < urls.length; i += 1 ) {
1044                                                                         addLink( media, urls[i] );
1045                                                                 }
1046                                                         }
1047                                                 }
1048                                         }
1049                                 }
1050
1051                                 // Kick off.
1052                                 cssHandlesRegistered = true;
1053                                 checkCssHandles();
1054                         }
1055
1056                         /**
1057                          * Adds a dependencies to the queue with optional callbacks to be run
1058                          * when the dependencies are ready or fail
1059                          *
1060                          * @private
1061                          * @param {string|string[]} dependencies Module name or array of string module names
1062                          * @param {Function} [ready] Callback to execute when all dependencies are ready
1063                          * @param {Function} [error] Callback to execute when any dependency fails
1064                          * @param {boolean} [async] If true, load modules asynchronously even if
1065                          *  document ready has not yet occurred.
1066                          */
1067                         function request( dependencies, ready, error, async ) {
1068                                 var n;
1069
1070                                 // Allow calling by single module name
1071                                 if ( typeof dependencies === 'string' ) {
1072                                         dependencies = [dependencies];
1073                                 }
1074
1075                                 // Add ready and error callbacks if they were given
1076                                 if ( ready !== undefined || error !== undefined ) {
1077                                         jobs[jobs.length] = {
1078                                                 'dependencies': filter(
1079                                                         ['registered', 'loading', 'loaded'],
1080                                                         dependencies
1081                                                 ),
1082                                                 'ready': ready,
1083                                                 'error': error
1084                                         };
1085                                 }
1086
1087                                 // Queue up any dependencies that are registered
1088                                 dependencies = filter( ['registered'], dependencies );
1089                                 for ( n = 0; n < dependencies.length; n += 1 ) {
1090                                         if ( $.inArray( dependencies[n], queue ) === -1 ) {
1091                                                 queue[queue.length] = dependencies[n];
1092                                                 if ( async ) {
1093                                                         // Mark this module as async in the registry
1094                                                         registry[dependencies[n]].async = true;
1095                                                 }
1096                                         }
1097                                 }
1098
1099                                 // Work the queue
1100                                 mw.loader.work();
1101                         }
1102
1103                         function sortQuery(o) {
1104                                 var sorted = {}, key, a = [];
1105                                 for ( key in o ) {
1106                                         if ( hasOwn.call( o, key ) ) {
1107                                                 a.push( key );
1108                                         }
1109                                 }
1110                                 a.sort();
1111                                 for ( key = 0; key < a.length; key += 1 ) {
1112                                         sorted[a[key]] = o[a[key]];
1113                                 }
1114                                 return sorted;
1115                         }
1116
1117                         /**
1118                          * Converts a module map of the form { foo: [ 'bar', 'baz' ], bar: [ 'baz, 'quux' ] }
1119                          * to a query string of the form foo.bar,baz|bar.baz,quux
1120                          * @private
1121                          */
1122                         function buildModulesString( moduleMap ) {
1123                                 var arr = [], p, prefix;
1124                                 for ( prefix in moduleMap ) {
1125                                         p = prefix === '' ? '' : prefix + '.';
1126                                         arr.push( p + moduleMap[prefix].join( ',' ) );
1127                                 }
1128                                 return arr.join( '|' );
1129                         }
1130
1131                         /**
1132                          * Asynchronously append a script tag to the end of the body
1133                          * that invokes load.php
1134                          * @private
1135                          * @param {Object} moduleMap Module map, see #buildModulesString
1136                          * @param {Object} currReqBase Object with other parameters (other than 'modules') to use in the request
1137                          * @param {string} sourceLoadScript URL of load.php
1138                          * @param {boolean} async If true, use an asynchrounous request even if document ready has not yet occurred
1139                          */
1140                         function doRequest( moduleMap, currReqBase, sourceLoadScript, async ) {
1141                                 var request = $.extend(
1142                                         { modules: buildModulesString( moduleMap ) },
1143                                         currReqBase
1144                                 );
1145                                 request = sortQuery( request );
1146                                 // Asynchronously append a script tag to the end of the body
1147                                 // Append &* to avoid triggering the IE6 extension check
1148                                 addScript( sourceLoadScript + '?' + $.param( request ) + '&*', null, async );
1149                         }
1150
1151                         /* Public Methods */
1152                         return {
1153                                 addStyleTag: addStyleTag,
1154
1155                                 /**
1156                                  * Requests dependencies from server, loading and executing when things when ready.
1157                                  */
1158                                 work: function () {
1159                                         var     reqBase, splits, maxQueryLength, q, b, bSource, bGroup, bSourceGroup,
1160                                                 source, group, g, i, modules, maxVersion, sourceLoadScript,
1161                                                 currReqBase, currReqBaseLength, moduleMap, l,
1162                                                 lastDotIndex, prefix, suffix, bytesAdded, async;
1163
1164                                         // Build a list of request parameters common to all requests.
1165                                         reqBase = {
1166                                                 skin: mw.config.get( 'skin' ),
1167                                                 lang: mw.config.get( 'wgUserLanguage' ),
1168                                                 debug: mw.config.get( 'debug' )
1169                                         };
1170                                         // Split module batch by source and by group.
1171                                         splits = {};
1172                                         maxQueryLength = mw.config.get( 'wgResourceLoaderMaxQueryLength', -1 );
1173
1174                                         // Appends a list of modules from the queue to the batch
1175                                         for ( q = 0; q < queue.length; q += 1 ) {
1176                                                 // Only request modules which are registered
1177                                                 if ( registry[queue[q]] !== undefined && registry[queue[q]].state === 'registered' ) {
1178                                                         // Prevent duplicate entries
1179                                                         if ( $.inArray( queue[q], batch ) === -1 ) {
1180                                                                 batch[batch.length] = queue[q];
1181                                                                 // Mark registered modules as loading
1182                                                                 registry[queue[q]].state = 'loading';
1183                                                         }
1184                                                 }
1185                                         }
1186                                         // Early exit if there's nothing to load...
1187                                         if ( !batch.length ) {
1188                                                 return;
1189                                         }
1190
1191                                         // The queue has been processed into the batch, clear up the queue.
1192                                         queue = [];
1193
1194                                         // Always order modules alphabetically to help reduce cache
1195                                         // misses for otherwise identical content.
1196                                         batch.sort();
1197
1198                                         // Split batch by source and by group.
1199                                         for ( b = 0; b < batch.length; b += 1 ) {
1200                                                 bSource = registry[batch[b]].source;
1201                                                 bGroup = registry[batch[b]].group;
1202                                                 if ( splits[bSource] === undefined ) {
1203                                                         splits[bSource] = {};
1204                                                 }
1205                                                 if ( splits[bSource][bGroup] === undefined ) {
1206                                                         splits[bSource][bGroup] = [];
1207                                                 }
1208                                                 bSourceGroup = splits[bSource][bGroup];
1209                                                 bSourceGroup[bSourceGroup.length] = batch[b];
1210                                         }
1211
1212                                         // Clear the batch - this MUST happen before we append any
1213                                         // script elements to the body or it's possible that a script
1214                                         // will be locally cached, instantly load, and work the batch
1215                                         // again, all before we've cleared it causing each request to
1216                                         // include modules which are already loaded.
1217                                         batch = [];
1218
1219                                         for ( source in splits ) {
1220
1221                                                 sourceLoadScript = sources[source].loadScript;
1222
1223                                                 for ( group in splits[source] ) {
1224
1225                                                         // Cache access to currently selected list of
1226                                                         // modules for this group from this source.
1227                                                         modules = splits[source][group];
1228
1229                                                         // Calculate the highest timestamp
1230                                                         maxVersion = 0;
1231                                                         for ( g = 0; g < modules.length; g += 1 ) {
1232                                                                 if ( registry[modules[g]].version > maxVersion ) {
1233                                                                         maxVersion = registry[modules[g]].version;
1234                                                                 }
1235                                                         }
1236
1237                                                         currReqBase = $.extend( { version: formatVersionNumber( maxVersion ) }, reqBase );
1238                                                         // For user modules append a user name to the request.
1239                                                         if ( group === 'user' && mw.config.get( 'wgUserName' ) !== null ) {
1240                                                                 currReqBase.user = mw.config.get( 'wgUserName' );
1241                                                         }
1242                                                         currReqBaseLength = $.param( currReqBase ).length;
1243                                                         async = true;
1244                                                         // We may need to split up the request to honor the query string length limit,
1245                                                         // so build it piece by piece.
1246                                                         l = currReqBaseLength + 9; // '&modules='.length == 9
1247
1248                                                         moduleMap = {}; // { prefix: [ suffixes ] }
1249
1250                                                         for ( i = 0; i < modules.length; i += 1 ) {
1251                                                                 // Determine how many bytes this module would add to the query string
1252                                                                 lastDotIndex = modules[i].lastIndexOf( '.' );
1253                                                                 // Note that these substr() calls work even if lastDotIndex == -1
1254                                                                 prefix = modules[i].substr( 0, lastDotIndex );
1255                                                                 suffix = modules[i].substr( lastDotIndex + 1 );
1256                                                                 bytesAdded = moduleMap[prefix] !== undefined
1257                                                                         ? suffix.length + 3 // '%2C'.length == 3
1258                                                                         : modules[i].length + 3; // '%7C'.length == 3
1259
1260                                                                 // If the request would become too long, create a new one,
1261                                                                 // but don't create empty requests
1262                                                                 if ( maxQueryLength > 0 && !$.isEmptyObject( moduleMap ) && l + bytesAdded > maxQueryLength ) {
1263                                                                         // This request would become too long, create a new one
1264                                                                         // and fire off the old one
1265                                                                         doRequest( moduleMap, currReqBase, sourceLoadScript, async );
1266                                                                         moduleMap = {};
1267                                                                         async = true;
1268                                                                         l = currReqBaseLength + 9;
1269                                                                 }
1270                                                                 if ( moduleMap[prefix] === undefined ) {
1271                                                                         moduleMap[prefix] = [];
1272                                                                 }
1273                                                                 moduleMap[prefix].push( suffix );
1274                                                                 if ( !registry[modules[i]].async ) {
1275                                                                         // If this module is blocking, make the entire request blocking
1276                                                                         // This is slightly suboptimal, but in practice mixing of blocking
1277                                                                         // and async modules will only occur in debug mode.
1278                                                                         async = false;
1279                                                                 }
1280                                                                 l += bytesAdded;
1281                                                         }
1282                                                         // If there's anything left in moduleMap, request that too
1283                                                         if ( !$.isEmptyObject( moduleMap ) ) {
1284                                                                 doRequest( moduleMap, currReqBase, sourceLoadScript, async );
1285                                                         }
1286                                                 }
1287                                         }
1288                                 },
1289
1290                                 /**
1291                                  * Register a source.
1292                                  *
1293                                  * @param {string} id Short lowercase a-Z string representing a source, only used internally.
1294                                  * @param {Object} props Object containing only the loadScript property which is a url to
1295                                  *  the load.php location of the source.
1296                                  * @return {boolean}
1297                                  */
1298                                 addSource: function ( id, props ) {
1299                                         var source;
1300                                         // Allow multiple additions
1301                                         if ( typeof id === 'object' ) {
1302                                                 for ( source in id ) {
1303                                                         mw.loader.addSource( source, id[source] );
1304                                                 }
1305                                                 return true;
1306                                         }
1307
1308                                         if ( sources[id] !== undefined ) {
1309                                                 throw new Error( 'source already registered: ' + id );
1310                                         }
1311
1312                                         sources[id] = props;
1313
1314                                         return true;
1315                                 },
1316
1317                                 /**
1318                                  * Registers a module, letting the system know about it and its
1319                                  * properties. Startup modules contain calls to this function.
1320                                  *
1321                                  * @param {string} module Module name
1322                                  * @param {number} version Module version number as a timestamp (falls backs to 0)
1323                                  * @param {string|Array|Function} dependencies One string or array of strings of module
1324                                  *  names on which this module depends, or a function that returns that array.
1325                                  * @param {string} [group=null] Group which the module is in
1326                                  * @param {string} [source='local'] Name of the source
1327                                  */
1328                                 register: function ( module, version, dependencies, group, source ) {
1329                                         var m;
1330                                         // Allow multiple registration
1331                                         if ( typeof module === 'object' ) {
1332                                                 for ( m = 0; m < module.length; m += 1 ) {
1333                                                         // module is an array of module names
1334                                                         if ( typeof module[m] === 'string' ) {
1335                                                                 mw.loader.register( module[m] );
1336                                                         // module is an array of arrays
1337                                                         } else if ( typeof module[m] === 'object' ) {
1338                                                                 mw.loader.register.apply( mw.loader, module[m] );
1339                                                         }
1340                                                 }
1341                                                 return;
1342                                         }
1343                                         // Validate input
1344                                         if ( typeof module !== 'string' ) {
1345                                                 throw new Error( 'module must be a string, not a ' + typeof module );
1346                                         }
1347                                         if ( registry[module] !== undefined ) {
1348                                                 throw new Error( 'module already registered: ' + module );
1349                                         }
1350                                         // List the module as registered
1351                                         registry[module] = {
1352                                                 version: version !== undefined ? parseInt( version, 10 ) : 0,
1353                                                 dependencies: [],
1354                                                 group: typeof group === 'string' ? group : null,
1355                                                 source: typeof source === 'string' ? source: 'local',
1356                                                 state: 'registered'
1357                                         };
1358                                         if ( typeof dependencies === 'string' ) {
1359                                                 // Allow dependencies to be given as a single module name
1360                                                 registry[module].dependencies = [ dependencies ];
1361                                         } else if ( typeof dependencies === 'object' || $.isFunction( dependencies ) ) {
1362                                                 // Allow dependencies to be given as an array of module names
1363                                                 // or a function which returns an array
1364                                                 registry[module].dependencies = dependencies;
1365                                         }
1366                                 },
1367
1368                                 /**
1369                                  * Implements a module, giving the system a course of action to take
1370                                  * upon loading. Results of a request for one or more modules contain
1371                                  * calls to this function.
1372                                  *
1373                                  * All arguments are required.
1374                                  *
1375                                  * @param {string} module Name of module
1376                                  * @param {Function|Array} script Function with module code or Array of URLs to
1377                                  *  be used as the src attribute of a new `<script>` tag.
1378                                  * @param {Object} style Should follow one of the following patterns:
1379                                  *     { "css": [css, ..] }
1380                                  *     { "url": { <media>: [url, ..] } }
1381                                  * And for backwards compatibility (needs to be supported forever due to caching):
1382                                  *     { <media>: css }
1383                                  *     { <media>: [url, ..] }
1384                                  *
1385                                  * The reason css strings are not concatenated anymore is bug 31676. We now check
1386                                  * whether it's safe to extend the stylesheet (see #canExpandStylesheetWith).
1387                                  *
1388                                  * @param {Object} msgs List of key/value pairs to be added to {@link mw#messages}.
1389                                  */
1390                                 implement: function ( module, script, style, msgs ) {
1391                                         // Validate input
1392                                         if ( typeof module !== 'string' ) {
1393                                                 throw new Error( 'module must be a string, not a ' + typeof module );
1394                                         }
1395                                         if ( !$.isFunction( script ) && !$.isArray( script ) ) {
1396                                                 throw new Error( 'script must be a function or an array, not a ' + typeof script );
1397                                         }
1398                                         if ( !$.isPlainObject( style ) ) {
1399                                                 throw new Error( 'style must be an object, not a ' + typeof style );
1400                                         }
1401                                         if ( !$.isPlainObject( msgs ) ) {
1402                                                 throw new Error( 'msgs must be an object, not a ' + typeof msgs );
1403                                         }
1404                                         // Automatically register module
1405                                         if ( registry[module] === undefined ) {
1406                                                 mw.loader.register( module );
1407                                         }
1408                                         // Check for duplicate implementation
1409                                         if ( registry[module] !== undefined && registry[module].script !== undefined ) {
1410                                                 throw new Error( 'module already implemented: ' + module );
1411                                         }
1412                                         // Attach components
1413                                         registry[module].script = script;
1414                                         registry[module].style = style;
1415                                         registry[module].messages = msgs;
1416                                         // The module may already have been marked as erroneous
1417                                         if ( $.inArray( registry[module].state, ['error', 'missing'] ) === -1 ) {
1418                                                 registry[module].state = 'loaded';
1419                                                 if ( allReady( registry[module].dependencies ) ) {
1420                                                         execute( module );
1421                                                 }
1422                                         }
1423                                 },
1424
1425                                 /**
1426                                  * Executes a function as soon as one or more required modules are ready
1427                                  *
1428                                  * @param {string|Array} dependencies Module name or array of modules names the callback
1429                                  *  dependends on to be ready before executing
1430                                  * @param {Function} [ready] callback to execute when all dependencies are ready
1431                                  * @param {Function} [error] callback to execute when if dependencies have a errors
1432                                  */
1433                                 using: function ( dependencies, ready, error ) {
1434                                         var tod = typeof dependencies;
1435                                         // Validate input
1436                                         if ( tod !== 'object' && tod !== 'string' ) {
1437                                                 throw new Error( 'dependencies must be a string or an array, not a ' + tod );
1438                                         }
1439                                         // Allow calling with a single dependency as a string
1440                                         if ( tod === 'string' ) {
1441                                                 dependencies = [ dependencies ];
1442                                         }
1443                                         // Resolve entire dependency map
1444                                         dependencies = resolve( dependencies );
1445                                         if ( allReady( dependencies ) ) {
1446                                                 // Run ready immediately
1447                                                 if ( $.isFunction( ready ) ) {
1448                                                         ready();
1449                                                 }
1450                                         } else if ( filter( ['error', 'missing'], dependencies ).length ) {
1451                                                 // Execute error immediately if any dependencies have errors
1452                                                 if ( $.isFunction( error ) ) {
1453                                                         error( new Error( 'one or more dependencies have state "error" or "missing"' ),
1454                                                                 dependencies );
1455                                                 }
1456                                         } else {
1457                                                 // Not all dependencies are ready: queue up a request
1458                                                 request( dependencies, ready, error );
1459                                         }
1460                                 },
1461
1462                                 /**
1463                                  * Loads an external script or one or more modules for future use
1464                                  *
1465                                  * @param {string|Array} modules Either the name of a module, array of modules,
1466                                  *  or a URL of an external script or style
1467                                  * @param {string} [type='text/javascript'] mime-type to use if calling with a URL of an
1468                                  *  external script or style; acceptable values are "text/css" and
1469                                  *  "text/javascript"; if no type is provided, text/javascript is assumed.
1470                                  * @param {boolean} [async] If true, load modules asynchronously
1471                                  *  even if document ready has not yet occurred. If false, block before
1472                                  *  document ready and load async after. If not set, true will be
1473                                  *  assumed if loading a URL, and false will be assumed otherwise.
1474                                  */
1475                                 load: function ( modules, type, async ) {
1476                                         var filtered, m, module, l;
1477
1478                                         // Validate input
1479                                         if ( typeof modules !== 'object' && typeof modules !== 'string' ) {
1480                                                 throw new Error( 'modules must be a string or an array, not a ' + typeof modules );
1481                                         }
1482                                         // Allow calling with an external url or single dependency as a string
1483                                         if ( typeof modules === 'string' ) {
1484                                                 // Support adding arbitrary external scripts
1485                                                 if ( /^(https?:)?\/\//.test( modules ) ) {
1486                                                         if ( async === undefined ) {
1487                                                                 // Assume async for bug 34542
1488                                                                 async = true;
1489                                                         }
1490                                                         if ( type === 'text/css' ) {
1491                                                                 // IE7-8 throws security warnings when inserting a <link> tag
1492                                                                 // with a protocol-relative URL set though attributes (instead of
1493                                                                 // properties) - when on HTTPS. See also bug #.
1494                                                                 l = document.createElement( 'link' );
1495                                                                 l.rel = 'stylesheet';
1496                                                                 l.href = modules;
1497                                                                 $( 'head' ).append( l );
1498                                                                 return;
1499                                                         }
1500                                                         if ( type === 'text/javascript' || type === undefined ) {
1501                                                                 addScript( modules, null, async );
1502                                                                 return;
1503                                                         }
1504                                                         // Unknown type
1505                                                         throw new Error( 'invalid type for external url, must be text/css or text/javascript. not ' + type );
1506                                                 }
1507                                                 // Called with single module
1508                                                 modules = [ modules ];
1509                                         }
1510
1511                                         // Filter out undefined modules, otherwise resolve() will throw
1512                                         // an exception for trying to load an undefined module.
1513                                         // Undefined modules are acceptable here in load(), because load() takes
1514                                         // an array of unrelated modules, whereas the modules passed to
1515                                         // using() are related and must all be loaded.
1516                                         for ( filtered = [], m = 0; m < modules.length; m += 1 ) {
1517                                                 module = registry[modules[m]];
1518                                                 if ( module !== undefined ) {
1519                                                         if ( $.inArray( module.state, ['error', 'missing'] ) === -1 ) {
1520                                                                 filtered[filtered.length] = modules[m];
1521                                                         }
1522                                                 }
1523                                         }
1524
1525                                         if ( filtered.length === 0 ) {
1526                                                 return;
1527                                         }
1528                                         // Resolve entire dependency map
1529                                         filtered = resolve( filtered );
1530                                         // If all modules are ready, nothing to be done
1531                                         if ( allReady( filtered ) ) {
1532                                                 return;
1533                                         }
1534                                         // If any modules have errors: also quit.
1535                                         if ( filter( ['error', 'missing'], filtered ).length ) {
1536                                                 return;
1537                                         }
1538                                         // Since some modules are not yet ready, queue up a request.
1539                                         request( filtered, undefined, undefined, async );
1540                                 },
1541
1542                                 /**
1543                                  * Changes the state of a module
1544                                  *
1545                                  * @param {string|Object} module module name or object of module name/state pairs
1546                                  * @param {string} state state name
1547                                  */
1548                                 state: function ( module, state ) {
1549                                         var m;
1550
1551                                         if ( typeof module === 'object' ) {
1552                                                 for ( m in module ) {
1553                                                         mw.loader.state( m, module[m] );
1554                                                 }
1555                                                 return;
1556                                         }
1557                                         if ( registry[module] === undefined ) {
1558                                                 mw.loader.register( module );
1559                                         }
1560                                         if ( $.inArray( state, ['ready', 'error', 'missing'] ) !== -1
1561                                                 && registry[module].state !== state ) {
1562                                                 // Make sure pending modules depending on this one get executed if their
1563                                                 // dependencies are now fulfilled!
1564                                                 registry[module].state = state;
1565                                                 handlePending( module );
1566                                         } else {
1567                                                 registry[module].state = state;
1568                                         }
1569                                 },
1570
1571                                 /**
1572                                  * Gets the version of a module
1573                                  *
1574                                  * @param {string} module name of module to get version for
1575                                  */
1576                                 getVersion: function ( module ) {
1577                                         if ( registry[module] !== undefined && registry[module].version !== undefined ) {
1578                                                 return formatVersionNumber( registry[module].version );
1579                                         }
1580                                         return null;
1581                                 },
1582
1583                                 /**
1584                                  * @deprecated since 1.18 use mw.loader.getVersion() instead
1585                                  */
1586                                 version: function () {
1587                                         return mw.loader.getVersion.apply( mw.loader, arguments );
1588                                 },
1589
1590                                 /**
1591                                  * Gets the state of a module
1592                                  *
1593                                  * @param {string} module name of module to get state for
1594                                  */
1595                                 getState: function ( module ) {
1596                                         if ( registry[module] !== undefined && registry[module].state !== undefined ) {
1597                                                 return registry[module].state;
1598                                         }
1599                                         return null;
1600                                 },
1601
1602                                 /**
1603                                  * Get names of all registered modules.
1604                                  *
1605                                  * @return {Array}
1606                                  */
1607                                 getModuleNames: function () {
1608                                         return $.map( registry, function ( i, key ) {
1609                                                 return key;
1610                                         } );
1611                                 },
1612
1613                                 /**
1614                                  * For backwards-compatibility with Squid-cached pages. Loads mw.user
1615                                  */
1616                                 go: function () {
1617                                         mw.loader.load( 'mediawiki.user' );
1618                                 }
1619                         };
1620                 }() ),
1621
1622                 /**
1623                  * HTML construction helper functions
1624                  * @class mw.html
1625                  * @singleton
1626                  */
1627                 html: ( function () {
1628                         function escapeCallback( s ) {
1629                                 switch ( s ) {
1630                                         case '\'':
1631                                                 return '&#039;';
1632                                         case '"':
1633                                                 return '&quot;';
1634                                         case '<':
1635                                                 return '&lt;';
1636                                         case '>':
1637                                                 return '&gt;';
1638                                         case '&':
1639                                                 return '&amp;';
1640                                 }
1641                         }
1642
1643                         return {
1644                                 /**
1645                                  * Escape a string for HTML. Converts special characters to HTML entities.
1646                                  * @param {string} s The string to escape
1647                                  */
1648                                 escape: function ( s ) {
1649                                         return s.replace( /['"<>&]/g, escapeCallback );
1650                                 },
1651
1652                                 /**
1653                                  * Wrapper object for raw HTML passed to mw.html.element().
1654                                  * @class mw.html.Raw
1655                                  */
1656                                 Raw: function ( value ) {
1657                                         this.value = value;
1658                                 },
1659
1660                                 /**
1661                                  * Wrapper object for CDATA element contents passed to mw.html.element()
1662                                  * @class mw.html.Cdata
1663                                  */
1664                                 Cdata: function ( value ) {
1665                                         this.value = value;
1666                                 },
1667
1668                                 /**
1669                                  * Create an HTML element string, with safe escaping.
1670                                  *
1671                                  * @param {string} name The tag name.
1672                                  * @param {Object} attrs An object with members mapping element names to values
1673                                  * @param {Mixed} contents The contents of the element. May be either:
1674                                  *  - string: The string is escaped.
1675                                  *  - null or undefined: The short closing form is used, e.g. <br/>.
1676                                  *  - this.Raw: The value attribute is included without escaping.
1677                                  *  - this.Cdata: The value attribute is included, and an exception is
1678                                  *   thrown if it contains an illegal ETAGO delimiter.
1679                                  *   See http://www.w3.org/TR/1999/REC-html401-19991224/appendix/notes.html#h-B.3.2
1680                                  *
1681                                  * Example:
1682                                  *      var h = mw.html;
1683                                  *      return h.element( 'div', {},
1684                                  *              new h.Raw( h.element( 'img', {src: '<'} ) ) );
1685                                  * Returns <div><img src="&lt;"/></div>
1686                                  */
1687                                 element: function ( name, attrs, contents ) {
1688                                         var v, attrName, s = '<' + name;
1689
1690                                         for ( attrName in attrs ) {
1691                                                 v = attrs[attrName];
1692                                                 // Convert name=true, to name=name
1693                                                 if ( v === true ) {
1694                                                         v = attrName;
1695                                                 // Skip name=false
1696                                                 } else if ( v === false ) {
1697                                                         continue;
1698                                                 }
1699                                                 s += ' ' + attrName + '="' + this.escape( String( v ) ) + '"';
1700                                         }
1701                                         if ( contents === undefined || contents === null ) {
1702                                                 // Self close tag
1703                                                 s += '/>';
1704                                                 return s;
1705                                         }
1706                                         // Regular open tag
1707                                         s += '>';
1708                                         switch ( typeof contents ) {
1709                                                 case 'string':
1710                                                         // Escaped
1711                                                         s += this.escape( contents );
1712                                                         break;
1713                                                 case 'number':
1714                                                 case 'boolean':
1715                                                         // Convert to string
1716                                                         s += String( contents );
1717                                                         break;
1718                                                 default:
1719                                                         if ( contents instanceof this.Raw ) {
1720                                                                 // Raw HTML inclusion
1721                                                                 s += contents.value;
1722                                                         } else if ( contents instanceof this.Cdata ) {
1723                                                                 // CDATA
1724                                                                 if ( /<\/[a-zA-z]/.test( contents.value ) ) {
1725                                                                         throw new Error( 'mw.html.element: Illegal end tag found in CDATA' );
1726                                                                 }
1727                                                                 s += contents.value;
1728                                                         } else {
1729                                                                 throw new Error( 'mw.html.element: Invalid type of contents' );
1730                                                         }
1731                                         }
1732                                         s += '</' + name + '>';
1733                                         return s;
1734                                 }
1735                         };
1736                 }() ),
1737
1738                 // Skeleton user object. mediawiki.user.js extends this
1739                 user: {
1740                         options: new Map(),
1741                         tokens: new Map()
1742                 },
1743
1744                 /**
1745                  * Registry and firing of events.
1746                  *
1747                  * MediaWiki has various interface components that are extended, enhanced
1748                  * or manipulated in some other way by extensions, gadgets and even
1749                  * in core itself.
1750                  *
1751                  * This framework helps streamlining the timing of when these other
1752                  * code paths fire their plugins (instead of using document-ready,
1753                  * which can and should be limited to firing only once).
1754                  *
1755                  * Features like navigating to other wiki pages, previewing an edit
1756                  * and editing itself – without a refresh – can then retrigger these
1757                  * hooks accordingly to ensure everything still works as expected.
1758                  *
1759                  * Example usage:
1760                  *
1761                  *     mw.hook( 'wikipage.content' ).add( fn ).remove( fn );
1762                  *     mw.hook( 'wikipage.content' ).fire( $content );
1763                  *
1764                  * Handlers can be added and fired for arbitrary event names at any time. The same
1765                  * event can be fired multiple times. The last run of an event is memorized
1766                  * (similar to `$(document).ready` and `$.Deferred().done`).
1767                  * This means if an event is fired, and a handler added afterwards, the added
1768                  * function will be fired right away with the last given event data.
1769                  *
1770                  * Like Deferreds and Promises, the mw.hook object is both detachable and chainable.
1771                  * Thus allowing flexible use and optimal maintainability and authority control.
1772                  * You can pass around the `add` and/or `fire` method to another piece of code
1773                  * without it having to know the event name (or `mw.hook` for that matter).
1774                  *
1775                  *     var h = mw.hook( 'bar.ready' );
1776                  *     new mw.Foo( .. ).fetch( { callback: h.fire } );
1777                  *
1778                  * @class mw.hook
1779                  */
1780                 hook: ( function () {
1781                         var lists = {};
1782
1783                         /**
1784                          * @method hook
1785                          * @member mw
1786                          * @param {string} name Name of hook.
1787                          * @return {mw.hook}
1788                          */
1789                         return function ( name ) {
1790                                 var list = lists[name] || ( lists[name] = $.Callbacks( 'memory' ) );
1791
1792                                 return {
1793                                         /**
1794                                          * Register a hook handler
1795                                          * @param {Function...} handler Function to bind.
1796                                          * @chainable
1797                                          */
1798                                         add: list.add,
1799
1800                                         /**
1801                                          * Unregister a hook handler
1802                                          * @param {Function...} handler Function to unbind.
1803                                          * @chainable
1804                                          */
1805                                         remove: list.remove,
1806
1807                                         /**
1808                                          * Run a hook.
1809                                          * @param {Mixed...} data
1810                                          * @chainable
1811                                          */
1812                                         fire: function () {
1813                                                 return list.fireWith( null, slice.call( arguments ) );
1814                                         }
1815                                 };
1816                         };
1817                 }() )
1818         };
1819
1820 }( jQuery ) );
1821
1822 // Alias $j to jQuery for backwards compatibility
1823 window.$j = jQuery;
1824
1825 // Attach to window and globally alias
1826 window.mw = window.mediaWiki = mw;
1827
1828 // Auto-register from pre-loaded startup scripts
1829 if ( jQuery.isFunction( window.startUp ) ) {
1830         window.startUp();
1831         window.startUp = undefined;
1832 }