resources/mediawiki/mediawiki.js

   1 /**
   2  * Base library for MediaWiki.
   3  *
   4  * @class mw
   5  * @alternateClassName mediaWiki
   6  * @singleton
   7  */
   8
   9 var mw = ( function ( $, undefined ) {
  10         'use strict';
  11
  12         /* Private Members */
  13
  14         var hasOwn = Object.prototype.hasOwnProperty,
  15                 slice = Array.prototype.slice;
  16
  17         /**
  18          * Log a message to window.console, if possible. Useful to force logging of some
  19          * errors that are otherwise hard to detect (I.e., this logs also in production mode).
  20          * Gets console references in each invocation, so that delayed debugging tools work
  21          * fine. No need for optimization here, which would only result in losing logs.
  22          *
  23          * @private
  24          * @param {string} msg text for the log entry.
  25          * @param {Error} [e]
  26          */
  27         function log( msg, e ) {
  28                 var console = window.console;
  29                 if ( console && console.log ) {
  30                         console.log( msg );
  31                         // If we have an exception object, log it through .error() to trigger
  32                         // proper stacktraces in browsers that support it. There are no (known)
  33                         // browsers that don't support .error(), that do support .log() and
  34                         // have useful exception handling through .log().
  35                         if ( e && console.error ) {
  36                                 console.error( String( e ), e );
  37                         }
  38                 }
  39         }
  40
  41         /* Object constructors */
  42
  43         /**
  44          * Creates an object that can be read from or written to from prototype functions
  45          * that allow both single and multiple variables at once.
  46          *
  47          *     @example
  48          *
  49          *     var addies, wanted, results;
  50          *
  51          *     // Create your address book
  52          *     addies = new mw.Map();
  53          *
  54          *     // This data could be coming from an external source (eg. API/AJAX)
  55          *     addies.set( {
  56          *         'John Doe' : '10 Wall Street, New York, USA',
  57          *         'Jane Jackson' : '21 Oxford St, London, UK',
  58          *         'Dominique van Halen' : 'Kalverstraat 7, Amsterdam, NL'
  59          *     } );
  60          *
  61          *     wanted = ['Dominique van Halen', 'George Johnson', 'Jane Jackson'];
  62          *
  63          *     // You can detect missing keys first
  64          *     if ( !addies.exists( wanted ) ) {
  65          *         // One or more are missing (in this case: "George Johnson")
  66          *         mw.log( 'One or more names were not found in your address book' );
  67          *     }
  68          *
  69          *     // Or just let it give you what it can
  70          *     results = addies.get( wanted, 'Middle of Nowhere, Alaska, US' );
  71          *     mw.log( results['Jane Jackson'] ); // "21 Oxford St, London, UK"
  72          *     mw.log( results['George Johnson'] ); // "Middle of Nowhere, Alaska, US"
  73          *
  74          * @class mw.Map
  75          *
  76          * @constructor
  77          * @param {boolean} [global=false] Whether to store the values in the global window
  78          *  object or a exclusively in the object property 'values'.
  79          */
  80         function Map( global ) {
  81                 this.values = global === true ? window : {};
  82                 return this;
  83         }
  84
  85         Map.prototype = {
  86                 /**
  87                  * Get the value of one or multiple a keys.
  88                  *
  89                  * If called with no arguments, all values will be returned.
  90                  *
  91                  * @param {string|Array} selection String key or array of keys to get values for.
  92                  * @param {Mixed} [fallback] Value to use in case key(s) do not exist.
  93                  * @return mixed If selection was a string returns the value or null,
  94                  *  If selection was an array, returns an object of key/values (value is null if not found),
  95                  *  If selection was not passed or invalid, will return the 'values' object member (be careful as
  96                  *  objects are always passed by reference in JavaScript!).
  97                  * @return {string|Object|null} Values as a string or object, null if invalid/inexistant.
  98                  */
  99                 get: function ( selection, fallback ) {
 100                         var results, i;
 101                         // If we only do this in the `return` block, it'll fail for the
 102                         // call to get() from the mutli-selection block.
 103                         fallback = arguments.length > 1 ? fallback : null;
 104
 105                         if ( $.isArray( selection ) ) {
 106                                 selection = slice.call( selection );
 107                                 results = {};
 108                                 for ( i = 0; i < selection.length; i++ ) {
 109                                         results[selection[i]] = this.get( selection[i], fallback );
 110                                 }
 111                                 return results;
 112                         }
 113
 114                         if ( typeof selection === 'string' ) {
 115                                 if ( !hasOwn.call( this.values, selection ) ) {
 116                                         return fallback;
 117                                 }
 118                                 return this.values[selection];
 119                         }
 120
 121                         if ( selection === undefined ) {
 122                                 return this.values;
 123                         }
 124
 125                         // invalid selection key
 126                         return null;
 127                 },
 128
 129                 /**
 130                  * Sets one or multiple key/value pairs.
 131                  *
 132                  * @param {string|Object} selection String key to set value for, or object mapping keys to values.
 133                  * @param {Mixed} [value] Value to set (optional, only in use when key is a string)
 134                  * @return {Boolean} This returns true on success, false on failure.
 135                  */
 136                 set: function ( selection, value ) {
 137                         var s;
 138
 139                         if ( $.isPlainObject( selection ) ) {
 140                                 for ( s in selection ) {
 141                                         this.values[s] = selection[s];
 142                                 }
 143                                 return true;
 144                         }
 145                         if ( typeof selection === 'string' && arguments.length > 1 ) {
 146                                 this.values[selection] = value;
 147                                 return true;
 148                         }
 149                         return false;
 150                 },
 151
 152                 /**
 153                  * Checks if one or multiple keys exist.
 154                  *
 155                  * @param {Mixed} selection String key or array of keys to check
 156                  * @return {boolean} Existence of key(s)
 157                  */
 158                 exists: function ( selection ) {
 159                         var s;
 160
 161                         if ( $.isArray( selection ) ) {
 162                                 for ( s = 0; s < selection.length; s++ ) {
 163                                         if ( typeof selection[s] !== 'string' || !hasOwn.call( this.values, selection[s] ) ) {
 164                                                 return false;
 165                                         }
 166                                 }
 167                                 return true;
 168                         }
 169                         return typeof selection === 'string' && hasOwn.call( this.values, selection );
 170                 }
 171         };
 172
 173         /**
 174          * Object constructor for messages.
 175          *
 176          * Similar to the Message class in MediaWiki PHP.
 177          *
 178          * Format defaults to 'text'.
 179          *
 180          * @class mw.Message
 181          *
 182          * @constructor
 183          * @param {mw.Map} map Message storage
 184          * @param {string} key
 185          * @param {Array} [parameters]
 186          */
 187         function Message( map, key, parameters ) {
 188                 this.format = 'text';
 189                 this.map = map;
 190                 this.key = key;
 191                 this.parameters = parameters === undefined ? [] : slice.call( parameters );
 192                 return this;
 193         }
 194
 195         Message.prototype = {
 196                 /**
 197                  * Simple message parser, does $N replacement and nothing else.
 198                  *
 199                  * This may be overridden to provide a more complex message parser.
 200                  *
 201                  * The primary override is in mediawiki.jqueryMsg.
 202                  *
 203                  * This function will not be called for nonexistent messages.
 204                  */
 205                 parser: function () {
 206                         var parameters = this.parameters;
 207                         return this.map.get( this.key ).replace( /\$(\d+)/g, function ( str, match ) {
 208                                 var index = parseInt( match, 10 ) - 1;
 209                                 return parameters[index] !== undefined ? parameters[index] : '$' + match;
 210                         } );
 211                 },
 212
 213                 /**
 214                  * Appends (does not replace) parameters for replacement to the .parameters property.
 215                  *
 216                  * @param {Array} parameters
 217                  * @chainable
 218                  */
 219                 params: function ( parameters ) {
 220                         var i;
 221                         for ( i = 0; i < parameters.length; i += 1 ) {
 222                                 this.parameters.push( parameters[i] );
 223                         }
 224                         return this;
 225                 },
 226
 227                 /**
 228                  * Converts message object to its string form based on the state of format.
 229                  *
 230                  * @return {string} Message as a string in the current form or `<key>` if key does not exist.
 231                  */
 232                 toString: function () {
 233                         var text;
 234
 235                         if ( !this.exists() ) {
 236                                 // Use <key> as text if key does not exist
 237                                 if ( this.format === 'escaped' || this.format === 'parse' ) {
 238                                         // format 'escaped' and 'parse' need to have the brackets and key html escaped
 239                                         return mw.html.escape( '<' + this.key + '>' );
 240                                 }
 241                                 return '<' + this.key + '>';
 242                         }
 243
 244                         if ( this.format === 'plain' || this.format === 'text' || this.format === 'parse' ) {
 245                                 text = this.parser();
 246                         }
 247
 248                         if ( this.format === 'escaped' ) {
 249                                 text = this.parser();
 250                                 text = mw.html.escape( text );
 251                         }
 252
 253                         return text;
 254                 },
 255
 256                 /**
 257                  * Changes format to 'parse' and converts message to string
 258                  *
 259                  * If jqueryMsg is loaded, this parses the message text from wikitext
 260                  * (where supported) to HTML
 261                  *
 262                  * Otherwise, it is equivalent to plain.
 263                  *
 264                  * @return {string} String form of parsed message
 265                  */
 266                 parse: function () {
 267                         this.format = 'parse';
 268                         return this.toString();
 269                 },
 270
 271                 /**
 272                  * Changes format to 'plain' and converts message to string
 273                  *
 274                  * This substitutes parameters, but otherwise does not change the
 275                  * message text.
 276                  *
 277                  * @return {string} String form of plain message
 278                  */
 279                 plain: function () {
 280                         this.format = 'plain';
 281                         return this.toString();
 282                 },
 283
 284                 /**
 285                  * Changes format to 'text' and converts message to string
 286                  *
 287                  * If jqueryMsg is loaded, {{-transformation is done where supported
 288                  * (such as {{plural:}}, {{gender:}}, {{int:}}).
 289                  *
 290                  * Otherwise, it is equivalent to plain.
 291                  */
 292                 text: function () {
 293                         this.format = 'text';
 294                         return this.toString();
 295                 },
 296
 297                 /**
 298                  * Changes the format to 'escaped' and converts message to string
 299                  *
 300                  * This is equivalent to using the 'text' format (see text method), then
 301                  * HTML-escaping the output.
 302                  *
 303                  * @return {string} String form of html escaped message
 304                  */
 305                 escaped: function () {
 306                         this.format = 'escaped';
 307                         return this.toString();
 308                 },
 309
 310                 /**
 311                  * Checks if message exists
 312                  *
 313                  * @see mw.Map#exists
 314                  * @return {boolean}
 315                  */
 316                 exists: function () {
 317                         return this.map.exists( this.key );
 318                 }
 319         };
 320
 321         return {
 322                 /* Public Members */
 323
 324                 /**
 325                  * Dummy placeholder for {@link mw.log}
 326                  * @method
 327                  */
 328                 log: ( function () {
 329                         var log = function () {};
 330                         log.warn = function () {};
 331                         log.deprecate = function ( obj, key, val ) {
 332                                 obj[key] = val;
 333                         };
 334                         return log;
 335                 }() ),
 336
 337                 // Make the Map constructor publicly available.
 338                 Map: Map,
 339
 340                 // Make the Message constructor publicly available.
 341                 Message: Message,
 342
 343                 /**
 344                  * Map of configuration values
 345                  *
 346                  * Check out [the complete list of configuration values](https://www.mediawiki.org/wiki/Manual:Interface/JavaScript#mw.config)
 347                  * on MediaWiki.org.
 348                  *
 349                  * If `$wgLegacyJavaScriptGlobals` is true, this Map will put its values in the
 350                  * global window object.
 351                  *
 352                  * @property {mw.Map} config
 353                  */
 354                 // Dummy placeholder. Re-assigned in ResourceLoaderStartupModule with an instance of `mw.Map`.
 355                 config: null,
 356
 357                 /**
 358                  * Empty object that plugins can be installed in.
 359                  * @property
 360                  */
 361                 libs: {},
 362
 363                 /**
 364                  * Access container for deprecated functionality that can be moved from
 365                  * from their legacy location and attached to this object (e.g. a global
 366                  * function that is deprecated and as stop-gap can be exposed through here).
 367                  *
 368                  * This was reserved for future use but never ended up being used.
 369                  *
 370                  * @deprecated since 1.22: Let deprecated identifiers keep their original name
 371                  * and use mw.log#deprecate to create an access container for tracking.
 372                  * @property
 373                  */
 374                 legacy: {},
 375
 376                 /**
 377                  * Localization system
 378                  * @property {mw.Map}
 379                  */
 380                 messages: new Map(),
 381
 382                 /* Public Methods */
 383
 384                 /**
 385                  * Get a message object.
 386                  *
 387                  * Similar to wfMessage() in MediaWiki PHP.
 388                  *
 389                  * @param {string} key Key of message to get
 390                  * @param {Mixed...} parameters Parameters for the $N replacements in messages.
 391                  * @return {mw.Message}
 392                  */
 393                 message: function ( key ) {
 394                         // Variadic arguments
 395                         var parameters = slice.call( arguments, 1 );
 396                         return new Message( mw.messages, key, parameters );
 397                 },
 398
 399                 /**
 400                  * Get a message string using 'text' format.
 401                  *
 402                  * Similar to wfMsg() in MediaWiki PHP.
 403                  *
 404                  * @see mw.Message
 405                  * @param {string} key Key of message to get
 406                  * @param {Mixed...} parameters Parameters for the $N replacements in messages.
 407                  * @return {string}
 408                  */
 409                 msg: function () {
 410                         return mw.message.apply( mw.message, arguments ).toString();
 411                 },
 412
 413                 /**
 414                  * Client-side module loader which integrates with the MediaWiki ResourceLoader
 415                  * @class mw.loader
 416                  * @singleton
 417                  */
 418                 loader: ( function () {
 419
 420                         /* Private Members */
 421
 422                         /**
 423                          * Mapping of registered modules
 424                          *
 425                          * The jquery module is pre-registered, because it must have already
 426                          * been provided for this object to have been built, and in debug mode
 427                          * jquery would have been provided through a unique loader request,
 428                          * making it impossible to hold back registration of jquery until after
 429                          * mediawiki.
 430                          *
 431                          * For exact details on support for script, style and messages, look at
 432                          * mw.loader.implement.
 433                          *
 434                          * Format:
 435                          *     {
 436                          *         'moduleName': {
 437                          *             'version': ############## (unix timestamp),
 438                          *             'dependencies': ['required.foo', 'bar.also', ...], (or) function () {}
 439                          *             'group': 'somegroup', (or) null,
 440                          *             'source': 'local', 'someforeignwiki', (or) null
 441                          *             'state': 'registered', 'loaded', 'loading', 'ready', 'error' or 'missing'
 442                          *             'script': ...,
 443                          *             'style': ...,
 444                          *             'messages': { 'key': 'value' },
 445                          *         }
 446                          *     }
 447                          *
 448                          * @property
 449                          * @private
 450                          */
 451                         var registry = {},
 452                                 //
 453                                 // Mapping of sources, keyed by source-id, values are objects.
 454                                 // Format:
 455                                 //      {
 456                                 //              'sourceId': {
 457                                 //                      'loadScript': 'http://foo.bar/w/load.php'
 458                                 //              }
 459                                 //      }
 460                                 //
 461                                 sources = {},
 462                                 // List of modules which will be loaded as when ready
 463                                 batch = [],
 464                                 // List of modules to be loaded
 465                                 queue = [],
 466                                 // List of callback functions waiting for modules to be ready to be called
 467                                 jobs = [],
 468                                 // Selector cache for the marker element. Use getMarker() to get/use the marker!
 469                                 $marker = null,
 470                                 // Buffer for addEmbeddedCSS.
 471                                 cssBuffer = '',
 472                                 // Callbacks for addEmbeddedCSS.
 473                                 cssCallbacks = $.Callbacks();
 474
 475                         /* Private methods */
 476
 477                         function getMarker() {
 478                                 // Cached ?
 479                                 if ( $marker ) {
 480                                         return $marker;
 481                                 }
 482
 483                                 $marker = $( 'meta[name="ResourceLoaderDynamicStyles"]' );
 484                                 if ( $marker.length ) {
 485                                         return $marker;
 486                                 }
 487                                 mw.log( 'getMarker> No <meta name="ResourceLoaderDynamicStyles"> found, inserting dynamically.' );
 488                                 $marker = $( '<meta>' ).attr( 'name', 'ResourceLoaderDynamicStyles' ).appendTo( 'head' );
 489
 490                                 return $marker;
 491                         }
 492
 493                         /**
 494                          * Create a new style tag and add it to the DOM.
 495                          *
 496                          * @private
 497                          * @param {string} text CSS text
 498                          * @param {HTMLElement|jQuery} [nextnode=document.head] The element where the style tag should be
 499                          *  inserted before. Otherwise it will be appended to `<head>`.
 500                          * @return {HTMLElement} Reference to the created `<style>` element.
 501                          */
 502                         function newStyleTag( text, nextnode ) {
 503                                 var s = document.createElement( 'style' );
 504                                 // Insert into document before setting cssText (bug 33305)
 505                                 if ( nextnode ) {
 506                                         // Must be inserted with native insertBefore, not $.fn.before.
 507                                         // When using jQuery to insert it, like $nextnode.before( s ),
 508                                         // then IE6 will throw "Access is denied" when trying to append
 509                                         // to .cssText later. Some kind of weird security measure.
 510                                         // http://stackoverflow.com/q/12586482/319266
 511                                         // Works: jsfiddle.net/zJzMy/1
 512                                         // Fails: jsfiddle.net/uJTQz
 513                                         // Works again: http://jsfiddle.net/Azr4w/ (diff: the next 3 lines)
 514                                         if ( nextnode.jquery ) {
 515                                                 nextnode = nextnode.get( 0 );
 516                                         }
 517                                         nextnode.parentNode.insertBefore( s, nextnode );
 518                                 } else {
 519                                         document.getElementsByTagName( 'head' )[0].appendChild( s );
 520                                 }
 521                                 if ( s.styleSheet ) {
 522                                         // IE
 523                                         s.styleSheet.cssText = text;
 524                                 } else {
 525                                         // Other browsers.
 526                                         // (Safari sometimes borks on non-string values,
 527                                         // play safe by casting to a string, just in case.)
 528                                         s.appendChild( document.createTextNode( String( text ) ) );
 529                                 }
 530                                 return s;
 531                         }
 532
 533                         /**
 534                          * Checks whether it is safe to add this css to a stylesheet.
 535                          *
 536                          * @private
 537                          * @param {string} cssText
 538                          * @return {boolean} False if a new one must be created.
 539                          */
 540                         function canExpandStylesheetWith( cssText ) {
 541                                 // Makes sure that cssText containing `@import`
 542                                 // rules will end up in a new stylesheet (as those only work when
 543                                 // placed at the start of a stylesheet; bug 35562).
 544                                 return cssText.indexOf( '@import' ) === -1;
 545                         }
 546
 547                         /**
 548                          * Add a bit of CSS text to the current browser page.
 549                          *
 550                          * The CSS will be appended to an existing ResourceLoader-created `<style>` tag
 551                          * or create a new one based on whether the given `cssText` is safe for extension.
 552                          *
 553                          * @param {string} [cssText=cssBuffer] If called without cssText,
 554                          *  the internal buffer will be inserted instead.
 555                          * @param {Function} [callback]
 556                          */
 557                         function addEmbeddedCSS( cssText, callback ) {
 558                                 var $style, styleEl;
 559
 560                                 if ( callback ) {
 561                                         cssCallbacks.add( callback );
 562                                 }
 563
 564                                 // Yield once before inserting the <style> tag. There are likely
 565                                 // more calls coming up which we can combine this way.
 566                                 // Appending a stylesheet and waiting for the browser to repaint
 567                                 // is fairly expensive, this reduces it (bug 45810)
 568                                 if ( cssText ) {
 569                                         // Be careful not to extend the buffer with css that needs a new stylesheet
 570                                         if ( !cssBuffer || canExpandStylesheetWith( cssText ) ) {
 571                                                 // Linebreak for somewhat distinguishable sections
 572                                                 // (the rl-cachekey comment separating each)
 573                                                 cssBuffer += '\n' + cssText;
 574                                                 // TODO: Use requestAnimationFrame in the future which will
 575                                                 // perform even better by not injecting styles while the browser
 576                                                 // is paiting.
 577                                                 setTimeout( function () {
 578                                                         // Can't pass addEmbeddedCSS to setTimeout directly because Firefox
 579                                                         // (below version 13) has the non-standard behaviour of passing a
 580                                                         // numerical "lateness" value as first argument to this callback
 581                                                         // http://benalman.com/news/2009/07/the-mysterious-firefox-settime/
 582                                                         addEmbeddedCSS();
 583                                                 } );
 584                                                 return;
 585                                         }
 586
 587                                 // This is a delayed call and we got a buffer still
 588                                 } else if ( cssBuffer ) {
 589                                         cssText = cssBuffer;
 590                                         cssBuffer = '';
 591                                 } else {
 592                                         // This is a delayed call, but buffer is already cleared by
 593                                         // another delayed call.
 594                                         return;
 595                                 }
 596
 597                                 // By default, always create a new <style>. Appending text
 598                                 // to a <style> tag means the contents have to be re-parsed (bug 45810).
 599                                 // Except, of course, in IE below 9, in there we default to
 600                                 // re-using and appending to a <style> tag due to the
 601                                 // IE stylesheet limit (bug 31676).
 602                                 if ( 'documentMode' in document && document.documentMode <= 9 ) {
 603
 604                                         $style = getMarker().prev();
 605                                         // Verify that the the element before Marker actually is a
 606                                         // <style> tag and one that came from ResourceLoader
 607                                         // (not some other style tag or even a `<meta>` or `<script>`).
 608                                         if ( $style.data( 'ResourceLoaderDynamicStyleTag' ) === true ) {
 609                                                 // There's already a dynamic <style> tag present and
 610                                                 // canExpandStylesheetWith() gave a green light to append more to it.
 611                                                 styleEl = $style.get( 0 );
 612                                                 if ( styleEl.styleSheet ) {
 613                                                         try {
 614                                                                 styleEl.styleSheet.cssText += cssText; // IE
 615                                                         } catch ( e ) {
 616                                                                 log( 'addEmbeddedCSS fail', e );
 617                                                         }
 618                                                 } else {
 619                                                         styleEl.appendChild( document.createTextNode( String( cssText ) ) );
 620                                                 }
 621                                                 cssCallbacks.fire().empty();
 622                                                 return;
 623                                         }
 624                                 }
 625
 626                                 $( newStyleTag( cssText, getMarker() ) ).data( 'ResourceLoaderDynamicStyleTag', true );
 627
 628                                 cssCallbacks.fire().empty();
 629                         }
 630
 631                         /**
 632                          * Generates an ISO8601 "basic" string from a UNIX timestamp
 633                          * @private
 634                          */
 635                         function formatVersionNumber( timestamp ) {
 636                                 var     d = new Date();
 637                                 function pad( a, b, c ) {
 638                                         return [a < 10 ? '0' + a : a, b < 10 ? '0' + b : b, c < 10 ? '0' + c : c].join( '' );
 639                                 }
 640                                 d.setTime( timestamp * 1000 );
 641                                 return [
 642                                         pad( d.getUTCFullYear(), d.getUTCMonth() + 1, d.getUTCDate() ), 'T',
 643                                         pad( d.getUTCHours(), d.getUTCMinutes(), d.getUTCSeconds() ), 'Z'
 644                                 ].join( '' );
 645                         }
 646
 647                         /**
 648                          * Resolves dependencies and detects circular references.
 649                          *
 650                          * @private
 651                          * @param {string} module Name of the top-level module whose dependencies shall be
 652                          *   resolved and sorted.
 653                          * @param {Array} resolved Returns a topological sort of the given module and its
 654                          *   dependencies, such that later modules depend on earlier modules. The array
 655                          *   contains the module names. If the array contains already some module names,
 656                          *   this function appends its result to the pre-existing array.
 657                          * @param {Object} [unresolved] Hash used to track the current dependency
 658                          *   chain; used to report loops in the dependency graph.
 659                          * @throws {Error} If any unregistered module or a dependency loop is encountered
 660                          */
 661                         function sortDependencies( module, resolved, unresolved ) {
 662                                 var n, deps, len;
 663
 664                                 if ( registry[module] === undefined ) {
 665                                         throw new Error( 'Unknown dependency: ' + module );
 666                                 }
 667                                 // Resolves dynamic loader function and replaces it with its own results
 668                                 if ( $.isFunction( registry[module].dependencies ) ) {
 669                                         registry[module].dependencies = registry[module].dependencies();
 670                                         // Ensures the module's dependencies are always in an array
 671                                         if ( typeof registry[module].dependencies !== 'object' ) {
 672                                                 registry[module].dependencies = [registry[module].dependencies];
 673                                         }
 674                                 }
 675                                 if ( $.inArray( module, resolved ) !== -1 ) {
 676                                         // Module already resolved; nothing to do.
 677                                         return;
 678                                 }
 679                                 // unresolved is optional, supply it if not passed in
 680                                 if ( !unresolved ) {
 681                                         unresolved = {};
 682                                 }
 683                                 // Tracks down dependencies
 684                                 deps = registry[module].dependencies;
 685                                 len = deps.length;
 686                                 for ( n = 0; n < len; n += 1 ) {
 687                                         if ( $.inArray( deps[n], resolved ) === -1 ) {
 688                                                 if ( unresolved[deps[n]] ) {
 689                                                         throw new Error(
 690                                                                 'Circular reference detected: ' + module +
 691                                                                 ' -> ' + deps[n]
 692                                                         );
 693                                                 }
 694
 695                                                 // Add to unresolved
 696                                                 unresolved[module] = true;
 697                                                 sortDependencies( deps[n], resolved, unresolved );
 698                                                 delete unresolved[module];
 699                                         }
 700                                 }
 701                                 resolved[resolved.length] = module;
 702                         }
 703
 704                         /**
 705                          * Gets a list of module names that a module depends on in their proper dependency
 706                          * order.
 707                          *
 708                          * @private
 709                          * @param {string} module Module name or array of string module names
 710                          * @return {Array} list of dependencies, including 'module'.
 711                          * @throws {Error} If circular reference is detected
 712                          */
 713                         function resolve( module ) {
 714                                 var m, resolved;
 715
 716                                 // Allow calling with an array of module names
 717                                 if ( $.isArray( module ) ) {
 718                                         resolved = [];
 719                                         for ( m = 0; m < module.length; m += 1 ) {
 720                                                 sortDependencies( module[m], resolved );
 721                                         }
 722                                         return resolved;
 723                                 }
 724
 725                                 if ( typeof module === 'string' ) {
 726                                         resolved = [];
 727                                         sortDependencies( module, resolved );
 728                                         return resolved;
 729                                 }
 730
 731                                 throw new Error( 'Invalid module argument: ' + module );
 732                         }
 733
 734                         /**
 735                          * Narrows a list of module names down to those matching a specific
 736                          * state (see comment on top of this scope for a list of valid states).
 737                          * One can also filter for 'unregistered', which will return the
 738                          * modules names that don't have a registry entry.
 739                          *
 740                          * @private
 741                          * @param {string|string[]} states Module states to filter by
 742                          * @param {Array} [modules] List of module names to filter (optional, by default the entire
 743                          * registry is used)
 744                          * @return {Array} List of filtered module names
 745                          */
 746                         function filter( states, modules ) {
 747                                 var list, module, s, m;
 748
 749                                 // Allow states to be given as a string
 750                                 if ( typeof states === 'string' ) {
 751                                         states = [states];
 752                                 }
 753                                 // If called without a list of modules, build and use a list of all modules
 754                                 list = [];
 755                                 if ( modules === undefined ) {
 756                                         modules = [];
 757                                         for ( module in registry ) {
 758                                                 modules[modules.length] = module;
 759                                         }
 760                                 }
 761                                 // Build a list of modules which are in one of the specified states
 762                                 for ( s = 0; s < states.length; s += 1 ) {
 763                                         for ( m = 0; m < modules.length; m += 1 ) {
 764                                                 if ( registry[modules[m]] === undefined ) {
 765                                                         // Module does not exist
 766                                                         if ( states[s] === 'unregistered' ) {
 767                                                                 // OK, undefined
 768                                                                 list[list.length] = modules[m];
 769                                                         }
 770                                                 } else {
 771                                                         // Module exists, check state
 772                                                         if ( registry[modules[m]].state === states[s] ) {
 773                                                                 // OK, correct state
 774                                                                 list[list.length] = modules[m];
 775                                                         }
 776                                                 }
 777                                         }
 778                                 }
 779                                 return list;
 780                         }
 781
 782                         /**
 783                          * Determine whether all dependencies are in state 'ready', which means we may
 784                          * execute the module or job now.
 785                          *
 786                          * @private
 787                          * @param {Array} dependencies Dependencies (module names) to be checked.
 788                          * @return {boolean} True if all dependencies are in state 'ready', false otherwise
 789                          */
 790                         function allReady( dependencies ) {
 791                                 return filter( 'ready', dependencies ).length === dependencies.length;
 792                         }
 793
 794                         /**
 795                          * A module has entered state 'ready', 'error', or 'missing'. Automatically update pending jobs
 796                          * and modules that depend upon this module. if the given module failed, propagate the 'error'
 797                          * state up the dependency tree; otherwise, execute all jobs/modules that now have all their
 798                          * dependencies satisfied. On jobs depending on a failed module, run the error callback, if any.
 799                          *
 800                          * @private
 801                          * @param {string} module Name of module that entered one of the states 'ready', 'error', or 'missing'.
 802                          */
 803                         function handlePending( module ) {
 804                                 var j, job, hasErrors, m, stateChange;
 805
 806                                 // Modules.
 807                                 if ( $.inArray( registry[module].state, ['error', 'missing'] ) !== -1 ) {
 808                                         // If the current module failed, mark all dependent modules also as failed.
 809                                         // Iterate until steady-state to propagate the error state upwards in the
 810                                         // dependency tree.
 811                                         do {
 812                                                 stateChange = false;
 813                                                 for ( m in registry ) {
 814                                                         if ( $.inArray( registry[m].state, ['error', 'missing'] ) === -1 ) {
 815                                                                 if ( filter( ['error', 'missing'], registry[m].dependencies ).length > 0 ) {
 816                                                                         registry[m].state = 'error';
 817                                                                         stateChange = true;
 818                                                                 }
 819                                                         }
 820                                                 }
 821                                         } while ( stateChange );
 822                                 }
 823
 824                                 // Execute all jobs whose dependencies are either all satisfied or contain at least one failed module.
 825                                 for ( j = 0; j < jobs.length; j += 1 ) {
 826                                         hasErrors = filter( ['error', 'missing'], jobs[j].dependencies ).length > 0;
 827                                         if ( hasErrors || allReady( jobs[j].dependencies ) ) {
 828                                                 // All dependencies satisfied, or some have errors
 829                                                 job = jobs[j];
 830                                                 jobs.splice( j, 1 );
 831                                                 j -= 1;
 832                                                 try {
 833                                                         if ( hasErrors ) {
 834                                                                 if ( $.isFunction( job.error ) ) {
 835                                                                         job.error( new Error( 'Module ' + module + ' has failed dependencies' ), [module] );
 836                                                                 }
 837                                                         } else {
 838                                                                 if ( $.isFunction( job.ready ) ) {
 839                                                                         job.ready();
 840                                                                 }
 841                                                         }
 842                                                 } catch ( e ) {
 843                                                         // A user-defined callback raised an exception.
 844                                                         // Swallow it to protect our state machine!
 845                                                         log( 'Exception thrown by job.error', e );
 846                                                 }
 847                                         }
 848                                 }
 849
 850                                 if ( registry[module].state === 'ready' ) {
 851                                         // The current module became 'ready'. Set it in the module store, and recursively execute all
 852                                         // dependent modules that are loaded and now have all dependencies satisfied.
 853                                         mw.loader.store.set( module, registry[module] );
 854                                         for ( m in registry ) {
 855                                                 if ( registry[m].state === 'loaded' && allReady( registry[m].dependencies ) ) {
 856                                                         execute( m );
 857                                                 }
 858                                         }
 859                                 }
 860                         }
 861
 862                         /**
 863                          * Adds a script tag to the DOM, either using document.write or low-level DOM manipulation,
 864                          * depending on whether document-ready has occurred yet and whether we are in async mode.
 865                          *
 866                          * @private
 867                          * @param {string} src URL to script, will be used as the src attribute in the script tag
 868                          * @param {Function} [callback] Callback which will be run when the script is done
 869                          */
 870                         function addScript( src, callback, async ) {
 871                                 /*jshint evil:true */
 872                                 var script, head, done;
 873
 874                                 // Using isReady directly instead of storing it locally from
 875                                 // a $.fn.ready callback (bug 31895).
 876                                 if ( $.isReady || async ) {
 877                                         // Can't use jQuery.getScript because that only uses <script> for cross-domain,
 878                                         // it uses XHR and eval for same-domain scripts, which we don't want because it
 879                                         // messes up line numbers.
 880                                         // The below is based on jQuery ([jquery@1.8.2]/src/ajax/script.js)
 881
 882                                         // IE-safe way of getting the <head>. document.head isn't supported
 883                                         // in old IE, and doesn't work when in the <head>.
 884                                         done = false;
 885                                         head = document.getElementsByTagName( 'head' )[0] || document.body;
 886
 887                                         script = document.createElement( 'script' );
 888                                         script.async = true;
 889                                         script.src = src;
 890                                         if ( $.isFunction( callback ) ) {
 891                                                 script.onload = script.onreadystatechange = function () {
 892                                                         if (
 893                                                                 !done
 894                                                                 && (
 895                                                                         !script.readyState
 896                                                                         || /loaded|complete/.test( script.readyState )
 897                                                                 )
 898                                                         ) {
 899                                                                 done = true;
 900
 901                                                                 // Handle memory leak in IE
 902                                                                 script.onload = script.onreadystatechange = null;
 903
 904                                                                 // Detach the element from the document
 905                                                                 if ( script.parentNode ) {
 906                                                                         script.parentNode.removeChild( script );
 907                                                                 }
 908
 909                                                                 // Dereference the element from javascript
 910                                                                 script = undefined;
 911
 912                                                                 callback();
 913                                                         }
 914                                                 };
 915                                         }
 916
 917                                         if ( window.opera ) {
 918                                                 // Appending to the <head> blocks rendering completely in Opera,
 919                                                 // so append to the <body> after document ready. This means the
 920                                                 // scripts only start loading after the document has been rendered,
 921                                                 // but so be it. Opera users don't deserve faster web pages if their
 922                                                 // browser makes it impossible.
 923                                                 $( function () {
 924                                                         document.body.appendChild( script );
 925                                                 } );
 926                                         } else {
 927                                                 head.appendChild( script );
 928                                         }
 929                                 } else {
 930                                         document.write( mw.html.element( 'script', { 'src': src }, '' ) );
 931                                         if ( $.isFunction( callback ) ) {
 932                                                 // Document.write is synchronous, so this is called when it's done
 933                                                 // FIXME: that's a lie. doc.write isn't actually synchronous
 934                                                 callback();
 935                                         }
 936                                 }
 937                         }
 938
 939                         /**
 940                          * Executes a loaded module, making it ready to use
 941                          *
 942                          * @private
 943                          * @param {string} module Module name to execute
 944                          */
 945                         function execute( module ) {
 946                                 var key, value, media, i, urls, cssHandle, checkCssHandles,
 947                                         cssHandlesRegistered = false;
 948
 949                                 if ( registry[module] === undefined ) {
 950                                         throw new Error( 'Module has not been registered yet: ' + module );
 951                                 } else if ( registry[module].state === 'registered' ) {
 952                                         throw new Error( 'Module has not been requested from the server yet: ' + module );
 953                                 } else if ( registry[module].state === 'loading' ) {
 954                                         throw new Error( 'Module has not completed loading yet: ' + module );
 955                                 } else if ( registry[module].state === 'ready' ) {
 956                                         throw new Error( 'Module has already been executed: ' + module );
 957                                 }
 958
 959                                 /**
 960                                  * Define loop-function here for efficiency
 961                                  * and to avoid re-using badly scoped variables.
 962                                  * @ignore
 963                                  */
 964                                 function addLink( media, url ) {
 965                                         var el = document.createElement( 'link' );
 966                                         getMarker().before( el ); // IE: Insert in dom before setting href
 967                                         el.rel = 'stylesheet';
 968                                         if ( media && media !== 'all' ) {
 969                                                 el.media = media;
 970                                         }
 971                                         el.href = url;
 972                                 }
 973
 974                                 function runScript() {
 975                                         var script, markModuleReady, nestedAddScript;
 976                                         try {
 977                                                 script = registry[module].script;
 978                                                 markModuleReady = function () {
 979                                                         registry[module].state = 'ready';
 980                                                         handlePending( module );
 981                                                 };
 982                                                 nestedAddScript = function ( arr, callback, async, i ) {
 983                                                         // Recursively call addScript() in its own callback
 984                                                         // for each element of arr.
 985                                                         if ( i >= arr.length ) {
 986                                                                 // We're at the end of the array
 987                                                                 callback();
 988                                                                 return;
 989                                                         }
 990
 991                                                         addScript( arr[i], function () {
 992                                                                 nestedAddScript( arr, callback, async, i + 1 );
 993                                                         }, async );
 994                                                 };
 995
 996                                                 if ( $.isArray( script ) ) {
 997                                                         nestedAddScript( script, markModuleReady, registry[module].async, 0 );
 998                                                 } else if ( $.isFunction( script ) ) {
 999                                                         registry[module].state = 'ready';
1000                                                         script( $ );
1001                                                         handlePending( module );
1002                                                 }
1003                                         } catch ( e ) {
1004                                                 // This needs to NOT use mw.log because these errors are common in production mode
1005                                                 // and not in debug mode, such as when a symbol that should be global isn't exported
1006                                                 log( 'Exception thrown by ' + module, e );
1007                                                 registry[module].state = 'error';
1008                                                 handlePending( module );
1009                                         }
1010                                 }
1011
1012                                 // This used to be inside runScript, but since that is now fired asychronously
1013                                 // (after CSS is loaded) we need to set it here right away. It is crucial that
1014                                 // when execute() is called this is set synchronously, otherwise modules will get
1015                                 // executed multiple times as the registry will state that it isn't loading yet.
1016                                 registry[module].state = 'loading';
1017
1018                                 // Add localizations to message system
1019                                 if ( $.isPlainObject( registry[module].messages ) ) {
1020                                         mw.messages.set( registry[module].messages );
1021                                 }
1022
1023                                 if ( $.isReady || registry[module].async ) {
1024                                         // Make sure we don't run the scripts until all (potentially asynchronous)
1025                                         // stylesheet insertions have completed.
1026                                         ( function () {
1027                                                 var pending = 0;
1028                                                 checkCssHandles = function () {
1029                                                         // cssHandlesRegistered ensures we don't take off too soon, e.g. when
1030                                                         // one of the cssHandles is fired while we're still creating more handles.
1031                                                         if ( cssHandlesRegistered && pending === 0 && runScript ) {
1032                                                                 runScript();
1033                                                                 runScript = undefined; // Revoke
1034                                                         }
1035                                                 };
1036                                                 cssHandle = function () {
1037                                                         var check = checkCssHandles;
1038                                                         pending++;
1039                                                         return function () {
1040                                                                 if (check) {
1041                                                                         pending--;
1042                                                                         check();
1043                                                                         check = undefined; // Revoke
1044                                                                 }
1045                                                         };
1046                                                 };
1047                                         }() );
1048                                 } else {
1049                                         // We are in blocking mode, and so we can't afford to wait for CSS
1050                                         cssHandle = function () {};
1051                                         // Run immediately
1052                                         checkCssHandles = runScript;
1053                                 }
1054
1055                                 // Process styles (see also mw.loader.implement)
1056                                 // * back-compat: { <media>: css }
1057                                 // * back-compat: { <media>: [url, ..] }
1058                                 // * { "css": [css, ..] }
1059                                 // * { "url": { <media>: [url, ..] } }
1060                                 if ( $.isPlainObject( registry[module].style ) ) {
1061                                         for ( key in registry[module].style ) {
1062                                                 value = registry[module].style[key];
1063                                                 media = undefined;
1064
1065                                                 if ( key !== 'url' && key !== 'css' ) {
1066                                                         // Backwards compatibility, key is a media-type
1067                                                         if ( typeof value === 'string' ) {
1068                                                                 // back-compat: { <media>: css }
1069                                                                 // Ignore 'media' because it isn't supported (nor was it used).
1070                                                                 // Strings are pre-wrapped in "@media". The media-type was just ""
1071                                                                 // (because it had to be set to something).
1072                                                                 // This is one of the reasons why this format is no longer used.
1073                                                                 addEmbeddedCSS( value, cssHandle() );
1074                                                         } else {
1075                                                                 // back-compat: { <media>: [url, ..] }
1076                                                                 media = key;
1077                                                                 key = 'bc-url';
1078                                                         }
1079                                                 }
1080
1081                                                 // Array of css strings in key 'css',
1082                                                 // or back-compat array of urls from media-type
1083                                                 if ( $.isArray( value ) ) {
1084                                                         for ( i = 0; i < value.length; i += 1 ) {
1085                                                                 if ( key === 'bc-url' ) {
1086                                                                         // back-compat: { <media>: [url, ..] }
1087                                                                         addLink( media, value[i] );
1088                                                                 } else if ( key === 'css' ) {
1089                                                                         // { "css": [css, ..] }
1090                                                                         addEmbeddedCSS( value[i], cssHandle() );
1091                                                                 }
1092                                                         }
1093                                                 // Not an array, but a regular object
1094                                                 // Array of urls inside media-type key
1095                                                 } else if ( typeof value === 'object' ) {
1096                                                         // { "url": { <media>: [url, ..] } }
1097                                                         for ( media in value ) {
1098                                                                 urls = value[media];
1099                                                                 for ( i = 0; i < urls.length; i += 1 ) {
1100                                                                         addLink( media, urls[i] );
1101                                                                 }
1102                                                         }
1103                                                 }
1104                                         }
1105                                 }
1106
1107                                 // Kick off.
1108                                 cssHandlesRegistered = true;
1109                                 checkCssHandles();
1110                         }
1111
1112                         /**
1113                          * Adds a dependencies to the queue with optional callbacks to be run
1114                          * when the dependencies are ready or fail
1115                          *
1116                          * @private
1117                          * @param {string|string[]} dependencies Module name or array of string module names
1118                          * @param {Function} [ready] Callback to execute when all dependencies are ready
1119                          * @param {Function} [error] Callback to execute when any dependency fails
1120                          * @param {boolean} [async] If true, load modules asynchronously even if
1121                          *  document ready has not yet occurred.
1122                          */
1123                         function request( dependencies, ready, error, async ) {
1124                                 var n;
1125
1126                                 // Allow calling by single module name
1127                                 if ( typeof dependencies === 'string' ) {
1128                                         dependencies = [dependencies];
1129                                 }
1130
1131                                 // Add ready and error callbacks if they were given
1132                                 if ( ready !== undefined || error !== undefined ) {
1133                                         jobs[jobs.length] = {
1134                                                 'dependencies': filter(
1135                                                         ['registered', 'loading', 'loaded'],
1136                                                         dependencies
1137                                                 ),
1138                                                 'ready': ready,
1139                                                 'error': error
1140                                         };
1141                                 }
1142
1143                                 // Queue up any dependencies that are registered
1144                                 dependencies = filter( ['registered'], dependencies );
1145                                 for ( n = 0; n < dependencies.length; n += 1 ) {
1146                                         if ( $.inArray( dependencies[n], queue ) === -1 ) {
1147                                                 queue[queue.length] = dependencies[n];
1148                                                 if ( async ) {
1149                                                         // Mark this module as async in the registry
1150                                                         registry[dependencies[n]].async = true;
1151                                                 }
1152                                         }
1153                                 }
1154
1155                                 // Work the queue
1156                                 mw.loader.work();
1157                         }
1158
1159                         function sortQuery(o) {
1160                                 var sorted = {}, key, a = [];
1161                                 for ( key in o ) {
1162                                         if ( hasOwn.call( o, key ) ) {
1163                                                 a.push( key );
1164                                         }
1165                                 }
1166                                 a.sort();
1167                                 for ( key = 0; key < a.length; key += 1 ) {
1168                                         sorted[a[key]] = o[a[key]];
1169                                 }
1170                                 return sorted;
1171                         }
1172
1173                         /**
1174                          * Converts a module map of the form { foo: [ 'bar', 'baz' ], bar: [ 'baz, 'quux' ] }
1175                          * to a query string of the form foo.bar,baz|bar.baz,quux
1176                          * @private
1177                          */
1178                         function buildModulesString( moduleMap ) {
1179                                 var arr = [], p, prefix;
1180                                 for ( prefix in moduleMap ) {
1181                                         p = prefix === '' ? '' : prefix + '.';
1182                                         arr.push( p + moduleMap[prefix].join( ',' ) );
1183                                 }
1184                                 return arr.join( '|' );
1185                         }
1186
1187                         /**
1188                          * Asynchronously append a script tag to the end of the body
1189                          * that invokes load.php
1190                          * @private
1191                          * @param {Object} moduleMap Module map, see #buildModulesString
1192                          * @param {Object} currReqBase Object with other parameters (other than 'modules') to use in the request
1193                          * @param {string} sourceLoadScript URL of load.php
1194                          * @param {boolean} async If true, use an asynchronous request even if document ready has not yet occurred
1195                          */
1196                         function doRequest( moduleMap, currReqBase, sourceLoadScript, async ) {
1197                                 var request = $.extend(
1198                                         { modules: buildModulesString( moduleMap ) },
1199                                         currReqBase
1200                                 );
1201                                 request = sortQuery( request );
1202                                 // Asynchronously append a script tag to the end of the body
1203                                 // Append &* to avoid triggering the IE6 extension check
1204                                 addScript( sourceLoadScript + '?' + $.param( request ) + '&*', null, async );
1205                         }
1206
1207                         /* Public Members */
1208                         return {
1209                                 /**
1210                                  * The module registry is exposed as an aid for debugging and inspecting page
1211                                  * state; it is not a public interface for modifying the registry.
1212                                  *
1213                                  * @see #registry
1214                                  * @property
1215                                  * @private
1216                                  */
1217                                 moduleRegistry: registry,
1218
1219                                 /**
1220                                  * @inheritdoc #newStyleTag
1221                                  * @method
1222                                  */
1223                                 addStyleTag: newStyleTag,
1224
1225                                 /**
1226                                  * Batch-request queued dependencies from the server.
1227                                  */
1228                                 work: function () {
1229                                         var     reqBase, splits, maxQueryLength, q, b, bSource, bGroup, bSourceGroup,
1230                                                 source, group, g, i, modules, maxVersion, sourceLoadScript,
1231                                                 currReqBase, currReqBaseLength, moduleMap, l,
1232                                                 lastDotIndex, prefix, suffix, bytesAdded, async;
1233
1234                                         // Build a list of request parameters common to all requests.
1235                                         reqBase = {
1236                                                 skin: mw.config.get( 'skin' ),
1237                                                 lang: mw.config.get( 'wgUserLanguage' ),
1238                                                 debug: mw.config.get( 'debug' )
1239                                         };
1240                                         // Split module batch by source and by group.
1241                                         splits = {};
1242                                         maxQueryLength = mw.config.get( 'wgResourceLoaderMaxQueryLength', -1 );
1243
1244                                         // Appends a list of modules from the queue to the batch
1245                                         for ( q = 0; q < queue.length; q += 1 ) {
1246                                                 // Only request modules which are registered
1247                                                 if ( registry[queue[q]] !== undefined && registry[queue[q]].state === 'registered' ) {
1248                                                         // Prevent duplicate entries
1249                                                         if ( $.inArray( queue[q], batch ) === -1 ) {
1250                                                                 batch[batch.length] = queue[q];
1251                                                                 // Mark registered modules as loading
1252                                                                 registry[queue[q]].state = 'loading';
1253                                                         }
1254                                                 }
1255                                         }
1256
1257                                         mw.loader.store.init();
1258                                         if ( mw.loader.store.enabled ) {
1259                                                 batch = $.grep( batch, function ( module ) {
1260                                                         var source = mw.loader.store.get( module );
1261                                                         if ( source ) {
1262                                                                 $.globalEval( source );
1263                                                                 return false; // Don't fetch
1264                                                         }
1265                                                         return true; // Fetch
1266                                                 } );
1267                                         }
1268
1269                                         // Early exit if there's nothing to load...
1270                                         if ( !batch.length ) {
1271                                                 return;
1272                                         }
1273
1274                                         // The queue has been processed into the batch, clear up the queue.
1275                                         queue = [];
1276
1277                                         // Always order modules alphabetically to help reduce cache
1278                                         // misses for otherwise identical content.
1279                                         batch.sort();
1280
1281                                         // Split batch by source and by group.
1282                                         for ( b = 0; b < batch.length; b += 1 ) {
1283                                                 bSource = registry[batch[b]].source;
1284                                                 bGroup = registry[batch[b]].group;
1285                                                 if ( splits[bSource] === undefined ) {
1286                                                         splits[bSource] = {};
1287                                                 }
1288                                                 if ( splits[bSource][bGroup] === undefined ) {
1289                                                         splits[bSource][bGroup] = [];
1290                                                 }
1291                                                 bSourceGroup = splits[bSource][bGroup];
1292                                                 bSourceGroup[bSourceGroup.length] = batch[b];
1293                                         }
1294
1295                                         // Clear the batch - this MUST happen before we append any
1296                                         // script elements to the body or it's possible that a script
1297                                         // will be locally cached, instantly load, and work the batch
1298                                         // again, all before we've cleared it causing each request to
1299                                         // include modules which are already loaded.
1300                                         batch = [];
1301
1302                                         for ( source in splits ) {
1303
1304                                                 sourceLoadScript = sources[source].loadScript;
1305
1306                                                 for ( group in splits[source] ) {
1307
1308                                                         // Cache access to currently selected list of
1309                                                         // modules for this group from this source.
1310                                                         modules = splits[source][group];
1311
1312                                                         // Calculate the highest timestamp
1313                                                         maxVersion = 0;
1314                                                         for ( g = 0; g < modules.length; g += 1 ) {
1315                                                                 if ( registry[modules[g]].version > maxVersion ) {
1316                                                                         maxVersion = registry[modules[g]].version;
1317                                                                 }
1318                                                         }
1319
1320                                                         currReqBase = $.extend( { version: formatVersionNumber( maxVersion ) }, reqBase );
1321                                                         // For user modules append a user name to the request.
1322                                                         if ( group === 'user' && mw.config.get( 'wgUserName' ) !== null ) {
1323                                                                 currReqBase.user = mw.config.get( 'wgUserName' );
1324                                                         }
1325                                                         currReqBaseLength = $.param( currReqBase ).length;
1326                                                         async = true;
1327                                                         // We may need to split up the request to honor the query string length limit,
1328                                                         // so build it piece by piece.
1329                                                         l = currReqBaseLength + 9; // '&modules='.length == 9
1330
1331                                                         moduleMap = {}; // { prefix: [ suffixes ] }
1332
1333                                                         for ( i = 0; i < modules.length; i += 1 ) {
1334                                                                 // Determine how many bytes this module would add to the query string
1335                                                                 lastDotIndex = modules[i].lastIndexOf( '.' );
1336                                                                 // Note that these substr() calls work even if lastDotIndex == -1
1337                                                                 prefix = modules[i].substr( 0, lastDotIndex );
1338                                                                 suffix = modules[i].substr( lastDotIndex + 1 );
1339                                                                 bytesAdded = moduleMap[prefix] !== undefined
1340                                                                         ? suffix.length + 3 // '%2C'.length == 3
1341                                                                         : modules[i].length + 3; // '%7C'.length == 3
1342
1343                                                                 // If the request would become too long, create a new one,
1344                                                                 // but don't create empty requests
1345                                                                 if ( maxQueryLength > 0 && !$.isEmptyObject( moduleMap ) && l + bytesAdded > maxQueryLength ) {
1346                                                                         // This request would become too long, create a new one
1347                                                                         // and fire off the old one
1348                                                                         doRequest( moduleMap, currReqBase, sourceLoadScript, async );
1349                                                                         moduleMap = {};
1350                                                                         async = true;
1351                                                                         l = currReqBaseLength + 9;
1352                                                                 }
1353                                                                 if ( moduleMap[prefix] === undefined ) {
1354                                                                         moduleMap[prefix] = [];
1355                                                                 }
1356                                                                 moduleMap[prefix].push( suffix );
1357                                                                 if ( !registry[modules[i]].async ) {
1358                                                                         // If this module is blocking, make the entire request blocking
1359                                                                         // This is slightly suboptimal, but in practice mixing of blocking
1360                                                                         // and async modules will only occur in debug mode.
1361                                                                         async = false;
1362                                                                 }
1363                                                                 l += bytesAdded;
1364                                                         }
1365                                                         // If there's anything left in moduleMap, request that too
1366                                                         if ( !$.isEmptyObject( moduleMap ) ) {
1367                                                                 doRequest( moduleMap, currReqBase, sourceLoadScript, async );
1368                                                         }
1369                                                 }
1370                                         }
1371                                 },
1372
1373                                 /**
1374                                  * Register a source.
1375                                  *
1376                                  * @param {string} id Short lowercase a-Z string representing a source, only used internally.
1377                                  * @param {Object} props Object containing only the loadScript property which is a url to
1378                                  *  the load.php location of the source.
1379                                  * @return {boolean}
1380                                  */
1381                                 addSource: function ( id, props ) {
1382                                         var source;
1383                                         // Allow multiple additions
1384                                         if ( typeof id === 'object' ) {
1385                                                 for ( source in id ) {
1386                                                         mw.loader.addSource( source, id[source] );
1387                                                 }
1388                                                 return true;
1389                                         }
1390
1391                                         if ( sources[id] !== undefined ) {
1392                                                 throw new Error( 'source already registered: ' + id );
1393                                         }
1394
1395                                         sources[id] = props;
1396
1397                                         return true;
1398                                 },
1399
1400                                 /**
1401                                  * Register a module, letting the system know about it and its
1402                                  * properties. Startup modules contain calls to this function.
1403                                  *
1404                                  * @param {string} module Module name
1405                                  * @param {number} version Module version number as a timestamp (falls backs to 0)
1406                                  * @param {string|Array|Function} dependencies One string or array of strings of module
1407                                  *  names on which this module depends, or a function that returns that array.
1408                                  * @param {string} [group=null] Group which the module is in
1409                                  * @param {string} [source='local'] Name of the source
1410                                  */
1411                                 register: function ( module, version, dependencies, group, source ) {
1412                                         var m;
1413                                         // Allow multiple registration
1414                                         if ( typeof module === 'object' ) {
1415                                                 for ( m = 0; m < module.length; m += 1 ) {
1416                                                         // module is an array of module names
1417                                                         if ( typeof module[m] === 'string' ) {
1418                                                                 mw.loader.register( module[m] );
1419                                                         // module is an array of arrays
1420                                                         } else if ( typeof module[m] === 'object' ) {
1421                                                                 mw.loader.register.apply( mw.loader, module[m] );
1422                                                         }
1423                                                 }
1424                                                 return;
1425                                         }
1426                                         // Validate input
1427                                         if ( typeof module !== 'string' ) {
1428                                                 throw new Error( 'module must be a string, not a ' + typeof module );
1429                                         }
1430                                         if ( registry[module] !== undefined ) {
1431                                                 throw new Error( 'module already registered: ' + module );
1432                                         }
1433                                         // List the module as registered
1434                                         registry[module] = {
1435                                                 version: version !== undefined ? parseInt( version, 10 ) : 0,
1436                                                 dependencies: [],
1437                                                 group: typeof group === 'string' ? group : null,
1438                                                 source: typeof source === 'string' ? source: 'local',
1439                                                 state: 'registered'
1440                                         };
1441                                         if ( typeof dependencies === 'string' ) {
1442                                                 // Allow dependencies to be given as a single module name
1443                                                 registry[module].dependencies = [ dependencies ];
1444                                         } else if ( typeof dependencies === 'object' || $.isFunction( dependencies ) ) {
1445                                                 // Allow dependencies to be given as an array of module names
1446                                                 // or a function which returns an array
1447                                                 registry[module].dependencies = dependencies;
1448                                         }
1449                                 },
1450
1451                                 /**
1452                                  * Implement a module given the components that make up the module.
1453                                  *
1454                                  * When #load or #using requests one or more modules, the server
1455                                  * response contain calls to this function.
1456                                  *
1457                                  * All arguments are required.
1458                                  *
1459                                  * @param {string} module Name of module
1460                                  * @param {Function|Array} script Function with module code or Array of URLs to
1461                                  *  be used as the src attribute of a new `<script>` tag.
1462                                  * @param {Object} style Should follow one of the following patterns:
1463                                  *     { "css": [css, ..] }
1464                                  *     { "url": { <media>: [url, ..] } }
1465                                  * And for backwards compatibility (needs to be supported forever due to caching):
1466                                  *     { <media>: css }
1467                                  *     { <media>: [url, ..] }
1468                                  *
1469                                  * The reason css strings are not concatenated anymore is bug 31676. We now check
1470                                  * whether it's safe to extend the stylesheet (see #canExpandStylesheetWith).
1471                                  *
1472                                  * @param {Object} msgs List of key/value pairs to be added to {@link mw#messages}.
1473                                  */
1474                                 implement: function ( module, script, style, msgs ) {
1475                                         // Validate input
1476                                         if ( typeof module !== 'string' ) {
1477                                                 throw new Error( 'module must be a string, not a ' + typeof module );
1478                                         }
1479                                         if ( !$.isFunction( script ) && !$.isArray( script ) ) {
1480                                                 throw new Error( 'script must be a function or an array, not a ' + typeof script );
1481                                         }
1482                                         if ( !$.isPlainObject( style ) ) {
1483                                                 throw new Error( 'style must be an object, not a ' + typeof style );
1484                                         }
1485                                         if ( !$.isPlainObject( msgs ) ) {
1486                                                 throw new Error( 'msgs must be an object, not a ' + typeof msgs );
1487                                         }
1488                                         // Automatically register module
1489                                         if ( registry[module] === undefined ) {
1490                                                 mw.loader.register( module );
1491                                         }
1492                                         // Check for duplicate implementation
1493                                         if ( registry[module] !== undefined && registry[module].script !== undefined ) {
1494                                                 throw new Error( 'module already implemented: ' + module );
1495                                         }
1496                                         // Attach components
1497                                         registry[module].script = script;
1498                                         registry[module].style = style;
1499                                         registry[module].messages = msgs;
1500                                         // The module may already have been marked as erroneous
1501                                         if ( $.inArray( registry[module].state, ['error', 'missing'] ) === -1 ) {
1502                                                 registry[module].state = 'loaded';
1503                                                 if ( allReady( registry[module].dependencies ) ) {
1504                                                         execute( module );
1505                                                 }
1506                                         }
1507                                 },
1508
1509                                 /**
1510                                  * Execute a function as soon as one or more required modules are ready.
1511                                  *
1512                                  * @param {string|Array} dependencies Module name or array of modules names the callback
1513                                  *  dependends on to be ready before executing
1514                                  * @param {Function} [ready] callback to execute when all dependencies are ready
1515                                  * @param {Function} [error] callback to execute when if dependencies have a errors
1516                                  */
1517                                 using: function ( dependencies, ready, error ) {
1518                                         var tod = typeof dependencies;
1519                                         // Validate input
1520                                         if ( tod !== 'object' && tod !== 'string' ) {
1521                                                 throw new Error( 'dependencies must be a string or an array, not a ' + tod );
1522                                         }
1523                                         // Allow calling with a single dependency as a string
1524                                         if ( tod === 'string' ) {
1525                                                 dependencies = [ dependencies ];
1526                                         }
1527                                         // Resolve entire dependency map
1528                                         dependencies = resolve( dependencies );
1529                                         if ( allReady( dependencies ) ) {
1530                                                 // Run ready immediately
1531                                                 if ( $.isFunction( ready ) ) {
1532                                                         ready();
1533                                                 }
1534                                         } else if ( filter( ['error', 'missing'], dependencies ).length ) {
1535                                                 // Execute error immediately if any dependencies have errors
1536                                                 if ( $.isFunction( error ) ) {
1537                                                         error( new Error( 'one or more dependencies have state "error" or "missing"' ),
1538                                                                 dependencies );
1539                                                 }
1540                                         } else {
1541                                                 // Not all dependencies are ready: queue up a request
1542                                                 request( dependencies, ready, error );
1543                                         }
1544                                 },
1545
1546                                 /**
1547                                  * Load an external script or one or more modules.
1548                                  *
1549                                  * @param {string|Array} modules Either the name of a module, array of modules,
1550                                  *  or a URL of an external script or style
1551                                  * @param {string} [type='text/javascript'] mime-type to use if calling with a URL of an
1552                                  *  external script or style; acceptable values are "text/css" and
1553                                  *  "text/javascript"; if no type is provided, text/javascript is assumed.
1554                                  * @param {boolean} [async] If true, load modules asynchronously
1555                                  *  even if document ready has not yet occurred. If false, block before
1556                                  *  document ready and load async after. If not set, true will be
1557                                  *  assumed if loading a URL, and false will be assumed otherwise.
1558                                  */
1559                                 load: function ( modules, type, async ) {
1560                                         var filtered, m, module, l;
1561
1562                                         // Validate input
1563                                         if ( typeof modules !== 'object' && typeof modules !== 'string' ) {
1564                                                 throw new Error( 'modules must be a string or an array, not a ' + typeof modules );
1565                                         }
1566                                         // Allow calling with an external url or single dependency as a string
1567                                         if ( typeof modules === 'string' ) {
1568                                                 // Support adding arbitrary external scripts
1569                                                 if ( /^(https?:)?\/\//.test( modules ) ) {
1570                                                         if ( async === undefined ) {
1571                                                                 // Assume async for bug 34542
1572                                                                 async = true;
1573                                                         }
1574                                                         if ( type === 'text/css' ) {
1575                                                                 // IE7-8 throws security warnings when inserting a <link> tag
1576                                                                 // with a protocol-relative URL set though attributes (instead of
1577                                                                 // properties) - when on HTTPS. See also bug #.
1578                                                                 l = document.createElement( 'link' );
1579                                                                 l.rel = 'stylesheet';
1580                                                                 l.href = modules;
1581                                                                 $( 'head' ).append( l );
1582                                                                 return;
1583                                                         }
1584                                                         if ( type === 'text/javascript' || type === undefined ) {
1585                                                                 addScript( modules, null, async );
1586                                                                 return;
1587                                                         }
1588                                                         // Unknown type
1589                                                         throw new Error( 'invalid type for external url, must be text/css or text/javascript. not ' + type );
1590                                                 }
1591                                                 // Called with single module
1592                                                 modules = [ modules ];
1593                                         }
1594
1595                                         // Filter out undefined modules, otherwise resolve() will throw
1596                                         // an exception for trying to load an undefined module.
1597                                         // Undefined modules are acceptable here in load(), because load() takes
1598                                         // an array of unrelated modules, whereas the modules passed to
1599                                         // using() are related and must all be loaded.
1600                                         for ( filtered = [], m = 0; m < modules.length; m += 1 ) {
1601                                                 module = registry[modules[m]];
1602                                                 if ( module !== undefined ) {
1603                                                         if ( $.inArray( module.state, ['error', 'missing'] ) === -1 ) {
1604                                                                 filtered[filtered.length] = modules[m];
1605                                                         }
1606                                                 }
1607                                         }
1608
1609                                         if ( filtered.length === 0 ) {
1610                                                 return;
1611                                         }
1612                                         // Resolve entire dependency map
1613                                         filtered = resolve( filtered );
1614                                         // If all modules are ready, nothing to be done
1615                                         if ( allReady( filtered ) ) {
1616                                                 return;
1617                                         }
1618                                         // If any modules have errors: also quit.
1619                                         if ( filter( ['error', 'missing'], filtered ).length ) {
1620                                                 return;
1621                                         }
1622                                         // Since some modules are not yet ready, queue up a request.
1623                                         request( filtered, undefined, undefined, async );
1624                                 },
1625
1626                                 /**
1627                                  * Change the state of one or more modules.
1628                                  *
1629                                  * @param {string|Object} module module name or object of module name/state pairs
1630                                  * @param {string} state state name
1631                                  */
1632                                 state: function ( module, state ) {
1633                                         var m;
1634
1635                                         if ( typeof module === 'object' ) {
1636                                                 for ( m in module ) {
1637                                                         mw.loader.state( m, module[m] );
1638                                                 }
1639                                                 return;
1640                                         }
1641                                         if ( registry[module] === undefined ) {
1642                                                 mw.loader.register( module );
1643                                         }
1644                                         if ( $.inArray( state, ['ready', 'error', 'missing'] ) !== -1
1645                                                 && registry[module].state !== state ) {
1646                                                 // Make sure pending modules depending on this one get executed if their
1647                                                 // dependencies are now fulfilled!
1648                                                 registry[module].state = state;
1649                                                 handlePending( module );
1650                                         } else {
1651                                                 registry[module].state = state;
1652                                         }
1653                                 },
1654
1655                                 /**
1656                                  * Get the version of a module.
1657                                  *
1658                                  * @param {string} module Name of module to get version for
1659                                  */
1660                                 getVersion: function ( module ) {
1661                                         if ( registry[module] !== undefined && registry[module].version !== undefined ) {
1662                                                 return formatVersionNumber( registry[module].version );
1663                                         }
1664                                         return null;
1665                                 },
1666
1667                                 /**
1668                                  * @inheritdoc #getVersion
1669                                  * @deprecated since 1.18 use #getVersion instead
1670                                  */
1671                                 version: function () {
1672                                         return mw.loader.getVersion.apply( mw.loader, arguments );
1673                                 },
1674
1675                                 /**
1676                                  * Get the state of a module.
1677                                  *
1678                                  * @param {string} module name of module to get state for
1679                                  */
1680                                 getState: function ( module ) {
1681                                         if ( registry[module] !== undefined && registry[module].state !== undefined ) {
1682                                                 return registry[module].state;
1683                                         }
1684                                         return null;
1685                                 },
1686
1687                                 /**
1688                                  * Get names of all registered modules.
1689                                  *
1690                                  * @return {Array}
1691                                  */
1692                                 getModuleNames: function () {
1693                                         return $.map( registry, function ( i, key ) {
1694                                                 return key;
1695                                         } );
1696                                 },
1697
1698                                 /**
1699                                  * Load the `mediawiki.user` module.
1700                                  *
1701                                  * For backwards-compatibility with cached pages from before 2013 where:
1702                                  *
1703                                  * - the `mediawiki.user` module didn't exist yet
1704                                  * - `mw.user` was still part of mediawiki.js
1705                                  * - `mw.loader.go` still existed and called after `mw.loader.load()`
1706                                  */
1707                                 go: function () {
1708                                         mw.loader.load( 'mediawiki.user' );
1709                                 },
1710
1711                                 /**
1712                                  * @inheritdoc mw.inspect#runReports
1713                                  * @method
1714                                  */
1715                                 inspect: function () {
1716                                         var args = slice.call( arguments );
1717                                         mw.loader.using( 'mediawiki.inspect', function () {
1718                                                 mw.inspect.runReports.apply( mw.inspect, args );
1719                                         } );
1720                                 },
1721
1722                                 /**
1723                                  * On browsers that implement the localStorage API, the module store serves as a
1724                                  * smart complement to the browser cache. Unlike the browser cache, the module store
1725                                  * can slice a concatenated response from ResourceLoader into its constituent
1726                                  * modules and cache each of them separately, using each module's versioning scheme
1727                                  * to determine when the cache should be invalidated.
1728                                  *
1729                                  * @singleton
1730                                  * @class mw.loader.store
1731                                  */
1732                                 store: {
1733                                         // Whether the store is in use on this page.
1734                                         enabled: null,
1735
1736                                         // The contents of the store, mapping '[module name]@[version]' keys
1737                                         // to module implementations.
1738                                         items: {},
1739
1740                                         // Cache hit stats
1741                                         stats: { hits: 0, misses: 0, expired: 0 },
1742
1743                                         /**
1744                                          * Construct a JSON-serializable object representing the content of the store.
1745                                          * @return {Object} Module store contents.
1746                                          */
1747                                         toJSON: function () {
1748                                                 return { items: mw.loader.store.items, vary: mw.loader.store.getVary() };
1749                                         },
1750
1751                                         /**
1752                                          * Get the localStorage key for the entire module store. The key references
1753                                          * $wgDBname to prevent clashes between wikis which share a common host.
1754                                          *
1755                                          * @return {string} localStorage item key
1756                                          */
1757                                         getStoreKey: function () {
1758                                                 return 'MediaWikiModuleStore:' + mw.config.get( 'wgDBname' );
1759                                         },
1760
1761                                         /**
1762                                          * Get a string key on which to vary the module cache.
1763                                          * @return {string} String of concatenated vary conditions.
1764                                          */
1765                                         getVary: function () {
1766                                                 return [
1767                                                         mw.config.get( 'skin' ),
1768                                                         mw.config.get( 'wgResourceLoaderStorageVersion' ),
1769                                                         mw.config.get( 'wgUserLanguage' )
1770                                                 ].join(':');
1771                                         },
1772
1773                                         /**
1774                                          * Get a string key for a specific module. The key format is '[name]@[version]'.
1775                                          *
1776                                          * @param {string} module Module name
1777                                          * @return {string|null} Module key or null if module does not exist
1778                                          */
1779                                         getModuleKey: function ( module ) {
1780                                                 return typeof registry[module] === 'object' ?
1781                                                         ( module + '@' + registry[module].version ) : null;
1782                                         },
1783
1784                                         /**
1785                                          * Initialize the store by retrieving it from localStorage and (if successfully
1786                                          * retrieved) decoding the stored JSON value to a plain object.
1787                                          *
1788                                          * The try / catch block is used for JSON & localStorage feature detection.
1789                                          * See the in-line documentation for Modernizr's localStorage feature detection
1790                                          * code for a full account of why we need a try / catch: <http://git.io/4NEwKg>.
1791                                          */
1792                                         init: function () {
1793                                                 var raw, data;
1794
1795                                                 if ( mw.loader.store.enabled !== null ) {
1796                                                         // #init already ran.
1797                                                         return;
1798                                                 }
1799
1800                                                 if ( !mw.config.get( 'wgResourceLoaderStorageEnabled' ) || mw.config.get( 'debug' ) ) {
1801                                                         // Disabled by configuration, or because debug mode is set.
1802                                                         mw.loader.store.enabled = false;
1803                                                         return;
1804                                                 }
1805
1806                                                 try {
1807                                                         raw = localStorage.getItem( mw.loader.store.getStoreKey() );
1808                                                         // If we get here, localStorage is available; mark enabled.
1809                                                         mw.loader.store.enabled = true;
1810                                                         data = JSON.parse( raw );
1811                                                         if ( data && typeof data.items === 'object' && data.vary === mw.loader.store.getVary() ) {
1812                                                                 mw.loader.store.items = data.items;
1813                                                                 return;
1814                                                         }
1815                                                 } catch (e) {}
1816
1817                                                 if ( raw === undefined ) {
1818                                                         mw.loader.store.enabled = false;  // localStorage failed; disable store.
1819                                                 } else {
1820                                                         mw.loader.store.update();
1821                                                 }
1822                                         },
1823
1824                                         /**
1825                                          * Retrieve a module from the store and update cache hit stats.
1826                                          *
1827                                          * @param {string} module Module name
1828                                          * @return {string|boolean} Module implementation or false if unavailable
1829                                          */
1830                                         get: function ( module ) {
1831                                                 var key;
1832
1833                                                 if ( mw.loader.store.enabled !== true ) {
1834                                                         return false;
1835                                                 }
1836
1837                                                 key = mw.loader.store.getModuleKey( module );
1838                                                 if ( key in mw.loader.store.items ) {
1839                                                         mw.loader.store.stats.hits++;
1840                                                         return mw.loader.store.items[key];
1841                                                 }
1842                                                 mw.loader.store.stats.misses++;
1843                                                 return false;
1844                                         },
1845
1846                                         /**
1847                                          * Stringify a module and queue it for storage.
1848                                          *
1849                                          * @param {string} module Module name
1850                                          * @param {Object} descriptor The module's descriptor as set in the registry
1851                                          */
1852                                         set: function ( module, descriptor ) {
1853                                                 var args, key;
1854
1855                                                 if ( mw.loader.store.enabled !== true ) {
1856                                                         return false;
1857                                                 }
1858
1859                                                 key = mw.loader.store.getModuleKey( module );
1860
1861                                                 if ( key in mw.loader.store.items ) {
1862                                                         // Already set; decline to store.
1863                                                         return false;
1864                                                 }
1865
1866                                                 if ( descriptor.state !== 'ready' ) {
1867                                                         // Module failed to load; decline to store.
1868                                                         return false;
1869                                                 }
1870
1871                                                 if ( !descriptor.version || $.inArray( descriptor.group, [ 'private', 'user', 'site' ] ) !== -1 ) {
1872                                                         // Unversioned, private, or site-/user-specific; decline to store.
1873                                                         return false;
1874                                                 }
1875
1876                                                 if ( $.inArray( undefined, [ descriptor.script, descriptor.style, descriptor.messages ] ) !== -1 ) {
1877                                                         // Partial descriptor; decline to store.
1878                                                         return false;
1879                                                 }
1880
1881                                                 try {
1882                                                         args = [
1883                                                                 JSON.stringify( module ),
1884                                                                 typeof descriptor.script === 'function' ?
1885                                                                         String( descriptor.script ) : JSON.stringify( descriptor.script ),
1886                                                                 JSON.stringify( descriptor.style ),
1887                                                                 JSON.stringify( descriptor.messages )
1888                                                         ];
1889                                                 } catch (e) {
1890                                                         return;
1891                                                 }
1892                                                 mw.loader.store.items[key] = 'mw.loader.implement(' + args.join(',') + ');';
1893                                                 mw.loader.store.update();
1894                                         },
1895
1896                                         /**
1897                                          * Iterate through the module store, removing any item that does not correspond
1898                                          * (in name and version) to an item in the module registry.
1899                                          */
1900                                         prune: function () {
1901                                                 var key, module;
1902
1903                                                 if ( mw.loader.store.enabled !== true ) {
1904                                                         return false;
1905                                                 }
1906
1907                                                 for ( key in mw.loader.store.items ) {
1908                                                         module = key.substring( 0, key.indexOf( '@' ) );
1909                                                         if ( mw.loader.store.getModuleKey( module ) !== key ) {
1910                                                                 mw.loader.store.stats.expired++;
1911                                                                 delete mw.loader.store.items[key];
1912                                                         }
1913                                                 }
1914                                         },
1915
1916                                         /**
1917                                          * Sync modules to localStorage.
1918                                          *
1919                                          * This function debounces localStorage updates. When called multiple times in
1920                                          * quick succession, the calls are coalesced into a single update operation.
1921                                          * This allows us to call #update without having to consider the module load
1922                                          * queue; the call to localStorage.setItem will be naturally deferred until the
1923                                          * page is quiescent.
1924                                          *
1925                                          * Because localStorage is shared by all pages with the same origin, if multiple
1926                                          * pages are loaded with different module sets, the possibility exists that
1927                                          * modules saved by one page will be clobbered by another. But the impact would
1928                                          * be minor and the problem would be corrected by subsequent page views.
1929                                          */
1930                                         update: ( function () {
1931                                                 var timer;
1932
1933                                                 function flush() {
1934                                                         var data;
1935                                                         if ( mw.loader.store.enabled !== true ) {
1936                                                                 return false;
1937                                                         }
1938                                                         mw.loader.store.prune();
1939                                                         try {
1940                                                                 data = JSON.stringify( mw.loader.store );
1941                                                                 localStorage.setItem( mw.loader.store.getStoreKey(), data );
1942                                                         } catch (e) {}
1943                                                 }
1944
1945                                                 return function () {
1946                                                         clearTimeout( timer );
1947                                                         timer = setTimeout( flush, 2000 );
1948                                                 };
1949                                         }() )
1950                                 }
1951                         };
1952                 }() ),
1953
1954                 /**
1955                  * HTML construction helper functions
1956                  *
1957                  *     @example
1958                  *
1959                  *     var Html, output;
1960                  *
1961                  *     Html = mw.html;
1962                  *     output = Html.element( 'div', {}, new Html.Raw(
1963                  *         Html.element( 'img', { src: '<' } )
1964                  *     ) );
1965                  *     mw.log( output ); // <div><img src="&lt;"/></div>
1966                  *
1967                  * @class mw.html
1968                  * @singleton
1969                  */
1970                 html: ( function () {
1971                         function escapeCallback( s ) {
1972                                 switch ( s ) {
1973                                         case '\'':
1974                                                 return '&#039;';
1975                                         case '"':
1976                                                 return '&quot;';
1977                                         case '<':
1978                                                 return '&lt;';
1979                                         case '>':
1980                                                 return '&gt;';
1981                                         case '&':
1982                                                 return '&amp;';
1983                                 }
1984                         }
1985
1986                         return {
1987                                 /**
1988                                  * Escape a string for HTML. Converts special characters to HTML entities.
1989                                  * @param {string} s The string to escape
1990                                  */
1991                                 escape: function ( s ) {
1992                                         return s.replace( /['"<>&]/g, escapeCallback );
1993                                 },
1994
1995                                 /**
1996                                  * Create an HTML element string, with safe escaping.
1997                                  *
1998                                  * @param {string} name The tag name.
1999                                  * @param {Object} attrs An object with members mapping element names to values
2000                                  * @param {Mixed} contents The contents of the element. May be either:
2001                                  *  - string: The string is escaped.
2002                                  *  - null or undefined: The short closing form is used, e.g. <br/>.
2003                                  *  - this.Raw: The value attribute is included without escaping.
2004                                  *  - this.Cdata: The value attribute is included, and an exception is
2005                                  *   thrown if it contains an illegal ETAGO delimiter.
2006                                  *   See http://www.w3.org/TR/1999/REC-html401-19991224/appendix/notes.html#h-B.3.2
2007                                  */
2008                                 element: function ( name, attrs, contents ) {
2009                                         var v, attrName, s = '<' + name;
2010
2011                                         for ( attrName in attrs ) {
2012                                                 v = attrs[attrName];
2013                                                 // Convert name=true, to name=name
2014                                                 if ( v === true ) {
2015                                                         v = attrName;
2016                                                 // Skip name=false
2017                                                 } else if ( v === false ) {
2018                                                         continue;
2019                                                 }
2020                                                 s += ' ' + attrName + '="' + this.escape( String( v ) ) + '"';
2021                                         }
2022                                         if ( contents === undefined || contents === null ) {
2023                                                 // Self close tag
2024                                                 s += '/>';
2025                                                 return s;
2026                                         }
2027                                         // Regular open tag
2028                                         s += '>';
2029                                         switch ( typeof contents ) {
2030                                                 case 'string':
2031                                                         // Escaped
2032                                                         s += this.escape( contents );
2033                                                         break;
2034                                                 case 'number':
2035                                                 case 'boolean':
2036                                                         // Convert to string
2037                                                         s += String( contents );
2038                                                         break;
2039                                                 default:
2040                                                         if ( contents instanceof this.Raw ) {
2041                                                                 // Raw HTML inclusion
2042                                                                 s += contents.value;
2043                                                         } else if ( contents instanceof this.Cdata ) {
2044                                                                 // CDATA
2045                                                                 if ( /<\/[a-zA-z]/.test( contents.value ) ) {
2046                                                                         throw new Error( 'mw.html.element: Illegal end tag found in CDATA' );
2047                                                                 }
2048                                                                 s += contents.value;
2049                                                         } else {
2050                                                                 throw new Error( 'mw.html.element: Invalid type of contents' );
2051                                                         }
2052                                         }
2053                                         s += '</' + name + '>';
2054                                         return s;
2055                                 },
2056
2057                                 /**
2058                                  * Wrapper object for raw HTML passed to mw.html.element().
2059                                  * @class mw.html.Raw
2060                                  */
2061                                 Raw: function ( value ) {
2062                                         this.value = value;
2063                                 },
2064
2065                                 /**
2066                                  * Wrapper object for CDATA element contents passed to mw.html.element()
2067                                  * @class mw.html.Cdata
2068                                  */
2069                                 Cdata: function ( value ) {
2070                                         this.value = value;
2071                                 }
2072                         };
2073                 }() ),
2074
2075                 // Skeleton user object. mediawiki.user.js extends this
2076                 user: {
2077                         options: new Map(),
2078                         tokens: new Map()
2079                 },
2080
2081                 /**
2082                  * Registry and firing of events.
2083                  *
2084                  * MediaWiki has various interface components that are extended, enhanced
2085                  * or manipulated in some other way by extensions, gadgets and even
2086                  * in core itself.
2087                  *
2088                  * This framework helps streamlining the timing of when these other
2089                  * code paths fire their plugins (instead of using document-ready,
2090                  * which can and should be limited to firing only once).
2091                  *
2092                  * Features like navigating to other wiki pages, previewing an edit
2093                  * and editing itself – without a refresh – can then retrigger these
2094                  * hooks accordingly to ensure everything still works as expected.
2095                  *
2096                  * Example usage:
2097                  *
2098                  *     mw.hook( 'wikipage.content' ).add( fn ).remove( fn );
2099                  *     mw.hook( 'wikipage.content' ).fire( $content );
2100                  *
2101                  * Handlers can be added and fired for arbitrary event names at any time. The same
2102                  * event can be fired multiple times. The last run of an event is memorized
2103                  * (similar to `$(document).ready` and `$.Deferred().done`).
2104                  * This means if an event is fired, and a handler added afterwards, the added
2105                  * function will be fired right away with the last given event data.
2106                  *
2107                  * Like Deferreds and Promises, the mw.hook object is both detachable and chainable.
2108                  * Thus allowing flexible use and optimal maintainability and authority control.
2109                  * You can pass around the `add` and/or `fire` method to another piece of code
2110                  * without it having to know the event name (or `mw.hook` for that matter).
2111                  *
2112                  *     var h = mw.hook( 'bar.ready' );
2113                  *     new mw.Foo( .. ).fetch( { callback: h.fire } );
2114                  *
2115                  * Note: Events are documented with an underscore instead of a dot in the event
2116                  * name due to jsduck not supporting dots in that position.
2117                  *
2118                  * @class mw.hook
2119                  */
2120                 hook: ( function () {
2121                         var lists = {};
2122
2123                         /**
2124                          * Create an instance of mw.hook.
2125                          *
2126                          * @method hook
2127                          * @member mw
2128                          * @param {string} name Name of hook.
2129                          * @return {mw.hook}
2130                          */
2131                         return function ( name ) {
2132                                 var list = lists[name] || ( lists[name] = $.Callbacks( 'memory' ) );
2133
2134                                 return {
2135                                         /**
2136                                          * Register a hook handler
2137                                          * @param {Function...} handler Function to bind.
2138                                          * @chainable
2139                                          */
2140                                         add: list.add,
2141
2142                                         /**
2143                                          * Unregister a hook handler
2144                                          * @param {Function...} handler Function to unbind.
2145                                          * @chainable
2146                                          */
2147                                         remove: list.remove,
2148
2149                                         /**
2150                                          * Run a hook.
2151                                          * @param {Mixed...} data
2152                                          * @chainable
2153                                          */
2154                                         fire: function () {
2155                                                 return list.fireWith( null, slice.call( arguments ) );
2156                                         }
2157                                 };
2158                         };
2159                 }() )
2160         };
2161
2162 }( jQuery ) );
2163
2164 // Alias $j to jQuery for backwards compatibility
2165 window.$j = jQuery;
2166
2167 // Attach to window and globally alias
2168 window.mw = window.mediaWiki = mw;
2169
2170 // Auto-register from pre-loaded startup scripts
2171 if ( jQuery.isFunction( window.startUp ) ) {
2172         window.startUp();
2173         window.startUp = undefined;
2174 }