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          * @method log_
  25          * @param {string} msg text for the log entry.
  26          * @param {Error} [e]
  27          */
  28         function log( msg, e ) {
  29                 var console = window.console;
  30                 if ( console && console.log ) {
  31                         console.log( msg );
  32                         // If we have an exception object, log it through .error() to trigger
  33                         // proper stacktraces in browsers that support it. There are no (known)
  34                         // browsers that don't support .error(), that do support .log() and
  35                         // have useful exception handling through .log().
  36                         if ( e && console.error ) {
  37                                 console.error( String( e ), e );
  38                         }
  39                 }
  40         }
  41
  42         /* Object constructors */
  43
  44         /**
  45          * Creates an object that can be read from or written to from prototype functions
  46          * that allow both single and multiple variables at once.
  47          *
  48          *     @example
  49          *
  50          *     var addies, wanted, results;
  51          *
  52          *     // Create your address book
  53          *     addies = new mw.Map();
  54          *
  55          *     // This data could be coming from an external source (eg. API/AJAX)
  56          *     addies.set( {
  57          *         'John Doe' : '10 Wall Street, New York, USA',
  58          *         'Jane Jackson' : '21 Oxford St, London, UK',
  59          *         'Dominique van Halen' : 'Kalverstraat 7, Amsterdam, NL'
  60          *     } );
  61          *
  62          *     wanted = ['Dominique van Halen', 'George Johnson', 'Jane Jackson'];
  63          *
  64          *     // You can detect missing keys first
  65          *     if ( !addies.exists( wanted ) ) {
  66          *         // One or more are missing (in this case: "George Johnson")
  67          *         mw.log( 'One or more names were not found in your address book' );
  68          *     }
  69          *
  70          *     // Or just let it give you what it can
  71          *     results = addies.get( wanted, 'Middle of Nowhere, Alaska, US' );
  72          *     mw.log( results['Jane Jackson'] ); // "21 Oxford St, London, UK"
  73          *     mw.log( results['George Johnson'] ); // "Middle of Nowhere, Alaska, US"
  74          *
  75          * @class mw.Map
  76          *
  77          * @constructor
  78          * @param {boolean} [global=false] Whether to store the values in the global window
  79          *  object or a exclusively in the object property 'values'.
  80          */
  81         function Map( global ) {
  82                 this.values = global === true ? window : {};
  83                 return this;
  84         }
  85
  86         Map.prototype = {
  87                 /**
  88                  * Get the value of one or multiple a keys.
  89                  *
  90                  * If called with no arguments, all values will be returned.
  91                  *
  92                  * @param {string|Array} selection String key or array of keys to get values for.
  93                  * @param {Mixed} [fallback] Value to use in case key(s) do not exist.
  94                  * @return mixed If selection was a string returns the value or null,
  95                  *  If selection was an array, returns an object of key/values (value is null if not found),
  96                  *  If selection was not passed or invalid, will return the 'values' object member (be careful as
  97                  *  objects are always passed by reference in JavaScript!).
  98                  * @return {string|Object|null} Values as a string or object, null if invalid/inexistant.
  99                  */
 100                 get: function ( selection, fallback ) {
 101                         var results, i;
 102                         // If we only do this in the `return` block, it'll fail for the
 103                         // call to get() from the mutli-selection block.
 104                         fallback = arguments.length > 1 ? fallback : null;
 105
 106                         if ( $.isArray( selection ) ) {
 107                                 selection = slice.call( selection );
 108                                 results = {};
 109                                 for ( i = 0; i < selection.length; i++ ) {
 110                                         results[selection[i]] = this.get( selection[i], fallback );
 111                                 }
 112                                 return results;
 113                         }
 114
 115                         if ( typeof selection === 'string' ) {
 116                                 if ( !hasOwn.call( this.values, selection ) ) {
 117                                         return fallback;
 118                                 }
 119                                 return this.values[selection];
 120                         }
 121
 122                         if ( selection === undefined ) {
 123                                 return this.values;
 124                         }
 125
 126                         // invalid selection key
 127                         return null;
 128                 },
 129
 130                 /**
 131                  * Sets one or multiple key/value pairs.
 132                  *
 133                  * @param {string|Object} selection String key to set value for, or object mapping keys to values.
 134                  * @param {Mixed} [value] Value to set (optional, only in use when key is a string)
 135                  * @return {Boolean} This returns true on success, false on failure.
 136                  */
 137                 set: function ( selection, value ) {
 138                         var s;
 139
 140                         if ( $.isPlainObject( selection ) ) {
 141                                 for ( s in selection ) {
 142                                         this.values[s] = selection[s];
 143                                 }
 144                                 return true;
 145                         }
 146                         if ( typeof selection === 'string' && arguments.length > 1 ) {
 147                                 this.values[selection] = value;
 148                                 return true;
 149                         }
 150                         return false;
 151                 },
 152
 153                 /**
 154                  * Checks if one or multiple keys exist.
 155                  *
 156                  * @param {Mixed} selection String key or array of keys to check
 157                  * @return {boolean} Existence of key(s)
 158                  */
 159                 exists: function ( selection ) {
 160                         var s;
 161
 162                         if ( $.isArray( selection ) ) {
 163                                 for ( s = 0; s < selection.length; s++ ) {
 164                                         if ( typeof selection[s] !== 'string' || !hasOwn.call( this.values, selection[s] ) ) {
 165                                                 return false;
 166                                         }
 167                                 }
 168                                 return true;
 169                         }
 170                         return typeof selection === 'string' && hasOwn.call( this.values, selection );
 171                 }
 172         };
 173
 174         /**
 175          * Object constructor for messages.
 176          *
 177          * Similar to the Message class in MediaWiki PHP.
 178          *
 179          * Format defaults to 'text'.
 180          *
 181          * @class mw.Message
 182          *
 183          * @constructor
 184          * @param {mw.Map} map Message storage
 185          * @param {string} key
 186          * @param {Array} [parameters]
 187          */
 188         function Message( map, key, parameters ) {
 189                 this.format = 'text';
 190                 this.map = map;
 191                 this.key = key;
 192                 this.parameters = parameters === undefined ? [] : slice.call( parameters );
 193                 return this;
 194         }
 195
 196         Message.prototype = {
 197                 /**
 198                  * Simple message parser, does $N replacement and nothing else.
 199                  *
 200                  * This may be overridden to provide a more complex message parser.
 201                  *
 202                  * The primary override is in mediawiki.jqueryMsg.
 203                  *
 204                  * This function will not be called for nonexistent messages.
 205                  */
 206                 parser: function () {
 207                         var parameters = this.parameters;
 208                         return this.map.get( this.key ).replace( /\$(\d+)/g, function ( str, match ) {
 209                                 var index = parseInt( match, 10 ) - 1;
 210                                 return parameters[index] !== undefined ? parameters[index] : '$' + match;
 211                         } );
 212                 },
 213
 214                 /**
 215                  * Appends (does not replace) parameters for replacement to the .parameters property.
 216                  *
 217                  * @param {Array} parameters
 218                  * @chainable
 219                  */
 220                 params: function ( parameters ) {
 221                         var i;
 222                         for ( i = 0; i < parameters.length; i += 1 ) {
 223                                 this.parameters.push( parameters[i] );
 224                         }
 225                         return this;
 226                 },
 227
 228                 /**
 229                  * Converts message object to its string form based on the state of format.
 230                  *
 231                  * @return {string} Message as a string in the current form or `<key>` if key does not exist.
 232                  */
 233                 toString: function () {
 234                         var text;
 235
 236                         if ( !this.exists() ) {
 237                                 // Use <key> as text if key does not exist
 238                                 if ( this.format === 'escaped' || this.format === 'parse' ) {
 239                                         // format 'escaped' and 'parse' need to have the brackets and key html escaped
 240                                         return mw.html.escape( '<' + this.key + '>' );
 241                                 }
 242                                 return '<' + this.key + '>';
 243                         }
 244
 245                         if ( this.format === 'plain' || this.format === 'text' || this.format === 'parse' ) {
 246                                 text = this.parser();
 247                         }
 248
 249                         if ( this.format === 'escaped' ) {
 250                                 text = this.parser();
 251                                 text = mw.html.escape( text );
 252                         }
 253
 254                         return text;
 255                 },
 256
 257                 /**
 258                  * Changes format to 'parse' and converts message to string
 259                  *
 260                  * If jqueryMsg is loaded, this parses the message text from wikitext
 261                  * (where supported) to HTML
 262                  *
 263                  * Otherwise, it is equivalent to plain.
 264                  *
 265                  * @return {string} String form of parsed message
 266                  */
 267                 parse: function () {
 268                         this.format = 'parse';
 269                         return this.toString();
 270                 },
 271
 272                 /**
 273                  * Changes format to 'plain' and converts message to string
 274                  *
 275                  * This substitutes parameters, but otherwise does not change the
 276                  * message text.
 277                  *
 278                  * @return {string} String form of plain message
 279                  */
 280                 plain: function () {
 281                         this.format = 'plain';
 282                         return this.toString();
 283                 },
 284
 285                 /**
 286                  * Changes format to 'text' and converts message to string
 287                  *
 288                  * If jqueryMsg is loaded, {{-transformation is done where supported
 289                  * (such as {{plural:}}, {{gender:}}, {{int:}}).
 290                  *
 291                  * Otherwise, it is equivalent to plain.
 292                  */
 293                 text: function () {
 294                         this.format = 'text';
 295                         return this.toString();
 296                 },
 297
 298                 /**
 299                  * Changes the format to 'escaped' and converts message to string
 300                  *
 301                  * This is equivalent to using the 'text' format (see text method), then
 302                  * HTML-escaping the output.
 303                  *
 304                  * @return {string} String form of html escaped message
 305                  */
 306                 escaped: function () {
 307                         this.format = 'escaped';
 308                         return this.toString();
 309                 },
 310
 311                 /**
 312                  * Checks if message exists
 313                  *
 314                  * @see mw.Map#exists
 315                  * @return {boolean}
 316                  */
 317                 exists: function () {
 318                         return this.map.exists( this.key );
 319                 }
 320         };
 321
 322         /**
 323          * @class mw
 324          */
 325         return {
 326                 /* Public Members */
 327
 328                 /**
 329                  * Dummy placeholder for {@link mw.log}
 330                  * @method
 331                  */
 332                 log: ( function () {
 333                         var log = function () {};
 334                         log.warn = function () {};
 335                         log.deprecate = function ( obj, key, val ) {
 336                                 obj[key] = val;
 337                         };
 338                         return log;
 339                 }() ),
 340
 341                 // Make the Map constructor publicly available.
 342                 Map: Map,
 343
 344                 // Make the Message constructor publicly available.
 345                 Message: Message,
 346
 347                 /**
 348                  * Map of configuration values
 349                  *
 350                  * Check out [the complete list of configuration values](https://www.mediawiki.org/wiki/Manual:Interface/JavaScript#mw.config)
 351                  * on MediaWiki.org.
 352                  *
 353                  * If `$wgLegacyJavaScriptGlobals` is true, this Map will put its values in the
 354                  * global window object.
 355                  *
 356                  * @property {mw.Map} config
 357                  */
 358                 // Dummy placeholder. Re-assigned in ResourceLoaderStartupModule with an instance of `mw.Map`.
 359                 config: null,
 360
 361                 /**
 362                  * Empty object that plugins can be installed in.
 363                  * @property
 364                  */
 365                 libs: {},
 366
 367                 /**
 368                  * Access container for deprecated functionality that can be moved from
 369                  * from their legacy location and attached to this object (e.g. a global
 370                  * function that is deprecated and as stop-gap can be exposed through here).
 371                  *
 372                  * This was reserved for future use but never ended up being used.
 373                  *
 374                  * @deprecated since 1.22: Let deprecated identifiers keep their original name
 375                  * and use mw.log#deprecate to create an access container for tracking.
 376                  * @property
 377                  */
 378                 legacy: {},
 379
 380                 /**
 381                  * Localization system
 382                  * @property {mw.Map}
 383                  */
 384                 messages: new Map(),
 385
 386                 /* Public Methods */
 387
 388                 /**
 389                  * Get a message object.
 390                  *
 391                  * Similar to wfMessage() in MediaWiki PHP.
 392                  *
 393                  * @param {string} key Key of message to get
 394                  * @param {Mixed...} parameters Parameters for the $N replacements in messages.
 395                  * @return {mw.Message}
 396                  */
 397                 message: function ( key ) {
 398                         // Variadic arguments
 399                         var parameters = slice.call( arguments, 1 );
 400                         return new Message( mw.messages, key, parameters );
 401                 },
 402
 403                 /**
 404                  * Get a message string using 'text' format.
 405                  *
 406                  * Similar to wfMsg() in MediaWiki PHP.
 407                  *
 408                  * @see mw.Message
 409                  * @param {string} key Key of message to get
 410                  * @param {Mixed...} parameters Parameters for the $N replacements in messages.
 411                  * @return {string}
 412                  */
 413                 msg: function () {
 414                         return mw.message.apply( mw.message, arguments ).toString();
 415                 },
 416
 417                 /**
 418                  * Client-side module loader which integrates with the MediaWiki ResourceLoader
 419                  * @class mw.loader
 420                  * @singleton
 421                  */
 422                 loader: ( function () {
 423
 424                         /* Private Members */
 425
 426                         /**
 427                          * Mapping of registered modules
 428                          *
 429                          * The jquery module is pre-registered, because it must have already
 430                          * been provided for this object to have been built, and in debug mode
 431                          * jquery would have been provided through a unique loader request,
 432                          * making it impossible to hold back registration of jquery until after
 433                          * mediawiki.
 434                          *
 435                          * For exact details on support for script, style and messages, look at
 436                          * mw.loader.implement.
 437                          *
 438                          * Format:
 439                          *     {
 440                          *         'moduleName': {
 441                          *             'version': ############## (unix timestamp),
 442                          *             'dependencies': ['required.foo', 'bar.also', ...], (or) function () {}
 443                          *             'group': 'somegroup', (or) null,
 444                          *             'source': 'local', 'someforeignwiki', (or) null
 445                          *             'state': 'registered', 'loaded', 'loading', 'ready', 'error' or 'missing'
 446                          *             'script': ...,
 447                          *             'style': ...,
 448                          *             'messages': { 'key': 'value' },
 449                          *         }
 450                          *     }
 451                          *
 452                          * @property
 453                          * @private
 454                          */
 455                         var registry = {},
 456                                 //
 457                                 // Mapping of sources, keyed by source-id, values are objects.
 458                                 // Format:
 459                                 //      {
 460                                 //              'sourceId': {
 461                                 //                      'loadScript': 'http://foo.bar/w/load.php'
 462                                 //              }
 463                                 //      }
 464                                 //
 465                                 sources = {},
 466                                 // List of modules which will be loaded as when ready
 467                                 batch = [],
 468                                 // List of modules to be loaded
 469                                 queue = [],
 470                                 // List of callback functions waiting for modules to be ready to be called
 471                                 jobs = [],
 472                                 // Selector cache for the marker element. Use getMarker() to get/use the marker!
 473                                 $marker = null,
 474                                 // Buffer for addEmbeddedCSS.
 475                                 cssBuffer = '',
 476                                 // Callbacks for addEmbeddedCSS.
 477                                 cssCallbacks = $.Callbacks();
 478
 479                         /* Private methods */
 480
 481                         function getMarker() {
 482                                 // Cached ?
 483                                 if ( $marker ) {
 484                                         return $marker;
 485                                 }
 486
 487                                 $marker = $( 'meta[name="ResourceLoaderDynamicStyles"]' );
 488                                 if ( $marker.length ) {
 489                                         return $marker;
 490                                 }
 491                                 mw.log( 'getMarker> No <meta name="ResourceLoaderDynamicStyles"> found, inserting dynamically.' );
 492                                 $marker = $( '<meta>' ).attr( 'name', 'ResourceLoaderDynamicStyles' ).appendTo( 'head' );
 493
 494                                 return $marker;
 495                         }
 496
 497                         /**
 498                          * Create a new style tag and add it to the DOM.
 499                          *
 500                          * @private
 501                          * @param {string} text CSS text
 502                          * @param {HTMLElement|jQuery} [nextnode=document.head] The element where the style tag should be
 503                          *  inserted before. Otherwise it will be appended to `<head>`.
 504                          * @return {HTMLElement} Reference to the created `<style>` element.
 505                          */
 506                         function newStyleTag( text, nextnode ) {
 507                                 var s = document.createElement( 'style' );
 508                                 // Insert into document before setting cssText (bug 33305)
 509                                 if ( nextnode ) {
 510                                         // Must be inserted with native insertBefore, not $.fn.before.
 511                                         // When using jQuery to insert it, like $nextnode.before( s ),
 512                                         // then IE6 will throw "Access is denied" when trying to append
 513                                         // to .cssText later. Some kind of weird security measure.
 514                                         // http://stackoverflow.com/q/12586482/319266
 515                                         // Works: jsfiddle.net/zJzMy/1
 516                                         // Fails: jsfiddle.net/uJTQz
 517                                         // Works again: http://jsfiddle.net/Azr4w/ (diff: the next 3 lines)
 518                                         if ( nextnode.jquery ) {
 519                                                 nextnode = nextnode.get( 0 );
 520                                         }
 521                                         nextnode.parentNode.insertBefore( s, nextnode );
 522                                 } else {
 523                                         document.getElementsByTagName( 'head' )[0].appendChild( s );
 524                                 }
 525                                 if ( s.styleSheet ) {
 526                                         // IE
 527                                         s.styleSheet.cssText = text;
 528                                 } else {
 529                                         // Other browsers.
 530                                         // (Safari sometimes borks on non-string values,
 531                                         // play safe by casting to a string, just in case.)
 532                                         s.appendChild( document.createTextNode( String( text ) ) );
 533                                 }
 534                                 return s;
 535                         }
 536
 537                         /**
 538                          * Checks whether it is safe to add this css to a stylesheet.
 539                          *
 540                          * @private
 541                          * @param {string} cssText
 542                          * @return {boolean} False if a new one must be created.
 543                          */
 544                         function canExpandStylesheetWith( cssText ) {
 545                                 // Makes sure that cssText containing `@import`
 546                                 // rules will end up in a new stylesheet (as those only work when
 547                                 // placed at the start of a stylesheet; bug 35562).
 548                                 return cssText.indexOf( '@import' ) === -1;
 549                         }
 550
 551                         /**
 552                          * Add a bit of CSS text to the current browser page.
 553                          *
 554                          * The CSS will be appended to an existing ResourceLoader-created `<style>` tag
 555                          * or create a new one based on whether the given `cssText` is safe for extension.
 556                          *
 557                          * @param {string} [cssText=cssBuffer] If called without cssText,
 558                          *  the internal buffer will be inserted instead.
 559                          * @param {Function} [callback]
 560                          */
 561                         function addEmbeddedCSS( cssText, callback ) {
 562                                 var $style, styleEl;
 563
 564                                 if ( callback ) {
 565                                         cssCallbacks.add( callback );
 566                                 }
 567
 568                                 // Yield once before inserting the <style> tag. There are likely
 569                                 // more calls coming up which we can combine this way.
 570                                 // Appending a stylesheet and waiting for the browser to repaint
 571                                 // is fairly expensive, this reduces it (bug 45810)
 572                                 if ( cssText ) {
 573                                         // Be careful not to extend the buffer with css that needs a new stylesheet
 574                                         if ( !cssBuffer || canExpandStylesheetWith( cssText ) ) {
 575                                                 // Linebreak for somewhat distinguishable sections
 576                                                 // (the rl-cachekey comment separating each)
 577                                                 cssBuffer += '\n' + cssText;
 578                                                 // TODO: Use requestAnimationFrame in the future which will
 579                                                 // perform even better by not injecting styles while the browser
 580                                                 // is paiting.
 581                                                 setTimeout( function () {
 582                                                         // Can't pass addEmbeddedCSS to setTimeout directly because Firefox
 583                                                         // (below version 13) has the non-standard behaviour of passing a
 584                                                         // numerical "lateness" value as first argument to this callback
 585                                                         // http://benalman.com/news/2009/07/the-mysterious-firefox-settime/
 586                                                         addEmbeddedCSS();
 587                                                 } );
 588                                                 return;
 589                                         }
 590
 591                                 // This is a delayed call and we got a buffer still
 592                                 } else if ( cssBuffer ) {
 593                                         cssText = cssBuffer;
 594                                         cssBuffer = '';
 595                                 } else {
 596                                         // This is a delayed call, but buffer is already cleared by
 597                                         // another delayed call.
 598                                         return;
 599                                 }
 600
 601                                 // By default, always create a new <style>. Appending text
 602                                 // to a <style> tag means the contents have to be re-parsed (bug 45810).
 603                                 // Except, of course, in IE below 9, in there we default to
 604                                 // re-using and appending to a <style> tag due to the
 605                                 // IE stylesheet limit (bug 31676).
 606                                 if ( 'documentMode' in document && document.documentMode <= 9 ) {
 607
 608                                         $style = getMarker().prev();
 609                                         // Verify that the the element before Marker actually is a
 610                                         // <style> tag and one that came from ResourceLoader
 611                                         // (not some other style tag or even a `<meta>` or `<script>`).
 612                                         if ( $style.data( 'ResourceLoaderDynamicStyleTag' ) === true ) {
 613                                                 // There's already a dynamic <style> tag present and
 614                                                 // canExpandStylesheetWith() gave a green light to append more to it.
 615                                                 styleEl = $style.get( 0 );
 616                                                 if ( styleEl.styleSheet ) {
 617                                                         try {
 618                                                                 styleEl.styleSheet.cssText += cssText; // IE
 619                                                         } catch ( e ) {
 620                                                                 log( 'addEmbeddedCSS fail', e );
 621                                                         }
 622                                                 } else {
 623                                                         styleEl.appendChild( document.createTextNode( String( cssText ) ) );
 624                                                 }
 625                                                 cssCallbacks.fire().empty();
 626                                                 return;
 627                                         }
 628                                 }
 629
 630                                 $( newStyleTag( cssText, getMarker() ) ).data( 'ResourceLoaderDynamicStyleTag', true );
 631
 632                                 cssCallbacks.fire().empty();
 633                         }
 634
 635                         /**
 636                          * Generates an ISO8601 "basic" string from a UNIX timestamp
 637                          * @private
 638                          */
 639                         function formatVersionNumber( timestamp ) {
 640                                 var     d = new Date();
 641                                 function pad( a, b, c ) {
 642                                         return [a < 10 ? '0' + a : a, b < 10 ? '0' + b : b, c < 10 ? '0' + c : c].join( '' );
 643                                 }
 644                                 d.setTime( timestamp * 1000 );
 645                                 return [
 646                                         pad( d.getUTCFullYear(), d.getUTCMonth() + 1, d.getUTCDate() ), 'T',
 647                                         pad( d.getUTCHours(), d.getUTCMinutes(), d.getUTCSeconds() ), 'Z'
 648                                 ].join( '' );
 649                         }
 650
 651                         /**
 652                          * Resolves dependencies and detects circular references.
 653                          *
 654                          * @private
 655                          * @param {string} module Name of the top-level module whose dependencies shall be
 656                          *   resolved and sorted.
 657                          * @param {Array} resolved Returns a topological sort of the given module and its
 658                          *   dependencies, such that later modules depend on earlier modules. The array
 659                          *   contains the module names. If the array contains already some module names,
 660                          *   this function appends its result to the pre-existing array.
 661                          * @param {Object} [unresolved] Hash used to track the current dependency
 662                          *   chain; used to report loops in the dependency graph.
 663                          * @throws {Error} If any unregistered module or a dependency loop is encountered
 664                          */
 665                         function sortDependencies( module, resolved, unresolved ) {
 666                                 var n, deps, len;
 667
 668                                 if ( registry[module] === undefined ) {
 669                                         throw new Error( 'Unknown dependency: ' + module );
 670                                 }
 671                                 // Resolves dynamic loader function and replaces it with its own results
 672                                 if ( $.isFunction( registry[module].dependencies ) ) {
 673                                         registry[module].dependencies = registry[module].dependencies();
 674                                         // Ensures the module's dependencies are always in an array
 675                                         if ( typeof registry[module].dependencies !== 'object' ) {
 676                                                 registry[module].dependencies = [registry[module].dependencies];
 677                                         }
 678                                 }
 679                                 if ( $.inArray( module, resolved ) !== -1 ) {
 680                                         // Module already resolved; nothing to do.
 681                                         return;
 682                                 }
 683                                 // unresolved is optional, supply it if not passed in
 684                                 if ( !unresolved ) {
 685                                         unresolved = {};
 686                                 }
 687                                 // Tracks down dependencies
 688                                 deps = registry[module].dependencies;
 689                                 len = deps.length;
 690                                 for ( n = 0; n < len; n += 1 ) {
 691                                         if ( $.inArray( deps[n], resolved ) === -1 ) {
 692                                                 if ( unresolved[deps[n]] ) {
 693                                                         throw new Error(
 694                                                                 'Circular reference detected: ' + module +
 695                                                                 ' -> ' + deps[n]
 696                                                         );
 697                                                 }
 698
 699                                                 // Add to unresolved
 700                                                 unresolved[module] = true;
 701                                                 sortDependencies( deps[n], resolved, unresolved );
 702                                                 delete unresolved[module];
 703                                         }
 704                                 }
 705                                 resolved[resolved.length] = module;
 706                         }
 707
 708                         /**
 709                          * Gets a list of module names that a module depends on in their proper dependency
 710                          * order.
 711                          *
 712                          * @private
 713                          * @param {string} module Module name or array of string module names
 714                          * @return {Array} list of dependencies, including 'module'.
 715                          * @throws {Error} If circular reference is detected
 716                          */
 717                         function resolve( module ) {
 718                                 var m, resolved;
 719
 720                                 // Allow calling with an array of module names
 721                                 if ( $.isArray( module ) ) {
 722                                         resolved = [];
 723                                         for ( m = 0; m < module.length; m += 1 ) {
 724                                                 sortDependencies( module[m], resolved );
 725                                         }
 726                                         return resolved;
 727                                 }
 728
 729                                 if ( typeof module === 'string' ) {
 730                                         resolved = [];
 731                                         sortDependencies( module, resolved );
 732                                         return resolved;
 733                                 }
 734
 735                                 throw new Error( 'Invalid module argument: ' + module );
 736                         }
 737
 738                         /**
 739                          * Narrows a list of module names down to those matching a specific
 740                          * state (see comment on top of this scope for a list of valid states).
 741                          * One can also filter for 'unregistered', which will return the
 742                          * modules names that don't have a registry entry.
 743                          *
 744                          * @private
 745                          * @param {string|string[]} states Module states to filter by
 746                          * @param {Array} [modules] List of module names to filter (optional, by default the entire
 747                          * registry is used)
 748                          * @return {Array} List of filtered module names
 749                          */
 750                         function filter( states, modules ) {
 751                                 var list, module, s, m;
 752
 753                                 // Allow states to be given as a string
 754                                 if ( typeof states === 'string' ) {
 755                                         states = [states];
 756                                 }
 757                                 // If called without a list of modules, build and use a list of all modules
 758                                 list = [];
 759                                 if ( modules === undefined ) {
 760                                         modules = [];
 761                                         for ( module in registry ) {
 762                                                 modules[modules.length] = module;
 763                                         }
 764                                 }
 765                                 // Build a list of modules which are in one of the specified states
 766                                 for ( s = 0; s < states.length; s += 1 ) {
 767                                         for ( m = 0; m < modules.length; m += 1 ) {
 768                                                 if ( registry[modules[m]] === undefined ) {
 769                                                         // Module does not exist
 770                                                         if ( states[s] === 'unregistered' ) {
 771                                                                 // OK, undefined
 772                                                                 list[list.length] = modules[m];
 773                                                         }
 774                                                 } else {
 775                                                         // Module exists, check state
 776                                                         if ( registry[modules[m]].state === states[s] ) {
 777                                                                 // OK, correct state
 778                                                                 list[list.length] = modules[m];
 779                                                         }
 780                                                 }
 781                                         }
 782                                 }
 783                                 return list;
 784                         }
 785
 786                         /**
 787                          * Determine whether all dependencies are in state 'ready', which means we may
 788                          * execute the module or job now.
 789                          *
 790                          * @private
 791                          * @param {Array} dependencies Dependencies (module names) to be checked.
 792                          * @return {boolean} True if all dependencies are in state 'ready', false otherwise
 793                          */
 794                         function allReady( dependencies ) {
 795                                 return filter( 'ready', dependencies ).length === dependencies.length;
 796                         }
 797
 798                         /**
 799                          * A module has entered state 'ready', 'error', or 'missing'. Automatically update pending jobs
 800                          * and modules that depend upon this module. if the given module failed, propagate the 'error'
 801                          * state up the dependency tree; otherwise, execute all jobs/modules that now have all their
 802                          * dependencies satisfied. On jobs depending on a failed module, run the error callback, if any.
 803                          *
 804                          * @private
 805                          * @param {string} module Name of module that entered one of the states 'ready', 'error', or 'missing'.
 806                          */
 807                         function handlePending( module ) {
 808                                 var j, job, hasErrors, m, stateChange;
 809
 810                                 // Modules.
 811                                 if ( $.inArray( registry[module].state, ['error', 'missing'] ) !== -1 ) {
 812                                         // If the current module failed, mark all dependent modules also as failed.
 813                                         // Iterate until steady-state to propagate the error state upwards in the
 814                                         // dependency tree.
 815                                         do {
 816                                                 stateChange = false;
 817                                                 for ( m in registry ) {
 818                                                         if ( $.inArray( registry[m].state, ['error', 'missing'] ) === -1 ) {
 819                                                                 if ( filter( ['error', 'missing'], registry[m].dependencies ).length > 0 ) {
 820                                                                         registry[m].state = 'error';
 821                                                                         stateChange = true;
 822                                                                 }
 823                                                         }
 824                                                 }
 825                                         } while ( stateChange );
 826                                 }
 827
 828                                 // Execute all jobs whose dependencies are either all satisfied or contain at least one failed module.
 829                                 for ( j = 0; j < jobs.length; j += 1 ) {
 830                                         hasErrors = filter( ['error', 'missing'], jobs[j].dependencies ).length > 0;
 831                                         if ( hasErrors || allReady( jobs[j].dependencies ) ) {
 832                                                 // All dependencies satisfied, or some have errors
 833                                                 job = jobs[j];
 834                                                 jobs.splice( j, 1 );
 835                                                 j -= 1;
 836                                                 try {
 837                                                         if ( hasErrors ) {
 838                                                                 if ( $.isFunction( job.error ) ) {
 839                                                                         job.error( new Error( 'Module ' + module + ' has failed dependencies' ), [module] );
 840                                                                 }
 841                                                         } else {
 842                                                                 if ( $.isFunction( job.ready ) ) {
 843                                                                         job.ready();
 844                                                                 }
 845                                                         }
 846                                                 } catch ( e ) {
 847                                                         // A user-defined callback raised an exception.
 848                                                         // Swallow it to protect our state machine!
 849                                                         log( 'Exception thrown by job.error', e );
 850                                                 }
 851                                         }
 852                                 }
 853
 854                                 if ( registry[module].state === 'ready' ) {
 855                                         // The current module became 'ready'. Set it in the module store, and recursively execute all
 856                                         // dependent modules that are loaded and now have all dependencies satisfied.
 857                                         mw.loader.store.set( module, registry[module] );
 858                                         for ( m in registry ) {
 859                                                 if ( registry[m].state === 'loaded' && allReady( registry[m].dependencies ) ) {
 860                                                         execute( m );
 861                                                 }
 862                                         }
 863                                 }
 864                         }
 865
 866                         /**
 867                          * Adds a script tag to the DOM, either using document.write or low-level DOM manipulation,
 868                          * depending on whether document-ready has occurred yet and whether we are in async mode.
 869                          *
 870                          * @private
 871                          * @param {string} src URL to script, will be used as the src attribute in the script tag
 872                          * @param {Function} [callback] Callback which will be run when the script is done
 873                          */
 874                         function addScript( src, callback, async ) {
 875                                 /*jshint evil:true */
 876                                 var script, head, done;
 877
 878                                 // Using isReady directly instead of storing it locally from
 879                                 // a $.fn.ready callback (bug 31895).
 880                                 if ( $.isReady || async ) {
 881                                         // Can't use jQuery.getScript because that only uses <script> for cross-domain,
 882                                         // it uses XHR and eval for same-domain scripts, which we don't want because it
 883                                         // messes up line numbers.
 884                                         // The below is based on jQuery ([jquery@1.8.2]/src/ajax/script.js)
 885
 886                                         // IE-safe way of getting the <head>. document.head isn't supported
 887                                         // in old IE, and doesn't work when in the <head>.
 888                                         done = false;
 889                                         head = document.getElementsByTagName( 'head' )[0] || document.body;
 890
 891                                         script = document.createElement( 'script' );
 892                                         script.async = true;
 893                                         script.src = src;
 894                                         if ( $.isFunction( callback ) ) {
 895                                                 script.onload = script.onreadystatechange = function () {
 896                                                         if (
 897                                                                 !done
 898                                                                 && (
 899                                                                         !script.readyState
 900                                                                         || /loaded|complete/.test( script.readyState )
 901                                                                 )
 902                                                         ) {
 903                                                                 done = true;
 904
 905                                                                 // Handle memory leak in IE
 906                                                                 script.onload = script.onreadystatechange = null;
 907
 908                                                                 // Detach the element from the document
 909                                                                 if ( script.parentNode ) {
 910                                                                         script.parentNode.removeChild( script );
 911                                                                 }
 912
 913                                                                 // Dereference the element from javascript
 914                                                                 script = undefined;
 915
 916                                                                 callback();
 917                                                         }
 918                                                 };
 919                                         }
 920
 921                                         if ( window.opera ) {
 922                                                 // Appending to the <head> blocks rendering completely in Opera,
 923                                                 // so append to the <body> after document ready. This means the
 924                                                 // scripts only start loading after the document has been rendered,
 925                                                 // but so be it. Opera users don't deserve faster web pages if their
 926                                                 // browser makes it impossible.
 927                                                 $( function () {
 928                                                         document.body.appendChild( script );
 929                                                 } );
 930                                         } else {
 931                                                 head.appendChild( script );
 932                                         }
 933                                 } else {
 934                                         document.write( mw.html.element( 'script', { 'src': src }, '' ) );
 935                                         if ( $.isFunction( callback ) ) {
 936                                                 // Document.write is synchronous, so this is called when it's done
 937                                                 // FIXME: that's a lie. doc.write isn't actually synchronous
 938                                                 callback();
 939                                         }
 940                                 }
 941                         }
 942
 943                         /**
 944                          * Executes a loaded module, making it ready to use
 945                          *
 946                          * @private
 947                          * @param {string} module Module name to execute
 948                          */
 949                         function execute( module ) {
 950                                 var key, value, media, i, urls, cssHandle, checkCssHandles,
 951                                         cssHandlesRegistered = false;
 952
 953                                 if ( registry[module] === undefined ) {
 954                                         throw new Error( 'Module has not been registered yet: ' + module );
 955                                 } else if ( registry[module].state === 'registered' ) {
 956                                         throw new Error( 'Module has not been requested from the server yet: ' + module );
 957                                 } else if ( registry[module].state === 'loading' ) {
 958                                         throw new Error( 'Module has not completed loading yet: ' + module );
 959                                 } else if ( registry[module].state === 'ready' ) {
 960                                         throw new Error( 'Module has already been executed: ' + module );
 961                                 }
 962
 963                                 /**
 964                                  * Define loop-function here for efficiency
 965                                  * and to avoid re-using badly scoped variables.
 966                                  * @ignore
 967                                  */
 968                                 function addLink( media, url ) {
 969                                         var el = document.createElement( 'link' );
 970                                         getMarker().before( el ); // IE: Insert in dom before setting href
 971                                         el.rel = 'stylesheet';
 972                                         if ( media && media !== 'all' ) {
 973                                                 el.media = media;
 974                                         }
 975                                         el.href = url;
 976                                 }
 977
 978                                 function runScript() {
 979                                         var script, markModuleReady, nestedAddScript;
 980                                         try {
 981                                                 script = registry[module].script;
 982                                                 markModuleReady = function () {
 983                                                         registry[module].state = 'ready';
 984                                                         handlePending( module );
 985                                                 };
 986                                                 nestedAddScript = function ( arr, callback, async, i ) {
 987                                                         // Recursively call addScript() in its own callback
 988                                                         // for each element of arr.
 989                                                         if ( i >= arr.length ) {
 990                                                                 // We're at the end of the array
 991                                                                 callback();
 992                                                                 return;
 993                                                         }
 994
 995                                                         addScript( arr[i], function () {
 996                                                                 nestedAddScript( arr, callback, async, i + 1 );
 997                                                         }, async );
 998                                                 };
 999
1000                                                 if ( $.isArray( script ) ) {
1001                                                         nestedAddScript( script, markModuleReady, registry[module].async, 0 );
1002                                                 } else if ( $.isFunction( script ) ) {
1003                                                         registry[module].state = 'ready';
1004                                                         script( $ );
1005                                                         handlePending( module );
1006                                                 }
1007                                         } catch ( e ) {
1008                                                 // This needs to NOT use mw.log because these errors are common in production mode
1009                                                 // and not in debug mode, such as when a symbol that should be global isn't exported
1010                                                 log( 'Exception thrown by ' + module, e );
1011                                                 registry[module].state = 'error';
1012                                                 handlePending( module );
1013                                         }
1014                                 }
1015
1016                                 // This used to be inside runScript, but since that is now fired asychronously
1017                                 // (after CSS is loaded) we need to set it here right away. It is crucial that
1018                                 // when execute() is called this is set synchronously, otherwise modules will get
1019                                 // executed multiple times as the registry will state that it isn't loading yet.
1020                                 registry[module].state = 'loading';
1021
1022                                 // Add localizations to message system
1023                                 if ( $.isPlainObject( registry[module].messages ) ) {
1024                                         mw.messages.set( registry[module].messages );
1025                                 }
1026
1027                                 if ( $.isReady || registry[module].async ) {
1028                                         // Make sure we don't run the scripts until all (potentially asynchronous)
1029                                         // stylesheet insertions have completed.
1030                                         ( function () {
1031                                                 var pending = 0;
1032                                                 checkCssHandles = function () {
1033                                                         // cssHandlesRegistered ensures we don't take off too soon, e.g. when
1034                                                         // one of the cssHandles is fired while we're still creating more handles.
1035                                                         if ( cssHandlesRegistered && pending === 0 && runScript ) {
1036                                                                 runScript();
1037                                                                 runScript = undefined; // Revoke
1038                                                         }
1039                                                 };
1040                                                 cssHandle = function () {
1041                                                         var check = checkCssHandles;
1042                                                         pending++;
1043                                                         return function () {
1044                                                                 if (check) {
1045                                                                         pending--;
1046                                                                         check();
1047                                                                         check = undefined; // Revoke
1048                                                                 }
1049                                                         };
1050                                                 };
1051                                         }() );
1052                                 } else {
1053                                         // We are in blocking mode, and so we can't afford to wait for CSS
1054                                         cssHandle = function () {};
1055                                         // Run immediately
1056                                         checkCssHandles = runScript;
1057                                 }
1058
1059                                 // Process styles (see also mw.loader.implement)
1060                                 // * back-compat: { <media>: css }
1061                                 // * back-compat: { <media>: [url, ..] }
1062                                 // * { "css": [css, ..] }
1063                                 // * { "url": { <media>: [url, ..] } }
1064                                 if ( $.isPlainObject( registry[module].style ) ) {
1065                                         for ( key in registry[module].style ) {
1066                                                 value = registry[module].style[key];
1067                                                 media = undefined;
1068
1069                                                 if ( key !== 'url' && key !== 'css' ) {
1070                                                         // Backwards compatibility, key is a media-type
1071                                                         if ( typeof value === 'string' ) {
1072                                                                 // back-compat: { <media>: css }
1073                                                                 // Ignore 'media' because it isn't supported (nor was it used).
1074                                                                 // Strings are pre-wrapped in "@media". The media-type was just ""
1075                                                                 // (because it had to be set to something).
1076                                                                 // This is one of the reasons why this format is no longer used.
1077                                                                 addEmbeddedCSS( value, cssHandle() );
1078                                                         } else {
1079                                                                 // back-compat: { <media>: [url, ..] }
1080                                                                 media = key;
1081                                                                 key = 'bc-url';
1082                                                         }
1083                                                 }
1084
1085                                                 // Array of css strings in key 'css',
1086                                                 // or back-compat array of urls from media-type
1087                                                 if ( $.isArray( value ) ) {
1088                                                         for ( i = 0; i < value.length; i += 1 ) {
1089                                                                 if ( key === 'bc-url' ) {
1090                                                                         // back-compat: { <media>: [url, ..] }
1091                                                                         addLink( media, value[i] );
1092                                                                 } else if ( key === 'css' ) {
1093                                                                         // { "css": [css, ..] }
1094                                                                         addEmbeddedCSS( value[i], cssHandle() );
1095                                                                 }
1096                                                         }
1097                                                 // Not an array, but a regular object
1098                                                 // Array of urls inside media-type key
1099                                                 } else if ( typeof value === 'object' ) {
1100                                                         // { "url": { <media>: [url, ..] } }
1101                                                         for ( media in value ) {
1102                                                                 urls = value[media];
1103                                                                 for ( i = 0; i < urls.length; i += 1 ) {
1104                                                                         addLink( media, urls[i] );
1105                                                                 }
1106                                                         }
1107                                                 }
1108                                         }
1109                                 }
1110
1111                                 // Kick off.
1112                                 cssHandlesRegistered = true;
1113                                 checkCssHandles();
1114                         }
1115
1116                         /**
1117                          * Adds a dependencies to the queue with optional callbacks to be run
1118                          * when the dependencies are ready or fail
1119                          *
1120                          * @private
1121                          * @param {string|string[]} dependencies Module name or array of string module names
1122                          * @param {Function} [ready] Callback to execute when all dependencies are ready
1123                          * @param {Function} [error] Callback to execute when any dependency fails
1124                          * @param {boolean} [async] If true, load modules asynchronously even if
1125                          *  document ready has not yet occurred.
1126                          */
1127                         function request( dependencies, ready, error, async ) {
1128                                 var n;
1129
1130                                 // Allow calling by single module name
1131                                 if ( typeof dependencies === 'string' ) {
1132                                         dependencies = [dependencies];
1133                                 }
1134
1135                                 // Add ready and error callbacks if they were given
1136                                 if ( ready !== undefined || error !== undefined ) {
1137                                         jobs[jobs.length] = {
1138                                                 'dependencies': filter(
1139                                                         ['registered', 'loading', 'loaded'],
1140                                                         dependencies
1141                                                 ),
1142                                                 'ready': ready,
1143                                                 'error': error
1144                                         };
1145                                 }
1146
1147                                 // Queue up any dependencies that are registered
1148                                 dependencies = filter( ['registered'], dependencies );
1149                                 for ( n = 0; n < dependencies.length; n += 1 ) {
1150                                         if ( $.inArray( dependencies[n], queue ) === -1 ) {
1151                                                 queue[queue.length] = dependencies[n];
1152                                                 if ( async ) {
1153                                                         // Mark this module as async in the registry
1154                                                         registry[dependencies[n]].async = true;
1155                                                 }
1156                                         }
1157                                 }
1158
1159                                 // Work the queue
1160                                 mw.loader.work();
1161                         }
1162
1163                         function sortQuery(o) {
1164                                 var sorted = {}, key, a = [];
1165                                 for ( key in o ) {
1166                                         if ( hasOwn.call( o, key ) ) {
1167                                                 a.push( key );
1168                                         }
1169                                 }
1170                                 a.sort();
1171                                 for ( key = 0; key < a.length; key += 1 ) {
1172                                         sorted[a[key]] = o[a[key]];
1173                                 }
1174                                 return sorted;
1175                         }
1176
1177                         /**
1178                          * Converts a module map of the form { foo: [ 'bar', 'baz' ], bar: [ 'baz, 'quux' ] }
1179                          * to a query string of the form foo.bar,baz|bar.baz,quux
1180                          * @private
1181                          */
1182                         function buildModulesString( moduleMap ) {
1183                                 var arr = [], p, prefix;
1184                                 for ( prefix in moduleMap ) {
1185                                         p = prefix === '' ? '' : prefix + '.';
1186                                         arr.push( p + moduleMap[prefix].join( ',' ) );
1187                                 }
1188                                 return arr.join( '|' );
1189                         }
1190
1191                         /**
1192                          * Asynchronously append a script tag to the end of the body
1193                          * that invokes load.php
1194                          * @private
1195                          * @param {Object} moduleMap Module map, see #buildModulesString
1196                          * @param {Object} currReqBase Object with other parameters (other than 'modules') to use in the request
1197                          * @param {string} sourceLoadScript URL of load.php
1198                          * @param {boolean} async If true, use an asynchronous request even if document ready has not yet occurred
1199                          */
1200                         function doRequest( moduleMap, currReqBase, sourceLoadScript, async ) {
1201                                 var request = $.extend(
1202                                         { modules: buildModulesString( moduleMap ) },
1203                                         currReqBase
1204                                 );
1205                                 request = sortQuery( request );
1206                                 // Asynchronously append a script tag to the end of the body
1207                                 // Append &* to avoid triggering the IE6 extension check
1208                                 addScript( sourceLoadScript + '?' + $.param( request ) + '&*', null, async );
1209                         }
1210
1211                         /* Public Members */
1212                         return {
1213                                 /**
1214                                  * The module registry is exposed as an aid for debugging and inspecting page
1215                                  * state; it is not a public interface for modifying the registry.
1216                                  *
1217                                  * @see #registry
1218                                  * @property
1219                                  * @private
1220                                  */
1221                                 moduleRegistry: registry,
1222
1223                                 /**
1224                                  * @inheritdoc #newStyleTag
1225                                  * @method
1226                                  */
1227                                 addStyleTag: newStyleTag,
1228
1229                                 /**
1230                                  * Batch-request queued dependencies from the server.
1231                                  */
1232                                 work: function () {
1233                                         var     reqBase, splits, maxQueryLength, q, b, bSource, bGroup, bSourceGroup,
1234                                                 source, group, g, i, modules, maxVersion, sourceLoadScript,
1235                                                 currReqBase, currReqBaseLength, moduleMap, l,
1236                                                 lastDotIndex, prefix, suffix, bytesAdded, async;
1237
1238                                         // Build a list of request parameters common to all requests.
1239                                         reqBase = {
1240                                                 skin: mw.config.get( 'skin' ),
1241                                                 lang: mw.config.get( 'wgUserLanguage' ),
1242                                                 debug: mw.config.get( 'debug' )
1243                                         };
1244                                         // Split module batch by source and by group.
1245                                         splits = {};
1246                                         maxQueryLength = mw.config.get( 'wgResourceLoaderMaxQueryLength', -1 );
1247
1248                                         // Appends a list of modules from the queue to the batch
1249                                         for ( q = 0; q < queue.length; q += 1 ) {
1250                                                 // Only request modules which are registered
1251                                                 if ( registry[queue[q]] !== undefined && registry[queue[q]].state === 'registered' ) {
1252                                                         // Prevent duplicate entries
1253                                                         if ( $.inArray( queue[q], batch ) === -1 ) {
1254                                                                 batch[batch.length] = queue[q];
1255                                                                 // Mark registered modules as loading
1256                                                                 registry[queue[q]].state = 'loading';
1257                                                         }
1258                                                 }
1259                                         }
1260
1261                                         mw.loader.store.init();
1262                                         if ( mw.loader.store.enabled ) {
1263                                                 batch = $.grep( batch, function ( module ) {
1264                                                         var source = mw.loader.store.get( module );
1265                                                         if ( source ) {
1266                                                                 $.globalEval( source );
1267                                                                 return false; // Don't fetch
1268                                                         }
1269                                                         return true; // Fetch
1270                                                 } );
1271                                         }
1272
1273                                         // Early exit if there's nothing to load...
1274                                         if ( !batch.length ) {
1275                                                 return;
1276                                         }
1277
1278                                         // The queue has been processed into the batch, clear up the queue.
1279                                         queue = [];
1280
1281                                         // Always order modules alphabetically to help reduce cache
1282                                         // misses for otherwise identical content.
1283                                         batch.sort();
1284
1285                                         // Split batch by source and by group.
1286                                         for ( b = 0; b < batch.length; b += 1 ) {
1287                                                 bSource = registry[batch[b]].source;
1288                                                 bGroup = registry[batch[b]].group;
1289                                                 if ( splits[bSource] === undefined ) {
1290                                                         splits[bSource] = {};
1291                                                 }
1292                                                 if ( splits[bSource][bGroup] === undefined ) {
1293                                                         splits[bSource][bGroup] = [];
1294                                                 }
1295                                                 bSourceGroup = splits[bSource][bGroup];
1296                                                 bSourceGroup[bSourceGroup.length] = batch[b];
1297                                         }
1298
1299                                         // Clear the batch - this MUST happen before we append any
1300                                         // script elements to the body or it's possible that a script
1301                                         // will be locally cached, instantly load, and work the batch
1302                                         // again, all before we've cleared it causing each request to
1303                                         // include modules which are already loaded.
1304                                         batch = [];
1305
1306                                         for ( source in splits ) {
1307
1308                                                 sourceLoadScript = sources[source].loadScript;
1309
1310                                                 for ( group in splits[source] ) {
1311
1312                                                         // Cache access to currently selected list of
1313                                                         // modules for this group from this source.
1314                                                         modules = splits[source][group];
1315
1316                                                         // Calculate the highest timestamp
1317                                                         maxVersion = 0;
1318                                                         for ( g = 0; g < modules.length; g += 1 ) {
1319                                                                 if ( registry[modules[g]].version > maxVersion ) {
1320                                                                         maxVersion = registry[modules[g]].version;
1321                                                                 }
1322                                                         }
1323
1324                                                         currReqBase = $.extend( { version: formatVersionNumber( maxVersion ) }, reqBase );
1325                                                         // For user modules append a user name to the request.
1326                                                         if ( group === 'user' && mw.config.get( 'wgUserName' ) !== null ) {
1327                                                                 currReqBase.user = mw.config.get( 'wgUserName' );
1328                                                         }
1329                                                         currReqBaseLength = $.param( currReqBase ).length;
1330                                                         async = true;
1331                                                         // We may need to split up the request to honor the query string length limit,
1332                                                         // so build it piece by piece.
1333                                                         l = currReqBaseLength + 9; // '&modules='.length == 9
1334
1335                                                         moduleMap = {}; // { prefix: [ suffixes ] }
1336
1337                                                         for ( i = 0; i < modules.length; i += 1 ) {
1338                                                                 // Determine how many bytes this module would add to the query string
1339                                                                 lastDotIndex = modules[i].lastIndexOf( '.' );
1340                                                                 // Note that these substr() calls work even if lastDotIndex == -1
1341                                                                 prefix = modules[i].substr( 0, lastDotIndex );
1342                                                                 suffix = modules[i].substr( lastDotIndex + 1 );
1343                                                                 bytesAdded = moduleMap[prefix] !== undefined
1344                                                                         ? suffix.length + 3 // '%2C'.length == 3
1345                                                                         : modules[i].length + 3; // '%7C'.length == 3
1346
1347                                                                 // If the request would become too long, create a new one,
1348                                                                 // but don't create empty requests
1349                                                                 if ( maxQueryLength > 0 && !$.isEmptyObject( moduleMap ) && l + bytesAdded > maxQueryLength ) {
1350                                                                         // This request would become too long, create a new one
1351                                                                         // and fire off the old one
1352                                                                         doRequest( moduleMap, currReqBase, sourceLoadScript, async );
1353                                                                         moduleMap = {};
1354                                                                         async = true;
1355                                                                         l = currReqBaseLength + 9;
1356                                                                 }
1357                                                                 if ( moduleMap[prefix] === undefined ) {
1358                                                                         moduleMap[prefix] = [];
1359                                                                 }
1360                                                                 moduleMap[prefix].push( suffix );
1361                                                                 if ( !registry[modules[i]].async ) {
1362                                                                         // If this module is blocking, make the entire request blocking
1363                                                                         // This is slightly suboptimal, but in practice mixing of blocking
1364                                                                         // and async modules will only occur in debug mode.
1365                                                                         async = false;
1366                                                                 }
1367                                                                 l += bytesAdded;
1368                                                         }
1369                                                         // If there's anything left in moduleMap, request that too
1370                                                         if ( !$.isEmptyObject( moduleMap ) ) {
1371                                                                 doRequest( moduleMap, currReqBase, sourceLoadScript, async );
1372                                                         }
1373                                                 }
1374                                         }
1375                                 },
1376
1377                                 /**
1378                                  * Register a source.
1379                                  *
1380                                  * @param {string} id Short lowercase a-Z string representing a source, only used internally.
1381                                  * @param {Object} props Object containing only the loadScript property which is a url to
1382                                  *  the load.php location of the source.
1383                                  * @return {boolean}
1384                                  */
1385                                 addSource: function ( id, props ) {
1386                                         var source;
1387                                         // Allow multiple additions
1388                                         if ( typeof id === 'object' ) {
1389                                                 for ( source in id ) {
1390                                                         mw.loader.addSource( source, id[source] );
1391                                                 }
1392                                                 return true;
1393                                         }
1394
1395                                         if ( sources[id] !== undefined ) {
1396                                                 throw new Error( 'source already registered: ' + id );
1397                                         }
1398
1399                                         sources[id] = props;
1400
1401                                         return true;
1402                                 },
1403
1404                                 /**
1405                                  * Register a module, letting the system know about it and its
1406                                  * properties. Startup modules contain calls to this function.
1407                                  *
1408                                  * @param {string} module Module name
1409                                  * @param {number} version Module version number as a timestamp (falls backs to 0)
1410                                  * @param {string|Array|Function} dependencies One string or array of strings of module
1411                                  *  names on which this module depends, or a function that returns that array.
1412                                  * @param {string} [group=null] Group which the module is in
1413                                  * @param {string} [source='local'] Name of the source
1414                                  */
1415                                 register: function ( module, version, dependencies, group, source ) {
1416                                         var m;
1417                                         // Allow multiple registration
1418                                         if ( typeof module === 'object' ) {
1419                                                 for ( m = 0; m < module.length; m += 1 ) {
1420                                                         // module is an array of module names
1421                                                         if ( typeof module[m] === 'string' ) {
1422                                                                 mw.loader.register( module[m] );
1423                                                         // module is an array of arrays
1424                                                         } else if ( typeof module[m] === 'object' ) {
1425                                                                 mw.loader.register.apply( mw.loader, module[m] );
1426                                                         }
1427                                                 }
1428                                                 return;
1429                                         }
1430                                         // Validate input
1431                                         if ( typeof module !== 'string' ) {
1432                                                 throw new Error( 'module must be a string, not a ' + typeof module );
1433                                         }
1434                                         if ( registry[module] !== undefined ) {
1435                                                 throw new Error( 'module already registered: ' + module );
1436                                         }
1437                                         // List the module as registered
1438                                         registry[module] = {
1439                                                 version: version !== undefined ? parseInt( version, 10 ) : 0,
1440                                                 dependencies: [],
1441                                                 group: typeof group === 'string' ? group : null,
1442                                                 source: typeof source === 'string' ? source: 'local',
1443                                                 state: 'registered'
1444                                         };
1445                                         if ( typeof dependencies === 'string' ) {
1446                                                 // Allow dependencies to be given as a single module name
1447                                                 registry[module].dependencies = [ dependencies ];
1448                                         } else if ( typeof dependencies === 'object' || $.isFunction( dependencies ) ) {
1449                                                 // Allow dependencies to be given as an array of module names
1450                                                 // or a function which returns an array
1451                                                 registry[module].dependencies = dependencies;
1452                                         }
1453                                 },
1454
1455                                 /**
1456                                  * Implement a module given the components that make up the module.
1457                                  *
1458                                  * When #load or #using requests one or more modules, the server
1459                                  * response contain calls to this function.
1460                                  *
1461                                  * All arguments are required.
1462                                  *
1463                                  * @param {string} module Name of module
1464                                  * @param {Function|Array} script Function with module code or Array of URLs to
1465                                  *  be used as the src attribute of a new `<script>` tag.
1466                                  * @param {Object} style Should follow one of the following patterns:
1467                                  *
1468                                  *     { "css": [css, ..] }
1469                                  *     { "url": { <media>: [url, ..] } }
1470                                  *
1471                                  * And for backwards compatibility (needs to be supported forever due to caching):
1472                                  *
1473                                  *     { <media>: css }
1474                                  *     { <media>: [url, ..] }
1475                                  *
1476                                  * The reason css strings are not concatenated anymore is bug 31676. We now check
1477                                  * whether it's safe to extend the stylesheet (see #canExpandStylesheetWith).
1478                                  *
1479                                  * @param {Object} msgs List of key/value pairs to be added to mw#messages.
1480                                  */
1481                                 implement: function ( module, script, style, msgs ) {
1482                                         // Validate input
1483                                         if ( typeof module !== 'string' ) {
1484                                                 throw new Error( 'module must be a string, not a ' + typeof module );
1485                                         }
1486                                         if ( !$.isFunction( script ) && !$.isArray( script ) ) {
1487                                                 throw new Error( 'script must be a function or an array, not a ' + typeof script );
1488                                         }
1489                                         if ( !$.isPlainObject( style ) ) {
1490                                                 throw new Error( 'style must be an object, not a ' + typeof style );
1491                                         }
1492                                         if ( !$.isPlainObject( msgs ) ) {
1493                                                 throw new Error( 'msgs must be an object, not a ' + typeof msgs );
1494                                         }
1495                                         // Automatically register module
1496                                         if ( registry[module] === undefined ) {
1497                                                 mw.loader.register( module );
1498                                         }
1499                                         // Check for duplicate implementation
1500                                         if ( registry[module] !== undefined && registry[module].script !== undefined ) {
1501                                                 throw new Error( 'module already implemented: ' + module );
1502                                         }
1503                                         // Attach components
1504                                         registry[module].script = script;
1505                                         registry[module].style = style;
1506                                         registry[module].messages = msgs;
1507                                         // The module may already have been marked as erroneous
1508                                         if ( $.inArray( registry[module].state, ['error', 'missing'] ) === -1 ) {
1509                                                 registry[module].state = 'loaded';
1510                                                 if ( allReady( registry[module].dependencies ) ) {
1511                                                         execute( module );
1512                                                 }
1513                                         }
1514                                 },
1515
1516                                 /**
1517                                  * Execute a function as soon as one or more required modules are ready.
1518                                  *
1519                                  * @param {string|Array} dependencies Module name or array of modules names the callback
1520                                  *  dependends on to be ready before executing
1521                                  * @param {Function} [ready] callback to execute when all dependencies are ready
1522                                  * @param {Function} [error] callback to execute when if dependencies have a errors
1523                                  */
1524                                 using: function ( dependencies, ready, error ) {
1525                                         var tod = typeof dependencies;
1526                                         // Validate input
1527                                         if ( tod !== 'object' && tod !== 'string' ) {
1528                                                 throw new Error( 'dependencies must be a string or an array, not a ' + tod );
1529                                         }
1530                                         // Allow calling with a single dependency as a string
1531                                         if ( tod === 'string' ) {
1532                                                 dependencies = [ dependencies ];
1533                                         }
1534                                         // Resolve entire dependency map
1535                                         dependencies = resolve( dependencies );
1536                                         if ( allReady( dependencies ) ) {
1537                                                 // Run ready immediately
1538                                                 if ( $.isFunction( ready ) ) {
1539                                                         ready();
1540                                                 }
1541                                         } else if ( filter( ['error', 'missing'], dependencies ).length ) {
1542                                                 // Execute error immediately if any dependencies have errors
1543                                                 if ( $.isFunction( error ) ) {
1544                                                         error( new Error( 'one or more dependencies have state "error" or "missing"' ),
1545                                                                 dependencies );
1546                                                 }
1547                                         } else {
1548                                                 // Not all dependencies are ready: queue up a request
1549                                                 request( dependencies, ready, error );
1550                                         }
1551                                 },
1552
1553                                 /**
1554                                  * Load an external script or one or more modules.
1555                                  *
1556                                  * @param {string|Array} modules Either the name of a module, array of modules,
1557                                  *  or a URL of an external script or style
1558                                  * @param {string} [type='text/javascript'] mime-type to use if calling with a URL of an
1559                                  *  external script or style; acceptable values are "text/css" and
1560                                  *  "text/javascript"; if no type is provided, text/javascript is assumed.
1561                                  * @param {boolean} [async] If true, load modules asynchronously
1562                                  *  even if document ready has not yet occurred. If false, block before
1563                                  *  document ready and load async after. If not set, true will be
1564                                  *  assumed if loading a URL, and false will be assumed otherwise.
1565                                  */
1566                                 load: function ( modules, type, async ) {
1567                                         var filtered, m, module, l;
1568
1569                                         // Validate input
1570                                         if ( typeof modules !== 'object' && typeof modules !== 'string' ) {
1571                                                 throw new Error( 'modules must be a string or an array, not a ' + typeof modules );
1572                                         }
1573                                         // Allow calling with an external url or single dependency as a string
1574                                         if ( typeof modules === 'string' ) {
1575                                                 // Support adding arbitrary external scripts
1576                                                 if ( /^(https?:)?\/\//.test( modules ) ) {
1577                                                         if ( async === undefined ) {
1578                                                                 // Assume async for bug 34542
1579                                                                 async = true;
1580                                                         }
1581                                                         if ( type === 'text/css' ) {
1582                                                                 // IE7-8 throws security warnings when inserting a <link> tag
1583                                                                 // with a protocol-relative URL set though attributes (instead of
1584                                                                 // properties) - when on HTTPS. See also bug #.
1585                                                                 l = document.createElement( 'link' );
1586                                                                 l.rel = 'stylesheet';
1587                                                                 l.href = modules;
1588                                                                 $( 'head' ).append( l );
1589                                                                 return;
1590                                                         }
1591                                                         if ( type === 'text/javascript' || type === undefined ) {
1592                                                                 addScript( modules, null, async );
1593                                                                 return;
1594                                                         }
1595                                                         // Unknown type
1596                                                         throw new Error( 'invalid type for external url, must be text/css or text/javascript. not ' + type );
1597                                                 }
1598                                                 // Called with single module
1599                                                 modules = [ modules ];
1600                                         }
1601
1602                                         // Filter out undefined modules, otherwise resolve() will throw
1603                                         // an exception for trying to load an undefined module.
1604                                         // Undefined modules are acceptable here in load(), because load() takes
1605                                         // an array of unrelated modules, whereas the modules passed to
1606                                         // using() are related and must all be loaded.
1607                                         for ( filtered = [], m = 0; m < modules.length; m += 1 ) {
1608                                                 module = registry[modules[m]];
1609                                                 if ( module !== undefined ) {
1610                                                         if ( $.inArray( module.state, ['error', 'missing'] ) === -1 ) {
1611                                                                 filtered[filtered.length] = modules[m];
1612                                                         }
1613                                                 }
1614                                         }
1615
1616                                         if ( filtered.length === 0 ) {
1617                                                 return;
1618                                         }
1619                                         // Resolve entire dependency map
1620                                         filtered = resolve( filtered );
1621                                         // If all modules are ready, nothing to be done
1622                                         if ( allReady( filtered ) ) {
1623                                                 return;
1624                                         }
1625                                         // If any modules have errors: also quit.
1626                                         if ( filter( ['error', 'missing'], filtered ).length ) {
1627                                                 return;
1628                                         }
1629                                         // Since some modules are not yet ready, queue up a request.
1630                                         request( filtered, undefined, undefined, async );
1631                                 },
1632
1633                                 /**
1634                                  * Change the state of one or more modules.
1635                                  *
1636                                  * @param {string|Object} module module name or object of module name/state pairs
1637                                  * @param {string} state state name
1638                                  */
1639                                 state: function ( module, state ) {
1640                                         var m;
1641
1642                                         if ( typeof module === 'object' ) {
1643                                                 for ( m in module ) {
1644                                                         mw.loader.state( m, module[m] );
1645                                                 }
1646                                                 return;
1647                                         }
1648                                         if ( registry[module] === undefined ) {
1649                                                 mw.loader.register( module );
1650                                         }
1651                                         if ( $.inArray( state, ['ready', 'error', 'missing'] ) !== -1
1652                                                 && registry[module].state !== state ) {
1653                                                 // Make sure pending modules depending on this one get executed if their
1654                                                 // dependencies are now fulfilled!
1655                                                 registry[module].state = state;
1656                                                 handlePending( module );
1657                                         } else {
1658                                                 registry[module].state = state;
1659                                         }
1660                                 },
1661
1662                                 /**
1663                                  * Get the version of a module.
1664                                  *
1665                                  * @param {string} module Name of module to get version for
1666                                  */
1667                                 getVersion: function ( module ) {
1668                                         if ( registry[module] !== undefined && registry[module].version !== undefined ) {
1669                                                 return formatVersionNumber( registry[module].version );
1670                                         }
1671                                         return null;
1672                                 },
1673
1674                                 /**
1675                                  * @inheritdoc #getVersion
1676                                  * @deprecated since 1.18 use #getVersion instead
1677                                  */
1678                                 version: function () {
1679                                         return mw.loader.getVersion.apply( mw.loader, arguments );
1680                                 },
1681
1682                                 /**
1683                                  * Get the state of a module.
1684                                  *
1685                                  * @param {string} module name of module to get state for
1686                                  */
1687                                 getState: function ( module ) {
1688                                         if ( registry[module] !== undefined && registry[module].state !== undefined ) {
1689                                                 return registry[module].state;
1690                                         }
1691                                         return null;
1692                                 },
1693
1694                                 /**
1695                                  * Get names of all registered modules.
1696                                  *
1697                                  * @return {Array}
1698                                  */
1699                                 getModuleNames: function () {
1700                                         return $.map( registry, function ( i, key ) {
1701                                                 return key;
1702                                         } );
1703                                 },
1704
1705                                 /**
1706                                  * Load the `mediawiki.user` module.
1707                                  *
1708                                  * For backwards-compatibility with cached pages from before 2013 where:
1709                                  *
1710                                  * - the `mediawiki.user` module didn't exist yet
1711                                  * - `mw.user` was still part of mediawiki.js
1712                                  * - `mw.loader.go` still existed and called after `mw.loader.load()`
1713                                  */
1714                                 go: function () {
1715                                         mw.loader.load( 'mediawiki.user' );
1716                                 },
1717
1718                                 /**
1719                                  * @inheritdoc mw.inspect#runReports
1720                                  * @method
1721                                  */
1722                                 inspect: function () {
1723                                         var args = slice.call( arguments );
1724                                         mw.loader.using( 'mediawiki.inspect', function () {
1725                                                 mw.inspect.runReports.apply( mw.inspect, args );
1726                                         } );
1727                                 },
1728
1729                                 /**
1730                                  * On browsers that implement the localStorage API, the module store serves as a
1731                                  * smart complement to the browser cache. Unlike the browser cache, the module store
1732                                  * can slice a concatenated response from ResourceLoader into its constituent
1733                                  * modules and cache each of them separately, using each module's versioning scheme
1734                                  * to determine when the cache should be invalidated.
1735                                  *
1736                                  * @singleton
1737                                  * @class mw.loader.store
1738                                  */
1739                                 store: {
1740                                         // Whether the store is in use on this page.
1741                                         enabled: null,
1742
1743                                         // The contents of the store, mapping '[module name]@[version]' keys
1744                                         // to module implementations.
1745                                         items: {},
1746
1747                                         // Cache hit stats
1748                                         stats: { hits: 0, misses: 0, expired: 0 },
1749
1750                                         /**
1751                                          * Construct a JSON-serializable object representing the content of the store.
1752                                          * @return {Object} Module store contents.
1753                                          */
1754                                         toJSON: function () {
1755                                                 return { items: mw.loader.store.items, vary: mw.loader.store.getVary() };
1756                                         },
1757
1758                                         /**
1759                                          * Get the localStorage key for the entire module store. The key references
1760                                          * $wgDBname to prevent clashes between wikis which share a common host.
1761                                          *
1762                                          * @return {string} localStorage item key
1763                                          */
1764                                         getStoreKey: function () {
1765                                                 return 'MediaWikiModuleStore:' + mw.config.get( 'wgDBname' );
1766                                         },
1767
1768                                         /**
1769                                          * Get a string key on which to vary the module cache.
1770                                          * @return {string} String of concatenated vary conditions.
1771                                          */
1772                                         getVary: function () {
1773                                                 return [
1774                                                         mw.config.get( 'skin' ),
1775                                                         mw.config.get( 'wgResourceLoaderStorageVersion' ),
1776                                                         mw.config.get( 'wgUserLanguage' )
1777                                                 ].join(':');
1778                                         },
1779
1780                                         /**
1781                                          * Get a string key for a specific module. The key format is '[name]@[version]'.
1782                                          *
1783                                          * @param {string} module Module name
1784                                          * @return {string|null} Module key or null if module does not exist
1785                                          */
1786                                         getModuleKey: function ( module ) {
1787                                                 return typeof registry[module] === 'object' ?
1788                                                         ( module + '@' + registry[module].version ) : null;
1789                                         },
1790
1791                                         /**
1792                                          * Initialize the store by retrieving it from localStorage and (if successfully
1793                                          * retrieved) decoding the stored JSON value to a plain object.
1794                                          *
1795                                          * The try / catch block is used for JSON & localStorage feature detection.
1796                                          * See the in-line documentation for Modernizr's localStorage feature detection
1797                                          * code for a full account of why we need a try / catch: <http://git.io/4NEwKg>.
1798                                          */
1799                                         init: function () {
1800                                                 var raw, data;
1801
1802                                                 if ( mw.loader.store.enabled !== null ) {
1803                                                         // #init already ran.
1804                                                         return;
1805                                                 }
1806
1807                                                 if ( !mw.config.get( 'wgResourceLoaderStorageEnabled' ) || mw.config.get( 'debug' ) ) {
1808                                                         // Disabled by configuration, or because debug mode is set.
1809                                                         mw.loader.store.enabled = false;
1810                                                         return;
1811                                                 }
1812
1813                                                 try {
1814                                                         raw = localStorage.getItem( mw.loader.store.getStoreKey() );
1815                                                         // If we get here, localStorage is available; mark enabled.
1816                                                         mw.loader.store.enabled = true;
1817                                                         data = JSON.parse( raw );
1818                                                         if ( data && typeof data.items === 'object' && data.vary === mw.loader.store.getVary() ) {
1819                                                                 mw.loader.store.items = data.items;
1820                                                                 return;
1821                                                         }
1822                                                 } catch (e) {}
1823
1824                                                 if ( raw === undefined ) {
1825                                                         mw.loader.store.enabled = false;  // localStorage failed; disable store.
1826                                                 } else {
1827                                                         mw.loader.store.update();
1828                                                 }
1829                                         },
1830
1831                                         /**
1832                                          * Retrieve a module from the store and update cache hit stats.
1833                                          *
1834                                          * @param {string} module Module name
1835                                          * @return {string|boolean} Module implementation or false if unavailable
1836                                          */
1837                                         get: function ( module ) {
1838                                                 var key;
1839
1840                                                 if ( mw.loader.store.enabled !== true ) {
1841                                                         return false;
1842                                                 }
1843
1844                                                 key = mw.loader.store.getModuleKey( module );
1845                                                 if ( key in mw.loader.store.items ) {
1846                                                         mw.loader.store.stats.hits++;
1847                                                         return mw.loader.store.items[key];
1848                                                 }
1849                                                 mw.loader.store.stats.misses++;
1850                                                 return false;
1851                                         },
1852
1853                                         /**
1854                                          * Stringify a module and queue it for storage.
1855                                          *
1856                                          * @param {string} module Module name
1857                                          * @param {Object} descriptor The module's descriptor as set in the registry
1858                                          */
1859                                         set: function ( module, descriptor ) {
1860                                                 var args, key;
1861
1862                                                 if ( mw.loader.store.enabled !== true ) {
1863                                                         return false;
1864                                                 }
1865
1866                                                 key = mw.loader.store.getModuleKey( module );
1867
1868                                                 if ( key in mw.loader.store.items ) {
1869                                                         // Already set; decline to store.
1870                                                         return false;
1871                                                 }
1872
1873                                                 if ( descriptor.state !== 'ready' ) {
1874                                                         // Module failed to load; decline to store.
1875                                                         return false;
1876                                                 }
1877
1878                                                 if ( !descriptor.version || $.inArray( descriptor.group, [ 'private', 'user', 'site' ] ) !== -1 ) {
1879                                                         // Unversioned, private, or site-/user-specific; decline to store.
1880                                                         return false;
1881                                                 }
1882
1883                                                 if ( $.inArray( undefined, [ descriptor.script, descriptor.style, descriptor.messages ] ) !== -1 ) {
1884                                                         // Partial descriptor; decline to store.
1885                                                         return false;
1886                                                 }
1887
1888                                                 try {
1889                                                         args = [
1890                                                                 JSON.stringify( module ),
1891                                                                 typeof descriptor.script === 'function' ?
1892                                                                         String( descriptor.script ) : JSON.stringify( descriptor.script ),
1893                                                                 JSON.stringify( descriptor.style ),
1894                                                                 JSON.stringify( descriptor.messages )
1895                                                         ];
1896                                                 } catch (e) {
1897                                                         return;
1898                                                 }
1899                                                 mw.loader.store.items[key] = 'mw.loader.implement(' + args.join(',') + ');';
1900                                                 mw.loader.store.update();
1901                                         },
1902
1903                                         /**
1904                                          * Iterate through the module store, removing any item that does not correspond
1905                                          * (in name and version) to an item in the module registry.
1906                                          */
1907                                         prune: function () {
1908                                                 var key, module;
1909
1910                                                 if ( mw.loader.store.enabled !== true ) {
1911                                                         return false;
1912                                                 }
1913
1914                                                 for ( key in mw.loader.store.items ) {
1915                                                         module = key.substring( 0, key.indexOf( '@' ) );
1916                                                         if ( mw.loader.store.getModuleKey( module ) !== key ) {
1917                                                                 mw.loader.store.stats.expired++;
1918                                                                 delete mw.loader.store.items[key];
1919                                                         }
1920                                                 }
1921                                         },
1922
1923                                         /**
1924                                          * Sync modules to localStorage.
1925                                          *
1926                                          * This function debounces localStorage updates. When called multiple times in
1927                                          * quick succession, the calls are coalesced into a single update operation.
1928                                          * This allows us to call #update without having to consider the module load
1929                                          * queue; the call to localStorage.setItem will be naturally deferred until the
1930                                          * page is quiescent.
1931                                          *
1932                                          * Because localStorage is shared by all pages with the same origin, if multiple
1933                                          * pages are loaded with different module sets, the possibility exists that
1934                                          * modules saved by one page will be clobbered by another. But the impact would
1935                                          * be minor and the problem would be corrected by subsequent page views.
1936                                          */
1937                                         update: ( function () {
1938                                                 var timer;
1939
1940                                                 function flush() {
1941                                                         var data;
1942                                                         if ( mw.loader.store.enabled !== true ) {
1943                                                                 return false;
1944                                                         }
1945                                                         mw.loader.store.prune();
1946                                                         try {
1947                                                                 data = JSON.stringify( mw.loader.store );
1948                                                                 localStorage.setItem( mw.loader.store.getStoreKey(), data );
1949                                                         } catch (e) {}
1950                                                 }
1951
1952                                                 return function () {
1953                                                         clearTimeout( timer );
1954                                                         timer = setTimeout( flush, 2000 );
1955                                                 };
1956                                         }() )
1957                                 }
1958                         };
1959                 }() ),
1960
1961                 /**
1962                  * HTML construction helper functions
1963                  *
1964                  *     @example
1965                  *
1966                  *     var Html, output;
1967                  *
1968                  *     Html = mw.html;
1969                  *     output = Html.element( 'div', {}, new Html.Raw(
1970                  *         Html.element( 'img', { src: '<' } )
1971                  *     ) );
1972                  *     mw.log( output ); // <div><img src="&lt;"/></div>
1973                  *
1974                  * @class mw.html
1975                  * @singleton
1976                  */
1977                 html: ( function () {
1978                         function escapeCallback( s ) {
1979                                 switch ( s ) {
1980                                         case '\'':
1981                                                 return '&#039;';
1982                                         case '"':
1983                                                 return '&quot;';
1984                                         case '<':
1985                                                 return '&lt;';
1986                                         case '>':
1987                                                 return '&gt;';
1988                                         case '&':
1989                                                 return '&amp;';
1990                                 }
1991                         }
1992
1993                         return {
1994                                 /**
1995                                  * Escape a string for HTML. Converts special characters to HTML entities.
1996                                  * @param {string} s The string to escape
1997                                  */
1998                                 escape: function ( s ) {
1999                                         return s.replace( /['"<>&]/g, escapeCallback );
2000                                 },
2001
2002                                 /**
2003                                  * Create an HTML element string, with safe escaping.
2004                                  *
2005                                  * @param {string} name The tag name.
2006                                  * @param {Object} attrs An object with members mapping element names to values
2007                                  * @param {Mixed} contents The contents of the element. May be either:
2008                                  *  - string: The string is escaped.
2009                                  *  - null or undefined: The short closing form is used, e.g. <br/>.
2010                                  *  - this.Raw: The value attribute is included without escaping.
2011                                  *  - this.Cdata: The value attribute is included, and an exception is
2012                                  *   thrown if it contains an illegal ETAGO delimiter.
2013                                  *   See http://www.w3.org/TR/1999/REC-html401-19991224/appendix/notes.html#h-B.3.2
2014                                  */
2015                                 element: function ( name, attrs, contents ) {
2016                                         var v, attrName, s = '<' + name;
2017
2018                                         for ( attrName in attrs ) {
2019                                                 v = attrs[attrName];
2020                                                 // Convert name=true, to name=name
2021                                                 if ( v === true ) {
2022                                                         v = attrName;
2023                                                 // Skip name=false
2024                                                 } else if ( v === false ) {
2025                                                         continue;
2026                                                 }
2027                                                 s += ' ' + attrName + '="' + this.escape( String( v ) ) + '"';
2028                                         }
2029                                         if ( contents === undefined || contents === null ) {
2030                                                 // Self close tag
2031                                                 s += '/>';
2032                                                 return s;
2033                                         }
2034                                         // Regular open tag
2035                                         s += '>';
2036                                         switch ( typeof contents ) {
2037                                                 case 'string':
2038                                                         // Escaped
2039                                                         s += this.escape( contents );
2040                                                         break;
2041                                                 case 'number':
2042                                                 case 'boolean':
2043                                                         // Convert to string
2044                                                         s += String( contents );
2045                                                         break;
2046                                                 default:
2047                                                         if ( contents instanceof this.Raw ) {
2048                                                                 // Raw HTML inclusion
2049                                                                 s += contents.value;
2050                                                         } else if ( contents instanceof this.Cdata ) {
2051                                                                 // CDATA
2052                                                                 if ( /<\/[a-zA-z]/.test( contents.value ) ) {
2053                                                                         throw new Error( 'mw.html.element: Illegal end tag found in CDATA' );
2054                                                                 }
2055                                                                 s += contents.value;
2056                                                         } else {
2057                                                                 throw new Error( 'mw.html.element: Invalid type of contents' );
2058                                                         }
2059                                         }
2060                                         s += '</' + name + '>';
2061                                         return s;
2062                                 },
2063
2064                                 /**
2065                                  * Wrapper object for raw HTML passed to mw.html.element().
2066                                  * @class mw.html.Raw
2067                                  */
2068                                 Raw: function ( value ) {
2069                                         this.value = value;
2070                                 },
2071
2072                                 /**
2073                                  * Wrapper object for CDATA element contents passed to mw.html.element()
2074                                  * @class mw.html.Cdata
2075                                  */
2076                                 Cdata: function ( value ) {
2077                                         this.value = value;
2078                                 }
2079                         };
2080                 }() ),
2081
2082                 // Skeleton user object. mediawiki.user.js extends this
2083                 user: {
2084                         options: new Map(),
2085                         tokens: new Map()
2086                 },
2087
2088                 /**
2089                  * Registry and firing of events.
2090                  *
2091                  * MediaWiki has various interface components that are extended, enhanced
2092                  * or manipulated in some other way by extensions, gadgets and even
2093                  * in core itself.
2094                  *
2095                  * This framework helps streamlining the timing of when these other
2096                  * code paths fire their plugins (instead of using document-ready,
2097                  * which can and should be limited to firing only once).
2098                  *
2099                  * Features like navigating to other wiki pages, previewing an edit
2100                  * and editing itself – without a refresh – can then retrigger these
2101                  * hooks accordingly to ensure everything still works as expected.
2102                  *
2103                  * Example usage:
2104                  *
2105                  *     mw.hook( 'wikipage.content' ).add( fn ).remove( fn );
2106                  *     mw.hook( 'wikipage.content' ).fire( $content );
2107                  *
2108                  * Handlers can be added and fired for arbitrary event names at any time. The same
2109                  * event can be fired multiple times. The last run of an event is memorized
2110                  * (similar to `$(document).ready` and `$.Deferred().done`).
2111                  * This means if an event is fired, and a handler added afterwards, the added
2112                  * function will be fired right away with the last given event data.
2113                  *
2114                  * Like Deferreds and Promises, the mw.hook object is both detachable and chainable.
2115                  * Thus allowing flexible use and optimal maintainability and authority control.
2116                  * You can pass around the `add` and/or `fire` method to another piece of code
2117                  * without it having to know the event name (or `mw.hook` for that matter).
2118                  *
2119                  *     var h = mw.hook( 'bar.ready' );
2120                  *     new mw.Foo( .. ).fetch( { callback: h.fire } );
2121                  *
2122                  * Note: Events are documented with an underscore instead of a dot in the event
2123                  * name due to jsduck not supporting dots in that position.
2124                  *
2125                  * @class mw.hook
2126                  */
2127                 hook: ( function () {
2128                         var lists = {};
2129
2130                         /**
2131                          * Create an instance of mw.hook.
2132                          *
2133                          * @method hook
2134                          * @member mw
2135                          * @param {string} name Name of hook.
2136                          * @return {mw.hook}
2137                          */
2138                         return function ( name ) {
2139                                 var list = lists[name] || ( lists[name] = $.Callbacks( 'memory' ) );
2140
2141                                 return {
2142                                         /**
2143                                          * Register a hook handler
2144                                          * @param {Function...} handler Function to bind.
2145                                          * @chainable
2146                                          */
2147                                         add: list.add,
2148
2149                                         /**
2150                                          * Unregister a hook handler
2151                                          * @param {Function...} handler Function to unbind.
2152                                          * @chainable
2153                                          */
2154                                         remove: list.remove,
2155
2156                                         /**
2157                                          * Run a hook.
2158                                          * @param {Mixed...} data
2159                                          * @chainable
2160                                          */
2161                                         fire: function () {
2162                                                 return list.fireWith( null, slice.call( arguments ) );
2163                                         }
2164                                 };
2165                         };
2166                 }() )
2167         };
2168
2169 }( jQuery ) );
2170
2171 // Alias $j to jQuery for backwards compatibility
2172 window.$j = jQuery;
2173
2174 // Attach to window and globally alias
2175 window.mw = window.mediaWiki = mw;
2176
2177 // Auto-register from pre-loaded startup scripts
2178 if ( jQuery.isFunction( window.startUp ) ) {
2179         window.startUp();
2180         window.startUp = undefined;
2181 }