resources/src/mediawiki.widgets/mw.widgets.CalendarWidget.js

   1 /*!
   2  * MediaWiki Widgets – CalendarWidget class.
   3  *
   4  * @copyright 2011-2015 MediaWiki Widgets Team and others; see AUTHORS.txt
   5  * @license The MIT License (MIT); see LICENSE.txt
   6  */
   7 /* global moment */
   8 ( function ( $, mw ) {
   9
  10         /**
  11          * Creates an mw.widgets.CalendarWidget object.
  12          *
  13          * You will most likely want to use mw.widgets.DateInputWidget instead of CalendarWidget directly.
  14          *
  15          * @class
  16          * @extends OO.ui.Widget
  17          * @mixins OO.ui.mixin.TabIndexedElement
  18          * @mixins OO.ui.mixin.FloatableElement
  19          *
  20          * @constructor
  21          * @param {Object} [config] Configuration options
  22          * @cfg {boolean} [lazyInitOnToggle=false] Don't build most of the interface until
  23          *     `.toggle( true )` is called. Meant to be used when the calendar is not immediately visible.
  24          * @cfg {string} [precision='day'] Date precision to use, 'day' or 'month'
  25          * @cfg {string|null} [date=null] Day or month date (depending on `precision`), in the format
  26          *     'YYYY-MM-DD' or 'YYYY-MM'. When null, the calendar will show today's date, but not select
  27          *     it.
  28          */
  29         mw.widgets.CalendarWidget = function MWWCalendarWidget( config ) {
  30                 // Config initialization
  31                 config = config || {};
  32
  33                 // Parent constructor
  34                 mw.widgets.CalendarWidget.parent.call( this, config );
  35
  36                 // Mixin constructors
  37                 OO.ui.mixin.TabIndexedElement.call( this, $.extend( {}, config, { $tabIndexed: this.$element } ) );
  38                 OO.ui.mixin.FloatableElement.call( this, config );
  39
  40                 // Properties
  41                 this.lazyInitOnToggle = !!config.lazyInitOnToggle;
  42                 this.precision = config.precision || 'day';
  43                 // Currently selected date (day or month)
  44                 this.date = null;
  45                 // Current UI state (date and precision we're displaying right now)
  46                 this.moment = null;
  47                 this.displayLayer = this.getDisplayLayers()[ 0 ]; // 'month', 'year', 'duodecade'
  48
  49                 this.$header = $( '<div>' ).addClass( 'mw-widget-calendarWidget-header' );
  50                 this.$bodyOuterWrapper = $( '<div>' ).addClass( 'mw-widget-calendarWidget-body-outer-wrapper' );
  51                 this.$bodyWrapper = $( '<div>' ).addClass( 'mw-widget-calendarWidget-body-wrapper' );
  52                 this.$body = $( '<div>' ).addClass( 'mw-widget-calendarWidget-body' );
  53
  54                 // Events
  55                 this.$element.on( {
  56                         focus: this.onFocus.bind( this ),
  57                         mousedown: this.onClick.bind( this ),
  58                         keydown: this.onKeyDown.bind( this )
  59                 } );
  60
  61                 // Initialization
  62                 this.$element
  63                         .addClass( 'mw-widget-calendarWidget' )
  64                         .append( this.$header, this.$bodyOuterWrapper.append( this.$bodyWrapper.append( this.$body ) ) );
  65                 if ( !this.lazyInitOnToggle ) {
  66                         this.buildHeaderButtons();
  67                 }
  68                 this.setDate( config.date !== undefined ? config.date : null );
  69         };
  70
  71         /* Inheritance */
  72
  73         OO.inheritClass( mw.widgets.CalendarWidget, OO.ui.Widget );
  74         OO.mixinClass( mw.widgets.CalendarWidget, OO.ui.mixin.TabIndexedElement );
  75         OO.mixinClass( mw.widgets.CalendarWidget, OO.ui.mixin.FloatableElement );
  76
  77         /* Events */
  78
  79         /**
  80          * @event change
  81          *
  82          * A change event is emitted when the chosen date changes.
  83          *
  84          * @param {string} date Day or month date, in the format 'YYYY-MM-DD' or 'YYYY-MM'
  85          */
  86
  87         /* Methods */
  88
  89         /**
  90          * Get the date format ('YYYY-MM-DD' or 'YYYY-MM', depending on precision), which is used
  91          * internally and for dates accepted by #setDate and returned by #getDate.
  92          *
  93          * @private
  94          * @return {string} Format
  95          */
  96         mw.widgets.CalendarWidget.prototype.getDateFormat = function () {
  97                 return {
  98                         day: 'YYYY-MM-DD',
  99                         month: 'YYYY-MM'
 100                 }[ this.precision ];
 101         };
 102
 103         /**
 104          * Get the date precision this calendar uses, 'day' or 'month'.
 105          *
 106          * @private
 107          * @return {string} Precision, 'day' or 'month'
 108          */
 109         mw.widgets.CalendarWidget.prototype.getPrecision = function () {
 110                 return this.precision;
 111         };
 112
 113         /**
 114          * Get list of possible display layers.
 115          *
 116          * @private
 117          * @return {string[]} Layers
 118          */
 119         mw.widgets.CalendarWidget.prototype.getDisplayLayers = function () {
 120                 return [ 'month', 'year', 'duodecade' ].slice( this.precision === 'month' ? 1 : 0 );
 121         };
 122
 123         /**
 124          * Update the calendar.
 125          *
 126          * @private
 127          * @param {string|null} [fade=null] Direction in which to fade out current calendar contents,
 128          *     'previous', 'next', 'up' or 'down'; or 'auto', which has the same result as 'previous' or
 129          *     'next' depending on whether the current date is later or earlier than the previous.
 130          */
 131         mw.widgets.CalendarWidget.prototype.updateUI = function ( fade ) {
 132                 var items, today, selected, currentMonth, currentYear, currentDay, i, needsFade,
 133                         $bodyWrapper = this.$bodyWrapper;
 134
 135                 if ( this.lazyInitOnToggle ) {
 136                         // We're being called from the constructor and not being shown yet, do nothing
 137                         return;
 138                 }
 139
 140                 if (
 141                         this.displayLayer === this.previousDisplayLayer &&
 142                         this.date === this.previousDate &&
 143                         this.previousMoment &&
 144                         this.previousMoment.isSame( this.moment, this.precision === 'month' ? 'month' : 'day' )
 145                 ) {
 146                         // Already displayed
 147                         return;
 148                 }
 149
 150                 if ( fade === 'auto' ) {
 151                         if ( !this.previousMoment ) {
 152                                 fade = null;
 153                         } else if ( this.previousMoment.isBefore( this.moment, this.precision === 'month' ? 'month' : 'day' ) ) {
 154                                 fade = 'next';
 155                         } else if ( this.previousMoment.isAfter( this.moment, this.precision === 'month' ? 'month' : 'day' ) ) {
 156                                 fade = 'previous';
 157                         } else {
 158                                 fade = null;
 159                         }
 160                 }
 161
 162                 items = [];
 163                 if ( this.$oldBody ) {
 164                         this.$oldBody.remove();
 165                 }
 166                 this.$oldBody = this.$body.addClass( 'mw-widget-calendarWidget-old-body' );
 167                 // Clone without children
 168                 this.$body = $( this.$body[ 0 ].cloneNode( false ) )
 169                         .removeClass( 'mw-widget-calendarWidget-old-body' )
 170                         .toggleClass( 'mw-widget-calendarWidget-body-month', this.displayLayer === 'month' )
 171                         .toggleClass( 'mw-widget-calendarWidget-body-year', this.displayLayer === 'year' )
 172                         .toggleClass( 'mw-widget-calendarWidget-body-duodecade', this.displayLayer === 'duodecade' );
 173
 174                 today = moment();
 175                 selected = moment( this.getDate(), this.getDateFormat() );
 176
 177                 switch ( this.displayLayer ) {
 178                         case 'month':
 179                                 this.labelButton.setLabel( this.moment.format( 'MMMM YYYY' ) );
 180                                 this.upButton.toggle( true );
 181
 182                                 // First week displayed is the first week spanned by the month, unless it begins on Monday, in
 183                                 // which case first week displayed is the previous week. This makes the calendar "balanced"
 184                                 // and also neatly handles 28-day February sometimes spanning only 4 weeks.
 185                                 currentDay = moment( this.moment ).startOf( 'month' ).subtract( 1, 'day' ).startOf( 'week' );
 186
 187                                 // Day-of-week labels. Localisation-independent: works with weeks starting on Saturday, Sunday
 188                                 // or Monday.
 189                                 for ( i = 0; i < 7; i++ ) {
 190                                         items.push(
 191                                                 $( '<div>' )
 192                                                         .addClass( 'mw-widget-calendarWidget-day-heading' )
 193                                                         .text( currentDay.format( 'dd' ) )
 194                                         );
 195                                         currentDay.add( 1, 'day' );
 196                                 }
 197                                 currentDay.subtract( 7, 'days' );
 198
 199                                 // Actual calendar month. Always displays 6 weeks, for consistency (months can span 4 to 6
 200                                 // weeks).
 201                                 for ( i = 0; i < 42; i++ ) {
 202                                         items.push(
 203                                                 $( '<div>' )
 204                                                         .addClass( 'mw-widget-calendarWidget-item mw-widget-calendarWidget-day' )
 205                                                         .toggleClass( 'mw-widget-calendarWidget-day-additional', !currentDay.isSame( this.moment, 'month' ) )
 206                                                         .toggleClass( 'mw-widget-calendarWidget-day-today', currentDay.isSame( today, 'day' ) )
 207                                                         .toggleClass( 'mw-widget-calendarWidget-item-selected', currentDay.isSame( selected, 'day' ) )
 208                                                         .text( currentDay.format( 'D' ) )
 209                                                         .data( 'date', currentDay.date() )
 210                                                         .data( 'month', currentDay.month() )
 211                                                         .data( 'year', currentDay.year() )
 212                                         );
 213                                         currentDay.add( 1, 'day' );
 214                                 }
 215                                 break;
 216
 217                         case 'year':
 218                                 this.labelButton.setLabel( this.moment.format( 'YYYY' ) );
 219                                 this.upButton.toggle( true );
 220
 221                                 currentMonth = moment( this.moment ).startOf( 'year' );
 222                                 for ( i = 0; i < 12; i++ ) {
 223                                         items.push(
 224                                                 $( '<div>' )
 225                                                         .addClass( 'mw-widget-calendarWidget-item mw-widget-calendarWidget-month' )
 226                                                         .toggleClass( 'mw-widget-calendarWidget-item-selected', currentMonth.isSame( selected, 'month' ) )
 227                                                         .text( currentMonth.format( 'MMMM' ) )
 228                                                         .data( 'month', currentMonth.month() )
 229                                         );
 230                                         currentMonth.add( 1, 'month' );
 231                                 }
 232                                 // Shuffle the array to display months in columns rather than rows:
 233                                 // | Jan | Jul |
 234                                 // | Feb | Aug |
 235                                 // | Mar | Sep |
 236                                 // | Apr | Oct |
 237                                 // | May | Nov |
 238                                 // | Jun | Dec |
 239                                 items = [
 240                                         items[ 0 ], items[ 6 ],
 241                                         items[ 1 ], items[ 7 ],
 242                                         items[ 2 ], items[ 8 ],
 243                                         items[ 3 ], items[ 9 ],
 244                                         items[ 4 ], items[ 10 ],
 245                                         items[ 5 ], items[ 11 ]
 246                                 ];
 247                                 break;
 248
 249                         case 'duodecade':
 250                                 this.labelButton.setLabel( null );
 251                                 this.upButton.toggle( false );
 252
 253                                 currentYear = moment( { year: Math.floor( this.moment.year() / 20 ) * 20 } );
 254                                 for ( i = 0; i < 20; i++ ) {
 255                                         items.push(
 256                                                 $( '<div>' )
 257                                                         .addClass( 'mw-widget-calendarWidget-item mw-widget-calendarWidget-year' )
 258                                                         .toggleClass( 'mw-widget-calendarWidget-item-selected', currentYear.isSame( selected, 'year' ) )
 259                                                         .text( currentYear.format( 'YYYY' ) )
 260                                                         .data( 'year', currentYear.year() )
 261                                         );
 262                                         currentYear.add( 1, 'year' );
 263                                 }
 264                                 break;
 265                 }
 266
 267                 this.$body.append.apply( this.$body, items );
 268
 269                 $bodyWrapper
 270                         .removeClass( 'mw-widget-calendarWidget-body-wrapper-fade-up' )
 271                         .removeClass( 'mw-widget-calendarWidget-body-wrapper-fade-down' )
 272                         .removeClass( 'mw-widget-calendarWidget-body-wrapper-fade-previous' )
 273                         .removeClass( 'mw-widget-calendarWidget-body-wrapper-fade-next' );
 274
 275                 needsFade = this.previousDisplayLayer !== this.displayLayer;
 276                 if ( this.displayLayer === 'month' ) {
 277                         needsFade = needsFade || !this.moment.isSame( this.previousMoment, 'month' );
 278                 } else if ( this.displayLayer === 'year' ) {
 279                         needsFade = needsFade || !this.moment.isSame( this.previousMoment, 'year' );
 280                 } else if ( this.displayLayer === 'duodecade' ) {
 281                         needsFade = needsFade || (
 282                                 Math.floor( this.moment.year() / 20 ) * 20 !==
 283                                         Math.floor( this.previousMoment.year() / 20 ) * 20
 284                         );
 285                 }
 286
 287                 if ( fade && needsFade ) {
 288                         this.$oldBody.find( '.mw-widget-calendarWidget-item-selected' )
 289                                 .removeClass( 'mw-widget-calendarWidget-item-selected' );
 290                         if ( fade === 'previous' || fade === 'up' ) {
 291                                 this.$body.insertBefore( this.$oldBody );
 292                         } else if ( fade === 'next' || fade === 'down' ) {
 293                                 this.$body.insertAfter( this.$oldBody );
 294                         }
 295                         setTimeout( function () {
 296                                 $bodyWrapper.addClass( 'mw-widget-calendarWidget-body-wrapper-fade-' + fade );
 297                         } );
 298                 } else {
 299                         this.$oldBody.replaceWith( this.$body );
 300                 }
 301
 302                 this.previousMoment = moment( this.moment );
 303                 this.previousDisplayLayer = this.displayLayer;
 304                 this.previousDate = this.date;
 305
 306                 this.$body.on( 'click', this.onBodyClick.bind( this ) );
 307         };
 308
 309         /**
 310          * Construct and display buttons to navigate the calendar.
 311          *
 312          * @private
 313          */
 314         mw.widgets.CalendarWidget.prototype.buildHeaderButtons = function () {
 315                 this.labelButton = new OO.ui.ButtonWidget( {
 316                         tabIndex: -1,
 317                         label: '',
 318                         framed: false,
 319                         classes: [ 'mw-widget-calendarWidget-labelButton' ]
 320                 } );
 321                 this.upButton = new OO.ui.ButtonWidget( {
 322                         tabIndex: -1,
 323                         framed: false,
 324                         icon: 'collapse',
 325                         classes: [ 'mw-widget-calendarWidget-upButton' ]
 326                 } );
 327                 this.prevButton = new OO.ui.ButtonWidget( {
 328                         tabIndex: -1,
 329                         framed: false,
 330                         icon: 'previous',
 331                         classes: [ 'mw-widget-calendarWidget-prevButton' ]
 332                 } );
 333                 this.nextButton = new OO.ui.ButtonWidget( {
 334                         tabIndex: -1,
 335                         framed: false,
 336                         icon: 'next',
 337                         classes: [ 'mw-widget-calendarWidget-nextButton' ]
 338                 } );
 339
 340                 this.labelButton.connect( this, { click: 'onUpButtonClick' } );
 341                 this.upButton.connect( this, { click: 'onUpButtonClick' } );
 342                 this.prevButton.connect( this, { click: 'onPrevButtonClick' } );
 343                 this.nextButton.connect( this, { click: 'onNextButtonClick' } );
 344
 345                 this.$header.append(
 346                         this.prevButton.$element,
 347                         this.nextButton.$element,
 348                         this.upButton.$element,
 349                         this.labelButton.$element
 350                 );
 351         };
 352
 353         /**
 354          * Handle click events on the "up" button, switching to less precise view.
 355          *
 356          * @private
 357          */
 358         mw.widgets.CalendarWidget.prototype.onUpButtonClick = function () {
 359                 var
 360                         layers = this.getDisplayLayers(),
 361                         currentLayer = layers.indexOf( this.displayLayer );
 362                 if ( currentLayer !== layers.length - 1 ) {
 363                         // One layer up
 364                         this.displayLayer = layers[ currentLayer + 1 ];
 365                         this.updateUI( 'up' );
 366                 } else {
 367                         this.updateUI();
 368                 }
 369         };
 370
 371         /**
 372          * Handle click events on the "previous" button, switching to previous pane.
 373          *
 374          * @private
 375          */
 376         mw.widgets.CalendarWidget.prototype.onPrevButtonClick = function () {
 377                 switch ( this.displayLayer ) {
 378                         case 'month':
 379                                 this.moment.subtract( 1, 'month' );
 380                                 break;
 381                         case 'year':
 382                                 this.moment.subtract( 1, 'year' );
 383                                 break;
 384                         case 'duodecade':
 385                                 this.moment.subtract( 20, 'years' );
 386                                 break;
 387                 }
 388                 this.updateUI( 'previous' );
 389         };
 390
 391         /**
 392          * Handle click events on the "next" button, switching to next pane.
 393          *
 394          * @private
 395          */
 396         mw.widgets.CalendarWidget.prototype.onNextButtonClick = function () {
 397                 switch ( this.displayLayer ) {
 398                         case 'month':
 399                                 this.moment.add( 1, 'month' );
 400                                 break;
 401                         case 'year':
 402                                 this.moment.add( 1, 'year' );
 403                                 break;
 404                         case 'duodecade':
 405                                 this.moment.add( 20, 'years' );
 406                                 break;
 407                 }
 408                 this.updateUI( 'next' );
 409         };
 410
 411         /**
 412          * Handle click events anywhere in the body of the widget, which contains the matrix of days,
 413          * months or years to choose. Maybe change the pane or switch to more precise view, depending on
 414          * what gets clicked.
 415          *
 416          * @private
 417          * @param {jQuery.Event} e Click event
 418          */
 419         mw.widgets.CalendarWidget.prototype.onBodyClick = function ( e ) {
 420                 var
 421                         $target = $( e.target ),
 422                         layers = this.getDisplayLayers(),
 423                         currentLayer = layers.indexOf( this.displayLayer );
 424                 if ( $target.data( 'year' ) !== undefined ) {
 425                         this.moment.year( $target.data( 'year' ) );
 426                 }
 427                 if ( $target.data( 'month' ) !== undefined ) {
 428                         this.moment.month( $target.data( 'month' ) );
 429                 }
 430                 if ( $target.data( 'date' ) !== undefined ) {
 431                         this.moment.date( $target.data( 'date' ) );
 432                 }
 433                 if ( currentLayer === 0 ) {
 434                         this.setDateFromMoment();
 435                         this.updateUI( 'auto' );
 436                 } else {
 437                         // One layer down
 438                         this.displayLayer = layers[ currentLayer - 1 ];
 439                         this.updateUI( 'down' );
 440                 }
 441         };
 442
 443         /**
 444          * Set the date.
 445          *
 446          * @param {string|null} [date=null] Day or month date, in the format 'YYYY-MM-DD' or 'YYYY-MM'.
 447          *     When null, the calendar will show today's date, but not select it. When invalid, the date
 448          *     is not changed.
 449          */
 450         mw.widgets.CalendarWidget.prototype.setDate = function ( date ) {
 451                 var mom = date !== null ? moment( date, this.getDateFormat() ) : moment();
 452                 if ( mom.isValid() ) {
 453                         this.moment = mom;
 454                         if ( date !== null ) {
 455                                 this.setDateFromMoment();
 456                         } else if ( this.date !== null ) {
 457                                 this.date = null;
 458                                 this.emit( 'change', this.date );
 459                         }
 460                         this.displayLayer = this.getDisplayLayers()[ 0 ];
 461                         this.updateUI();
 462                 }
 463         };
 464
 465         /**
 466          * Reset the user interface of this widget to reflect selected date.
 467          */
 468         mw.widgets.CalendarWidget.prototype.resetUI = function () {
 469                 this.moment = this.getDate() !== null ? moment( this.getDate(), this.getDateFormat() ) : moment();
 470                 this.displayLayer = this.getDisplayLayers()[ 0 ];
 471                 this.updateUI();
 472         };
 473
 474         /**
 475          * Set the date from moment object.
 476          *
 477          * @private
 478          */
 479         mw.widgets.CalendarWidget.prototype.setDateFromMoment = function () {
 480                 // Switch to English locale to avoid number formatting. We want the internal value to be
 481                 // '2015-07-24' and not '٢٠١٥-٠٧-٢٤' even if the UI language is Arabic.
 482                 var newDate = moment( this.moment ).locale( 'en' ).format( this.getDateFormat() );
 483                 if ( this.date !== newDate ) {
 484                         this.date = newDate;
 485                         this.emit( 'change', this.date );
 486                 }
 487         };
 488
 489         /**
 490          * Get current date, in the format 'YYYY-MM-DD' or 'YYYY-MM', depending on precision. Digits will
 491          * not be localised.
 492          *
 493          * @return {string|null} Date string
 494          */
 495         mw.widgets.CalendarWidget.prototype.getDate = function () {
 496                 return this.date;
 497         };
 498
 499         /**
 500          * Handle focus events.
 501          *
 502          * @private
 503          */
 504         mw.widgets.CalendarWidget.prototype.onFocus = function () {
 505                 this.displayLayer = this.getDisplayLayers()[ 0 ];
 506                 this.updateUI( 'down' );
 507         };
 508
 509         /**
 510          * Handle mouse click events.
 511          *
 512          * @private
 513          * @param {jQuery.Event} e Mouse click event
 514          * @return {boolean} False to cancel the default event
 515          */
 516         mw.widgets.CalendarWidget.prototype.onClick = function ( e ) {
 517                 if ( !this.isDisabled() && e.which === 1 ) {
 518                         // Prevent unintended focussing
 519                         return false;
 520                 }
 521         };
 522
 523         /**
 524          * Handle key down events.
 525          *
 526          * @private
 527          * @param {jQuery.Event} e Key down event
 528          * @return {boolean} False to cancel the default event
 529          */
 530         mw.widgets.CalendarWidget.prototype.onKeyDown = function ( e ) {
 531                 var
 532                         dir = OO.ui.Element.static.getDir( this.$element ),
 533                         nextDirectionKey = dir === 'ltr' ? OO.ui.Keys.RIGHT : OO.ui.Keys.LEFT,
 534                         prevDirectionKey = dir === 'ltr' ? OO.ui.Keys.LEFT : OO.ui.Keys.RIGHT,
 535                         changed = true;
 536
 537                 if ( !this.isDisabled() ) {
 538                         switch ( e.which ) {
 539                                 case prevDirectionKey:
 540                                         this.moment.subtract( 1, this.precision === 'month' ? 'month' : 'day' );
 541                                         break;
 542                                 case nextDirectionKey:
 543                                         this.moment.add( 1, this.precision === 'month' ? 'month' : 'day' );
 544                                         break;
 545                                 case OO.ui.Keys.UP:
 546                                         this.moment.subtract( 1, this.precision === 'month' ? 'month' : 'week' );
 547                                         break;
 548                                 case OO.ui.Keys.DOWN:
 549                                         this.moment.add( 1, this.precision === 'month' ? 'month' : 'week' );
 550                                         break;
 551                                 case OO.ui.Keys.PAGEUP:
 552                                         this.moment.subtract( 1, this.precision === 'month' ? 'year' : 'month' );
 553                                         break;
 554                                 case OO.ui.Keys.PAGEDOWN:
 555                                         this.moment.add( 1, this.precision === 'month' ? 'year' : 'month' );
 556                                         break;
 557                                 default:
 558                                         changed = false;
 559                                         break;
 560                         }
 561
 562                         if ( changed ) {
 563                                 this.displayLayer = this.getDisplayLayers()[ 0 ];
 564                                 this.setDateFromMoment();
 565                                 this.updateUI( 'auto' );
 566                                 return false;
 567                         }
 568                 }
 569         };
 570
 571         /**
 572          * @inheritdoc
 573          */
 574         mw.widgets.CalendarWidget.prototype.toggle = function ( visible ) {
 575                 if ( this.lazyInitOnToggle && visible ) {
 576                         this.lazyInitOnToggle = false;
 577                         this.buildHeaderButtons();
 578                         this.updateUI();
 579                 }
 580
 581                 // Parent method
 582                 mw.widgets.CalendarWidget.parent.prototype.toggle.call( this, visible );
 583
 584                 if ( this.$floatableContainer ) {
 585                         this.togglePositioning( this.isVisible() );
 586                 }
 587
 588                 return this;
 589         };
 590
 591 }( jQuery, mediaWiki ) );