jquery.ui.tabs.js

/*!
 * jQuery UI Tabs @VERSION
 * http://jqueryui.com
 *
 * Copyright 2012 jQuery Foundation and other contributors
 * Released under the MIT license.
 * http://jquery.org/license
 *
 * http://api.jqueryui.com/tabs/
 *
 * Depends:
 *	jquery.ui.core.js
 *	jquery.ui.widget.js
 */
(function( $, undefined ) {

var tabId = 0,
	rhash = /#.*$/;

function getNextTabId() {
	return ++tabId;
}

function isLocal( anchor ) {
	return anchor.hash.length > 1 &&
		anchor.href.replace( rhash, "" ) === location.href.replace( rhash, "" );
}

$.widget( "ui.tabs", {
	version: "@VERSION",
	delay: 300,
	options: {
		active: null,
		collapsible: false,
		event: "click",
		heightStyle: "content",
		hide: null,
		show: null,

		// callbacks
		activate: null,
		beforeActivate: null,
		beforeLoad: null,
		load: null
	},

	_create: function() {
		var that = this,
			options = this.options,
			active = options.active,
			locationHash = location.hash.substring( 1 );

		this.running = false;

		this.element
			.addClass( "ui-tabs ui-widget ui-widget-content ui-corner-all" )
			.toggleClass( "ui-tabs-collapsible", options.collapsible )
			// Prevent users from focusing disabled tabs via click
			.delegate( ".ui-tabs-nav > li", "mousedown" + this.eventNamespace, function( event ) {
				if ( $( this ).is( ".ui-state-disabled" ) ) {
					event.preventDefault();
				}
			})
			// support: IE <9
			// Preventing the default action in mousedown doesn't prevent IE
			// from focusing the element, so if the anchor gets focused, blur.
			// We don't have to worry about focusing the previously focused
			// element since clicking on a non-focusable element should focus
			// the body anyway.
			.delegate( ".ui-tabs-anchor", "focus" + this.eventNamespace, function() {
				if ( $( this ).closest( "li" ).is( ".ui-state-disabled" ) ) {
					this.blur();
				}
			});

		this._processTabs();

		if ( active === null ) {
			// check the fragment identifier in the URL
			if ( locationHash ) {
				this.tabs.each(function( i, tab ) {
					if ( $( tab ).attr( "aria-controls" ) === locationHash ) {
						active = i;
						return false;
					}
				});
			}

			// check for a tab marked active via a class
			if ( active === null ) {
				active = this.tabs.index( this.tabs.filter( ".ui-tabs-active" ) );
			}

			// no active tab, set to false
			if ( active === null || active === -1 ) {
				active = this.tabs.length ? 0 : false;
			}
		}

		// handle numbers: negative, out of range
		if ( active !== false ) {
			active = this.tabs.index( this.tabs.eq( active ) );
			if ( active === -1 ) {
				active = options.collapsible ? false : 0;
			}
		}
		options.active = active;

		// don't allow collapsible: false and active: false
		if ( !options.collapsible && options.active === false && this.anchors.length ) {
			options.active = 0;
		}

		// Take disabling tabs via class attribute from HTML
		// into account and update option properly.
		if ( $.isArray( options.disabled ) ) {
			options.disabled = $.unique( options.disabled.concat(
				$.map( this.tabs.filter( ".ui-state-disabled" ), function( li ) {
					return that.tabs.index( li );
				})
			) ).sort();
		}

		// check for length avoids error when initializing empty list
		if ( this.options.active !== false && this.anchors.length ) {
			this.active = this._findActive( this.options.active );
		} else {
			this.active = $();
		}

		this._refresh();

		if ( this.active.length ) {
			this.load( options.active );
		}
	},

	_getCreateEventData: function() {
		return {
			tab: this.active,
			panel: !this.active.length ? $() : this._getPanelForTab( this.active )
		};
	},

	_tabKeydown: function( event ) {
		var focusedTab = $( this.document[0].activeElement ).closest( "li" ),
			selectedIndex = this.tabs.index( focusedTab ),
			goingForward = true;

		if ( this._handlePageNav( event ) ) {
			return;
		}

		switch ( event.keyCode ) {
			case $.ui.keyCode.RIGHT:
			case $.ui.keyCode.DOWN:
				selectedIndex++;
				break;
			case $.ui.keyCode.UP:
			case $.ui.keyCode.LEFT:
				goingForward = false;
				selectedIndex--;
				break;
			case $.ui.keyCode.END:
				selectedIndex = this.anchors.length - 1;
				break;
			case $.ui.keyCode.HOME:
				selectedIndex = 0;
				break;
			case $.ui.keyCode.SPACE:
				// Activate only, no collapsing
				event.preventDefault();
				clearTimeout( this.activating );
				this._activate( selectedIndex );
				return;
			case $.ui.keyCode.ENTER:
				// Toggle (cancel delayed activation, allow collapsing)
				event.preventDefault();
				clearTimeout( this.activating );
				// Determine if we should collapse or activate
				this._activate( selectedIndex === this.options.active ? false : selectedIndex );
				return;
			default:
				return;
		}

		// Focus the appropriate tab, based on which key was pressed
		event.preventDefault();
		clearTimeout( this.activating );
		selectedIndex = this._focusNextTab( selectedIndex, goingForward );

		// Navigating with control key will prevent automatic activation
		if ( !event.ctrlKey ) {
			// Update aria-selected immediately so that AT think the tab is already selected.
			// Otherwise AT may confuse the user by stating that they need to activate the tab,
			// but the tab will already be activated by the time the announcement finishes.
			focusedTab.attr( "aria-selected", "false" );
			this.tabs.eq( selectedIndex ).attr( "aria-selected", "true" );

			this.activating = this._delay(function() {
				this.option( "active", selectedIndex );
			}, this.delay );
		}
	},

	_panelKeydown: function( event ) {
		if ( this._handlePageNav( event ) ) {
			return;
		}

		// Ctrl+up moves focus to the current tab
		if ( event.ctrlKey && event.keyCode === $.ui.keyCode.UP ) {
			event.preventDefault();
			this.active.focus();
		}
	},

	// Alt+page up/down moves focus to the previous/next tab (and activates)
	_handlePageNav: function( event ) {
		if ( event.altKey && event.keyCode === $.ui.keyCode.PAGE_UP ) {
			this._activate( this._focusNextTab( this.options.active - 1, false ) );
			return true;
		}
		if ( event.altKey && event.keyCode === $.ui.keyCode.PAGE_DOWN ) {
			this._activate( this._focusNextTab( this.options.active + 1, true ) );
			return true;
		}
	},

	_findNextTab: function( index, goingForward ) {
		var lastTabIndex = this.tabs.length - 1;

		function constrain() {
			if ( index > lastTabIndex ) {
				index = 0;
			}
			if ( index < 0 ) {
				index = lastTabIndex;
			}
			return index;
		}

		while ( $.inArray( constrain(), this.options.disabled ) !== -1 ) {
			index = goingForward ? index + 1 : index - 1;
		}

		return index;
	},

	_focusNextTab: function( index, goingForward ) {
		index = this._findNextTab( index, goingForward );
		this.tabs.eq( index ).focus();
		return index;
	},

	_setOption: function( key, value ) {
		if ( key === "active" ) {
			// _activate() will handle invalid values and update this.options
			this._activate( value );
			return;
		}

		if ( key === "disabled" ) {
			// don't use the widget factory's disabled handling
			this._setupDisabled( value );
			return;
		}

		this._super( key, value);

		if ( key === "collapsible" ) {
			this.element.toggleClass( "ui-tabs-collapsible", value );
			// Setting collapsible: false while collapsed; open first panel
			if ( !value && this.options.active === false ) {
				this._activate( 0 );
			}
		}

		if ( key === "event" ) {
			this._setupEvents( value );
		}

		if ( key === "heightStyle" ) {
			this._setupHeightStyle( value );
		}
	},

	_tabId: function( tab ) {
		return tab.attr( "aria-controls" ) || "ui-tabs-" + getNextTabId();
	},

	_sanitizeSelector: function( hash ) {
		return hash ? hash.replace( /[!"$%&'()*+,.\/:;<=>?@\[\]\^`{|}~]/g, "\\$&" ) : "";
	},

	refresh: function() {
		var options = this.options,
			lis = this.tablist.children( ":has(a[href])" );

		// get disabled tabs from class attribute from HTML
		// this will get converted to a boolean if needed in _refresh()
		options.disabled = $.map( lis.filter( ".ui-state-disabled" ), function( tab ) {
			return lis.index( tab );
		});

		this._processTabs();

		// was collapsed or no tabs
		if ( options.active === false || !this.anchors.length ) {
			options.active = false;
			this.active = $();
		// was active, but active tab is gone
		} else if ( this.active.length && !$.contains( this.tablist[ 0 ], this.active[ 0 ] ) ) {
			// all remaining tabs are disabled
			if ( this.tabs.length === options.disabled.length ) {
				options.active = false;
				this.active = $();
			// activate previous tab
			} else {
				this._activate( this._findNextTab( Math.max( 0, options.active - 1 ), false ) );
			}
		// was active, active tab still exists
		} else {
			// make sure active index is correct
			options.active = this.tabs.index( this.active );
		}

		this._refresh();
	},

	_refresh: function() {
		this._setupDisabled( this.options.disabled );
		this._setupEvents( this.options.event );
		this._setupHeightStyle( this.options.heightStyle );

		this.tabs.not( this.active ).attr({
			"aria-selected": "false",
			tabIndex: -1
		});
		this.panels.not( this._getPanelForTab( this.active ) )
			.hide()
			.attr({
				"aria-expanded": "false",
				"aria-hidden": "true"
			});

		// Make sure one tab is in the tab order
		if ( !this.active.length ) {
			this.tabs.eq( 0 ).attr( "tabIndex", 0 );
		} else {
			this.active
				.addClass( "ui-tabs-active ui-state-active" )
				.attr({
					"aria-selected": "true",
					tabIndex: 0
				});
			this._getPanelForTab( this.active )
				.show()
				.attr({
					"aria-expanded": "true",
					"aria-hidden": "false"
				});
		}
	},

	_processTabs: function() {
		var that = this;

		this.tablist = this._getList()
			.addClass( "ui-tabs-nav ui-helper-reset ui-helper-clearfix ui-widget-header ui-corner-all" )
			.attr( "role", "tablist" );

		this.tabs = this.tablist.find( "> li:has(a[href])" )
			.addClass( "ui-state-default ui-corner-top" )
			.attr({
				role: "tab",
				tabIndex: -1
			});

		this.anchors = this.tabs.map(function() {
				return $( "a", this )[ 0 ];
			})
			.addClass( "ui-tabs-anchor" )
			.attr({
				role: "presentation",
				tabIndex: -1
			});

		this.panels = $();

		this.anchors.each(function( i, anchor ) {
			var selector, panel, panelId,
				anchorId = $( anchor ).uniqueId().attr( "id" ),
				tab = $( anchor ).closest( "li" ),
				originalAriaControls = tab.attr( "aria-controls" );

			// inline tab
			if ( isLocal( anchor ) ) {
				selector = anchor.hash;
				panel = that.element.find( that._sanitizeSelector( selector ) );
			// remote tab
			} else {
				panelId = that._tabId( tab );
				selector = "#" + panelId;
				panel = that.element.find( selector );
				if ( !panel.length ) {
					panel = that._createPanel( panelId );
					panel.insertAfter( that.panels[ i - 1 ] || that.tablist );
				}
				panel.attr( "aria-live", "polite" );
			}

			if ( panel.length) {
				that.panels = that.panels.add( panel );
			}
			if ( originalAriaControls ) {
				tab.data( "ui-tabs-aria-controls", originalAriaControls );
			}
			tab.attr({
				"aria-controls": selector.substring( 1 ),
				"aria-labelledby": anchorId
			});
			panel.attr( "aria-labelledby", anchorId );
		});

		this.panels
			.addClass( "ui-tabs-panel ui-widget-content ui-corner-bottom" )
			.attr( "role", "tabpanel" );
	},

	// allow overriding how to find the list for rare usage scenarios (#7715)
	_getList: function() {
		return this.element.find( "ol,ul" ).eq( 0 );
	},

	_createPanel: function( id ) {
		return $( "<div>" )
			.attr( "id", id )
			.addClass( "ui-tabs-panel ui-widget-content ui-corner-bottom" )
			.data( "ui-tabs-destroy", true );
	},

	_setupDisabled: function( disabled ) {
		if ( $.isArray( disabled ) ) {
			if ( !disabled.length ) {
				disabled = false;
			} else if ( disabled.length === this.anchors.length ) {
				disabled = true;
			}
		}

		// disable tabs
		for ( var i = 0, li; ( li = this.tabs[ i ] ); i++ ) {
			if ( disabled === true || $.inArray( i, disabled ) !== -1 ) {
				$( li )
					.addClass( "ui-state-disabled" )
					.attr( "aria-disabled", "true" );
			} else {
				$( li )
					.removeClass( "ui-state-disabled" )
					.removeAttr( "aria-disabled" );
			}
		}

		this.options.disabled = disabled;
	},

	_setupEvents: function( event ) {
		var events = {
			click: function( event ) {
				event.preventDefault();
			}
		};
		if ( event ) {
			$.each( event.split(" "), function( index, eventName ) {
				events[ eventName ] = "_eventHandler";
			});
		}

		this._off( this.anchors.add( this.tabs ).add( this.panels ) );
		this._on( this.anchors, events );
		this._on( this.tabs, { keydown: "_tabKeydown" } );
		this._on( this.panels, { keydown: "_panelKeydown" } );

		this._focusable( this.tabs );
		this._hoverable( this.tabs );
	},

	_setupHeightStyle: function( heightStyle ) {
		var maxHeight, overflow,
			parent = this.element.parent();

		if ( heightStyle === "fill" ) {
			// IE 6 treats height like minHeight, so we need to turn off overflow
			// in order to get a reliable height
			// we use the minHeight support test because we assume that only
			// browsers that don't support minHeight will treat height as minHeight
			if ( !$.support.minHeight ) {
				overflow = parent.css( "overflow" );
				parent.css( "overflow", "hidden");
			}
			maxHeight = parent.height();
			this.element.siblings( ":visible" ).each(function() {
				var elem = $( this ),
					position = elem.css( "position" );

				if ( position === "absolute" || position === "fixed" ) {
					return;
				}
				maxHeight -= elem.outerHeight( true );
			});
			if ( overflow ) {
				parent.css( "overflow", overflow );
			}

			this.element.children().not( this.panels ).each(function() {
				maxHeight -= $( this ).outerHeight( true );
			});

			this.panels.each(function() {
				$( this ).height( Math.max( 0, maxHeight -
					$( this ).innerHeight() + $( this ).height() ) );
			})
			.css( "overflow", "auto" );
		} else if ( heightStyle === "auto" ) {
			maxHeight = 0;
			this.panels.each(function() {
				maxHeight = Math.max( maxHeight, $( this ).height( "" ).height() );
			}).height( maxHeight );
		}
	},

	_eventHandler: function( event ) {
		var options = this.options,
			active = this.active,
			anchor = $( event.currentTarget ),
			tab = anchor.closest( "li" ),
			clickedIsActive = tab[ 0 ] === active[ 0 ],
			collapsing = clickedIsActive && options.collapsible,
			toShow = collapsing ? $() : this._getPanelForTab( tab ),
			toHide = !active.length ? $() : this._getPanelForTab( active ),
			eventData = {
				oldTab: active,
				oldPanel: toHide,
				newTab: collapsing ? $() : tab,
				newPanel: toShow
			};

		event.preventDefault();

		if ( tab.hasClass( "ui-state-disabled" ) ||
				// tab is already loading
				tab.hasClass( "ui-tabs-loading" ) ||
				// can't switch durning an animation
				this.running ||
				// click on active header, but not collapsible
				( clickedIsActive && !options.collapsible ) ||
				// allow canceling activation
				( this._trigger( "beforeActivate", event, eventData ) === false ) ) {
			return;
		}

		options.active = collapsing ? false : this.tabs.index( tab );

		this.active = clickedIsActive ? $() : tab;
		if ( this.xhr ) {
			this.xhr.abort();
		}

		if ( !toHide.length && !toShow.length ) {
			$.error( "jQuery UI Tabs: Mismatching fragment identifier." );
		}

		if ( toShow.length ) {
			this.load( this.tabs.index( tab ), event );
		}
		this._toggle( event, eventData );
	},

	// handles show/hide for selecting tabs
	_toggle: function( event, eventData ) {
		var that = this,
			toShow = eventData.newPanel,
			toHide = eventData.oldPanel;

		this.running = true;

		function complete() {
			that.running = false;
			that._trigger( "activate", event, eventData );
		}

		function show() {
			eventData.newTab.closest( "li" ).addClass( "ui-tabs-active ui-state-active" );

			if ( toShow.length && that.options.show ) {
				that._show( toShow, that.options.show, complete );
			} else {
				toShow.show();
				complete();
			}
		}

		// start out by hiding, then showing, then completing
		if ( toHide.length && this.options.hide ) {
			this._hide( toHide, this.options.hide, function() {
				eventData.oldTab.closest( "li" ).removeClass( "ui-tabs-active ui-state-active" );
				show();
			});
		} else {
			eventData.oldTab.closest( "li" ).removeClass( "ui-tabs-active ui-state-active" );
			toHide.hide();
			show();
		}

		toHide.attr({
			"aria-expanded": "false",
			"aria-hidden": "true"
		});
		eventData.oldTab.attr( "aria-selected", "false" );
		// If we're switching tabs, remove the old tab from the tab order.
		// If we're opening from collapsed state, remove the previous tab from the tab order.
		// If we're collapsing, then keep the collapsing tab in the tab order.
		if ( toShow.length && toHide.length ) {
			eventData.oldTab.attr( "tabIndex", -1 );
		} else if ( toShow.length ) {
			this.tabs.filter(function() {
				return $( this ).attr( "tabIndex" ) === 0;
			})
			.attr( "tabIndex", -1 );
		}

		toShow.attr({
			"aria-expanded": "true",
			"aria-hidden": "false"
		});
		eventData.newTab.attr({
			"aria-selected": "true",
			tabIndex: 0
		});
	},

	_activate: function( index ) {
		var anchor,
			active = this._findActive( index );

		// trying to activate the already active panel
		if ( active[ 0 ] === this.active[ 0 ] ) {
			return;
		}

		// trying to collapse, simulate a click on the current active header
		if ( !active.length ) {
			active = this.active;
		}

		anchor = active.find( ".ui-tabs-anchor" )[ 0 ];
		this._eventHandler({
			target: anchor,
			currentTarget: anchor,
			preventDefault: $.noop
		});
	},

	_findActive: function( index ) {
		return index === false ? $() : this.tabs.eq( index );
	},

	_getIndex: function( index ) {
		// meta-function to give users option to provide a href string instead of a numerical index.
		if ( typeof index === "string" ) {
			index = this.anchors.index( this.anchors.filter( "[href$='" + index + "']" ) );
		}

		return index;
	},

	_destroy: function() {
		if ( this.xhr ) {
			this.xhr.abort();
		}

		this.element.removeClass( "ui-tabs ui-widget ui-widget-content ui-corner-all ui-tabs-collapsible" );

		this.tablist
			.removeClass( "ui-tabs-nav ui-helper-reset ui-helper-clearfix ui-widget-header ui-corner-all" )
			.removeAttr( "role" );

		this.anchors
			.removeClass( "ui-tabs-anchor" )
			.removeAttr( "role" )
			.removeAttr( "tabIndex" )
			.removeData( "href.tabs" )
			.removeData( "load.tabs" )
			.removeUniqueId();

		this.tabs.add( this.panels ).each(function() {
			if ( $.data( this, "ui-tabs-destroy" ) ) {
				$( this ).remove();
			} else {
				$( this )
					.removeClass( "ui-state-default ui-state-active ui-state-disabled " +
						"ui-corner-top ui-corner-bottom ui-widget-content ui-tabs-active ui-tabs-panel" )
					.removeAttr( "tabIndex" )
					.removeAttr( "aria-live" )
					.removeAttr( "aria-busy" )
					.removeAttr( "aria-selected" )
					.removeAttr( "aria-labelledby" )
					.removeAttr( "aria-hidden" )
					.removeAttr( "aria-expanded" )
					.removeAttr( "role" );
			}
		});

		this.tabs.each(function() {
			var li = $( this ),
				prev = li.data( "ui-tabs-aria-controls" );
			if ( prev ) {
				li.attr( "aria-controls", prev );
			} else {
				li.removeAttr( "aria-controls" );
			}
		});

		if ( this.options.heightStyle !== "content" ) {
			this.panels.css( "height", "" );
		}
	},

	enable: function( index ) {
		var disabled = this.options.disabled;
		if ( disabled === false ) {
			return;
		}

		if ( index === undefined ) {
			disabled = false;
		} else {
			index = this._getIndex( index );
			if ( $.isArray( disabled ) ) {
				disabled = $.map( disabled, function( num ) {
					return num !== index ? num : null;
				});
			} else {
				disabled = $.map( this.tabs, function( li, num ) {
					return num !== index ? num : null;
				});
			}
		}
		this._setupDisabled( disabled );
	},

	disable: function( index ) {
		var disabled = this.options.disabled;
		if ( disabled === true ) {
			return;
		}

		if ( index === undefined ) {
			disabled = true;
		} else {
			index = this._getIndex( index );
			if ( $.inArray( index, disabled ) !== -1 ) {
				return;
			}
			if ( $.isArray( disabled ) ) {
				disabled = $.merge( [ index ], disabled ).sort();
			} else {
				disabled = [ index ];
			}
		}
		this._setupDisabled( disabled );
	},

	load: function( index, event ) {
		index = this._getIndex( index );
		var that = this,
			tab = this.tabs.eq( index ),
			anchor = tab.find( ".ui-tabs-anchor" ),
			panel = this._getPanelForTab( tab ),
			eventData = {
				tab: tab,
				panel: panel
			};

		// not remote
		if ( isLocal( anchor[ 0 ] ) ) {
			return;
		}

		this.xhr = $.ajax( this._ajaxSettings( anchor, event, eventData ) );

		// support: jQuery <1.8
		// jQuery <1.8 returns false if the request is canceled in beforeSend,
		// but as of 1.8, $.ajax() always returns a jqXHR object.
		if ( this.xhr && this.xhr.statusText !== "canceled" ) {
			tab.addClass( "ui-tabs-loading" );
			panel.attr( "aria-busy", "true" );

			this.xhr
				.success(function( response ) {
					// support: jQuery <1.8
					// http://bugs.jquery.com/ticket/11778
					setTimeout(function() {
						panel.html( response );
						that._trigger( "load", event, eventData );
					}, 1 );
				})
				.complete(function( jqXHR, status ) {
					// support: jQuery <1.8
					// http://bugs.jquery.com/ticket/11778
					setTimeout(function() {
						if ( status === "abort" ) {
							that.panels.stop( false, true );
						}

						tab.removeClass( "ui-tabs-loading" );
						panel.removeAttr( "aria-busy" );

						if ( jqXHR === that.xhr ) {
							delete that.xhr;
						}
					}, 1 );
				});
		}
	},

	_ajaxSettings: function( anchor, event, eventData ) {
		var that = this;
		return {
			url: anchor.attr( "href" ),
			beforeSend: function( jqXHR, settings ) {
				return that._trigger( "beforeLoad", event,
					$.extend( { jqXHR : jqXHR, ajaxSettings: settings }, eventData ) );
			}
		};
	},

	_getPanelForTab: function( tab ) {
		var id = $( tab ).attr( "aria-controls" );
		return this.element.find( this._sanitizeSelector( "#" + id ) );
	}
});

// DEPRECATED
if ( $.uiBackCompat !== false ) {

	// helper method for a lot of the back compat extensions
	$.ui.tabs.prototype._ui = function( tab, panel ) {
		return {
			tab: tab,
			panel: panel,
			index: this.anchors.index( tab )
		};
	};

	// abort method
	$.widget( "ui.tabs", $.ui.tabs, {
		abort: function() {
			if ( this.xhr ) {
				this.xhr.abort();
			}
		}
	});

	// add/remove methods and events
	$.widget( "ui.tabs", $.ui.tabs, {
		options: {
			add: null,
			remove: null,
			tabTemplate: "<li><a href='#{href}'><span>#{label}</span></a></li>"
		},

		add: function( url, label, index ) {
			if ( index === undefined ) {
				index = this.anchors.length;
			}

			var doInsertAfter, panel,
				options = this.options,
				li = $( options.tabTemplate
					.replace( /#\{href\}/g, url )
					.replace( /#\{label\}/g, label ) ),
				id = !url.indexOf( "#" ) ?
					url.replace( "#", "" ) :
					this._tabId( li );

			li.addClass( "ui-state-default ui-corner-top" ).data( "ui-tabs-destroy", true );
			li.attr( "aria-controls", id );

			doInsertAfter = index >= this.tabs.length;

			// try to find an existing element before creating a new one
			panel = this.element.find( "#" + id );
			if ( !panel.length ) {
				panel = this._createPanel( id );
				if ( doInsertAfter ) {
					if ( index > 0 ) {
						panel.insertAfter( this.panels.eq( -1 ) );
					} else {
						panel.appendTo( this.element );
					}
				} else {
					panel.insertBefore( this.panels[ index ] );
				}
			}
			panel.addClass( "ui-tabs-panel ui-widget-content ui-corner-bottom" ).hide();

			if ( doInsertAfter ) {
				li.appendTo( this.tablist );
			} else {
				li.insertBefore( this.tabs[ index ] );
			}

			options.disabled = $.map( options.disabled, function( n ) {
				return n >= index ? ++n : n;
			});

			this.refresh();
			if ( this.tabs.length === 1 && options.active === false ) {
				this.option( "active", 0 );
			}

			this._trigger( "add", null, this._ui( this.anchors[ index ], this.panels[ index ] ) );
			return this;
		},

		remove: function( index ) {
			index = this._getIndex( index );
			var options = this.options,
				tab = this.tabs.eq( index ).remove(),
				panel = this._getPanelForTab( tab ).remove();

			// If selected tab was removed focus tab to the right or
			// in case the last tab was removed the tab to the left.
			// We check for more than 2 tabs, because if there are only 2,
			// then when we remove this tab, there will only be one tab left
			// so we don't need to detect which tab to activate.
			if ( tab.hasClass( "ui-tabs-active" ) && this.anchors.length > 2 ) {
				this._activate( index + ( index + 1 < this.anchors.length ? 1 : -1 ) );
			}

			options.disabled = $.map(
				$.grep( options.disabled, function( n ) {
					return n !== index;
				}),
				function( n ) {
					return n >= index ? --n : n;
				});

			this.refresh();

			this._trigger( "remove", null, this._ui( tab.find( "a" )[ 0 ], panel[ 0 ] ) );
			return this;
		}
	});

	// panel ids (idPrefix option + title attribute)
	$.widget( "ui.tabs", $.ui.tabs, {
		options: {
			idPrefix: "ui-tabs-"
		},

		_tabId: function( tab ) {
			var a = tab.is( "li" ) ? tab.find( "a[href]" ) : tab;
			a = a[0];
			return $( a ).closest( "li" ).attr( "aria-controls" ) ||
				a.title && a.title.replace( /\s/g, "_" ).replace( /[^\w\u00c0-\uFFFF\-]/g, "" ) ||
				this.options.idPrefix + getNextTabId();
		}
	});

	// _createPanel method
	$.widget( "ui.tabs", $.ui.tabs, {
		options: {
			panelTemplate: "<div></div>"
		},

		_createPanel: function( id ) {
			return $( this.options.panelTemplate )
				.attr( "id", id )
				.addClass( "ui-tabs-panel ui-widget-content ui-corner-bottom" )
				.data( "ui-tabs-destroy", true );
		}
	});

	// load event
	$.widget( "ui.tabs", $.ui.tabs, {
		_trigger: function( type, event, data ) {
			var _data = $.extend( {}, data );
			if ( type === "load" ) {
				_data.panel = _data.panel[ 0 ];
				_data.tab = _data.tab.find( ".ui-tabs-anchor" )[ 0 ];
			}
			return this._super( type, event, _data );
		}
	});
}

})( jQuery );