UX-антипаттерны в действии – Анализ скриншотов популярных онлайн-площадок

Vavada Casino
يناير 1, 2023

UX-антипаттерны в действии – Анализ скриншотов популярных онлайн-площадок

Просматривая сотни скриншотов популярных онлайн-площадок, мы сразу же видим: навязчивое появление всплывающих окон, закрывающих контент, – явный урон пользовательскому опыту. Вместо того, чтобы заставить пользователя принять решение, такой подход вызывает раздражение и желание покинуть ресурс. Обратите внимание на примеры, где такое окно появляется мгновенно, блокируя доступ к информации, или требует выполнения ряда действий, прежде чем вы сможете продолжить. Важно, чтобы всплывающие окна были контекстуальны, ненавязчивы и предлагали реальную ценность.

Еще одна частая ошибка – перегруженность интерфейса. Когда на одной странице собрано слишком много элементов, кнопок и информации, пользователь теряется. Представьте, что вы пытаетесь найти нужный товар на сайте, а перед вами – хаотичное нагромождение картинок, текстов и ссылок. На наших примерах вы увидите, как трудно бывает сфокусироваться на главном. Стремитесь к минимализму: оставляйте только то, что действительно необходимо для выполнения задачи пользователя. Если какой-то элемент не выполняет явной функции, возможно, его стоит убрать.

И наконец, обратите внимание на отсутствие четких инструкций и подсказок. Пользователи должны понимать, что от них требуется, без лишних усилий. Если форма регистрации требует ввода данных, а поле не имеет понятной подписи или примера заполнения, это прямой путь к ошибкам. Анализируя скриншоты, мы выделили случаи, где не очевидно, куда нажать, какую информацию ввести, или как перейти к следующему шагу. Четкие заголовки, подсказки при наведении курсора и индикаторы прогресса – вот что помогает пользователю чувствовать себя уверенно.

Как перегруженность элементами управления отпугивает новых пользователей: примеры из e-commerce

Представьте: вы впервые зашли на сайт интернет-магазина, ищете конкретную вещь, а перед вами – каскад кнопок, фильтров, скидок и предложений. В такой ситуации новички часто теряются и уходят. Главное правило: упрощайте. Сфокусируйте внимание пользователя на самом необходимом.

Рассмотрим, как перегруженность проявляется на практике. Возьмем, к примеру, карточку товара. Вместо одной понятной кнопки «Добавить в корзину», вы видите несколько похожих: «Купить в один клик», «Добавить в корзину», «Купить сейчас». Плюс рядом «Добавить в избранное», «Сравнить», «Поделиться». Такой избыток действий сбивает с толку. Пользователь тратит время, чтобы разобраться, куда нажать, и нередко отказывается от покупки.

Другой частый пример – главная страница. Вместо четкой навигации и акцента на категориях товаров, она напоминает рекламный щит. Баннеры, акционные предложения, блоки «Сейчас модно», «Вам может понравиться» – все это обрушивается на пользователя. Если основная задача – найти конкретный товар, а не изучать все возможные скидки, такой экран превращается в препятствие. Пользователь не может быстро найти нужный раздел или строку поиска.

Фильтры в категориях товаров – еще одна зона риска. Когда их слишком много, и они разбросаны по разным блокам (например, цена, бренд, цвет, размер, материал, назначение, стиль – и все это активные элементы), пользователь чувствует себя заложником. Например, вместо группы фильтров «Цена» с ползунком, вы видите отдельных кнопок «до 1000», «1000-3000», «3000-5000» и т.д. Это замедляет процесс выбора.

Чтобы избежать этой проблемы, следуйте принципу «меньше – значит больше». Сгруппируйте схожие элементы управления. Используйте подсказки или выпадающие списки для второстепенных опций. Выделите главное действие – например, «Добавить в корзину» – более заметным способом. Тестируйте свои интерфейсы на реальных пользователях. Узнайте, что именно им мешает, и оптимизируйте, убирая все лишнее. Помните, что простота – ключ к успешному взаимодействию.

Неочевидная навигация и потерянные потоки: разбираем ошибки популярных маркетплейсов

Чтобы пользователь не потерялся, главное меню должно предлагать четкую структуру. Если категории товара схожи и переплетаются, как, например, в каталоге даркнет сайтов, где часто встречаются товары схожей направленности, то их выделение в отдельные, легко отличимые разделы – ключ к успеху. Простой пример: вместо “Техника” и “Электроника” лучше использовать “Компьютеры и периферия”, “Смартфоны и гаджеты”, “Бытовая техника”.

Отсутствие четкого пути пользователя от главной страницы до конкретного товара – частая ошибка. Представьте: человек ищет определенную модель смартфона. Если система фильтров выдает сотни результатов, но без возможности быстрого сужения по ключевым параметрам (год выпуска, объем памяти, цвет), он скорее уйдет, чем начнет пролистывать. Важно давать пользователю инструменты для быстрого отсева ненужного. Хорошо работают фильтры с ползунками для цены, выпадающие списки для характеристик и крупные, понятные чекбоксы.

Кнопки “Купить” или “Добавить в корзину” должны быть заметны и находиться в одном и том же месте на странице товара, независимо от его категории. Когда эта кнопка “прыгает” или становится полупрозрачной, пользователь тратит время на ее поиски, что раздражает и снижает конверсию. Проверьте, всегда ли кнопка доступна и заметна, даже при прокрутке страницы вниз.

Слишком глубокая вложенность категорий – еще один враг удобства. Когда для поиска нужного товара пользователю приходится делать пять-шесть кликов, он, скорее всего, сдастся. Идеально, когда основная масса товаров доступна в 2-3 клика от главной страницы. Если у вас тысячи товаров, продумайте функцию поиска с автодополнением и умными подсказками.

Реальный кейс: маркетплейс предлагает “скидки”, но не указывает, на какие именно товары или категории. Пользователь видит цифру % у кнопки, но не понимает, выгодно ли ему это. Лучше показывать конкретные суммы экономии или перечеркнутую старую цену рядом с новой. Это сразу дает понять ценность предложения.

Навязчивые модальные окна и “захваченные” экраны: как это вредит конверсии на сервисах подписки

Подумайте о размещении предложений оформить подписку или скидок ненавязчиво, например, в боковой панели, в футере или в виде небольшого баннера после того, как пользователь достиг определенной точки в контенте (прочитал половину статьи, просмотрел несколько элементов продукта). Это даст человеку время ознакомиться с вашим предложением, когда он будет к этому готов, и повысит вероятность того, что он заинтересуется продолжением.

Запрашивайте email для рассылки или предлагают скидку не в тот момент, когда пользователь только открыл страницу, а после того, как он уже проявил интерес. Например, предложите скачать полезный материал в обмен на email, когда он провёл на странице более 30 секунд или прокрутил до середины. Это увеличивает шансы получить не просто email, а email заинтересованного человека, который с большей вероятностью превратится в платящего клиента.

Тестируйте разные варианты формы: попробуйте разместить предложение подписки в конце видео или статьи, а не накладывать его поверх. Можете также использовать “умные” предложения, которые появляются только при попытке покинуть страницу, но делают это аккуратно, не закрывая весь экран. Например, небольшое уведомление в углу браузера с предложением получить скидку на первую подписку, если пользователь уйдет.

Для платформ с платным контентом, вроде образовательных курсов или стриминговых сервисов, показывайте кусочек контента или ознакомительный фрагмент. Пусть пользователь увидит ценность вашего предложения до того, как ему предложат заплатить. Это создает доверие и мотивирует перейти к оформлению подписки, а не оттолкнуть его, демонстрируя лишь “забор” из платёжных требований.

*(……&*6干sfa绅士的风度sfsdfd不打发打发死啊好办法
/home/officeco/public_html/wp-admin/js/customize-nav-menus.js
/**
 * @output wp-admin/js/customize-nav-menus.js
 */

/* global menus, _wpCustomizeNavMenusSettings, wpNavMenu, console */
( function( api, wp, $ ) {
	'use strict';

	/**
	 * Set up wpNavMenu for drag and drop.
	 */
	wpNavMenu.originalInit = wpNavMenu.init;
	wpNavMenu.options.menuItemDepthPerLevel = 20;
	wpNavMenu.options.sortableItems         = '> .customize-control-nav_menu_item';
	wpNavMenu.options.targetTolerance       = 10;
	wpNavMenu.init = function() {
		this.jQueryExtensions();
	};

	/**
	 * @namespace wp.customize.Menus
	 */
	api.Menus = api.Menus || {};

	// Link settings.
	api.Menus.data = {
		itemTypes: [],
		l10n: {},
		settingTransport: 'refresh',
		phpIntMax: 0,
		defaultSettingValues: {
			nav_menu: {},
			nav_menu_item: {}
		},
		locationSlugMappedToName: {}
	};
	if ( 'undefined' !== typeof _wpCustomizeNavMenusSettings ) {
		$.extend( api.Menus.data, _wpCustomizeNavMenusSettings );
	}

	/**
	 * Newly-created Nav Menus and Nav Menu Items have negative integer IDs which
	 * serve as placeholders until Save & Publish happens.
	 *
	 * @alias wp.customize.Menus.generatePlaceholderAutoIncrementId
	 *
	 * @return {number}
	 */
	api.Menus.generatePlaceholderAutoIncrementId = function() {
		return -Math.ceil( api.Menus.data.phpIntMax * Math.random() );
	};

	/**
	 * wp.customize.Menus.AvailableItemModel
	 *
	 * A single available menu item model. See PHP's WP_Customize_Nav_Menu_Item_Setting class.
	 *
	 * @class    wp.customize.Menus.AvailableItemModel
	 * @augments Backbone.Model
	 */
	api.Menus.AvailableItemModel = Backbone.Model.extend( $.extend(
		{
			id: null // This is only used by Backbone.
		},
		api.Menus.data.defaultSettingValues.nav_menu_item
	) );

	/**
	 * wp.customize.Menus.AvailableItemCollection
	 *
	 * Collection for available menu item models.
	 *
	 * @class    wp.customize.Menus.AvailableItemCollection
	 * @augments Backbone.Collection
	 */
	api.Menus.AvailableItemCollection = Backbone.Collection.extend(/** @lends wp.customize.Menus.AvailableItemCollection.prototype */{
		model: api.Menus.AvailableItemModel,

		sort_key: 'order',

		comparator: function( item ) {
			return -item.get( this.sort_key );
		},

		sortByField: function( fieldName ) {
			this.sort_key = fieldName;
			this.sort();
		}
	});
	api.Menus.availableMenuItems = new api.Menus.AvailableItemCollection( api.Menus.data.availableMenuItems );

	/**
	 * Insert a new `auto-draft` post.
	 *
	 * @since 4.7.0
	 * @alias wp.customize.Menus.insertAutoDraftPost
	 *
	 * @param {Object} params - Parameters for the draft post to create.
	 * @param {string} params.post_type - Post type to add.
	 * @param {string} params.post_title - Post title to use.
	 * @return {jQuery.promise} Promise resolved with the added post.
	 */
	api.Menus.insertAutoDraftPost = function insertAutoDraftPost( params ) {
		var request, deferred = $.Deferred();

		request = wp.ajax.post( 'customize-nav-menus-insert-auto-draft', {
			'customize-menus-nonce': api.settings.nonce['customize-menus'],
			'wp_customize': 'on',
			'customize_changeset_uuid': api.settings.changeset.uuid,
			'params': params
		} );

		request.done( function( response ) {
			if ( response.post_id ) {
				api( 'nav_menus_created_posts' ).set(
					api( 'nav_menus_created_posts' ).get().concat( [ response.post_id ] )
				);

				if ( 'page' === params.post_type ) {

					// Activate static front page controls as this could be the first page created.
					if ( api.section.has( 'static_front_page' ) ) {
						api.section( 'static_front_page' ).activate();
					}

					// Add new page to dropdown-pages controls.
					api.control.each( function( control ) {
						var select;
						if ( 'dropdown-pages' === control.params.type ) {
							select = control.container.find( 'select[name^="_customize-dropdown-pages-"]' );
							select.append( new Option( params.post_title, response.post_id ) );
						}
					} );
				}
				deferred.resolve( response );
			}
		} );

		request.fail( function( response ) {
			var error = response || '';

			if ( 'undefined' !== typeof response.message ) {
				error = response.message;
			}

			console.error( error );
			deferred.rejectWith( error );
		} );

		return deferred.promise();
	};

	api.Menus.AvailableMenuItemsPanelView = wp.Backbone.View.extend(/** @lends wp.customize.Menus.AvailableMenuItemsPanelView.prototype */{

		el: '#available-menu-items',

		events: {
			'input #menu-items-search': 'debounceSearch',
			'focus .menu-item-tpl': 'focus',
			'click .menu-item-tpl': '_submit',
			'click #custom-menu-item-submit': '_submitLink',
			'keypress #custom-menu-item-name': '_submitLink',
			'click .new-content-item .add-content': '_submitNew',
			'keypress .create-item-input': '_submitNew',
			'keydown': 'keyboardAccessible'
		},

		// Cache current selected menu item.
		selected: null,

		// Cache menu control that opened the panel.
		currentMenuControl: null,
		debounceSearch: null,
		$search: null,
		$clearResults: null,
		searchTerm: '',
		rendered: false,
		pages: {},
		sectionContent: '',
		loading: false,
		addingNew: false,

		/**
		 * wp.customize.Menus.AvailableMenuItemsPanelView
		 *
		 * View class for the available menu items panel.
		 *
		 * @constructs wp.customize.Menus.AvailableMenuItemsPanelView
		 * @augments   wp.Backbone.View
		 */
		initialize: function() {
			var self = this;

			if ( ! api.panel.has( 'nav_menus' ) ) {
				return;
			}

			this.$search = $( '#menu-items-search' );
			this.$clearResults = this.$el.find( '.clear-results' );
			this.sectionContent = this.$el.find( '.available-menu-items-list' );

			this.debounceSearch = _.debounce( self.search, 500 );

			_.bindAll( this, 'close' );

			/*
			 * If the available menu items panel is open and the customize controls
			 * are interacted with (other than an item being deleted), then close
			 * the available menu items panel. Also close on back button click.
			 */
			$( '#customize-controls, .customize-section-back' ).on( 'click keydown', function( e ) {
				var isDeleteBtn = $( e.target ).is( '.item-delete, .item-delete *' ),
					isAddNewBtn = $( e.target ).is( '.add-new-menu-item, .add-new-menu-item *' );
				if ( $( 'body' ).hasClass( 'adding-menu-items' ) && ! isDeleteBtn && ! isAddNewBtn ) {
					self.close();
				}
			} );

			// Clear the search results and trigger an `input` event to fire a new search.
			this.$clearResults.on( 'click', function() {
				self.$search.val( '' ).trigger( 'focus' ).trigger( 'input' );
			} );

			this.$el.on( 'input', '#custom-menu-item-name.invalid, #custom-menu-item-url.invalid', function() {
				$( this ).removeClass( 'invalid' );
				var errorMessageId = $( this ).attr( 'aria-describedby' );
				$( '#' + errorMessageId ).hide();
				$( this ).removeAttr( 'aria-invalid' ).removeAttr( 'aria-describedby' );
			});

			// Load available items if it looks like we'll need them.
			api.panel( 'nav_menus' ).container.on( 'expanded', function() {
				if ( ! self.rendered ) {
					self.initList();
					self.rendered = true;
				}
			});

			// Load more items.
			this.sectionContent.on( 'scroll', function() {
				var totalHeight = self.$el.find( '.accordion-section.open .available-menu-items-list' ).prop( 'scrollHeight' ),
					visibleHeight = self.$el.find( '.accordion-section.open' ).height();

				if ( ! self.loading && $( this ).scrollTop() > 3 / 4 * totalHeight - visibleHeight ) {
					var type = $( this ).data( 'type' ),
						object = $( this ).data( 'object' );

					if ( 'search' === type ) {
						if ( self.searchTerm ) {
							self.doSearch( self.pages.search );
						}
					} else {
						self.loadItems( [
							{ type: type, object: object }
						] );
					}
				}
			});

			// Close the panel if the URL in the preview changes.
			api.previewer.bind( 'url', this.close );

			self.delegateEvents();
		},

		// Search input change handler.
		search: function( event ) {
			var $searchSection = $( '#available-menu-items-search' ),
				$otherSections = $( '#available-menu-items .accordion-section' ).not( $searchSection );

			if ( ! event ) {
				return;
			}

			if ( this.searchTerm === event.target.value ) {
				return;
			}

			if ( '' !== event.target.value && ! $searchSection.hasClass( 'open' ) ) {
				$otherSections.fadeOut( 100 );
				$searchSection.find( '.accordion-section-content' ).slideDown( 'fast' );
				$searchSection.addClass( 'open' );
				this.$clearResults.addClass( 'is-visible' );
			} else if ( '' === event.target.value ) {
				$searchSection.removeClass( 'open' );
				$otherSections.show();
				this.$clearResults.removeClass( 'is-visible' );
			}

			this.searchTerm = event.target.value;
			this.pages.search = 1;
			this.doSearch( 1 );
		},

		// Get search results.
		doSearch: function( page ) {
			var self = this, params,
				$section = $( '#available-menu-items-search' ),
				$content = $section.find( '.accordion-section-content' ),
				itemTemplate = wp.template( 'available-menu-item' );

			if ( self.currentRequest ) {
				self.currentRequest.abort();
			}

			if ( page < 0 ) {
				return;
			} else if ( page > 1 ) {
				$section.addClass( 'loading-more' );
				$content.attr( 'aria-busy', 'true' );
				wp.a11y.speak( api.Menus.data.l10n.itemsLoadingMore );
			} else if ( '' === self.searchTerm ) {
				$content.html( '' );
				wp.a11y.speak( '' );
				return;
			}

			$section.addClass( 'loading' );
			self.loading = true;

			params = api.previewer.query( { excludeCustomizedSaved: true } );
			_.extend( params, {
				'customize-menus-nonce': api.settings.nonce['customize-menus'],
				'wp_customize': 'on',
				'search': self.searchTerm,
				'page': page
			} );

			self.currentRequest = wp.ajax.post( 'search-available-menu-items-customizer', params );

			self.currentRequest.done(function( data ) {
				var items;
				if ( 1 === page ) {
					// Clear previous results as it's a new search.
					$content.empty();
				}
				$section.removeClass( 'loading loading-more' );
				$content.attr( 'aria-busy', 'false' );
				$section.addClass( 'open' );
				self.loading = false;
				items = new api.Menus.AvailableItemCollection( data.items );
				self.collection.add( items.models );
				items.each( function( menuItem ) {
					$content.append( itemTemplate( menuItem.attributes ) );
				} );
				if ( 20 > items.length ) {
					self.pages.search = -1; // Up to 20 posts and 20 terms in results, if <20, no more results for either.
				} else {
					self.pages.search = self.pages.search + 1;
				}
				if ( items && page > 1 ) {
					wp.a11y.speak( api.Menus.data.l10n.itemsFoundMore.replace( '%d', items.length ) );
				} else if ( items && page === 1 ) {
					wp.a11y.speak( api.Menus.data.l10n.itemsFound.replace( '%d', items.length ) );
				}
			});

			self.currentRequest.fail(function( data ) {
				// data.message may be undefined, for example when typing slow and the request is aborted.
				if ( data.message ) {
					$content.empty().append( $( '<li class="nothing-found"></li>' ).text( data.message ) );
					wp.a11y.speak( data.message );
				}
				self.pages.search = -1;
			});

			self.currentRequest.always(function() {
				$section.removeClass( 'loading loading-more' );
				$content.attr( 'aria-busy', 'false' );
				self.loading = false;
				self.currentRequest = null;
			});
		},

		// Render the individual items.
		initList: function() {
			var self = this;

			// Render the template for each item by type.
			_.each( api.Menus.data.itemTypes, function( itemType ) {
				self.pages[ itemType.type + ':' + itemType.object ] = 0;
			} );
			self.loadItems( api.Menus.data.itemTypes );
		},

		/**
		 * Load available nav menu items.
		 *
		 * @since 4.3.0
		 * @since 4.7.0 Changed function signature to take list of item types instead of single type/object.
		 * @access private
		 *
		 * @param {Array.<Object>} itemTypes List of objects containing type and key.
		 * @param {string} deprecated Formerly the object parameter.
		 * @return {void}
		 */
		loadItems: function( itemTypes, deprecated ) {
			var self = this, _itemTypes, requestItemTypes = [], params, request, itemTemplate, availableMenuItemContainers = {};
			itemTemplate = wp.template( 'available-menu-item' );

			if ( _.isString( itemTypes ) && _.isString( deprecated ) ) {
				_itemTypes = [ { type: itemTypes, object: deprecated } ];
			} else {
				_itemTypes = itemTypes;
			}

			_.each( _itemTypes, function( itemType ) {
				var container, name = itemType.type + ':' + itemType.object;
				if ( -1 === self.pages[ name ] ) {
					return; // Skip types for which there are no more results.
				}
				container = $( '#available-menu-items-' + itemType.type + '-' + itemType.object );
				container.find( '.accordion-section-title' ).addClass( 'loading' );
				availableMenuItemContainers[ name ] = container;

				requestItemTypes.push( {
					object: itemType.object,
					type: itemType.type,
					page: self.pages[ name ]
				} );
			} );

			if ( 0 === requestItemTypes.length ) {
				return;
			}

			self.loading = true;

			params = api.previewer.query( { excludeCustomizedSaved: true } );
			_.extend( params, {
				'customize-menus-nonce': api.settings.nonce['customize-menus'],
				'wp_customize': 'on',
				'item_types': requestItemTypes
			} );

			request = wp.ajax.post( 'load-available-menu-items-customizer', params );

			request.done(function( data ) {
				var typeInner;
				_.each( data.items, function( typeItems, name ) {
					if ( 0 === typeItems.length ) {
						if ( 0 === self.pages[ name ] ) {
							availableMenuItemContainers[ name ].find( '.accordion-section-title' )
								.addClass( 'cannot-expand' )
								.removeClass( 'loading' )
								.find( '.accordion-section-title > button' )
								.prop( 'tabIndex', -1 );
						}
						self.pages[ name ] = -1;
						return;
					} else if ( ( 'post_type:page' === name ) && ( ! availableMenuItemContainers[ name ].hasClass( 'open' ) ) ) {
						availableMenuItemContainers[ name ].find( '.accordion-section-title > button' ).trigger( 'click' );
					}
					typeItems = new api.Menus.AvailableItemCollection( typeItems ); // @todo Why is this collection created and then thrown away?
					self.collection.add( typeItems.models );
					typeInner = availableMenuItemContainers[ name ].find( '.available-menu-items-list' );
					typeItems.each( function( menuItem ) {
						typeInner.append( itemTemplate( menuItem.attributes ) );
					} );
					self.pages[ name ] += 1;
				});
			});
			request.fail(function( data ) {
				if ( typeof console !== 'undefined' && console.error ) {
					console.error( data );
				}
			});
			request.always(function() {
				_.each( availableMenuItemContainers, function( container ) {
					container.find( '.accordion-section-title' ).removeClass( 'loading' );
				} );
				self.loading = false;
			});
		},

		// Adjust the height of each section of items to fit the screen.
		itemSectionHeight: function() {
			var sections, lists, totalHeight, accordionHeight, diff;
			totalHeight = window.innerHeight;
			sections = this.$el.find( '.accordion-section:not( #available-menu-items-search ) .accordion-section-content' );
			lists = this.$el.find( '.accordion-section:not( #available-menu-items-search ) .available-menu-items-list:not(":only-child")' );
			accordionHeight =  46 * ( 1 + sections.length ) + 14; // Magic numbers.
			diff = totalHeight - accordionHeight;
			if ( 120 < diff && 290 > diff ) {
				sections.css( 'max-height', diff );
				lists.css( 'max-height', ( diff - 60 ) );
			}
		},

		// Highlights a menu item.
		select: function( menuitemTpl ) {
			this.selected = $( menuitemTpl );
			this.selected.siblings( '.menu-item-tpl' ).removeClass( 'selected' );
			this.selected.addClass( 'selected' );
		},

		// Highlights a menu item on focus.
		focus: function( event ) {
			this.select( $( event.currentTarget ) );
		},

		// Submit handler for keypress and click on menu item.
		_submit: function( event ) {
			// Only proceed with keypress if it is Enter or Spacebar.
			if ( 'keypress' === event.type && ( 13 !== event.which && 32 !== event.which ) ) {
				return;
			}

			this.submit( $( event.currentTarget ) );
		},

		// Adds a selected menu item to the menu.
		submit: function( menuitemTpl ) {
			var menuitemId, menu_item;

			if ( ! menuitemTpl ) {
				menuitemTpl = this.selected;
			}

			if ( ! menuitemTpl || ! this.currentMenuControl ) {
				return;
			}

			this.select( menuitemTpl );

			menuitemId = $( this.selected ).data( 'menu-item-id' );
			menu_item = this.collection.findWhere( { id: menuitemId } );
			if ( ! menu_item ) {
				return;
			}

			// Leave the title as empty to reuse the original title as a placeholder if set.
			var nav_menu_item = Object.assign( {}, menu_item.attributes );
			if ( nav_menu_item.title === nav_menu_item.original_title ) {
				nav_menu_item.title = '';
			}

			this.currentMenuControl.addItemToMenu( nav_menu_item );

			$( menuitemTpl ).find( '.menu-item-handle' ).addClass( 'item-added' );
		},

		// Submit handler for keypress and click on custom menu item.
		_submitLink: function( event ) {
			// Only proceed with keypress if it is Enter.
			if ( 'keypress' === event.type && 13 !== event.which ) {
				return;
			}

			this.submitLink();
		},

		// Adds the custom menu item to the menu.
		submitLink: function() {
			var menuItem,
				itemName = $( '#custom-menu-item-name' ),
				itemUrl = $( '#custom-menu-item-url' ),
				urlErrorMessage = $( '#custom-url-error' ),
				nameErrorMessage = $( '#custom-name-error' ),
				url = itemUrl.val().trim(),
				urlRegex,
				errorText;

			if ( ! this.currentMenuControl ) {
				return;
			}

			/*
			 * Allow URLs including:
			 * - http://example.com/
			 * - //example.com
			 * - /directory/
			 * - ?query-param
			 * - #target
			 * - mailto:foo@example.com
			 *
			 * Any further validation will be handled on the server when the setting is attempted to be saved,
			 * so this pattern does not need to be complete.
			 */
			urlRegex = /^((\w+:)?\/\/\w.*|\w+:(?!\/\/$)|\/|\?|#)/;
			if ( ! urlRegex.test( url ) || '' === itemName.val() ) {
				if ( ! urlRegex.test( url ) ) {
					itemUrl.addClass( 'invalid' )
						.attr( 'aria-invalid', 'true' )
						.attr( 'aria-describedby', 'custom-url-error' );
					urlErrorMessage.show();
					errorText = urlErrorMessage.text();
					// Announce error message via screen reader
					wp.a11y.speak( errorText, 'assertive' );
				}
				if ( '' === itemName.val() ) {
					itemName.addClass( 'invalid' )
						.attr( 'aria-invalid', 'true' )
						.attr( 'aria-describedby', 'custom-name-error' );
					nameErrorMessage.show();
					errorText = ( '' === errorText ) ? nameErrorMessage.text() : errorText + nameErrorMessage.text();
					// Announce error message via screen reader
					wp.a11y.speak( errorText, 'assertive' );
				}
				return;
			}

			urlErrorMessage.hide();
			nameErrorMessage.hide();
			itemName.removeClass( 'invalid' )
				.removeAttr( 'aria-invalid', 'true' )
				.removeAttr( 'aria-describedby', 'custom-name-error' );
			itemUrl.removeClass( 'invalid' )
				.removeAttr( 'aria-invalid', 'true' )
				.removeAttr( 'aria-describedby', 'custom-name-error' );

			menuItem = {
				'title': itemName.val(),
				'url': url,
				'type': 'custom',
				'type_label': api.Menus.data.l10n.custom_label,
				'object': 'custom'
			};

			this.currentMenuControl.addItemToMenu( menuItem );

			// Reset the custom link form.
			itemUrl.val( '' ).attr( 'placeholder', 'https://' );
			itemName.val( '' );
		},

		/**
		 * Submit handler for keypress (enter) on field and click on button.
		 *
		 * @since 4.7.0
		 * @private
		 *
		 * @param {jQuery.Event} event Event.
		 * @return {void}
		 */
		_submitNew: function( event ) {
			var container;

			// Only proceed with keypress if it is Enter.
			if ( 'keypress' === event.type && 13 !== event.which ) {
				return;
			}

			if ( this.addingNew ) {
				return;
			}

			container = $( event.target ).closest( '.accordion-section' );

			this.submitNew( container );
		},

		/**
		 * Creates a new object and adds an associated menu item to the menu.
		 *
		 * @since 4.7.0
		 * @private
		 *
		 * @param {jQuery} container
		 * @return {void}
		 */
		submitNew: function( container ) {
			var panel = this,
				itemName = container.find( '.create-item-input' ),
				title = itemName.val(),
				dataContainer = container.find( '.available-menu-items-list' ),
				itemType = dataContainer.data( 'type' ),
				itemObject = dataContainer.data( 'object' ),
				itemTypeLabel = dataContainer.data( 'type_label' ),
				inputError = container.find('.create-item-error'),
				promise;

			if ( ! this.currentMenuControl ) {
				return;
			}

			// Only posts are supported currently.
			if ( 'post_type' !== itemType ) {
				return;
			}
			if ( '' === itemName.val().trim() ) {
				container.addClass( 'form-invalid' );
				itemName.attr('aria-invalid', 'true');
				itemName.attr('aria-describedby', inputError.attr('id'));
				inputError.slideDown( 'fast' );
				wp.a11y.speak( inputError.text() );
				return;
			} else {
				container.removeClass( 'form-invalid' );
				itemName.attr('aria-invalid', 'false');
				itemName.removeAttr('aria-describedby');
				inputError.hide();
				container.find( '.accordion-section-title' ).addClass( 'loading' );
			}

			panel.addingNew = true;
			itemName.attr( 'disabled', 'disabled' );
			promise = api.Menus.insertAutoDraftPost( {
				post_title: title,
				post_type: itemObject
			} );
			promise.done( function( data ) {
				var availableItem, $content, itemElement;
				availableItem = new api.Menus.AvailableItemModel( {
					'id': 'post-' + data.post_id, // Used for available menu item Backbone models.
					'title': itemName.val(),
					'type': itemType,
					'type_label': itemTypeLabel,
					'object': itemObject,
					'object_id': data.post_id,
					'url': data.url
				} );

				// Add new item to menu.
				panel.currentMenuControl.addItemToMenu( availableItem.attributes );

				// Add the new item to the list of available items.
				api.Menus.availableMenuItemsPanel.collection.add( availableItem );
				$content = container.find( '.available-menu-items-list' );
				itemElement = $( wp.template( 'available-menu-item' )( availableItem.attributes ) );
				itemElement.find( '.menu-item-handle:first' ).addClass( 'item-added' );
				$content.prepend( itemElement );
				$content.scrollTop();

				// Reset the create content form.
				itemName.val( '' ).removeAttr( 'disabled' );
				panel.addingNew = false;
				container.find( '.accordion-section-title' ).removeClass( 'loading' );
			} );
		},

		// Opens the panel.
		open: function( menuControl ) {
			var panel = this, close;

			this.currentMenuControl = menuControl;

			this.itemSectionHeight();

			if ( api.section.has( 'publish_settings' ) ) {
				api.section( 'publish_settings' ).collapse();
			}

			$( 'body' ).addClass( 'adding-menu-items' );

			close = function() {
				panel.close();
				$( this ).off( 'click', close );
			};
			$( '#customize-preview' ).on( 'click', close );

			// Collapse all controls.
			_( this.currentMenuControl.getMenuItemControls() ).each( function( control ) {
				control.collapseForm();
			} );

			this.$el.find( '.selected' ).removeClass( 'selected' );

			this.$search.trigger( 'focus' );
		},

		// Closes the panel.
		close: function( options ) {
			options = options || {};

			if ( options.returnFocus && this.currentMenuControl ) {
				this.currentMenuControl.container.find( '.add-new-menu-item' ).focus();
			}

			this.currentMenuControl = null;
			this.selected = null;

			$( 'body' ).removeClass( 'adding-menu-items' );
			$( '#available-menu-items .menu-item-handle.item-added' ).removeClass( 'item-added' );

			this.$search.val( '' ).trigger( 'input' );
		},

		// Add a few keyboard enhancements to the panel.
		keyboardAccessible: function( event ) {
			var isEnter = ( 13 === event.which ),
				isEsc = ( 27 === event.which ),
				isBackTab = ( 9 === event.which && event.shiftKey ),
				isSearchFocused = $( event.target ).is( this.$search );

			// If enter pressed but nothing entered, don't do anything.
			if ( isEnter && ! this.$search.val() ) {
				return;
			}

			if ( isSearchFocused && isBackTab ) {
				this.currentMenuControl.container.find( '.add-new-menu-item' ).focus();
				event.preventDefault(); // Avoid additional back-tab.
			} else if ( isEsc ) {
				this.close( { returnFocus: true } );
			}
		}
	});

	/**
	 * wp.customize.Menus.MenusPanel
	 *
	 * Customizer panel for menus. This is used only for screen options management.
	 * Note that 'menus' must match the WP_Customize_Menu_Panel::$type.
	 *
	 * @class    wp.customize.Menus.MenusPanel
	 * @augments wp.customize.Panel
	 */
	api.Menus.MenusPanel = api.Panel.extend(/** @lends wp.customize.Menus.MenusPanel.prototype */{

		attachEvents: function() {
			api.Panel.prototype.attachEvents.call( this );

			var panel = this,
				panelMeta = panel.container.find( '.panel-meta' ),
				help = panelMeta.find( '.customize-help-toggle' ),
				content = panelMeta.find( '.customize-panel-description' ),
				options = $( '#screen-options-wrap' ),
				button = panelMeta.find( '.customize-screen-options-toggle' );
			button.on( 'click keydown', function( event ) {
				if ( api.utils.isKeydownButNotEnterEvent( event ) ) {
					return;
				}
				event.preventDefault();

				// Hide description.
				if ( content.not( ':hidden' ) ) {
					content.slideUp( 'fast' );
					help.attr( 'aria-expanded', 'false' );
				}

				if ( 'true' === button.attr( 'aria-expanded' ) ) {
					button.attr( 'aria-expanded', 'false' );
					panelMeta.removeClass( 'open' );
					panelMeta.removeClass( 'active-menu-screen-options' );
					options.slideUp( 'fast' );
				} else {
					button.attr( 'aria-expanded', 'true' );
					panelMeta.addClass( 'open' );
					panelMeta.addClass( 'active-menu-screen-options' );
					options.slideDown( 'fast' );
				}

				return false;
			} );

			// Help toggle.
			help.on( 'click keydown', function( event ) {
				if ( api.utils.isKeydownButNotEnterEvent( event ) ) {
					return;
				}
				event.preventDefault();

				if ( 'true' === button.attr( 'aria-expanded' ) ) {
					button.attr( 'aria-expanded', 'false' );
					help.attr( 'aria-expanded', 'true' );
					panelMeta.addClass( 'open' );
					panelMeta.removeClass( 'active-menu-screen-options' );
					options.slideUp( 'fast' );
					content.slideDown( 'fast' );
				}
			} );
		},

		/**
		 * Update field visibility when clicking on the field toggles.
		 */
		ready: function() {
			var panel = this;
			panel.container.find( '.hide-column-tog' ).on( 'click', function() {
				panel.saveManageColumnsState();
			});

			// Inject additional heading into the menu locations section's head container.
			api.section( 'menu_locations', function( section ) {
				section.headContainer.prepend(
					wp.template( 'nav-menu-locations-header' )( api.Menus.data )
				);
			} );
		},

		/**
		 * Save hidden column states.
		 *
		 * @since 4.3.0
		 * @private
		 *
		 * @return {void}
		 */
		saveManageColumnsState: _.debounce( function() {
			var panel = this;
			if ( panel._updateHiddenColumnsRequest ) {
				panel._updateHiddenColumnsRequest.abort();
			}

			panel._updateHiddenColumnsRequest = wp.ajax.post( 'hidden-columns', {
				hidden: panel.hidden(),
				screenoptionnonce: $( '#screenoptionnonce' ).val(),
				page: 'nav-menus'
			} );
			panel._updateHiddenColumnsRequest.always( function() {
				panel._updateHiddenColumnsRequest = null;
			} );
		}, 2000 ),

		/**
		 * @deprecated Since 4.7.0 now that the nav_menu sections are responsible for toggling the classes on their own containers.
		 */
		checked: function() {},

		/**
		 * @deprecated Since 4.7.0 now that the nav_menu sections are responsible for toggling the classes on their own containers.
		 */
		unchecked: function() {},

		/**
		 * Get hidden fields.
		 *
		 * @since 4.3.0
		 * @private
		 *
		 * @return {Array} Fields (columns) that are hidden.
		 */
		hidden: function() {
			return $( '.hide-column-tog' ).not( ':checked' ).map( function() {
				var id = this.id;
				return id.substring( 0, id.length - 5 );
			}).get().join( ',' );
		}
	} );

	/**
	 * wp.customize.Menus.MenuSection
	 *
	 * Customizer section for menus. This is used only for lazy-loading child controls.
	 * Note that 'nav_menu' must match the WP_Customize_Menu_Section::$type.
	 *
	 * @class    wp.customize.Menus.MenuSection
	 * @augments wp.customize.Section
	 */
	api.Menus.MenuSection = api.Section.extend(/** @lends wp.customize.Menus.MenuSection.prototype */{

		/**
		 * Initialize.
		 *
		 * @since 4.3.0
		 *
		 * @param {string} id
		 * @param {Object} options
		 */
		initialize: function( id, options ) {
			var section = this;
			api.Section.prototype.initialize.call( section, id, options );
			section.deferred.initSortables = $.Deferred();
		},

		/**
		 * Ready.
		 */
		ready: function() {
			var section = this, fieldActiveToggles, handleFieldActiveToggle;

			if ( 'undefined' === typeof section.params.menu_id ) {
				throw new Error( 'params.menu_id was not defined' );
			}

			/*
			 * Since newly created sections won't be registered in PHP, we need to prevent the
			 * preview's sending of the activeSections to result in this control
			 * being deactivated when the preview refreshes. So we can hook onto
			 * the setting that has the same ID and its presence can dictate
			 * whether the section is active.
			 */
			section.active.validate = function() {
				if ( ! api.has( section.id ) ) {
					return false;
				}
				return !! api( section.id ).get();
			};

			section.populateControls();

			section.navMenuLocationSettings = {};
			section.assignedLocations = new api.Value( [] );

			api.each(function( setting, id ) {
				var matches = id.match( /^nav_menu_locations\[(.+?)]/ );
				if ( matches ) {
					section.navMenuLocationSettings[ matches[1] ] = setting;
					setting.bind( function() {
						section.refreshAssignedLocations();
					});
				}
			});

			section.assignedLocations.bind(function( to ) {
				section.updateAssignedLocationsInSectionTitle( to );
			});

			section.refreshAssignedLocations();

			api.bind( 'pane-contents-reflowed', function() {
				// Skip menus that have been removed.
				if ( ! section.contentContainer.parent().length ) {
					return;
				}
				section.container.find( '.menu-item .menu-item-reorder-nav button' ).attr({ 'tabindex': '0', 'aria-hidden': 'false' });
				section.container.find( '.menu-item.move-up-disabled .menus-move-up' ).attr({ 'tabindex': '-1', 'aria-hidden': 'true' });
				section.container.find( '.menu-item.move-down-disabled .menus-move-down' ).attr({ 'tabindex': '-1', 'aria-hidden': 'true' });
				section.container.find( '.menu-item.move-left-disabled .menus-move-left' ).attr({ 'tabindex': '-1', 'aria-hidden': 'true' });
				section.container.find( '.menu-item.move-right-disabled .menus-move-right' ).attr({ 'tabindex': '-1', 'aria-hidden': 'true' });
			} );

			/**
			 * Update the active field class for the content container for a given checkbox toggle.
			 *
			 * @this {jQuery}
			 * @return {void}
			 */
			handleFieldActiveToggle = function() {
				var className = 'field-' + $( this ).val() + '-active';
				section.contentContainer.toggleClass( className, $( this ).prop( 'checked' ) );
			};
			fieldActiveToggles = api.panel( 'nav_menus' ).contentContainer.find( '.metabox-prefs:first' ).find( '.hide-column-tog' );
			fieldActiveToggles.each( handleFieldActiveToggle );
			fieldActiveToggles.on( 'click', handleFieldActiveToggle );
		},

		populateControls: function() {
			var section = this,
				menuNameControlId,
				menuLocationsControlId,
				menuAutoAddControlId,
				menuDeleteControlId,
				menuControl,
				menuNameControl,
				menuLocationsControl,
				menuAutoAddControl,
				menuDeleteControl;

			// Add the control for managing the menu name.
			menuNameControlId = section.id + '[name]';
			menuNameControl = api.control( menuNameControlId );
			if ( ! menuNameControl ) {
				menuNameControl = new api.controlConstructor.nav_menu_name( menuNameControlId, {
					type: 'nav_menu_name',
					label: api.Menus.data.l10n.menuNameLabel,
					section: section.id,
					priority: 0,
					settings: {
						'default': section.id
					}
				} );
				api.control.add( menuNameControl );
				menuNameControl.active.set( true );
			}

			// Add the menu control.
			menuControl = api.control( section.id );
			if ( ! menuControl ) {
				menuControl = new api.controlConstructor.nav_menu( section.id, {
					type: 'nav_menu',
					section: section.id,
					priority: 998,
					settings: {
						'default': section.id
					},
					menu_id: section.params.menu_id
				} );
				api.control.add( menuControl );
				menuControl.active.set( true );
			}

			// Add the menu locations control.
			menuLocationsControlId = section.id + '[locations]';
			menuLocationsControl = api.control( menuLocationsControlId );
			if ( ! menuLocationsControl ) {
				menuLocationsControl = new api.controlConstructor.nav_menu_locations( menuLocationsControlId, {
					section: section.id,
					priority: 999,
					settings: {
						'default': section.id
					},
					menu_id: section.params.menu_id
				} );
				api.control.add( menuLocationsControl.id, menuLocationsControl );
				menuControl.active.set( true );
			}

			// Add the control for managing the menu auto_add.
			menuAutoAddControlId = section.id + '[auto_add]';
			menuAutoAddControl = api.control( menuAutoAddControlId );
			if ( ! menuAutoAddControl ) {
				menuAutoAddControl = new api.controlConstructor.nav_menu_auto_add( menuAutoAddControlId, {
					type: 'nav_menu_auto_add',
					label: '',
					section: section.id,
					priority: 1000,
					settings: {
						'default': section.id
					}
				} );
				api.control.add( menuAutoAddControl );
				menuAutoAddControl.active.set( true );
			}

			// Add the control for deleting the menu.
			menuDeleteControlId = section.id + '[delete]';
			menuDeleteControl = api.control( menuDeleteControlId );
			if ( ! menuDeleteControl ) {
				menuDeleteControl = new api.Control( menuDeleteControlId, {
					section: section.id,
					priority: 1001,
					templateId: 'nav-menu-delete-button'
				} );
				api.control.add( menuDeleteControl.id, menuDeleteControl );
				menuDeleteControl.active.set( true );
				menuDeleteControl.deferred.embedded.done( function () {
					menuDeleteControl.container.find( 'button' ).on( 'click', function() {
						var menuId = section.params.menu_id;
						var menuControl = api.Menus.getMenuControl( menuId );
						menuControl.setting.set( false );
					});
				} );
			}
		},

		/**
		 *
		 */
		refreshAssignedLocations: function() {
			var section = this,
				menuTermId = section.params.menu_id,
				currentAssignedLocations = [];
			_.each( section.navMenuLocationSettings, function( setting, themeLocation ) {
				if ( setting() === menuTermId ) {
					currentAssignedLocations.push( themeLocation );
				}
			});
			section.assignedLocations.set( currentAssignedLocations );
		},

		/**
		 * @param {Array} themeLocationSlugs Theme location slugs.
		 */
		updateAssignedLocationsInSectionTitle: function( themeLocationSlugs ) {
			var section = this,
				$title;

			$title = section.container.find( '.accordion-section-title button:first' );
			$title.find( '.menu-in-location' ).remove();
			_.each( themeLocationSlugs, function( themeLocationSlug ) {
				var $label, locationName;
				$label = $( '<span class="menu-in-location"></span>' );
				locationName = api.Menus.data.locationSlugMappedToName[ themeLocationSlug ];
				$label.text( api.Menus.data.l10n.menuLocation.replace( '%s', locationName ) );
				$title.append( $label );
			});

			section.container.toggleClass( 'assigned-to-menu-location', 0 !== themeLocationSlugs.length );

		},

		onChangeExpanded: function( expanded, args ) {
			var section = this, completeCallback;

			if ( expanded ) {
				wpNavMenu.menuList = section.contentContainer;
				wpNavMenu.targetList = wpNavMenu.menuList;

				// Add attributes needed by wpNavMenu.
				$( '#menu-to-edit' ).removeAttr( 'id' );
				wpNavMenu.menuList.attr( 'id', 'menu-to-edit' ).addClass( 'menu' );

				api.Menus.MenuItemControl.prototype.initAccessibility();

				_.each( api.section( section.id ).controls(), function( control ) {
					if ( 'nav_menu_item' === control.params.type ) {
						control.actuallyEmbed();
					}
				} );

				// Make sure Sortables is initialized after the section has been expanded to prevent `offset` issues.
				if ( args.completeCallback ) {
					completeCallback = args.completeCallback;
				}
				args.completeCallback = function() {
					if ( 'resolved' !== section.deferred.initSortables.state() ) {
						wpNavMenu.initSortables(); // Depends on menu-to-edit ID being set above.
						section.deferred.initSortables.resolve( wpNavMenu.menuList ); // Now MenuControl can extend the sortable.

						// @todo Note that wp.customize.reflowPaneContents() is debounced,
						// so this immediate change will show a slight flicker while priorities get updated.
						api.control( 'nav_menu[' + String( section.params.menu_id ) + ']' ).reflowMenuItems();
					}
					if ( _.isFunction( completeCallback ) ) {
						completeCallback();
					}
				};
			}
			api.Section.prototype.onChangeExpanded.call( section, expanded, args );
		},

		/**
		 * Highlight how a user may create new menu items.
		 *
		 * This method reminds the user to create new menu items and how.
		 * It's exposed this way because this class knows best which UI needs
		 * highlighted but those expanding this section know more about why and
		 * when the affordance should be highlighted.
		 *
		 * @since 4.9.0
		 *
		 * @return {void}
		 */
		highlightNewItemButton: function() {
			api.utils.highlightButton( this.contentContainer.find( '.add-new-menu-item' ), { delay: 2000 } );
		}
	});

	/**
	 * Create a nav menu setting and section.
	 *
	 * @since 4.9.0
	 *
	 * @param {string} [name=''] Nav menu name.
	 * @return {wp.customize.Menus.MenuSection} Added nav menu.
	 */
	api.Menus.createNavMenu = function createNavMenu( name ) {
		var customizeId, placeholderId, setting;
		placeholderId = api.Menus.generatePlaceholderAutoIncrementId();

		customizeId = 'nav_menu[' + String( placeholderId ) + ']';

		// Register the menu control setting.
		setting = api.create( customizeId, customizeId, {}, {
			type: 'nav_menu',
			transport: api.Menus.data.settingTransport,
			previewer: api.previewer
		} );
		setting.set( $.extend(
			{},
			api.Menus.data.defaultSettingValues.nav_menu,
			{
				name: name || ''
			}
		) );

		/*
		 * Add the menu section (and its controls).
		 * Note that this will automatically create the required controls
		 * inside via the Section's ready method.
		 */
		return api.section.add( new api.Menus.MenuSection( customizeId, {
			panel: 'nav_menus',
			title: displayNavMenuName( name ),
			customizeAction: api.Menus.data.l10n.customizingMenus,
			priority: 10,
			menu_id: placeholderId
		} ) );
	};

	/**
	 * wp.customize.Menus.NewMenuSection
	 *
	 * Customizer section for new menus.
	 *
	 * @class    wp.customize.Menus.NewMenuSection
	 * @augments wp.customize.Section
	 */
	api.Menus.NewMenuSection = api.Section.extend(/** @lends wp.customize.Menus.NewMenuSection.prototype */{

		/**
		 * Add behaviors for the accordion section.
		 *
		 * @since 4.3.0
		 */
		attachEvents: function() {
			var section = this,
				container = section.container,
				contentContainer = section.contentContainer,
				navMenuSettingPattern = /^nav_menu\[/;

			section.headContainer.find( '.accordion-section-title' ).replaceWith(
				wp.template( 'nav-menu-create-menu-section-title' )
			);

			/*
			 * We have to manually handle section expanded because we do not
			 * apply the `accordion-section-title` class to this button-driven section.
			 */
			container.on( 'click', '.customize-add-menu-button', function() {
				section.expand();
			});

			contentContainer.on( 'keydown', '.menu-name-field', function( event ) {
				if ( 13 === event.which ) { // Enter.
					section.submit();
				}
			} );
			contentContainer.on( 'click', '#customize-new-menu-submit', function( event ) {
				section.submit();
				event.stopPropagation();
				event.preventDefault();
			} );

			/**
			 * Get number of non-deleted nav menus.
			 *
			 * @since 4.9.0
			 * @return {number} Count.
			 */
			function getNavMenuCount() {
				var count = 0;
				api.each( function( setting ) {
					if ( navMenuSettingPattern.test( setting.id ) && false !== setting.get() ) {
						count += 1;
					}
				} );
				return count;
			}

			/**
			 * Update visibility of notice to prompt users to create menus.
			 *
			 * @since 4.9.0
			 * @return {void}
			 */
			function updateNoticeVisibility() {
				container.find( '.add-new-menu-notice' ).prop( 'hidden', getNavMenuCount() > 0 );
			}

			/**
			 * Handle setting addition.
			 *
			 * @since 4.9.0
			 * @param {wp.customize.Setting} setting - Added setting.
			 * @return {void}
			 */
			function addChangeEventListener( setting ) {
				if ( navMenuSettingPattern.test( setting.id ) ) {
					setting.bind( updateNoticeVisibility );
					updateNoticeVisibility();
				}
			}

			/**
			 * Handle setting removal.
			 *
			 * @since 4.9.0
			 * @param {wp.customize.Setting} setting - Removed setting.
			 * @return {void}
			 */
			function removeChangeEventListener( setting ) {
				if ( navMenuSettingPattern.test( setting.id ) ) {
					setting.unbind( updateNoticeVisibility );
					updateNoticeVisibility();
				}
			}

			api.each( addChangeEventListener );
			api.bind( 'add', addChangeEventListener );
			api.bind( 'removed', removeChangeEventListener );
			updateNoticeVisibility();

			api.Section.prototype.attachEvents.apply( section, arguments );
		},

		/**
		 * Set up the control.
		 *
		 * @since 4.9.0
		 */
		ready: function() {
			this.populateControls();
		},

		/**
		 * Create the controls for this section.
		 *
		 * @since 4.9.0
		 */
		populateControls: function() {
			var section = this,
				menuNameControlId,
				menuLocationsControlId,
				newMenuSubmitControlId,
				menuNameControl,
				menuLocationsControl,
				newMenuSubmitControl;

			menuNameControlId = section.id + '[name]';
			menuNameControl = api.control( menuNameControlId );
			if ( ! menuNameControl ) {
				menuNameControl = new api.controlConstructor.nav_menu_name( menuNameControlId, {
					label: api.Menus.data.l10n.menuNameLabel,
					description: api.Menus.data.l10n.newMenuNameDescription,
					section: section.id,
					priority: 0
				} );
				api.control.add( menuNameControl.id, menuNameControl );
				menuNameControl.active.set( true );
			}

			menuLocationsControlId = section.id + '[locations]';
			menuLocationsControl = api.control( menuLocationsControlId );
			if ( ! menuLocationsControl ) {
				menuLocationsControl = new api.controlConstructor.nav_menu_locations( menuLocationsControlId, {
					section: section.id,
					priority: 1,
					menu_id: '',
					isCreating: true
				} );
				api.control.add( menuLocationsControlId, menuLocationsControl );
				menuLocationsControl.active.set( true );
			}

			newMenuSubmitControlId = section.id + '[submit]';
			newMenuSubmitControl = api.control( newMenuSubmitControlId );
			if ( !newMenuSubmitControl ) {
				newMenuSubmitControl = new api.Control( newMenuSubmitControlId, {
					section: section.id,
					priority: 1,
					templateId: 'nav-menu-submit-new-button'
				} );
				api.control.add( newMenuSubmitControlId, newMenuSubmitControl );
				newMenuSubmitControl.active.set( true );
			}
		},

		/**
		 * Create the new menu with name and location supplied by the user.
		 *
		 * @since 4.9.0
		 */
		submit: function() {
			var section = this,
				contentContainer = section.contentContainer,
				nameInput = contentContainer.find( '.menu-name-field' ).first(),
				name = nameInput.val(),
				menuSection;

			if ( ! name ) {
				nameInput.addClass( 'invalid' );
				nameInput.focus();
				return;
			}

			menuSection = api.Menus.createNavMenu( name );

			// Clear name field.
			nameInput.val( '' );
			nameInput.removeClass( 'invalid' );

			contentContainer.find( '.assigned-menu-location input[type=checkbox]' ).each( function() {
				var checkbox = $( this ),
				navMenuLocationSetting;

				if ( checkbox.prop( 'checked' ) ) {
					navMenuLocationSetting = api( 'nav_menu_locations[' + checkbox.data( 'location-id' ) + ']' );
					navMenuLocationSetting.set( menuSection.params.menu_id );

					// Reset state for next new menu.
					checkbox.prop( 'checked', false );
				}
			} );

			wp.a11y.speak( api.Menus.data.l10n.menuAdded );

			// Focus on the new menu section.
			menuSection.focus( {
				completeCallback: function() {
					menuSection.highlightNewItemButton();
				}
			} );
		},

		/**
		 * Select a default location.
		 *
		 * This method selects a single location by default so we can support
		 * creating a menu for a specific menu location.
		 *
		 * @since 4.9.0
		 *
		 * @param {string|null} locationId - The ID of the location to select. `null` clears all selections.
		 * @return {void}
		 */
		selectDefaultLocation: function( locationId ) {
			var locationControl = api.control( this.id + '[locations]' ),
				locationSelections = {};

			if ( locationId !== null ) {
				locationSelections[ locationId ] = true;
			}

			locationControl.setSelections( locationSelections );
		}
	});

	/**
	 * wp.customize.Menus.MenuLocationControl
	 *
	 * Customizer control for menu locations (rendered as a <select>).
	 * Note that 'nav_menu_location' must match the WP_Customize_Nav_Menu_Location_Control::$type.
	 *
	 * @class    wp.customize.Menus.MenuLocationControl
	 * @augments wp.customize.Control
	 */
	api.Menus.MenuLocationControl = api.Control.extend(/** @lends wp.customize.Menus.MenuLocationControl.prototype */{
		initialize: function( id, options ) {
			var control = this,
				matches = id.match( /^nav_menu_locations\[(.+?)]/ );
			control.themeLocation = matches[1];
			api.Control.prototype.initialize.call( control, id, options );
		},

		ready: function() {
			var control = this, navMenuIdRegex = /^nav_menu\[(-?\d+)]/;

			// @todo It would be better if this was added directly on the setting itself, as opposed to the control.
			control.setting.validate = function( value ) {
				if ( '' === value ) {
					return 0;
				} else {
					return parseInt( value, 10 );
				}
			};

			// Create and Edit menu buttons.
			control.container.find( '.create-menu' ).on( 'click', function() {
				var addMenuSection = api.section( 'add_menu' );
				addMenuSection.selectDefaultLocation( this.dataset.locationId );
				addMenuSection.focus();
			} );
			control.container.find( '.edit-menu' ).on( 'click', function() {
				var menuId = control.setting();
				api.section( 'nav_menu[' + menuId + ']' ).focus();
			});
			control.setting.bind( 'change', function() {
				var menuIsSelected = 0 !== control.setting();
				control.container.find( '.create-menu' ).toggleClass( 'hidden', menuIsSelected );
				control.container.find( '.edit-menu' ).toggleClass( 'hidden', ! menuIsSelected );
			});

			// Add/remove menus from the available options when they are added and removed.
			api.bind( 'add', function( setting ) {
				var option, menuId, matches = setting.id.match( navMenuIdRegex );
				if ( ! matches || false === setting() ) {
					return;
				}
				menuId = matches[1];
				option = new Option( displayNavMenuName( setting().name ), menuId );
				control.container.find( 'select' ).append( option );
			});
			api.bind( 'remove', function( setting ) {
				var menuId, matches = setting.id.match( navMenuIdRegex );
				if ( ! matches ) {
					return;
				}
				menuId = parseInt( matches[1], 10 );
				if ( control.setting() === menuId ) {
					control.setting.set( '' );
				}
				control.container.find( 'option[value=' + menuId + ']' ).remove();
			});
			api.bind( 'change', function( setting ) {
				var menuId, matches = setting.id.match( navMenuIdRegex );
				if ( ! matches ) {
					return;
				}
				menuId = parseInt( matches[1], 10 );
				if ( false === setting() ) {
					if ( control.setting() === menuId ) {
						control.setting.set( '' );
					}
					control.container.find( 'option[value=' + menuId + ']' ).remove();
				} else {
					control.container.find( 'option[value=' + menuId + ']' ).text( displayNavMenuName( setting().name ) );
				}
			});
		}
	});

	api.Menus.MenuItemControl = api.Control.extend(/** @lends wp.customize.Menus.MenuItemControl.prototype */{

		/**
		 * wp.customize.Menus.MenuItemControl
		 *
		 * Customizer control for menu items.
		 * Note that 'menu_item' must match the WP_Customize_Menu_Item_Control::$type.
		 *
		 * @constructs wp.customize.Menus.MenuItemControl
		 * @augments   wp.customize.Control
		 *
		 * @inheritDoc
		 */
		initialize: function( id, options ) {
			var control = this;
			control.expanded = new api.Value( false );
			control.expandedArgumentsQueue = [];
			control.expanded.bind( function( expanded ) {
				var args = control.expandedArgumentsQueue.shift();
				args = $.extend( {}, control.defaultExpandedArguments, args );
				control.onChangeExpanded( expanded, args );
			});
			api.Control.prototype.initialize.call( control, id, options );
			control.active.validate = function() {
				var value, section = api.section( control.section() );
				if ( section ) {
					value = section.active();
				} else {
					value = false;
				}
				return value;
			};
		},

		/**
		 * Set up the initial state of the screen reader accessibility information for menu items.
		 *
		 * @since 6.6.0
		 */
		initAccessibility: function() {
			var control = this,
				menu = $( '#menu-to-edit' );

			// Refresh the accessibility when the user comes close to the item in any way.
			menu.on( 'mouseenter.refreshAccessibility focus.refreshAccessibility touchstart.refreshAccessibility', '.menu-item', function(){
				control.refreshAdvancedAccessibilityOfItem( $( this ).find( 'button.item-edit' ) );
			} );

			// We have to update on click as well because we might hover first, change the item, and then click.
			menu.on( 'click', 'button.item-edit', function() {
				control.refreshAdvancedAccessibilityOfItem( $( this ) );
			} );
		},

		/**
		 * refreshAdvancedAccessibilityOfItem( [itemToRefresh] )
		 *
		 * Refreshes advanced accessibility buttons for one menu item.
		 * Shows or hides buttons based on the location of the menu item.
		 *
		 * @param {Object} itemToRefresh The menu item that might need its advanced accessibility buttons refreshed
		 * 
		 * @since 6.6.0
		 */
		refreshAdvancedAccessibilityOfItem: function( itemToRefresh ) {
			// Only refresh accessibility when necessary.
			if ( true !== $( itemToRefresh ).data( 'needs_accessibility_refresh' ) ) {
				return;
			}

			var primaryItems, itemPosition, title,
				parentItem, parentItemId, parentItemName, subItems, totalSubItems,
				$this = $( itemToRefresh ),
				menuItem = $this.closest( 'li.menu-item' ).first(),
				depth = menuItem.menuItemDepth(),
				isPrimaryMenuItem = ( 0 === depth ),
				itemName = $this.closest( '.menu-item-handle' ).find( '.menu-item-title' ).text(),
				menuItemType = $this.closest( '.menu-item-handle' ).find( '.item-type' ).text(),
				totalMenuItems = $( '#menu-to-edit li' ).length;

			if ( isPrimaryMenuItem ) {
				primaryItems = $( '.menu-item-depth-0' ),
				itemPosition = primaryItems.index( menuItem ) + 1,
				totalMenuItems = primaryItems.length,
				// String together help text for primary menu items.
				title = menus.menuFocus.replace( '%1$s', itemName ).replace( '%2$s', menuItemType ).replace( '%3$d', itemPosition ).replace( '%4$d', totalMenuItems );
			} else {
				parentItem = menuItem.prevAll( '.menu-item-depth-' + parseInt( depth - 1, 10 ) ).first(),
				parentItemId = parentItem.find( '.menu-item-data-db-id' ).val(),
				parentItemName = parentItem.find( '.menu-item-title' ).text(),
				subItems = $( '.menu-item .menu-item-data-parent-id[value="' + parentItemId + '"]' ),
				totalSubItems = subItems.length,
				itemPosition = $( subItems.parents( '.menu-item' ).get().reverse() ).index( menuItem ) + 1;

				// String together help text for sub menu items.
				if ( depth < 2 ) {
					title = menus.subMenuFocus.replace( '%1$s', itemName ).replace( '%2$s', menuItemType ).replace( '%3$d', itemPosition ).replace( '%4$d', totalSubItems ).replace( '%5$s', parentItemName );
				} else {
					title = menus.subMenuMoreDepthFocus.replace( '%1$s', itemName ).replace( '%2$s', menuItemType ).replace( '%3$d', itemPosition ).replace( '%4$d', totalSubItems ).replace( '%5$s', parentItemName ).replace( '%6$d', depth );
				}
			}

			$this.find( '.screen-reader-text' ).text( title );

			// Mark this item's accessibility as refreshed.
			$this.data( 'needs_accessibility_refresh', false );
		},

		/**
		 * Override the embed() method to do nothing,
		 * so that the control isn't embedded on load,
		 * unless the containing section is already expanded.
		 *
		 * @since 4.3.0
		 */
		embed: function() {
			var control = this,
				sectionId = control.section(),
				section;
			if ( ! sectionId ) {
				return;
			}
			section = api.section( sectionId );
			if ( ( section && section.expanded() ) || api.settings.autofocus.control === control.id ) {
				control.actuallyEmbed();
			}
		},

		/**
		 * This function is called in Section.onChangeExpanded() so the control
		 * will only get embedded when the Section is first expanded.
		 *
		 * @since 4.3.0
		 */
		actuallyEmbed: function() {
			var control = this;
			if ( 'resolved' === control.deferred.embedded.state() ) {
				return;
			}
			control.renderContent();
			control.deferred.embedded.resolve(); // This triggers control.ready().
			
			// Mark all menu items as unprocessed.
			$( 'button.item-edit' ).data( 'needs_accessibility_refresh', true );
		},

		/**
		 * Set up the control.
		 */
		ready: function() {
			if ( 'undefined' === typeof this.params.menu_item_id ) {
				throw new Error( 'params.menu_item_id was not defined' );
			}

			this._setupControlToggle();
			this._setupReorderUI();
			this._setupUpdateUI();
			this._setupRemoveUI();
			this._setupLinksUI();
			this._setupTitleUI();
		},

		/**
		 * Show/hide the settings when clicking on the menu item handle.
		 */
		_setupControlToggle: function() {
			var control = this;

			this.container.find( '.menu-item-handle' ).on( 'click', function( e ) {
				e.preventDefault();
				e.stopPropagation();
				var menuControl = control.getMenuControl(),
					isDeleteBtn = $( e.target ).is( '.item-delete, .item-delete *' ),
					isAddNewBtn = $( e.target ).is( '.add-new-menu-item, .add-new-menu-item *' );

				if ( $( 'body' ).hasClass( 'adding-menu-items' ) && ! isDeleteBtn && ! isAddNewBtn ) {
					api.Menus.availableMenuItemsPanel.close();
				}

				if ( menuControl.isReordering || menuControl.isSorting ) {
					return;
				}
				control.toggleForm();
			} );
		},

		/**
		 * Set up the menu-item-reorder-nav
		 */
		_setupReorderUI: function() {
			var control = this, template, $reorderNav;

			template = wp.template( 'menu-item-reorder-nav' );

			// Add the menu item reordering elements to the menu item control.
			control.container.find( '.item-controls' ).after( template );

			// Handle clicks for up/down/left-right on the reorder nav.
			$reorderNav = control.container.find( '.menu-item-reorder-nav' );
			$reorderNav.find( '.menus-move-up, .menus-move-down, .menus-move-left, .menus-move-right' ).on( 'click', function() {
				var moveBtn = $( this );
				control.params.depth = control.getDepth();

				moveBtn.focus();

				var isMoveUp = moveBtn.is( '.menus-move-up' ),
					isMoveDown = moveBtn.is( '.menus-move-down' ),
					isMoveLeft = moveBtn.is( '.menus-move-left' ),
					isMoveRight = moveBtn.is( '.menus-move-right' );

				if ( isMoveUp ) {
					control.moveUp();
				} else if ( isMoveDown ) {
					control.moveDown();
				} else if ( isMoveLeft ) {
					control.moveLeft();
				} else if ( isMoveRight ) {
					control.moveRight();
					control.params.depth += 1;
				}
				
				moveBtn.focus(); // Re-focus after the container was moved.

				// Mark all menu items as unprocessed.
				$( 'button.item-edit' ).data( 'needs_accessibility_refresh', true );
			} );
		},

		/**
		 * Set up event handlers for menu item updating.
		 */
		_setupUpdateUI: function() {
			var control = this,
				settingValue = control.setting(),
				updateNotifications;

			control.elements = {};
			control.elements.url = new api.Element( control.container.find( '.edit-menu-item-url' ) );
			control.elements.title = new api.Element( control.container.find( '.edit-menu-item-title' ) );
			control.elements.attr_title = new api.Element( control.container.find( '.edit-menu-item-attr-title' ) );
			control.elements.target = new api.Element( control.container.find( '.edit-menu-item-target' ) );
			control.elements.classes = new api.Element( control.container.find( '.edit-menu-item-classes' ) );
			control.elements.xfn = new api.Element( control.container.find( '.edit-menu-item-xfn' ) );
			control.elements.description = new api.Element( control.container.find( '.edit-menu-item-description' ) );
			// @todo Allow other elements, added by plugins, to be automatically picked up here;
			// allow additional values to be added to setting array.

			_.each( control.elements, function( element, property ) {
				element.bind(function( value ) {
					if ( element.element.is( 'input[type=checkbox]' ) ) {
						value = ( value ) ? element.element.val() : '';
					}

					var settingValue = control.setting();
					if ( settingValue && settingValue[ property ] !== value ) {
						settingValue = _.clone( settingValue );
						settingValue[ property ] = value;
						control.setting.set( settingValue );
					}
				});
				if ( settingValue ) {
					if ( ( property === 'classes' || property === 'xfn' ) && _.isArray( settingValue[ property ] ) ) {
						element.set( settingValue[ property ].join( ' ' ) );
					} else {
						element.set( settingValue[ property ] );
					}
				}
			});

			control.setting.bind(function( to, from ) {
				var itemId = control.params.menu_item_id,
					followingSiblingItemControls = [],
					childrenItemControls = [],
					menuControl;

				if ( false === to ) {
					menuControl = api.control( 'nav_menu[' + String( from.nav_menu_term_id ) + ']' );
					control.container.remove();

					_.each( menuControl.getMenuItemControls(), function( otherControl ) {
						if ( from.menu_item_parent === otherControl.setting().menu_item_parent && otherControl.setting().position > from.position ) {
							followingSiblingItemControls.push( otherControl );
						} else if ( otherControl.setting().menu_item_parent === itemId ) {
							childrenItemControls.push( otherControl );
						}
					});

					// Shift all following siblings by the number of children this item has.
					_.each( followingSiblingItemControls, function( followingSiblingItemControl ) {
						var value = _.clone( followingSiblingItemControl.setting() );
						value.position += childrenItemControls.length;
						followingSiblingItemControl.setting.set( value );
					});

					// Now move the children up to be the new subsequent siblings.
					_.each( childrenItemControls, function( childrenItemControl, i ) {
						var value = _.clone( childrenItemControl.setting() );
						value.position = from.position + i;
						value.menu_item_parent = from.menu_item_parent;
						childrenItemControl.setting.set( value );
					});

					menuControl.debouncedReflowMenuItems();
				} else {
					// Update the elements' values to match the new setting properties.
					_.each( to, function( value, key ) {
						if ( control.elements[ key] ) {
							control.elements[ key ].set( to[ key ] );
						}
					} );
					control.container.find( '.menu-item-data-parent-id' ).val( to.menu_item_parent );

					// Handle UI updates when the position or depth (parent) change.
					if ( to.position !== from.position || to.menu_item_parent !== from.menu_item_parent ) {
						control.getMenuControl().debouncedReflowMenuItems();
					}
				}
			});

			// Style the URL field as invalid when there is an invalid_url notification.
			updateNotifications = function() {
				control.elements.url.element.toggleClass( 'invalid', control.setting.notifications.has( 'invalid_url' ) );
			};
			control.setting.notifications.bind( 'add', updateNotifications );
			control.setting.notifications.bind( 'removed', updateNotifications );
		},

		/**
		 * Set up event handlers for menu item deletion.
		 */
		_setupRemoveUI: function() {
			var control = this, $removeBtn;

			// Configure delete button.
			$removeBtn = control.container.find( '.item-delete' );

			$removeBtn.on( 'click', function() {
				// Find an adjacent element to add focus to when this menu item goes away.
				var addingItems = true, $adjacentFocusTarget, $next, $prev,
					instanceCounter = 0, // Instance count of the menu item deleted.
					deleteItemOriginalItemId = control.params.original_item_id,
					addedItems = control.getMenuControl().$sectionContent.find( '.menu-item' ),
					availableMenuItem;

				if ( ! $( 'body' ).hasClass( 'adding-menu-items' ) ) {
					addingItems = false;
				}

				$next = control.container.nextAll( '.customize-control-nav_menu_item:visible' ).first();
				$prev = control.container.prevAll( '.customize-control-nav_menu_item:visible' ).first();

				if ( $next.length ) {
					$adjacentFocusTarget = $next.find( false === addingItems ? '.item-edit' : '.item-delete' ).first();
				} else if ( $prev.length ) {
					$adjacentFocusTarget = $prev.find( false === addingItems ? '.item-edit' : '.item-delete' ).first();
				} else {
					$adjacentFocusTarget = control.container.nextAll( '.customize-control-nav_menu' ).find( '.add-new-menu-item' ).first();
				}

				/*
				 * If the menu item deleted is the only of its instance left,
				 * remove the check icon of this menu item in the right panel.
				 */
				_.each( addedItems, function( addedItem ) {
					var menuItemId, menuItemControl, matches;

					// This is because menu item that's deleted is just hidden.
					if ( ! $( addedItem ).is( ':visible' ) ) {
						return;
					}

					matches = addedItem.getAttribute( 'id' ).match( /^customize-control-nav_menu_item-(-?\d+)$/, '' );
					if ( ! matches ) {
						return;
					}

					menuItemId      = parseInt( matches[1], 10 );
					menuItemControl = api.control( 'nav_menu_item[' + String( menuItemId ) + ']' );

					// Check for duplicate menu items.
					if ( menuItemControl && deleteItemOriginalItemId == menuItemControl.params.original_item_id ) {
						instanceCounter++;
					}
				} );

				if ( instanceCounter <= 1 ) {
					// Revert the check icon to add icon.
					availableMenuItem = $( '#menu-item-tpl-' + control.params.original_item_id );
					availableMenuItem.removeClass( 'selected' );
					availableMenuItem.find( '.menu-item-handle' ).removeClass( 'item-added' );
				}

				control.container.slideUp( function() {
					control.setting.set( false );
					wp.a11y.speak( api.Menus.data.l10n.itemDeleted );
					$adjacentFocusTarget.focus(); // Keyboard accessibility.
				} );

				control.setting.set( false );
			} );
		},

		_setupLinksUI: function() {
			var $origBtn;

			// Configure original link.
			$origBtn = this.container.find( 'a.original-link' );

			$origBtn.on( 'click', function( e ) {
				e.preventDefault();
				api.previewer.previewUrl( e.target.toString() );
			} );
		},

		/**
		 * Update item handle title when changed.
		 */
		_setupTitleUI: function() {
			var control = this, titleEl;

			// Ensure that whitespace is trimmed on blur so placeholder can be shown.
			control.container.find( '.edit-menu-item-title' ).on( 'blur', function() {
				$( this ).val( $( this ).val().trim() );
			} );

			titleEl = control.container.find( '.menu-item-title' );
			control.setting.bind( function( item ) {
				var trimmedTitle, titleText;
				if ( ! item ) {
					return;
				}
				item.title = item.title || '';
				trimmedTitle = item.title.trim();

				titleText = trimmedTitle || item.original_title || api.Menus.data.l10n.untitled;

				if ( item._invalid ) {
					titleText = api.Menus.data.l10n.invalidTitleTpl.replace( '%s', titleText );
				}

				// Don't update to an empty title.
				if ( trimmedTitle || item.original_title ) {
					titleEl
						.text( titleText )
						.removeClass( 'no-title' );
				} else {
					titleEl
						.text( titleText )
						.addClass( 'no-title' );
				}
			} );
		},

		/**
		 *
		 * @return {number}
		 */
		getDepth: function() {
			var control = this, setting = control.setting(), depth = 0;
			if ( ! setting ) {
				return 0;
			}
			while ( setting && setting.menu_item_parent ) {
				depth += 1;
				control = api.control( 'nav_menu_item[' + setting.menu_item_parent + ']' );
				if ( ! control ) {
					break;
				}
				setting = control.setting();
			}
			return depth;
		},

		/**
		 * Amend the control's params with the data necessary for the JS template just in time.
		 */
		renderContent: function() {
			var control = this,
				settingValue = control.setting(),
				containerClasses;

			control.params.title = settingValue.title || '';
			control.params.depth = control.getDepth();
			control.container.data( 'item-depth', control.params.depth );
			containerClasses = [
				'menu-item',
				'menu-item-depth-' + String( control.params.depth ),
				'menu-item-' + settingValue.object,
				'menu-item-edit-inactive'
			];

			if ( settingValue._invalid ) {
				containerClasses.push( 'menu-item-invalid' );
				control.params.title = api.Menus.data.l10n.invalidTitleTpl.replace( '%s', control.params.title );
			} else if ( 'draft' === settingValue.status ) {
				containerClasses.push( 'pending' );
				control.params.title = api.Menus.data.pendingTitleTpl.replace( '%s', control.params.title );
			}

			control.params.el_classes = containerClasses.join( ' ' );
			control.params.item_type_label = settingValue.type_label;
			control.params.item_type = settingValue.type;
			control.params.url = settingValue.url;
			control.params.target = settingValue.target;
			control.params.attr_title = settingValue.attr_title;
			control.params.classes = _.isArray( settingValue.classes ) ? settingValue.classes.join( ' ' ) : settingValue.classes;
			control.params.xfn = settingValue.xfn;
			control.params.description = settingValue.description;
			control.params.parent = settingValue.menu_item_parent;
			control.params.original_title = settingValue.original_title || '';

			control.container.addClass( control.params.el_classes );

			api.Control.prototype.renderContent.call( control );
		},

		/***********************************************************************
		 * Begin public API methods
		 **********************************************************************/

		/**
		 * @return {wp.customize.controlConstructor.nav_menu|null}
		 */
		getMenuControl: function() {
			var control = this, settingValue = control.setting();
			if ( settingValue && settingValue.nav_menu_term_id ) {
				return api.control( 'nav_menu[' + settingValue.nav_menu_term_id + ']' );
			} else {
				return null;
			}
		},

		/**
		 * Expand the accordion section containing a control
		 */
		expandControlSection: function() {
			var $section = this.container.closest( '.accordion-section' );
			if ( ! $section.hasClass( 'open' ) ) {
				$section.find( '.accordion-section-title:first' ).trigger( 'click' );
			}
		},

		/**
		 * @since 4.6.0
		 *
		 * @param {Boolean} expanded
		 * @param {Object} [params]
		 * @return {Boolean} False if state already applied.
		 */
		_toggleExpanded: api.Section.prototype._toggleExpanded,

		/**
		 * @since 4.6.0
		 *
		 * @param {Object} [params]
		 * @return {Boolean} False if already expanded.
		 */
		expand: api.Section.prototype.expand,

		/**
		 * Expand the menu item form control.
		 *
		 * @since 4.5.0 Added params.completeCallback.
		 *
		 * @param {Object}   [params] - Optional params.
		 * @param {Function} [params.completeCallback] - Function to call when the form toggle has finished animating.
		 */
		expandForm: function( params ) {
			this.expand( params );
		},

		/**
		 * @since 4.6.0
		 *
		 * @param {Object} [params]
		 * @return {Boolean} False if already collapsed.
		 */
		collapse: api.Section.prototype.collapse,

		/**
		 * Collapse the menu item form control.
		 *
		 * @since 4.5.0 Added params.completeCallback.
		 *
		 * @param {Object}   [params] - Optional params.
		 * @param {Function} [params.completeCallback] - Function to call when the form toggle has finished animating.
		 */
		collapseForm: function( params ) {
			this.collapse( params );
		},

		/**
		 * Expand or collapse the menu item control.
		 *
		 * @deprecated this is poor naming, and it is better to directly set control.expanded( showOrHide )
		 * @since 4.5.0 Added params.completeCallback.
		 *
		 * @param {boolean}  [showOrHide] - If not supplied, will be inverse of current visibility
		 * @param {Object}   [params] - Optional params.
		 * @param {Function} [params.completeCallback] - Function to call when the form toggle has finished animating.
		 */
		toggleForm: function( showOrHide, params ) {
			if ( typeof showOrHide === 'undefined' ) {
				showOrHide = ! this.expanded();
			}
			if ( showOrHide ) {
				this.expand( params );
			} else {
				this.collapse( params );
			}
		},

		/**
		 * Expand or collapse the menu item control.
		 *
		 * @since 4.6.0
		 * @param {boolean}  [showOrHide] - If not supplied, will be inverse of current visibility
		 * @param {Object}   [params] - Optional params.
		 * @param {Function} [params.completeCallback] - Function to call when the form toggle has finished animating.
		 */
		onChangeExpanded: function( showOrHide, params ) {
			var self = this, $menuitem, $inside, complete;

			$menuitem = this.container;
			$inside = $menuitem.find( '.menu-item-settings:first' );
			if ( 'undefined' === typeof showOrHide ) {
				showOrHide = ! $inside.is( ':visible' );
			}

			// Already expanded or collapsed.
			if ( $inside.is( ':visible' ) === showOrHide ) {
				if ( params && params.completeCallback ) {
					params.completeCallback();
				}
				return;
			}

			if ( showOrHide ) {
				// Close all other menu item controls before expanding this one.
				api.control.each( function( otherControl ) {
					if ( self.params.type === otherControl.params.type && self !== otherControl ) {
						otherControl.collapseForm();
					}
				} );

				complete = function() {
					$menuitem
						.removeClass( 'menu-item-edit-inactive' )
						.addClass( 'menu-item-edit-active' );
					self.container.trigger( 'expanded' );

					if ( params && params.completeCallback ) {
						params.completeCallback();
					}
				};

				$menuitem.find( '.item-edit' ).attr( 'aria-expanded', 'true' );
				$inside.slideDown( 'fast', complete );

				self.container.trigger( 'expand' );
			} else {
				complete = function() {
					$menuitem
						.addClass( 'menu-item-edit-inactive' )
						.removeClass( 'menu-item-edit-active' );
					self.container.trigger( 'collapsed' );

					if ( params && params.completeCallback ) {
						params.completeCallback();
					}
				};

				self.container.trigger( 'collapse' );

				$menuitem.find( '.item-edit' ).attr( 'aria-expanded', 'false' );
				$inside.slideUp( 'fast', complete );
			}
		},

		/**
		 * Expand the containing menu section, expand the form, and focus on
		 * the first input in the control.
		 *
		 * @since 4.5.0 Added params.completeCallback.
		 *
		 * @param {Object}   [params] - Params object.
		 * @param {Function} [params.completeCallback] - Optional callback function when focus has completed.
		 */
		focus: function( params ) {
			params = params || {};
			var control = this, originalCompleteCallback = params.completeCallback, focusControl;

			focusControl = function() {
				control.expandControlSection();

				params.completeCallback = function() {
					var focusable;

					// Note that we can't use :focusable due to a jQuery UI issue. See: https://github.com/jquery/jquery-ui/pull/1583
					focusable = control.container.find( '.menu-item-settings' ).find( 'input, select, textarea, button, object, a[href], [tabindex]' ).filter( ':visible' );
					focusable.first().focus();

					if ( originalCompleteCallback ) {
						originalCompleteCallback();
					}
				};

				control.expandForm( params );
			};

			if ( api.section.has( control.section() ) ) {
				api.section( control.section() ).expand( {
					completeCallback: focusControl
				} );
			} else {
				focusControl();
			}
		},

		/**
		 * Move menu item up one in the menu.
		 */
		moveUp: function() {
			this._changePosition( -1 );
			wp.a11y.speak( api.Menus.data.l10n.movedUp );
		},

		/**
		 * Move menu item up one in the menu.
		 */
		moveDown: function() {
			this._changePosition( 1 );
			wp.a11y.speak( api.Menus.data.l10n.movedDown );
		},
		/**
		 * Move menu item and all children up one level of depth.
		 */
		moveLeft: function() {
			this._changeDepth( -1 );
			wp.a11y.speak( api.Menus.data.l10n.movedLeft );
		},

		/**
		 * Move menu item and children one level deeper, as a submenu of the previous item.
		 */
		moveRight: function() {
			this._changeDepth( 1 );
			wp.a11y.speak( api.Menus.data.l10n.movedRight );
		},

		/**
		 * Note that this will trigger a UI update, causing child items to
		 * move as well and cardinal order class names to be updated.
		 *
		 * @private
		 *
		 * @param {number} offset 1|-1
		 */
		_changePosition: function( offset ) {
			var control = this,
				adjacentSetting,
				settingValue = _.clone( control.setting() ),
				siblingSettings = [],
				realPosition;

			if ( 1 !== offset && -1 !== offset ) {
				throw new Error( 'Offset changes by 1 are only supported.' );
			}

			// Skip moving deleted items.
			if ( ! control.setting() ) {
				return;
			}

			// Locate the other items under the same parent (siblings).
			_( control.getMenuControl().getMenuItemControls() ).each(function( otherControl ) {
				if ( otherControl.setting().menu_item_parent === settingValue.menu_item_parent ) {
					siblingSettings.push( otherControl.setting );
				}
			});
			siblingSettings.sort(function( a, b ) {
				return a().position - b().position;
			});

			realPosition = _.indexOf( siblingSettings, control.setting );
			if ( -1 === realPosition ) {
				throw new Error( 'Expected setting to be among siblings.' );
			}

			// Skip doing anything if the item is already at the edge in the desired direction.
			if ( ( realPosition === 0 && offset < 0 ) || ( realPosition === siblingSettings.length - 1 && offset > 0 ) ) {
				// @todo Should we allow a menu item to be moved up to break it out of a parent? Adopt with previous or following parent?
				return;
			}

			// Update any adjacent menu item setting to take on this item's position.
			adjacentSetting = siblingSettings[ realPosition + offset ];
			if ( adjacentSetting ) {
				adjacentSetting.set( $.extend(
					_.clone( adjacentSetting() ),
					{
						position: settingValue.position
					}
				) );
			}

			settingValue.position += offset;
			control.setting.set( settingValue );
		},

		/**
		 * Note that this will trigger a UI update, causing child items to
		 * move as well and cardinal order class names to be updated.
		 *
		 * @private
		 *
		 * @param {number} offset 1|-1
		 */
		_changeDepth: function( offset ) {
			if ( 1 !== offset && -1 !== offset ) {
				throw new Error( 'Offset changes by 1 are only supported.' );
			}
			var control = this,
				settingValue = _.clone( control.setting() ),
				siblingControls = [],
				realPosition,
				siblingControl,
				parentControl;

			// Locate the other items under the same parent (siblings).
			_( control.getMenuControl().getMenuItemControls() ).each(function( otherControl ) {
				if ( otherControl.setting().menu_item_parent === settingValue.menu_item_parent ) {
					siblingControls.push( otherControl );
				}
			});
			siblingControls.sort(function( a, b ) {
				return a.setting().position - b.setting().position;
			});

			realPosition = _.indexOf( siblingControls, control );
			if ( -1 === realPosition ) {
				throw new Error( 'Expected control to be among siblings.' );
			}

			if ( -1 === offset ) {
				// Skip moving left an item that is already at the top level.
				if ( ! settingValue.menu_item_parent ) {
					return;
				}

				parentControl = api.control( 'nav_menu_item[' + settingValue.menu_item_parent + ']' );

				// Make this control the parent of all the following siblings.
				_( siblingControls ).chain().slice( realPosition ).each(function( siblingControl, i ) {
					siblingControl.setting.set(
						$.extend(
							{},
							siblingControl.setting(),
							{
								menu_item_parent: control.params.menu_item_id,
								position: i
							}
						)
					);
				});

				// Increase the positions of the parent item's subsequent children to make room for this one.
				_( control.getMenuControl().getMenuItemControls() ).each(function( otherControl ) {
					var otherControlSettingValue, isControlToBeShifted;
					isControlToBeShifted = (
						otherControl.setting().menu_item_parent === parentControl.setting().menu_item_parent &&
						otherControl.setting().position > parentControl.setting().position
					);
					if ( isControlToBeShifted ) {
						otherControlSettingValue = _.clone( otherControl.setting() );
						otherControl.setting.set(
							$.extend(
								otherControlSettingValue,
								{ position: otherControlSettingValue.position + 1 }
							)
						);
					}
				});

				// Make this control the following sibling of its parent item.
				settingValue.position = parentControl.setting().position + 1;
				settingValue.menu_item_parent = parentControl.setting().menu_item_parent;
				control.setting.set( settingValue );

			} else if ( 1 === offset ) {
				// Skip moving right an item that doesn't have a previous sibling.
				if ( realPosition === 0 ) {
					return;
				}

				// Make the control the last child of the previous sibling.
				siblingControl = siblingControls[ realPosition - 1 ];
				settingValue.menu_item_parent = siblingControl.params.menu_item_id;
				settingValue.position = 0;
				_( control.getMenuControl().getMenuItemControls() ).each(function( otherControl ) {
					if ( otherControl.setting().menu_item_parent === settingValue.menu_item_parent ) {
						settingValue.position = Math.max( settingValue.position, otherControl.setting().position );
					}
				});
				settingValue.position += 1;
				control.setting.set( settingValue );
			}
		}
	} );

	/**
	 * wp.customize.Menus.MenuNameControl
	 *
	 * Customizer control for a nav menu's name.
	 *
	 * @class    wp.customize.Menus.MenuNameControl
	 * @augments wp.customize.Control
	 */
	api.Menus.MenuNameControl = api.Control.extend(/** @lends wp.customize.Menus.MenuNameControl.prototype */{

		ready: function() {
			var control = this;

			if ( control.setting ) {
				var settingValue = control.setting();

				control.nameElement = new api.Element( control.container.find( '.menu-name-field' ) );

				control.nameElement.bind(function( value ) {
					var settingValue = control.setting();
					if ( settingValue && settingValue.name !== value ) {
						settingValue = _.clone( settingValue );
						settingValue.name = value;
						control.setting.set( settingValue );
					}
				});
				if ( settingValue ) {
					control.nameElement.set( settingValue.name );
				}

				control.setting.bind(function( object ) {
					if ( object ) {
						control.nameElement.set( object.name );
					}
				});
			}
		}
	});

	/**
	 * wp.customize.Menus.MenuLocationsControl
	 *
	 * Customizer control for a nav menu's locations.
	 *
	 * @since 4.9.0
	 * @class    wp.customize.Menus.MenuLocationsControl
	 * @augments wp.customize.Control
	 */
	api.Menus.MenuLocationsControl = api.Control.extend(/** @lends wp.customize.Menus.MenuLocationsControl.prototype */{

		/**
		 * Set up the control.
		 *
		 * @since 4.9.0
		 */
		ready: function () {
			var control = this;

			control.container.find( '.assigned-menu-location' ).each(function() {
				var container = $( this ),
					checkbox = container.find( 'input[type=checkbox]' ),
					element = new api.Element( checkbox ),
					navMenuLocationSetting = api( 'nav_menu_locations[' + checkbox.data( 'location-id' ) + ']' ),
					isNewMenu = control.params.menu_id === '',
					updateCheckbox = isNewMenu ? _.noop : function( checked ) {
						element.set( checked );
					},
					updateSetting = isNewMenu ? _.noop : function( checked ) {
						navMenuLocationSetting.set( checked ? control.params.menu_id : 0 );
					},
					updateSelectedMenuLabel = function( selectedMenuId ) {
						var menuSetting = api( 'nav_menu[' + String( selectedMenuId ) + ']' );
						if ( ! selectedMenuId || ! menuSetting || ! menuSetting() ) {
							container.find( '.theme-location-set' ).hide();
						} else {
							container.find( '.theme-location-set' ).show().find( 'span' ).text( displayNavMenuName( menuSetting().name ) );
						}
					};

				updateCheckbox( navMenuLocationSetting.get() === control.params.menu_id );

				checkbox.on( 'change', function() {
					// Note: We can't use element.bind( function( checked ){ ... } ) here because it will trigger a change as well.
					updateSetting( this.checked );
				} );

				navMenuLocationSetting.bind( function( selectedMenuId ) {
					updateCheckbox( selectedMenuId === control.params.menu_id );
					updateSelectedMenuLabel( selectedMenuId );
				} );
				updateSelectedMenuLabel( navMenuLocationSetting.get() );
			});
		},

		/**
		 * Set the selected locations.
		 *
		 * This method sets the selected locations and allows us to do things like
		 * set the default location for a new menu.
		 *
		 * @since 4.9.0
		 *
		 * @param {Object.<string,boolean>} selections - A map of location selections.
		 * @return {void}
		 */
		setSelections: function( selections ) {
			this.container.find( '.menu-location' ).each( function( i, checkboxNode ) {
				var locationId = checkboxNode.dataset.locationId;
				checkboxNode.checked = locationId in selections ? selections[ locationId ] : false;
			} );
		}
	});

	/**
	 * wp.customize.Menus.MenuAutoAddControl
	 *
	 * Customizer control for a nav menu's auto add.
	 *
	 * @class    wp.customize.Menus.MenuAutoAddControl
	 * @augments wp.customize.Control
	 */
	api.Menus.MenuAutoAddControl = api.Control.extend(/** @lends wp.customize.Menus.MenuAutoAddControl.prototype */{

		ready: function() {
			var control = this,
				settingValue = control.setting();

			/*
			 * Since the control is not registered in PHP, we need to prevent the
			 * preview's sending of the activeControls to result in this control
			 * being deactivated.
			 */
			control.active.validate = function() {
				var value, section = api.section( control.section() );
				if ( section ) {
					value = section.active();
				} else {
					value = false;
				}
				return value;
			};

			control.autoAddElement = new api.Element( control.container.find( 'input[type=checkbox].auto_add' ) );

			control.autoAddElement.bind(function( value ) {
				var settingValue = control.setting();
				if ( settingValue && settingValue.name !== value ) {
					settingValue = _.clone( settingValue );
					settingValue.auto_add = value;
					control.setting.set( settingValue );
				}
			});
			if ( settingValue ) {
				control.autoAddElement.set( settingValue.auto_add );
			}

			control.setting.bind(function( object ) {
				if ( object ) {
					control.autoAddElement.set( object.auto_add );
				}
			});
		}

	});

	/**
	 * wp.customize.Menus.MenuControl
	 *
	 * Customizer control for menus.
	 * Note that 'nav_menu' must match the WP_Menu_Customize_Control::$type
	 *
	 * @class    wp.customize.Menus.MenuControl
	 * @augments wp.customize.Control
	 */
	api.Menus.MenuControl = api.Control.extend(/** @lends wp.customize.Menus.MenuControl.prototype */{
		/**
		 * Set up the control.
		 */
		ready: function() {
			var control = this,
				section = api.section( control.section() ),
				menuId = control.params.menu_id,
				menu = control.setting(),
				name,
				widgetTemplate,
				select;

			if ( 'undefined' === typeof this.params.menu_id ) {
				throw new Error( 'params.menu_id was not defined' );
			}

			/*
			 * Since the control is not registered in PHP, we need to prevent the
			 * preview's sending of the activeControls to result in this control
			 * being deactivated.
			 */
			control.active.validate = function() {
				var value;
				if ( section ) {
					value = section.active();
				} else {
					value = false;
				}
				return value;
			};

			control.$controlSection = section.headContainer;
			control.$sectionContent = control.container.closest( '.accordion-section-content' );

			this._setupModel();

			api.section( control.section(), function( section ) {
				section.deferred.initSortables.done(function( menuList ) {
					control._setupSortable( menuList );
				});
			} );

			this._setupAddition();
			this._setupTitle();

			// Add menu to Navigation Menu widgets.
			if ( menu ) {
				name = displayNavMenuName( menu.name );

				// Add the menu to the existing controls.
				api.control.each( function( widgetControl ) {
					if ( ! widgetControl.extended( api.controlConstructor.widget_form ) || 'nav_menu' !== widgetControl.params.widget_id_base ) {
						return;
					}
					widgetControl.container.find( '.nav-menu-widget-form-controls:first' ).show();
					widgetControl.container.find( '.nav-menu-widget-no-menus-message:first' ).hide();

					select = widgetControl.container.find( 'select' );
					if ( 0 === select.find( 'option[value=' + String( menuId ) + ']' ).length ) {
						select.append( new Option( name, menuId ) );
					}
				} );

				// Add the menu to the widget template.
				widgetTemplate = $( '#available-widgets-list .widget-tpl:has( input.id_base[ value=nav_menu ] )' );
				widgetTemplate.find( '.nav-menu-widget-form-controls:first' ).show();
				widgetTemplate.find( '.nav-menu-widget-no-menus-message:first' ).hide();
				select = widgetTemplate.find( '.widget-inside select:first' );
				if ( 0 === select.find( 'option[value=' + String( menuId ) + ']' ).length ) {
					select.append( new Option( name, menuId ) );
				}
			}

			/*
			 * Wait for menu items to be added.
			 * Ideally, we'd bind to an event indicating construction is complete,
			 * but deferring appears to be the best option today.
			 */
			_.defer( function () {
				control.updateInvitationVisibility();
			} );
		},

		/**
		 * Update ordering of menu item controls when the setting is updated.
		 */
		_setupModel: function() {
			var control = this,
				menuId = control.params.menu_id;

			control.setting.bind( function( to ) {
				var name;
				if ( false === to ) {
					control._handleDeletion();
				} else {
					// Update names in the Navigation Menu widgets.
					name = displayNavMenuName( to.name );
					api.control.each( function( widgetControl ) {
						if ( ! widgetControl.extended( api.controlConstructor.widget_form ) || 'nav_menu' !== widgetControl.params.widget_id_base ) {
							return;
						}
						var select = widgetControl.container.find( 'select' );
						select.find( 'option[value=' + String( menuId ) + ']' ).text( name );
					});
				}
			} );
		},

		/**
		 * Allow items in each menu to be re-ordered, and for the order to be previewed.
		 *
		 * Notice that the UI aspects here are handled by wpNavMenu.initSortables()
		 * which is called in MenuSection.onChangeExpanded()
		 *
		 * @param {Object} menuList - The element that has sortable().
		 */
		_setupSortable: function( menuList ) {
			var control = this;

			if ( ! menuList.is( control.$sectionContent ) ) {
				throw new Error( 'Unexpected menuList.' );
			}

			menuList.on( 'sortstart', function() {
				control.isSorting = true;
			});

			menuList.on( 'sortstop', function() {
				setTimeout( function() { // Next tick.
					var menuItemContainerIds = control.$sectionContent.sortable( 'toArray' ),
						menuItemControls = [],
						position = 0,
						priority = 10;

					control.isSorting = false;

					// Reset horizontal scroll position when done dragging.
					control.$sectionContent.scrollLeft( 0 );

					_.each( menuItemContainerIds, function( menuItemContainerId ) {
						var menuItemId, menuItemControl, matches;
						matches = menuItemContainerId.match( /^customize-control-nav_menu_item-(-?\d+)$/, '' );
						if ( ! matches ) {
							return;
						}
						menuItemId = parseInt( matches[1], 10 );
						menuItemControl = api.control( 'nav_menu_item[' + String( menuItemId ) + ']' );
						if ( menuItemControl ) {
							menuItemControls.push( menuItemControl );
						}
					} );

					_.each( menuItemControls, function( menuItemControl ) {
						if ( false === menuItemControl.setting() ) {
							// Skip deleted items.
							return;
						}
						var setting = _.clone( menuItemControl.setting() );
						position += 1;
						priority += 1;
						setting.position = position;
						menuItemControl.priority( priority );

						// Note that wpNavMenu will be setting this .menu-item-data-parent-id input's value.
						setting.menu_item_parent = parseInt( menuItemControl.container.find( '.menu-item-data-parent-id' ).val(), 10 );
						if ( ! setting.menu_item_parent ) {
							setting.menu_item_parent = 0;
						}

						menuItemControl.setting.set( setting );
					});

					// Mark all menu items as unprocessed.
					$( 'button.item-edit' ).data( 'needs_accessibility_refresh', true );
				});

			});
			control.isReordering = false;

			/**
			 * Keyboard-accessible reordering.
			 */
			this.container.find( '.reorder-toggle' ).on( 'click', function() {
				control.toggleReordering( ! control.isReordering );
			} );
		},

		/**
		 * Set up UI for adding a new menu item.
		 */
		_setupAddition: function() {
			var self = this;

			this.container.find( '.add-new-menu-item' ).on( 'click', function( event ) {
				if ( self.$sectionContent.hasClass( 'reordering' ) ) {
					return;
				}

				if ( ! $( 'body' ).hasClass( 'adding-menu-items' ) ) {
					$( this ).attr( 'aria-expanded', 'true' );
					api.Menus.availableMenuItemsPanel.open( self );
				} else {
					$( this ).attr( 'aria-expanded', 'false' );
					api.Menus.availableMenuItemsPanel.close();
					event.stopPropagation();
				}
			} );
		},

		_handleDeletion: function() {
			var control = this,
				section,
				menuId = control.params.menu_id,
				removeSection,
				widgetTemplate,
				navMenuCount = 0;
			section = api.section( control.section() );
			removeSection = function() {
				section.container.remove();
				api.section.remove( section.id );
			};

			if ( section && section.expanded() ) {
				section.collapse({
					completeCallback: function() {
						removeSection();
						wp.a11y.speak( api.Menus.data.l10n.menuDeleted );
						api.panel( 'nav_menus' ).focus();
					}
				});
			} else {
				removeSection();
			}

			api.each(function( setting ) {
				if ( /^nav_menu\[/.test( setting.id ) && false !== setting() ) {
					navMenuCount += 1;
				}
			});

			// Remove the menu from any Navigation Menu widgets.
			api.control.each(function( widgetControl ) {
				if ( ! widgetControl.extended( api.controlConstructor.widget_form ) || 'nav_menu' !== widgetControl.params.widget_id_base ) {
					return;
				}
				var select = widgetControl.container.find( 'select' );
				if ( select.val() === String( menuId ) ) {
					select.prop( 'selectedIndex', 0 ).trigger( 'change' );
				}

				widgetControl.container.find( '.nav-menu-widget-form-controls:first' ).toggle( 0 !== navMenuCount );
				widgetControl.container.find( '.nav-menu-widget-no-menus-message:first' ).toggle( 0 === navMenuCount );
				widgetControl.container.find( 'option[value=' + String( menuId ) + ']' ).remove();
			});

			// Remove the menu to the nav menu widget template.
			widgetTemplate = $( '#available-widgets-list .widget-tpl:has( input.id_base[ value=nav_menu ] )' );
			widgetTemplate.find( '.nav-menu-widget-form-controls:first' ).toggle( 0 !== navMenuCount );
			widgetTemplate.find( '.nav-menu-widget-no-menus-message:first' ).toggle( 0 === navMenuCount );
			widgetTemplate.find( 'option[value=' + String( menuId ) + ']' ).remove();
		},

		/**
		 * Update Section Title as menu name is changed.
		 */
		_setupTitle: function() {
			var control = this;

			control.setting.bind( function( menu ) {
				if ( ! menu ) {
					return;
				}

				var section = api.section( control.section() ),
					menuId = control.params.menu_id,
					controlTitle = section.headContainer.find( '.accordion-section-title' ),
					sectionTitle = section.contentContainer.find( '.customize-section-title h3' ),
					location = section.headContainer.find( '.menu-in-location' ),
					action = sectionTitle.find( '.customize-action' ),
					name = displayNavMenuName( menu.name );

				// Update the control title.
				controlTitle.text( name );
				if ( location.length ) {
					location.appendTo( controlTitle );
				}

				// Update the section title.
				sectionTitle.text( name );
				if ( action.length ) {
					action.prependTo( sectionTitle );
				}

				// Update the nav menu name in location selects.
				api.control.each( function( control ) {
					if ( /^nav_menu_locations\[/.test( control.id ) ) {
						control.container.find( 'option[value=' + menuId + ']' ).text( name );
					}
				} );

				// Update the nav menu name in all location checkboxes.
				section.contentContainer.find( '.customize-control-checkbox input' ).each( function() {
					if ( $( this ).prop( 'checked' ) ) {
						$( '.current-menu-location-name-' + $( this ).data( 'location-id' ) ).text( name );
					}
				} );
			} );
		},

		/***********************************************************************
		 * Begin public API methods
		 **********************************************************************/

		/**
		 * Enable/disable the reordering UI
		 *
		 * @param {boolean} showOrHide to enable/disable reordering
		 */
		toggleReordering: function( showOrHide ) {
			var addNewItemBtn = this.container.find( '.add-new-menu-item' ),
				reorderBtn = this.container.find( '.reorder-toggle' ),
				itemsTitle = this.$sectionContent.find( '.item-title' );

			showOrHide = Boolean( showOrHide );

			if ( showOrHide === this.$sectionContent.hasClass( 'reordering' ) ) {
				return;
			}

			this.isReordering = showOrHide;
			this.$sectionContent.toggleClass( 'reordering', showOrHide );
			this.$sectionContent.sortable( this.isReordering ? 'disable' : 'enable' );
			if ( this.isReordering ) {
				addNewItemBtn.attr({ 'tabindex': '-1', 'aria-hidden': 'true' });
				reorderBtn.attr( 'aria-label', api.Menus.data.l10n.reorderLabelOff );
				wp.a11y.speak( api.Menus.data.l10n.reorderModeOn );
				itemsTitle.attr( 'aria-hidden', 'false' );
			} else {
				addNewItemBtn.removeAttr( 'tabindex aria-hidden' );
				reorderBtn.attr( 'aria-label', api.Menus.data.l10n.reorderLabelOn );
				wp.a11y.speak( api.Menus.data.l10n.reorderModeOff );
				itemsTitle.attr( 'aria-hidden', 'true' );
			}

			if ( showOrHide ) {
				_( this.getMenuItemControls() ).each( function( formControl ) {
					formControl.collapseForm();
				} );
			}
		},

		/**
		 * @return {wp.customize.controlConstructor.nav_menu_item[]}
		 */
		getMenuItemControls: function() {
			var menuControl = this,
				menuItemControls = [],
				menuTermId = menuControl.params.menu_id;

			api.control.each(function( control ) {
				if ( 'nav_menu_item' === control.params.type && control.setting() && menuTermId === control.setting().nav_menu_term_id ) {
					menuItemControls.push( control );
				}
			});

			return menuItemControls;
		},

		/**
		 * Make sure that each menu item control has the proper depth.
		 */
		reflowMenuItems: function() {
			var menuControl = this,
				menuItemControls = menuControl.getMenuItemControls(),
				reflowRecursively;

			reflowRecursively = function( context ) {
				var currentMenuItemControls = [],
					thisParent = context.currentParent;
				_.each( context.menuItemControls, function( menuItemControl ) {
					if ( thisParent === menuItemControl.setting().menu_item_parent ) {
						currentMenuItemControls.push( menuItemControl );
						// @todo We could remove this item from menuItemControls now, for efficiency.
					}
				});
				currentMenuItemControls.sort( function( a, b ) {
					return a.setting().position - b.setting().position;
				});

				_.each( currentMenuItemControls, function( menuItemControl ) {
					// Update position.
					context.currentAbsolutePosition += 1;
					menuItemControl.priority.set( context.currentAbsolutePosition ); // This will change the sort order.

					// Update depth.
					if ( ! menuItemControl.container.hasClass( 'menu-item-depth-' + String( context.currentDepth ) ) ) {
						_.each( menuItemControl.container.prop( 'className' ).match( /menu-item-depth-\d+/g ), function( className ) {
							menuItemControl.container.removeClass( className );
						});
						menuItemControl.container.addClass( 'menu-item-depth-' + String( context.currentDepth ) );
					}
					menuItemControl.container.data( 'item-depth', context.currentDepth );

					// Process any children items.
					context.currentDepth += 1;
					context.currentParent = menuItemControl.params.menu_item_id;
					reflowRecursively( context );
					context.currentDepth -= 1;
					context.currentParent = thisParent;
				});

				// Update class names for reordering controls.
				if ( currentMenuItemControls.length ) {
					_( currentMenuItemControls ).each(function( menuItemControl ) {
						menuItemControl.container.removeClass( 'move-up-disabled move-down-disabled move-left-disabled move-right-disabled' );
						if ( 0 === context.currentDepth ) {
							menuItemControl.container.addClass( 'move-left-disabled' );
						} else if ( 10 === context.currentDepth ) {
							menuItemControl.container.addClass( 'move-right-disabled' );
						}
					});

					currentMenuItemControls[0].container
						.addClass( 'move-up-disabled' )
						.addClass( 'move-right-disabled' )
						.toggleClass( 'move-down-disabled', 1 === currentMenuItemControls.length );
					currentMenuItemControls[ currentMenuItemControls.length - 1 ].container
						.addClass( 'move-down-disabled' )
						.toggleClass( 'move-up-disabled', 1 === currentMenuItemControls.length );
				}
			};

			reflowRecursively( {
				menuItemControls: menuItemControls,
				currentParent: 0,
				currentDepth: 0,
				currentAbsolutePosition: 0
			} );

			menuControl.updateInvitationVisibility( menuItemControls );
			menuControl.container.find( '.reorder-toggle' ).toggle( menuItemControls.length > 1 );
		},

		/**
		 * Note that this function gets debounced so that when a lot of setting
		 * changes are made at once, for instance when moving a menu item that
		 * has child items, this function will only be called once all of the
		 * settings have been updated.
		 */
		debouncedReflowMenuItems: _.debounce( function() {
			this.reflowMenuItems.apply( this, arguments );
		}, 0 ),

		/**
		 * Add a new item to this menu.
		 *
		 * @param {Object} item - Value for the nav_menu_item setting to be created.
		 * @return {wp.customize.Menus.controlConstructor.nav_menu_item} The newly-created nav_menu_item control instance.
		 */
		addItemToMenu: function( item ) {
			var menuControl = this, customizeId, settingArgs, setting, menuItemControl, placeholderId, position = 0, priority = 10,
				originalItemId = item.id || '';

			_.each( menuControl.getMenuItemControls(), function( control ) {
				if ( false === control.setting() ) {
					return;
				}
				priority = Math.max( priority, control.priority() );
				if ( 0 === control.setting().menu_item_parent ) {
					position = Math.max( position, control.setting().position );
				}
			});
			position += 1;
			priority += 1;

			item = $.extend(
				{},
				api.Menus.data.defaultSettingValues.nav_menu_item,
				item,
				{
					nav_menu_term_id: menuControl.params.menu_id,
					position: position
				}
			);
			delete item.id; // Only used by Backbone.

			placeholderId = api.Menus.generatePlaceholderAutoIncrementId();
			customizeId = 'nav_menu_item[' + String( placeholderId ) + ']';
			settingArgs = {
				type: 'nav_menu_item',
				transport: api.Menus.data.settingTransport,
				previewer: api.previewer
			};
			setting = api.create( customizeId, customizeId, {}, settingArgs );
			setting.set( item ); // Change from initial empty object to actual item to mark as dirty.

			// Add the menu item control.
			menuItemControl = new api.controlConstructor.nav_menu_item( customizeId, {
				type: 'nav_menu_item',
				section: menuControl.id,
				priority: priority,
				settings: {
					'default': customizeId
				},
				menu_item_id: placeholderId,
				original_item_id: originalItemId
			} );

			api.control.add( menuItemControl );
			setting.preview();
			menuControl.debouncedReflowMenuItems();

			wp.a11y.speak( api.Menus.data.l10n.itemAdded );

			return menuItemControl;
		},

		/**
		 * Show an invitation to add new menu items when there are no menu items.
		 *
		 * @since 4.9.0
		 *
		 * @param {wp.customize.controlConstructor.nav_menu_item[]} optionalMenuItemControls
		 */
		updateInvitationVisibility: function ( optionalMenuItemControls ) {
			var menuItemControls = optionalMenuItemControls || this.getMenuItemControls();

			this.container.find( '.new-menu-item-invitation' ).toggle( menuItemControls.length === 0 );
		}
	} );

	/**
	 * Extends wp.customize.controlConstructor with control constructor for
	 * menu_location, menu_item, nav_menu, and new_menu.
	 */
	$.extend( api.controlConstructor, {
		nav_menu_location: api.Menus.MenuLocationControl,
		nav_menu_item: api.Menus.MenuItemControl,
		nav_menu: api.Menus.MenuControl,
		nav_menu_name: api.Menus.MenuNameControl,
		nav_menu_locations: api.Menus.MenuLocationsControl,
		nav_menu_auto_add: api.Menus.MenuAutoAddControl
	});

	/**
	 * Extends wp.customize.panelConstructor with section constructor for menus.
	 */
	$.extend( api.panelConstructor, {
		nav_menus: api.Menus.MenusPanel
	});

	/**
	 * Extends wp.customize.sectionConstructor with section constructor for menu.
	 */
	$.extend( api.sectionConstructor, {
		nav_menu: api.Menus.MenuSection,
		new_menu: api.Menus.NewMenuSection
	});

	/**
	 * Init Customizer for menus.
	 */
	api.bind( 'ready', function() {

		// Set up the menu items panel.
		api.Menus.availableMenuItemsPanel = new api.Menus.AvailableMenuItemsPanelView({
			collection: api.Menus.availableMenuItems
		});

		api.bind( 'saved', function( data ) {
			if ( data.nav_menu_updates || data.nav_menu_item_updates ) {
				api.Menus.applySavedData( data );
			}
		} );

		/*
		 * Reset the list of posts created in the customizer once published.
		 * The setting is updated quietly (bypassing events being triggered)
		 * so that the customized state doesn't become immediately dirty.
		 */
		api.state( 'changesetStatus' ).bind( function( status ) {
			if ( 'publish' === status ) {
				api( 'nav_menus_created_posts' )._value = [];
			}
		} );

		// Open and focus menu control.
		api.previewer.bind( 'focus-nav-menu-item-control', api.Menus.focusMenuItemControl );
	} );

	/**
	 * When customize_save comes back with a success, make sure any inserted
	 * nav menus and items are properly re-added with their newly-assigned IDs.
	 *
	 * @alias wp.customize.Menus.applySavedData
	 *
	 * @param {Object} data
	 * @param {Array} data.nav_menu_updates
	 * @param {Array} data.nav_menu_item_updates
	 */
	api.Menus.applySavedData = function( data ) {

		var insertedMenuIdMapping = {}, insertedMenuItemIdMapping = {};

		_( data.nav_menu_updates ).each(function( update ) {
			var oldCustomizeId, newCustomizeId, customizeId, oldSetting, newSetting, setting, settingValue, oldSection, newSection, wasSaved, widgetTemplate, navMenuCount, shouldExpandNewSection;
			if ( 'inserted' === update.status ) {
				if ( ! update.previous_term_id ) {
					throw new Error( 'Expected previous_term_id' );
				}
				if ( ! update.term_id ) {
					throw new Error( 'Expected term_id' );
				}
				oldCustomizeId = 'nav_menu[' + String( update.previous_term_id ) + ']';
				if ( ! api.has( oldCustomizeId ) ) {
					throw new Error( 'Expected setting to exist: ' + oldCustomizeId );
				}
				oldSetting = api( oldCustomizeId );
				if ( ! api.section.has( oldCustomizeId ) ) {
					throw new Error( 'Expected control to exist: ' + oldCustomizeId );
				}
				oldSection = api.section( oldCustomizeId );

				settingValue = oldSetting.get();
				if ( ! settingValue ) {
					throw new Error( 'Did not expect setting to be empty (deleted).' );
				}
				settingValue = $.extend( _.clone( settingValue ), update.saved_value );

				insertedMenuIdMapping[ update.previous_term_id ] = update.term_id;
				newCustomizeId = 'nav_menu[' + String( update.term_id ) + ']';
				newSetting = api.create( newCustomizeId, newCustomizeId, settingValue, {
					type: 'nav_menu',
					transport: api.Menus.data.settingTransport,
					previewer: api.previewer
				} );

				shouldExpandNewSection = oldSection.expanded();
				if ( shouldExpandNewSection ) {
					oldSection.collapse();
				}

				// Add the menu section.
				newSection = new api.Menus.MenuSection( newCustomizeId, {
					panel: 'nav_menus',
					title: settingValue.name,
					customizeAction: api.Menus.data.l10n.customizingMenus,
					type: 'nav_menu',
					priority: oldSection.priority.get(),
					menu_id: update.term_id
				} );

				// Add new control for the new menu.
				api.section.add( newSection );

				// Update the values for nav menus in Navigation Menu controls.
				api.control.each( function( setting ) {
					if ( ! setting.extended( api.controlConstructor.widget_form ) || 'nav_menu' !== setting.params.widget_id_base ) {
						return;
					}
					var select, oldMenuOption, newMenuOption;
					select = setting.container.find( 'select' );
					oldMenuOption = select.find( 'option[value=' + String( update.previous_term_id ) + ']' );
					newMenuOption = select.find( 'option[value=' + String( update.term_id ) + ']' );
					newMenuOption.prop( 'selected', oldMenuOption.prop( 'selected' ) );
					oldMenuOption.remove();
				} );

				// Delete the old placeholder nav_menu.
				oldSetting.callbacks.disable(); // Prevent setting triggering Customizer dirty state when set.
				oldSetting.set( false );
				oldSetting.preview();
				newSetting.preview();
				oldSetting._dirty = false;

				// Remove nav_menu section.
				oldSection.container.remove();
				api.section.remove( oldCustomizeId );

				// Update the nav_menu widget to reflect removed placeholder menu.
				navMenuCount = 0;
				api.each(function( setting ) {
					if ( /^nav_menu\[/.test( setting.id ) && false !== setting() ) {
						navMenuCount += 1;
					}
				});
				widgetTemplate = $( '#available-widgets-list .widget-tpl:has( input.id_base[ value=nav_menu ] )' );
				widgetTemplate.find( '.nav-menu-widget-form-controls:first' ).toggle( 0 !== navMenuCount );
				widgetTemplate.find( '.nav-menu-widget-no-menus-message:first' ).toggle( 0 === navMenuCount );
				widgetTemplate.find( 'option[value=' + String( update.previous_term_id ) + ']' ).remove();

				// Update the nav_menu_locations[...] controls to remove the placeholder menus from the dropdown options.
				wp.customize.control.each(function( control ){
					if ( /^nav_menu_locations\[/.test( control.id ) ) {
						control.container.find( 'option[value=' + String( update.previous_term_id ) + ']' ).remove();
					}
				});

				// Update nav_menu_locations to reference the new ID.
				api.each( function( setting ) {
					var wasSaved = api.state( 'saved' ).get();
					if ( /^nav_menu_locations\[/.test( setting.id ) && setting.get() === update.previous_term_id ) {
						setting.set( update.term_id );
						setting._dirty = false; // Not dirty because this is has also just been done on server in WP_Customize_Nav_Menu_Setting::update().
						api.state( 'saved' ).set( wasSaved );
						setting.preview();
					}
				} );

				if ( shouldExpandNewSection ) {
					newSection.expand();
				}
			} else if ( 'updated' === update.status ) {
				customizeId = 'nav_menu[' + String( update.term_id ) + ']';
				if ( ! api.has( customizeId ) ) {
					throw new Error( 'Expected setting to exist: ' + customizeId );
				}

				// Make sure the setting gets updated with its sanitized server value (specifically the conflict-resolved name).
				setting = api( customizeId );
				if ( ! _.isEqual( update.saved_value, setting.get() ) ) {
					wasSaved = api.state( 'saved' ).get();
					setting.set( update.saved_value );
					setting._dirty = false;
					api.state( 'saved' ).set( wasSaved );
				}
			}
		} );

		// Build up mapping of nav_menu_item placeholder IDs to inserted IDs.
		_( data.nav_menu_item_updates ).each(function( update ) {
			if ( update.previous_post_id ) {
				insertedMenuItemIdMapping[ update.previous_post_id ] = update.post_id;
			}
		});

		_( data.nav_menu_item_updates ).each(function( update ) {
			var oldCustomizeId, newCustomizeId, oldSetting, newSetting, settingValue, oldControl, newControl;
			if ( 'inserted' === update.status ) {
				if ( ! update.previous_post_id ) {
					throw new Error( 'Expected previous_post_id' );
				}
				if ( ! update.post_id ) {
					throw new Error( 'Expected post_id' );
				}
				oldCustomizeId = 'nav_menu_item[' + String( update.previous_post_id ) + ']';
				if ( ! api.has( oldCustomizeId ) ) {
					throw new Error( 'Expected setting to exist: ' + oldCustomizeId );
				}
				oldSetting = api( oldCustomizeId );
				if ( ! api.control.has( oldCustomizeId ) ) {
					throw new Error( 'Expected control to exist: ' + oldCustomizeId );
				}
				oldControl = api.control( oldCustomizeId );

				settingValue = oldSetting.get();
				if ( ! settingValue ) {
					throw new Error( 'Did not expect setting to be empty (deleted).' );
				}
				settingValue = _.clone( settingValue );

				// If the parent menu item was also inserted, update the menu_item_parent to the new ID.
				if ( settingValue.menu_item_parent < 0 ) {
					if ( ! insertedMenuItemIdMapping[ settingValue.menu_item_parent ] ) {
						throw new Error( 'inserted ID for menu_item_parent not available' );
					}
					settingValue.menu_item_parent = insertedMenuItemIdMapping[ settingValue.menu_item_parent ];
				}

				// If the menu was also inserted, then make sure it uses the new menu ID for nav_menu_term_id.
				if ( insertedMenuIdMapping[ settingValue.nav_menu_term_id ] ) {
					settingValue.nav_menu_term_id = insertedMenuIdMapping[ settingValue.nav_menu_term_id ];
				}

				newCustomizeId = 'nav_menu_item[' + String( update.post_id ) + ']';
				newSetting = api.create( newCustomizeId, newCustomizeId, settingValue, {
					type: 'nav_menu_item',
					transport: api.Menus.data.settingTransport,
					previewer: api.previewer
				} );

				// Add the menu control.
				newControl = new api.controlConstructor.nav_menu_item( newCustomizeId, {
					type: 'nav_menu_item',
					menu_id: update.post_id,
					section: 'nav_menu[' + String( settingValue.nav_menu_term_id ) + ']',
					priority: oldControl.priority.get(),
					settings: {
						'default': newCustomizeId
					},
					menu_item_id: update.post_id
				} );

				// Remove old control.
				oldControl.container.remove();
				api.control.remove( oldCustomizeId );

				// Add new control to take its place.
				api.control.add( newControl );

				// Delete the placeholder and preview the new setting.
				oldSetting.callbacks.disable(); // Prevent setting triggering Customizer dirty state when set.
				oldSetting.set( false );
				oldSetting.preview();
				newSetting.preview();
				oldSetting._dirty = false;

				newControl.container.toggleClass( 'menu-item-edit-inactive', oldControl.container.hasClass( 'menu-item-edit-inactive' ) );
			}
		});

		/*
		 * Update the settings for any nav_menu widgets that had selected a placeholder ID.
		 */
		_.each( data.widget_nav_menu_updates, function( widgetSettingValue, widgetSettingId ) {
			var setting = api( widgetSettingId );
			if ( setting ) {
				setting._value = widgetSettingValue;
				setting.preview(); // Send to the preview now so that menu refresh will use the inserted menu.
			}
		});
	};

	/**
	 * Focus a menu item control.
	 *
	 * @alias wp.customize.Menus.focusMenuItemControl
	 *
	 * @param {string} menuItemId
	 */
	api.Menus.focusMenuItemControl = function( menuItemId ) {
		var control = api.Menus.getMenuItemControl( menuItemId );
		if ( control ) {
			control.focus();
		}
	};

	/**
	 * Get the control for a given menu.
	 *
	 * @alias wp.customize.Menus.getMenuControl
	 *
	 * @param menuId
	 * @return {wp.customize.controlConstructor.menus[]}
	 */
	api.Menus.getMenuControl = function( menuId ) {
		return api.control( 'nav_menu[' + menuId + ']' );
	};

	/**
	 * Given a menu item ID, get the control associated with it.
	 *
	 * @alias wp.customize.Menus.getMenuItemControl
	 *
	 * @param {string} menuItemId
	 * @return {Object|null}
	 */
	api.Menus.getMenuItemControl = function( menuItemId ) {
		return api.control( menuItemIdToSettingId( menuItemId ) );
	};

	/**
	 * @alias wp.customize.Menus~menuItemIdToSettingId
	 *
	 * @param {string} menuItemId
	 */
	function menuItemIdToSettingId( menuItemId ) {
		return 'nav_menu_item[' + menuItemId + ']';
	}

	/**
	 * Apply sanitize_text_field()-like logic to the supplied name, returning a
	 * "unnammed" fallback string if the name is then empty.
	 *
	 * @alias wp.customize.Menus~displayNavMenuName
	 *
	 * @param {string} name
	 * @return {string}
	 */
	function displayNavMenuName( name ) {
		name = name || '';
		name = wp.sanitize.stripTagsAndEncodeText( name ); // Remove any potential tags from name.
		name = name.toString().trim();
		return name || api.Menus.data.l10n.unnamed;
	}

})( wp.customize, wp, jQuery );