@atlassian/aui/src/js/aui/navigation.js

import { I18n } from './i18n';
import $ from './jquery';
import skate from './internal/skate';
import globalize from './internal/globalize';
import widget from './internal/widget';

/**
 * Navigation (".aui-nav" elements).
 *
 * @param {(string|HtmlElement|jQuery)} selector - An expression
 *     representing a single .aui-nav element; you may also pass an expression
 *     for a descendent element, in which case the closest containing
 *     .aui-nav element is used.
 * @constructor
 */
function Navigation (selector) {
    this.$el = $(selector).closest('.aui-nav');

    // If there are multiple objects, initialise them separately
    if (this.$el.length > 1) {
        return this.$el.map(function (idx, elm) {
            return new Navigation(elm);
        })[0];
    }

    // If already initialised, return existing object
    if (this.$el.data('aui-navigation')) {
        return this.$el.data('aui-navigation');
    }

    this.$el.data('aui-navigation', this);

    this.$treeParent = this.$el.parent('li[aria-expanded]');
    this.$subtreeToggleIcon = this.$treeParent
        .children('.aui-nav-subtree-toggle')
        .children('span.aui-icon');

    // Add child-selected class to relevant attributes
    this.$el.children('li:has(.aui-nav-selected)').addClass('aui-nav-child-selected');

    // Auto-expand if child is selected
    var $selected = this.$el.children('.aui-nav-selected');
    $selected
        .parents('.aui-nav > [aria-expanded=false]')
        .add($selected.filter('[aria-expanded=false]'))
        .each(function () {
            var nav = navigationWidget($(this).children('.aui-nav'));
            nav.expand();
        });

    // Toggle expand on click
    var $togglers = this.$el.find('> li[aria-expanded] > .aui-nav-subtree-toggle');
    $togglers.on('click', function () {
        var nav = navigationWidget($(this).siblings('.aui-nav'));
        nav.toggle();
    });

    // Make sure subtree togglers have proper a11y label
    $togglers.each(function () {
        var $parent = $(this).parent('li[aria-expanded]');
        var $icon = $(this).find('.aui-icon');
        var isListItemExpanded = $parent.attr('aria-expanded') === 'true';

        $icon.text(
            isListItemExpanded ?
                I18n.getText('aui.words.collapse') :
                I18n.getText('aui.words.expand')
        );
    })

    return this;
}

Navigation.prototype.isNested = function () {
    return this.$treeParent.length === 1;
};

Navigation.prototype.isCollapsed = function () {
    return this.$treeParent.attr('aria-expanded') === 'false';
};

Navigation.prototype.expand = function () {
    this.$treeParent.attr('aria-expanded', 'true');
    this.$subtreeToggleIcon
        .removeClass('aui-iconfont-collapsed')
        .addClass('aui-iconfont-expanded')
        .text(I18n.getText('aui.words.collapse'));
    return this;
};

Navigation.prototype.collapse = function () {
    this.$treeParent.attr('aria-expanded', 'false');
    this.$subtreeToggleIcon
        .removeClass('aui-iconfont-expanded')
        .addClass('aui-iconfont-collapsed')
        .text(I18n.getText('aui.words.expand'));
    return this;
};

Navigation.prototype.toggle = function () {
    if (this.isCollapsed()) {
        this.expand();
    } else {
        this.collapse();
    }
    return this;
};

const navigationWidget = widget('navigation', Navigation);

// Initialise nav elements
const NavigationEl = skate('aui-nav', {
    type: skate.type.CLASSNAME,
    attached: function (element) {
        new Navigation(element);
    },
    detached: function (element) {
        $(element).removeData();
    }
});

globalize('navigation', navigationWidget);

export default navigationWidget;
export {
    NavigationEl
};