https://animalfacts.com/wp-content/themes/animal-facts/js/navigation.js?ver=1.1.10

1/**
2 * File navigation.js.
3 *
4 * Handles toggling the navigation menu for small screens and enables TAB key
5 * navigation support for dropdown menus.
6 */
7( function() {
8	const siteNavigation = document.getElementById( 'site-navigation' );
9
10	// Return early if the navigation doesn't exist.
11	if ( ! siteNavigation ) {
12		return;
13	}
14
15	const button = siteNavigation.getElementsByTagName( 'button' )[ 0 ];
16
17	// Return early if the button doesn't exist.
18	if ( 'undefined' === typeof button ) {
19		return;
20	}
21
22	const menu = siteNavigation.getElementsByTagName( 'ul' )[ 0 ];
23
24	// Hide menu toggle button if menu is empty and return early.
25	if ( 'undefined' === typeof menu ) {
26		button.style.display = 'none';
27		return;
28	}
29
30	if ( ! menu.classList.contains( 'nav-menu' ) ) {
31		menu.classList.add( 'nav-menu' );
32	}
33
34	// Toggle the .toggled class and the aria-expanded value each time the button is clicked.
35	button.addEventListener(
36		'click',
37		function() {
38			siteNavigation.classList.toggle( 'toggled' );
39
40			if ( button.getAttribute( 'aria-expanded' ) === 'true' ) {
41				button.setAttribute( 'aria-expanded', 'false' );
42			} else {
43				button.setAttribute( 'aria-expanded', 'true' );
44			}
45		}
46	);
47
48	// Remove the .toggled class and set aria-expanded to false when the user clicks outside the navigation.
49	document.addEventListener(
50		'click',
51		function( event ) {
52			const isClickInside = siteNavigation.contains( event.target );
53
54			if ( ! isClickInside ) {
55				siteNavigation.classList.remove( 'toggled' );
56				button.setAttribute( 'aria-expanded', 'false' );
57			}
58		}
59	);
60
61	// Get all the link elements within the menu.
62	const links = menu.getElementsByTagName( 'a' );
63
64	// Get all the link elements with children within the menu.
65	const linksWithChildren = menu.querySelectorAll( '.menu-item-has-children > a, .page_item_has_children > a' );
66
67	// Toggle focus each time a menu link is focused or blurred.
68	for ( const link of links ) {
69		link.addEventListener( 'focus', toggleFocus, true );
70		link.addEventListener( 'blur', toggleFocus, true );
71	}
72
73	// Toggle focus each time a menu link with children receive a touch event.
74	for ( const link of linksWithChildren ) {
75		link.addEventListener( 'touchstart', toggleFocus, false );
76	}
77
78	/**
79	 * Sets or removes .focus class on an element.
80	 */
81	function toggleFocus() {
82		if ( event.type === 'focus' || event.type === 'blur' ) {
83			let self = this;
84			// Move up through the ancestors of the current link until we hit .nav-menu.
85			while ( ! self.classList.contains( 'nav-menu' ) ) {
86				// On li elements toggle the class .focus.
87				if ( 'li' === self.tagName.toLowerCase() ) {
88					self.classList.toggle( 'focus' );
89				}
90				self = self.parentNode;
91			}
92		}
93
94		if ( event.type === 'touchstart' ) {
95			const menuItem = this.parentNode;
96			event.preventDefault();
97			for ( const link of menuItem.parentNode.children ) {
98				if ( menuItem !== link ) {
99					link.classList.remove( 'focus' );
100				}
101			}
102			menuItem.classList.toggle( 'focus' );
103		}
104	}
105}() );