1 /**

     2  * File skip-link-focus-fix.js.

     3  *

     4  * Helps with accessibility for keyboard only users.

     5  *

     6  * Learn more: https://git.io/vWdr2

     7  */

     8 (function() {

     9 	var isIe = /(trident|msie)/i.test( navigator.userAgent );

    10 

    11 	if ( isIe && document.getElementById && window.addEventListener ) {

    12 		window.addEventListener( 'hashchange', function() {

    13 			var id = location.hash.substring( 1 ),

    14 				element;

    15 

    16 			if ( ! ( /^[A-z0-9_-]+$/.test( id ) ) ) {

    17 				return;

    18 			}

    19 

    20 			element = document.getElementById( id );

    21 

    22 			if ( element ) {

    23 				if ( ! ( /^(?:a|select|input|button|textarea)$/i.test( element.tagName ) ) ) {

    24 					element.tabIndex = -1;

    25 				}

    26 

    27 				element.focus();

    28 			}

    29 		}, false );

    30 	}

    31 })();