https://www.energy-transitions.org/wp-content/themes/etc/js/classie.js?ver=7.0.6

1/*!
2 * classie - class helper functions
3 * from bonzo https://github.com/ded/bonzo
4 *
5 * classie.has( elem, 'my-class' ) -> true/false
6 * classie.add( elem, 'my-new-class' )
7 * classie.remove( elem, 'my-unwanted-class' )
8 * classie.toggle( elem, 'my-class' )
9 */
10
11/*jshint browser: true, strict: true, undef: true */
12
13(function (window) {
14  "use strict";
15
16  // class helper functions from bonzo https://github.com/ded/bonzo
17
18  function classReg(className) {
19    return new RegExp("(^|\\s+)" + className + "(\\s+|$)");
20  }
21
22  // classList support for class management
23  // altho to be fair, the api sucks because it won't accept multiple classes at once
24  var hasClass, addClass, removeClass;
25
26  if ("classList" in document.documentElement) {
27    hasClass = function (elem, c) {
28      return elem.classList.contains(c);
29    };
30    addClass = function (elem, c) {
31      elem.classList.add(c);
32    };
33    removeClass = function (elem, c) {
34      elem.classList.remove(c);
35    };
36  } else {
37    hasClass = function (elem, c) {
38      return classReg(c).test(elem.className);
39    };
40    addClass = function (elem, c) {
41      if (!hasClass(elem, c)) {
42        elem.className = elem.className + " " + c;
43      }
44    };
45    removeClass = function (elem, c) {
46      elem.className = elem.className.replace(classReg(c), " ");
47    };
48  }
49
50  function toggleClass(elem, c) {
51    var fn = hasClass(elem, c) ? removeClass : addClass;
52    fn(elem, c);
53  }
54
55  window.classie = {
56    // full names
57    hasClass: hasClass,
58    addClass: addClass,
59    removeClass: removeClass,
60    toggleClass: toggleClass,
61    // short names
62    has: hasClass,
63    add: addClass,
64    remove: removeClass,
65    toggle: toggleClass,
66  };
67})(window);