Vanilla JS Document Ready

documentReady.js

(function (exports, d) {
    function domReady(fn, context) {

        function callFn() {
            return fn.call(context || exports, event);
        }

        if (d.readyState === 'interactive' || d.readyState === 'complete') {
            return callFn();
        }
        
        if (d.addEventListener) {
            d.addEventListener('DOMContentLoaded', function () {
                return callFn();
            })
        } else {
            d.attachEvent('onreadystatechange', function () {
                if (d.readyState === 'complete') {
                    return callFn();
                }
            });
        }
    }

    exports.domReady = domReady;
})(window, document);