Uncaught TypeError: Cannot call method 'addEventListener' of undefined

Question

can't figure out where is the error in this code. Chrome debug console keep saying "Uncaught TypeError: Cannot call method 'addEventListener' of undefined" at line 31!

jewel.dom = (function() {

    var $ = Sizzle;

    function hasClass(el, clsName){

        var regex = new RegExp("(^|\\s) + clsName + (\\s|$)");
        return regex.test(el.className);
    }

    function addClass(el, clsName) {

        if (!hasClass(el,clsName)) {
            el.className += ""+ clsName;
        }
    }

    function removeClass (el, clsName) {

        var regex = new RegExp("(^|\\s)" + clsName + "(\\s|$)");
        el.className = el.className.replace(regex, " ");
    }

    function bind(element, event, handler) {

        if (typeof element == "string") {
            element = $(element)[0];
        }

        element.addEventListener(event, handler, false)
}

    return {
        $:$,
        hasClass : hasClass,
        addClass : addClass,
        removeClass : removeClass,
        bind : bind
    };
;}) ();

Answer 1

In my case, this is caused by Evernote Clipper extension script. You will find "Evernote" in comment when you click to that script who throws out the error.

Answer 2

Could it be the case that your bind invocation ends up with an undefined element ? (eg you pass a selector that does not match any of the elements in your DOM)

Answer 3

some browsers don't know what "addEventListener" is. Try this:

Element.prototype.setEvent = function(eventName, handler)
{
    if(document.addEventListener)
    {
        this.addEventListener(eventName, handler);
    }
    else
    {
        if(document.attachEvent)
        {
            this.attachEvent("on" + eventName, handler);
        }
    }
}
element.setEvent(eventName, handler);

The same goes for removeEventListener.

Also, try to replace

 element = $(element)[0];

with

 element = $("#" + element);

provided that string contains the id of the element, or

 element = $("." + element)[0];

if the string contains the className of the element.