addEventListener polyfill for IE6+

addEventListener-polyfill.js

//addEventListener polyfill 1.0 / Eirik Backer / MIT Licence
(function(win, doc){
	if(win.addEventListener)return;		//No need to polyfill

	function docHijack(p){var old = doc[p];doc[p] = function(v){return addListen(old(v))}}
	function addEvent(on, fn, self){
		return (self = this).attachEvent('on' + on, function(e){
			var e = e || win.event;
			e.preventDefault  = e.preventDefault  || function(){e.returnValue = false}
			e.stopPropagation = e.stopPropagation || function(){e.cancelBubble = true}
			fn.call(self, e);
		});
	}
	function addListen(obj, i){
		if(i = obj.length)while(i--)obj[i].addEventListener = addEvent;
		else obj.addEventListener = addEvent;
		return obj;
	}

	addListen([doc, win]);
	if('Element' in win)win.Element.prototype.addEventListener = addEvent;			//IE8
	else{		//IE < 8
		doc.attachEvent('onreadystatechange', function(){addListen(doc.all)});		//Make sure we also init at domReady
		docHijack('getElementsByTagName');
		docHijack('getElementById');
		docHijack('createElement');
		addListen(doc.all);	
	}
})(window, document);

@sounisi5011 Great stuff, I took the liberty to add your work in Git to give the opportunity for anyone to contribute: https://github.com/nbouvrette/eventListenerPolyfill

I started using it in one of my projects and so far no issues.

The original version, it occurs an error while use it with jQuery in lte IE 8 after bundled via WebPack with jQuery. It fills only addEventListener. When jQuery loaded then detect eventListener via only addEventListener then jQuery try to use removeEventListener that you can see on Ready.js in jQuery 1.12.4.

@nbouvrette Could I sure to use your version for "DOMContentLoaded" also?

Fine work, thank you. There may be an issue with line 11:

fn.call(self, e);

In case that fn is an empty object. When running IE11 in emulation mode for IE8, then it reports that this method is unavailable:

Das Objekt unterstützt diese Aktion nicht.

Adding a condition helps:

if ("call" in fn) fn.call(self, e);