Legacy JS

legacy.js

// THE GOAL
// Write $('ul').on('click', 'a', fn); in JavaScript
// Must support old IE (so no Selectors API (matchesSelector) or anything)
// Can you shorten this?

var addEvent = (window.addEventListener ? 
        function (el, ev, fn) {
            el.addEventListener(ev, fn, false); 
        } : 
        function (el, ev, fn) {
            el.attachEvent('on' + ev, function() {
                return fn.call(el, window.event);
            });
        }
);

var uls = document.getElementsByTagName('ul');

for ( var i = 0, len = uls.length; i < len; i++ ) {
	addEvent(uls[i], 'click', function() {
		if ( e.target && e.target.nodeName.toLowerCase() === 'a' ) {
			// proceed
		}
	});
}