A simple event maker. Creates a function to which other functions can be added and removed for execution when the outer function is called.

event.js

function event() {
    var a = [].slice.call(arguments);
    var fn = function() {
        var scope = this;
        var args = [].slice.call(arguments);
        a.forEach(function(f){f.apply(scope, args);});
    };
    fn.add = function() {
        a.push.apply(a, arguments);
        return fn;
    };
    fn.remove = function(f) {
        for(var i = a.length - 1; i >= 0; i--) {
            if(a[i] === f) {
                a.splice(i, 1);
            }
        }
        return fn;
    };
    fn.clear = function() {
        a.length = 0;
    };
    return fn;
}

// example usage

var el = document.body;

el.onclick = event();

el.onclick.add(function(){this.style.backgroundColor = 'red'});
el.onclick.add(function(){ var that = this; setTimeout( function() {that.style.backgroundColor = 'white'}, 1000); });