custom EventTargets à la the DOM variant.

gistfile1.txt

CustomEventTarget = (function () {
    function CustomEventTarget() {
        if (!(this instanceof CustomEventTarget)) {
            return new CustomEventTarget();
        };
        Object.defineProperty(this, '_listeners_', {
            value: {}
        });
    };
    method(CustomEventTarget, 'addEventListener', function (type, func) {
        this._listeners_[type] = this._listeners_[type] || [];
        this._listeners_[type].push(func);
    });
    method(CustomEventTarget, 'removeEventListener', function (type, func) {
        if (typeof this._listeners_[type] !== 'undefined') {
            var index = this._listeners_[type].indexOf(func);
            if (index !== -1) {
                this._listeners_[type].splice(index, 1);
            };
        };
    });
    method(CustomEventTarget, 'dispatchEvent', function (type) {
        if (typeof this._listeners_[type] !== 'undefined') {
            var args = Array.prototype.slice.call(arguments).slice(1);
            var self = this;
            self._listeners_[type].forEach(function (elem) {
                elem.apply(self, args);
            });
        };
    });
    
    return CustomEventTarget
})();