Some super-simple event-emitter functions

gistfile1.txt

  function createEmitter(object) {
    // a place to hold callbacks for event subscribers
    object._eventStore = {};

    object.on = function(eventName, fn) {
      if (!this._eventStore[eventName]) {
        this._eventStore[eventName] = [];
      }
      this._eventStore[eventName].push(fn);
    };

    object.off = function(eventName) {
      this._eventStore[eventName] = null;
    };

    object.trigger = function(eventName) {
      if (!this._eventStore[eventName]) {
        return;
      }
      this._eventStore[eventName].forEach(function (cb) {
        cb();
      });
    };
  }