EventDispatcher.js

/**
 * EventDispatcherEvent
 *
 * @param eventName
 * @param payload
 * @constructor
 */
var EventDispatcherEvent = function (eventName, payload) {
  this._stoppped = false;
  this._name = eventName;

  // make shure the payload is an array
  if (!payload || Object.prototype.toString.call(payload) !== '[object Array]') {
    this._payload = [];
  }
  else {
    this._payload = payload;
  }
};


/**
 * Returns the event-name
 *
 * @returns {*}
 */
EventDispatcherEvent.prototype.getName = function () {
  return this._name;
};


/**
 * Stops the event to it won't be dispatches to the remaining callbacks
 *
 * @returns {EventDispatcherEvent}
 */
EventDispatcherEvent.prototype.stopPropagation = function () {
  this._stoppped = true;
  return this;
};


/**
 * Returns the stopped flag
 *
 * @returns {boolean}
 */
EventDispatcherEvent.prototype.isStopped = function () {
  return (true === this._stoppped);
};


/**
 * Executs the given callback for this event (if it's not stopped yet)
 *
 * @param callback
 * @returns {EventDispatcherEvent}
 */
EventDispatcherEvent.prototype.executeCallback = function (callback) {

  // event already stopped?
  if (!this.isStopped()) {

    // create a copy if the payload
    var args = this._payload.slice(0);

    // add the event to the end of the callback args
    args.push(this);

    // run the callback
    callback.apply(null, args)
  }

  return this;
};

/******************************************************************************************/

/**
 * EventDispatcher
 *
 * @constructor
 */
var EventDispatcher = function () {
  this.registry = {};
};


/**
 * Registers the given callback for the event
 *
 * @param eventName
 * @param callback
 * @returns {EventDispatcher}
 */
EventDispatcher.prototype.on = function (eventName, callback) {
  if (callback) {
    if (typeof this.registry[eventName] === 'undefined') {
      this.registry[eventName] = [];
    }
    this.registry[eventName].push(callback);
  }

  return this;
};


/**
 * Unregisters the given callback for the event, if no callback is provided ALL callbacks will be removed
 *
 * @param eventName
 * @param callback
 * @returns {EventDispatcher}
 */
EventDispatcher.prototype.off = function (eventName, callback) {
  if (typeof this.registry[eventName] !== 'undefined') {
    if (callback) {
      for (var i = 0; i < this.registry[eventName].length; i++) {
        if (this.registry[eventName][i] === callback) {
          delete this.registry[eventName][i];
          i--;
        }
      }
    }
    else {
      delete this.registry[eventName];
    }
  }

  return this;
};


/**
 * Fires an event and dispatch payload to all events
 *
 * @param eventName
 * @param payload
 * @returns {EventDispatcher}
 */
EventDispatcher.prototype.fire = function (eventName, payload) {
  if (typeof this.registry[eventName] !== 'undefined') {
    var fireEvent = new EventDispatcherEvent(eventName, payload);
    for (var i = 0; i < this.registry[eventName].length; i++) {
      fireEvent.executeCallback(this.registry[eventName][i]);
    }
  }

  return this;
};