eventdispatcher

Various ways of dispatching event (eventdispatcher and eventbus).

Basic usage:

// The example below will cause an event to be created and dispatched on the default event channel.
var bus = new EventBus();

var Car = function() {
  bus.listen("turnLeft", this, this._onTurnLeft);
};

Car.prototype._onTurnLeft = function() {
  console.log("turn");
};

var Wheel = function() {
}

Wheel.prototype.turn = function() {
  bus.dispatch("turnLeft");
}

var car = new Car();
new Wheel().turn;

Event channels:

// The example below makes use of a custom event channel to dispatch events.
var bus = new EventBus();
var channel = bus.getChannel("VW");

var Car = function(channel) {
  channel.listen("turnLeft", this._onTurnLeft, this);
  // OR bus.listen("turnLeft", this._onTurnLeft, this, "VW");
};

Car.prototype._onTurnLeft = function() {
  console.log("turn");
};

var Wheel = function(channel) {
  this._channel = channel;
}

Wheel.prototype.turn = function() {
  this._channel.dispatch("turnLeft");
  // OR bus.dispatch("turnLeft", "VW");
}

var car = new Car();
new Wheel().turn;

Putting it all together, Events, EventChannel & the Bus.

// We will now also use a custom Event class.
var bus = new EventBus();
var channel = bus.getChannel("VW");

/**
 * A custom event class to store all event names and define what can be passed in the message.
 */
var DrivingEvent = function(eventName, turnAngle, target) {
  this.turnAngle = turnAngle;
}
DrivingEvent.prototype = Object.create(Event.Prototype); // Event being the custom event class used in the library.

DrivingEvent.TURN_LEFT = "turnLeft"; // Store the events as 'constants' for documentation and clarity.
DrivingEvent.TURN_RIGHT = "turnRight"; // etc...

var Car = function(channel) {
  channel.listen(DrivingEvent.TURN_LEFT, this, this._onTurnLeft);
  // OR bus.listen(DrivingEvent.TURN_LEFT, this, this._onTurnLeft, "VW");
};

Car.prototype._onTurnLeft = function(event) {
  console.log("turning by " + event.turnAngle);
};

var Wheel = function(channel) {
  this._channel = channel;
}

Wheel.prototype.turn = function() {
  var event = new DrivingEvent(DrivingEvent.TURN_LEFT, 20);
  this._channel.dispatch(event);
  // OR bus.dispatch(event, "VW");
}

var car = new Car();
new Wheel().turn;