cocktail-trait-eventable

A CocktailJS Trait Extension

A trait to use an Emitter as a delegate.

$3

```bash
npm install cocktail --save
npm install cocktail-trait-eventable --save
``

$3

A getEmitter method is required as a glue code for this trait.

getEmitter(): should return an EventEmitter instance or any other object with the same api as node events.EventEmitter class.

$3

MyClass.js

``javascript
var cocktail = require('cocktail'),
Eventable = require('cocktail-trait-eventable'),
EventEmitter = require('events').EventEmitter;

cocktail.mix({
'@exports': module,
'@as' : 'class',

'@traits' : [Eventable],

constructor: function() {
this._emitter = new EventEmitter();
},

// glue code for Eventable Trait
getEmitter: function() {
return this._emitter;
},

doSomethingAndFireEvent: function(){
// ... do something here
// and
// now fire an event 'firing'
this.emit('firing', this);
}
});
``

And then in your index you can do:

index.js

``javascript

var MyClass = require('./MyClass'),
obj;

obj = new MyClass();

//we can call on or addListener here since our MyClass is Eventable
obj.on('firing', function(){ console.log('Event Fired!'); });

obj.doSomethingAndFireEvent();
``

$3

The following methods will be publicly available on the host class:

- addListener(eventName, handler): Adds a listener to the end of the listeners array for the specified event.
- eventName: {String} the event name to be listened to.
- handler: {Function} the event handler.

``javascript
myObj.addListener('event', function(){/handler/});
``

- addListener(options): Adds a listener to the end of the listeners array for the specified event.
- options: {Object} an object containing value-pairs of event name and handler and an optional scope.

``javascript
myObj.addListener({event: myObj.onEvent, scope: myObj});
``

- emit(eventName, arg1, arg2, ..., argN): Execute each of the listeners in order with the supplied arguments.
- eventName: {String} the event name to be listened to.
- arg1..N: {Any} arguments to be passed as parameters in the event handler.

``javascript
myObj.emit('event', myObj, true, 1, 'another param');
``

- on(eventName, handler): Idem addListener method.

``javascript
myObj.on('event', function(){/handler/});
``

- on(options): Idem addListener method.

``javascript
myObj.on({event: myObj.onEvent, scope: myObj});
``

- once(eventName, handler): Adds a one time event listener.
- eventName: {String} the event name to be listened to.
- handler: {Function} the event handler.

``javascript
myObj.once('event', function(){/handler/});
``

- once(options): Adds a one time event listener.
- options: {Object} an object containing value-pairs of event name and handler and an optional scope.

``javascript
myObj.once({event: myObj.onEvent, scope: myObj});
``

- removeListener(eventName, handler): Removes the given handler for the event.
- eventName: {String} the event name.
- handler: {Function} the event handler.

``javascript
myObj.removeListener('event', funcHandler);
``

- removeListener(options): Removes the given handler for the event.
- options: {Object} an object containing value-pairs of event name and handler.

``javascript
myObj.removeListener({event: myObj.onEvent});
``

- removeAllListeners(eventName): Remove all listeners for the given event.
- eventName: {String} the event name.

``javascript
myObj.removeAllListeners();
```