cocktail-trait-eventable
v0.0.7
Published
EventEmitter as delegate trait
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cocktail-trait-eventable
A CocktailJS Trait Extension
A trait to use an Emitter as a delegate.
Install
npm install cocktail --save
npm install cocktail-trait-eventable --save
Trait requires (glue code)
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.
Usage
MyClass.js
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
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();
API
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.
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.
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.
myObj.emit('event', myObj, true, 1, 'another param');
on(eventName, handler)
: IdemaddListener
method.
myObj.on('event', function(){/*handler*/});
on(options)
: IdemaddListener
method.
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.
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.
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.
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.
myObj.removeListener({event: myObj.onEvent});
removeAllListeners(eventName)
: Remove all listeners for the given event.- eventName: {String} the event name.
myObj.removeAllListeners();