EventEmitter3 is a faster alternative to EventEmitter2 and the built-in EventEmitter that ships within Node.js. It removes some features that you might not need:
- Domain support.
- Thrown errors when there are no error listeners specified.
- That a
newListener
event is emitted when an event is emitted. - No silly
setMaxListeners
. - No silly
listenerCount
function.. Just doEventEmitter.listeners(event).length
And adds some features you want:
- Emit events with a custom context without binding:
EE.on(event, fn, context)
which also works with onceEE.once(event, fn, context)
It's a drop in replacement of your existing EventEmitters, but just faster. Free performance, who wouldn't want that?
The source of the EventEmitter is compatible for browser usage, no fancy pancy
Array.isArray
stuff is used, it's just plain ol JavaScript that should even
work IE5 if you want to. This module currently serves its use in
Primus's client file.
$ npm install --save eventemitter3
or as a component
$ component install eventemitter3
then
var EventEmitter = require('eventemitter3');
// or
var EventEmitter = require('eventemitter3').EventEmitter;
For API methods see the official Node.js documentation: