namespace-emitter

A small event emitter with namespaces.

Not meant as a replacement for node's events module, but as a small component for browser js.

Install

npm install --save namespace-emitter

Example

1var emitter = require('namespace-emitter')()
2
3emitter.on('*', function () {
4  console.log('all events emitted', this.event)
5})
6
7emitter.on('example', function () {
8  console.log('example event emitted')
9})
10
11emitter.emit('example')
12// -> example event emitted
13// -> all events emitted example
14
15emitter.on('demo', function () {
16  console.log('multiple events with `demo` namespace emitted', this.event)
17})
18
19emitter.emit('demo:cool')
20// -> all events emitted demo:cool
21// -> multiple events with `demo` namespace emitted demo:cool
22
23emitter.emit('demo:awesome')
24// -> all events emitted demo:awesome
25// -> multiple events with `demo` namespace emitted demo:awesome
26
27emitter.emit('demo:great')
28// -> all events emitted demo:great
29// -> multiple events with `demo` namespace emitted demo:great

API

createNamespaceEmitter

Create an event emitter with namespaces

Examples

1var emitter = require('./index')()
2
3emitter.on('*', function () {
4  console.log('all events emitted', this.event)
5})
6
7emitter.on('example', function () {
8  console.log('example event emitted')
9})

emit

Emit an event. Optionally namespace the event. Handlers are fired in the order in which they were added with exact matches taking precedence. Separate the namespace and event with a :

Parameters

• event String – the name of the event, with optional namespace
• data ...Any – data variables that will be passed as arguments to the event listener

Examples

1emitter.emit('example')
2emitter.emit('demo:test')
3emitter.emit('data', { example: true}, 'a string', 1)

off

Stop listening to an event. Stop all listeners on an event by only passing the event name. Stop a single listener by passing that event handler as a callback. You must be explicit about what will be unsubscribed: emitter.off('demo') will unsubscribe an emitter.on('demo') listener, emitter.off('demo:example') will unsubscribe an emitter.on('demo:example') listener

Parameters

• event String
• fn [Function] – the specific handler

Examples

1emitter.off('example')
2emitter.off('demo', function () {})

on

Create en event listener.

Parameters

• event String
• fn Function

Examples

1emitter.on('example', function () {})
2emitter.on('demo', function () {})

once

Create en event listener that fires once.

Parameters

• event String
• fn Function

Examples

1emitter.once('example', function () {})
2emitter.once('demo', function () {})

License

MIT