namespace-emitter

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

var emitter = require('namespace-emitter')()

emitter.on('*', function () {
  console.log('all events emitted', this.event)
})

emitter.on('example', function () {
  console.log('example event emitted')
})

emitter.emit('example')
// -> example event emitted
// -> all events emitted example

emitter.on('demo', function () {
  console.log('multiple events with `demo` namespace emitted', this.event)
})

emitter.emit('demo:cool')
// -> all events emitted demo:cool
// -> multiple events with `demo` namespace emitted demo:cool

emitter.emit('demo:awesome')
// -> all events emitted demo:awesome
// -> multiple events with `demo` namespace emitted demo:awesome

emitter.emit('demo:great')
// -> all events emitted demo:great
// -> multiple events with `demo` namespace emitted demo:great

API

createNamespaceEmitter

Create an event emitter with namespaces

Examples

var emitter = require('./index')()

emitter.on('*', function () {
  console.log('all events emitted', this.event)
})

emitter.on('example', function () {
  console.log('example event emitted')
})

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

emitter.emit('example')
emitter.emit('demo:test')
emitter.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

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

on

Create en event listener.

Parameters

• event String
• fn Function

Examples

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

once

Create en event listener that fires once.

Parameters

• event String
• fn Function

Examples

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

License

MIT