@jkroso/emitter v1.0.0

Emitter

A simple but optimized event emitter.

Features

• inherited subscriptions: This allows you to define subscriptions on the class rather than on each instance of a class which is both more efficient in terms of memery and sometimes cleaner too.

Installation

npm install @jkroso/emitter

import Emitter from 'emitter'

API

Emitter(obj)

Emitter constructor. Can optionally also act as a mixin

Emitter#emit(topic, ...args)

Process event. All arguments after topic will be passed to all listeners

emitter.emit('event', new Date)

Emitter#on(topic, fn)

Add a subscription under a topic name

emitter.on('event', function(data){})

Emitter#off(topic, fn)

Remove subscriptions

emitter.off()            // clears all listeners
emitter.off('topic')     // clears all `topic` listeners
emitter.off('topic', fn) // as above but only where `listener == fn`

Emitter#once(topic, fn)

subscribe fn but remove if after its first invocation

Emitter.hasSubscription(emitter, topic, fn)

see if emitter has any subscriptions matching topic and optionally also fn

Emitter.subscriptions(emitter, topic)

get an Array of subscriptions for topic