arbitrary-emitter

arbitrary-emitter

High performance event emitter with Map/Set sugar for node.js and browsers (<500 bytes when gzipped)

arbitrary-emitter stores listeners and actions in ES6 Map and Sets, this allows to use arbitrary values as keys for your listeners

arbitrary-emitter is written in vanilla ES6, so you will have to transpile it before using it in old browsers or node.js < v5.9

Create a new emitter

const emitter = arbitraryEmitter()

Emitter API

on(key, action)

Add a listener with key which will trigger action function. key can be any type of value.

on returns unsubscribe method

const obj = {}
let removeAction = emitter.on(obj, () => doSomething())
emitter.emit(obj) // will `doSomething`
removeAction()
emitter.emit(obj) // won't do anything

once(key, action)

Add a listener for key which will trigger action function just one time, then listener will be removed. key can be any type of value

const obj = {}
emitter.once(obj, () => doSomethingOnce())
emitter.emit(obj) // will `doSomething`
emitter.emit(obj) // won't do anything

emit(key[, ...args])

emit methods binded to key, and pass the rest of the arguments to it

emitter.on('test', (a, b) => console.log(a + b))
emitter.emit('test', 1, 2) // => 3

off(key[, action])

Remove action from listener key. If no action is specified will remove all listeners binded to key

emitter.off(key, action) // will remove action from listener `key`
emitter.off(key) // will remove the listener `key` and all actions binded to it

Testing

Node

npm test

Browser

Build browser tests (npm run build-tests) and open test/test.html

Building

• Build UMD file: npm run build-umd
• Build browser tests: npm run build-tests
• Run both builds: npm run build

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© 2016 Jacobo Tabernero - Released under MIT License