MicroEmitter

micro event emitter in TypeScript.
Before v1.2.0, micro-emitter made by es6. If you want see that, please check it.

Motivation

I wanted a simple emitter for my apps I created. So, I made an independent, no-dependency emitter under 100 lines.

Getting Started

$ npm install micro-emitter

import MicroEmitter from 'micro-emitter';

let emitter = new MicroEmitter();

var MicroEmitter = require('micro-emitter');

var emitter = new MicroEmitter();

API

It has 4 API and some alias only.

• addListener(on)
• addOnceListener(once)
• removeLister(off)
• emit(trigger)

addListene(on)/addOnceListener(once)

const CHANGE_EVENT = 'CHANGE_EVENT';

emitter.addListener(CHANGE_EVENT, callbak);
emitter.on(CHANGE_EVENT, callbak);
emitter.addOnceListener(CHANGE_EVENT, callbak); // only first time
emitter.once(CHANGE_EVENT, callbak); // only first time

removeListener(off)

const CHANGE_EVENT = 'CHANGE_EVENT';

emitter.removeListener(CHANGE_EVENT);
emitter.off(CHANGE_EVENT);

emit(trigger)

const CHANGE_EVENT = 'CHANGE_EVENT';

emitter.addListener(CHANGE_EVENT, (payload) => {
    console.log(payload); // { message: 'Hello MicroEmitter!' }
});
emitter.emit(CHANGE_EVENT, { message: 'Hello MicroEmitter!' });

Example

simple and complete example.

import MicroEmitter from 'micro-emitter';

const CHANGE_EVENT = 'CHANGE_EVENT';

const emitter = new MicroEmitter();

emitter.addListener(CHANGE_EVENT, (payload) => {
  alert(payload.message);
});

setTimeout(() => {
  emitter.emit(CHANGE_EVENT, { message: 'Hello MicroEmitter!' }});
}, 1000);