nitish24p/signal

A 700 byte zero dependency single instance of an event emitter. 🎉

Signal

 

Signal is a light ~700 Bytes Singleton instance of an Event bus. It works directly in the browser or has support for commonJS and amd modules.

Its Really tiny. Check it out here;

 

Motivation

I got the concept of creating a unified event bus whilst reading this article. What if an app had multiple tech stacks, was there was a way to communicate between them?? This can be super useful for people migrating their stacks from one to another. A unified bus is one of the ways for microservices / micro apps to communicate with one another. Typically they follow a pub sub design pattern

Installation

Using npm

npm install signal-event

yarn add signal-event

Usage

signal-event exports a function which when invoked with a consturctor will generate the same instance every single time. Thereby keeping all your events at one place.

const Signal = require('signal-event');

const S1 = new Signal();

Register An Event handler

S1.on('foo', function(data) {
  console.log(`got data for event name foo`, data)
});

Register Multiple Event handlers

S1.on('foo', handlerFunction1);
S1.on('foo', handlerFunction2);
S1.on('foo', handlerFunction3);
S1.on('foo', handlerFunction4);

S1.emit('foo', { foo: 'bar' })

// This will get triggered in all the handlers;

Emit an Event

S1.emit('foo', { foo: 'bar' })

Remove an Event Hanlder

function beepEventHandler(data) {
  // do something with data
}

S1.on('beep', beepEventHandler);

S1.emit('beep', 'bloop');

S1.remove('beep', beepEventHandler);

/*
* If you need to remove an event handler the function specified
 must have a name, annonymous arrow fn wont work
 S1.remove('beep', () => {}); will not work
*/

Remove All event handlers for an event

S1.remove('beep', null, true);

API

1. Add Event Listener

Signal.on(eventName, handlerFunction)

2. Emit Event

Signal.emit(eventName, data)

3. Remove Event Handler

Signal.remove(eventName, handlerFunction, removeAllHandlers)

Dev Setup

yarn run test
yarn run cover

 

Liked the repo ⭐ it.

Found any Bugs File them here