nanoevents

What is nanoevents?

Nanoevents is a tiny (less than 1KB) event emitter library for JavaScript. It provides a simple and efficient way to handle events in your application, making it ideal for both client-side and server-side development.

What are nanoevents's main functionalities?

Event Emission

This feature allows you to emit events with associated data. The `emit` method triggers all listeners attached to the specified event.

const { createNanoEvents } = require('nanoevents');
const emitter = createNanoEvents();
emitter.emit('event', 'data');

Event Listening

This feature allows you to listen for specific events. The `on` method registers a callback function that will be called whenever the specified event is emitted.

const { createNanoEvents } = require('nanoevents');
const emitter = createNanoEvents();
emitter.on('event', data => {
  console.log(data);
});
emitter.emit('event', 'data');

Event Unsubscription

This feature allows you to unsubscribe from events. The `on` method returns an unsubscribe function that can be called to remove the listener.

const { createNanoEvents } = require('nanoevents');
const emitter = createNanoEvents();
const unsubscribe = emitter.on('event', data => {
  console.log(data);
});
emitter.emit('event', 'data');
unsubscribe();
emitter.emit('event', 'data');

Other packages similar to nanoevents

eventemitter3

EventEmitter3 is a high-performance event emitter for Node.js and the browser. It is more feature-rich compared to Nanoevents, offering wildcard event listeners and more advanced event handling capabilities.

mitt

Mitt is another tiny event emitter library. It is similar in size and simplicity to Nanoevents but offers a slightly different API. Mitt is also less than 1KB and is designed for minimal overhead.

events

The 'events' package is the Node.js core EventEmitter module extracted for use in browser environments. It is more heavyweight compared to Nanoevents but offers a robust set of features and is widely used in the Node.js ecosystem.

README

Nano Events

Simple and tiny event emitter library for JavaScript.

• Only 108 bytes (minified and brotlied). It uses Size Limit to control size.
• The on method returns unbind function. You don’t need to save callback to variable for removeListener.
• TypeScript and ES modules support.
• No aliases, just emit and on methods. No Node.js EventEmitter compatibility.

import { createNanoEvents } from 'nanoevents'

const emitter = createNanoEvents()

const unbind = emitter.on('tick', volume => {
  summary += volume
})

emitter.emit('tick', 2)
summary //=> 2

unbind()
emitter.emit('tick', 2)
summary //=> 2

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  Made at Evil Martians, product consulting for developer tools.

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Docs

Read full docs here.

Changelog

9.1.0

• Added EmitterMixin type (by @fuadsaud).

9.0

• Dropped Node.js 16 support.
• Reduced size (by @igisev).

8.0

• Dropped Node.js 14 support.
• Fixed types (by @jakub791).