nitt v1.0.2

Nitt

Small, functional event emitter / pubsub.

• Small: less than 300 bytes gzipped
• Familiar: similar names (on, off, once, emit) & ideas as Node's EventEmitter
• Functional: methods don't rely on this, unless you want to...
• No dependency: Nitt has no external dependencies

Table of Contents

• Nitt
  • Table of Contents
  • Install
  • Usage
  • API
    • nitt
    • on
    • once
    • when
    • off
    • emit
  • Contribute
• Acknowledments
  • License

Install

This project uses node and npm. Go check them out if you don't have them locally installed.

$ npm install --save nitt

Usage

import nitt from 'nitt';

const emitter = nitt();

// listen to an event
emitter.on('foo', e => console.log('foo', e));

// listen to all events
emitter.on('*', (type, e) => console.log(type, e));

// listen to a single event
emitter.once('foo', e => console.log('foo', e));

// fire an event
emitter.emit('foo', { a: 'b' });

// working with handler references:
function onFoo() {}
emitter.on('foo', onFoo); // listen
emitter.off('foo', onFoo); // unlisten
emitter.once('foo', onFoo); // listen to a single event

// using a promise
const promise = emitter.when('bar');
promise.then(evt => console.log(evt));
emitter.emit('bar', 'done'); // prints 'done' in the console

API

nitt

Nitt: Small (<300B) functional event emitter / pubsub.

Parameters

• all EventHandlerMap

Returns Nitt

on

Register an event handler for the given type.

Parameters

• type String Type of event to listen for, or "*" for all events
• handler Function Function to call in response to given event

once

Register an event handler that is executed just once.

Parameters

• type String Type of event to listen for, or "*" for all events
• handler Function Function to call in response to given event

when

Returns a promise for a single event

Parameters

• type String Type of event to listen for, or "*" for all events

Returns Promise

off

Remove an event handler for the given type.

Parameters

• type String Type of event to unregister handler from, or "*"
• handler Function Handler function to remove

emit

Invoke all handlers for the given type. If present, "*" handlers are invoked after type-matched handlers.

Parameters

• type String The event type to invoke
• evt Any? Any value (object is recommended and powerful), passed to each handler

Caveats

Keep in mind, due to the nature, of the once handlers that self deregister, you are currently not able to remove (off) a once / when handlers.

Contribute

If you want to contribute, I would be happy to look in to your PRs.

Acknowledments

I would like to thank Jason Miller (@developit) for developing mitt. nitt is no more than just mitt with a few extras.

License

MIT License