https://github.com/raineorshine/emitter20

A small event emitter with no dependencies.
https://github.com/raineorshine/emitter20

Last synced: about 1 month ago
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A small event emitter with no dependencies.

• Host: GitHub
• URL: https://github.com/raineorshine/emitter20
• Owner: raineorshine
• License: isc
• Created: 2016-01-06T21:45:24.000Z (almost 10 years ago)
• Default Branch: master
• Last Pushed: 2024-07-21T22:17:44.000Z (about 1 year ago)
• Last Synced: 2025-08-30T00:05:02.569Z (about 2 months ago)
• Language: JavaScript
• Homepage:
• Size: 126 KB
• Stars: 7
• Watchers: 2
• Forks: 1
• Open Issues: 9
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          
# emitter20

[![npm version](https://img.shields.io/npm/v/emitter20.svg)](https://npmjs.org/package/emitter20)

[![Build Status](https://travis-ci.org/metaraine/emitter20.svg?branch=master)](https://travis-ci.org/metaraine/emitter20)

An event emitter that used to be 20 lines of code but is still quite small. No dependencies.

## Install

```sh

$ npm install --save emitter20

```

## Methods

- `on: (eventName: string, callback: Function) => void` - Subscribe a callback to the given event type.

- `off: (eventName: string, callback: Function) => void` - Remove a callback from the given event type.

- `trigger: (eventName: string, callback: Function) => void` - Trigger an event, invoking all subscribers.

- `clear: (eventName?: string) => void` - Remove all subscribers from the given event type, or all subscribers if no event type is specified.

## Usage

```js

var Emitter = require('emitter20')

var emitter = new Emitter()

emitter.on('karate-chop', function() {

  console.log('Haiaaaaaa!')

})

emitter.trigger('karate-chop') // Haiaaaaa!'

```

Pass arbitrary data to the event handler:

```js

var emitter = new Emitter()

emitter.on('welcome', function(name) {

  console.log(`Welcome {name}!`)

})

emitter.trigger('welcome', 'bob') // Welcome bob!

```

Can be used as a mixin:

```js

var assign = require('lodash.assign')

var obj = { a: 1, b: 2 }

assign(obj, new Emitter())

obj.on('karate-chop', function() {

  console.log('Haiaaaaaa!')

})

obj.trigger('karate-chop') // Haiaaaaa!'

```

## License

ISC © [Raine Revere](https://github.com/raineorshine)