Table of Contents

• Features
• Install
• Usage
• API
• Benchmark
• Development

Features

• Simple 87 LOC
• Lightweight 522 bytes
• Performant
• Inheritable

Install

npm install --save @librpc/ee

or download dev or prod version

Usage

import EventEmitter from '@librpc/ee'

var emitter = new EventEmitter()

function listener (data) {
  console.log(data)
}

emitter.on('event', listener)
emitter.emit('event', { foo: 'bar' }) // -> { foo: 'bar' } in console
emitter.off('event', listener)

API

Emitter

• new Emitter()
• .on(event, listener) ⇒ Emitter
• .off(event, listener) ⇒ Emitter
• .emit(event, data) ⇒ Emitter

new Emitter()

Create an event emitter

Example

var emitter = new Emitter()

emitter.on(event, listener) ⇒ Emitter

Add listener to event. No context provided, use Function.prototype.bind(), arrow function or closure instead.

Kind: instance method of Emitter Returns: Emitter - Return self

| Param | Type | Description | | --- | --- | --- | | event | string | Event name | | listener | listener | Event listener |

Example

function listener (data) {
 console.log(data)
}

emitter.on('event', listener)

emitter.off(event, listener) ⇒ Emitter

Remove listener from event.

Kind: instance method of Emitter Returns: Emitter - Return self

| Param | Type | Description | | --- | --- | --- | | event | string | Event name | | listener | listener | Event listener |

Example

emitter.off('event', listener)

emitter.emit(event, data) ⇒ Emitter

Trigger an event. Multiple arguments not supported, use destructuring instead.

Kind: instance method of Emitter Returns: Emitter - Return self

| Param | Type | Description | | --- | --- | --- | | event | string | Event name | | data | * | Event data |

Example

emitter.emit('event', { foo: 'bar' })

listener : function

| Param | Type | Description | | --- | --- | --- | | data | * | Any data could be passed to event listener |

Benchmark

> @librpc/[email protected] bench D:\Projects\event-emitter
> node bench/

┌──────────────────────────────┬─────────┬───────────┬─────────┐
│ EMITTER                      │ ON      │ EMIT      │ OFF     │
├──────────────────────────────┼─────────┼───────────┼─────────┤
│ events                       │ 99,258  │ 2,147,706 │ 187,842 │
├──────────────────────────────┼─────────┼───────────┼─────────┤
│ minivents                    │ 39,103  │ 1,737,633 │ 11,219  │
├──────────────────────────────┼─────────┼───────────┼─────────┤
│ mitt                         │ 134,112 │ 1,792,035 │ 231,187 │
├──────────────────────────────┼─────────┼───────────┼─────────┤
│ eventemitter3                │ 31,669  │ 2,188,591 │ 16,539  │
├──────────────────────────────┼─────────┼───────────┼─────────┤
│ ../dist/event-emitter.umd.js │ 142,386 │ 2,231,370 │ 269,298 │
└──────────────────────────────┴─────────┴───────────┴─────────┘

Development

Command | Description --------| ----------- npm run check | Check standard code style by snazzy npm run build | Wrap source code in UMD by rollup npm run bench | Run benchmark npm run test | Run tests by tape and compute code coverage by nyc npm run min | Minify code by UglifyJS npm run docs | Create docs by jsdoc-to-markdown