Core Events

A simple publish/subscribe pattern

• Plain old vanilla JS
• Just 1.2kb gzipped

Installation

npm install core-events

Usage

import Event from 'core-events'

const event = new Event()

event.subscribe('createWorld', () => {
  console.log('hello world')
})

event.publish('createWorld')

A slightly more complex example:

import Event from 'core-events'

const event = new Event()

const token = event.subscribe('personBorn', ({ name }) => {
  console.log(`hello ${name}`)
})

event.publish('personBorn', {
  'name': 'Colin'
})

event.unsubscribe(token)

Global events

Core Events also provides some handy functions to publish events when a global event occurs.

Click

import Event, { publishClick } from 'core-events'

const event = new Event()

publishClick({ event })

event.subscribe('global.click', ({ target }) => {
  console.log('Somebody clicked on', target)
})

Escape

import Event, { publishEscape } from 'core-events'

const event = new Event()

publishEscape({ event })

event.subscribe('global.escape', () => {
  console.log('Somebody hit escape')
})

Resize

import Event, { publishResize } from 'core-events'

const event = new Event()

publishResize({ event })

event.subscribe('global.resize', () => {
  console.log(`Somebody resizes the browser`)
})

Scroll

import Event, { publishScroll } from 'core-events'

const event = new Event()

publishScroll({ event })

event.subscribe('global.scroll', ({ direction, speed }) => {
  console.log(`Somebody scrolled ${direction} at ${speed} px per ms`)
})

Swipe

import Event, { publishSwipe } from 'core-events'

const event = new Event()

publishSwipe({ event, sensitivity: { x: 10, y: 50 } })

event.subscribe('global.swipe', ({ direction, target }) => {
  console.log(`Somebody swiped ${direction} on`, target)
})

Browser support

Core Events is packaged with Babel, and makes use of Array.from. If you want Core Events to work on browsers that don't support this method (e.g. IE11), then you will need to polyfill Array.from before calling Event.