README

usePubSub

A React hook to add Publish and Subscribe to a React application.

The usePubSub hook provides your React component with access to the current PubSubContext, on which you can publish messages to channels, and subscribe to channels to receive messages.

You provide a PubSubContext to your application using the <PubSubProvider> at the root level of your application (or wherever).

You may also explicitly create a PubSubContext using createPubSubContext() and provide it to <PubSubProvider context={myContext}>, and then use the publish, subscribe and unsubscribe methods of the PubSubContext anywhere in your application.

Install

npm install --save @cactuslab/usepubsub

Usage

import * as React from 'react'

import { usePubSub, PubSubProvider } from '@cactuslab/usepubsub'

/* Add a top-level PubSubProvider to your app to initialise the PubSub context */
const App = () => {
   return (
    <PubSubProvider>
      ...
    </PubSubProvider>
  )
}

const ExampleSubscriber = () => {
  const { subscribe } = usePubSub()
  React.useEffect(function() {
    return subscribe('CHANNEL', function(message) {
      ...
    })
  })
}

const ExamplePublisher = () => {
  const { publish } = usePubSub()
  
  function sendMessage() {
    publish('CHANNEL', nextMessage)
  }
}

Provide a custom context

Use createPubSubContext() to create the PubSubContext, and then call publish, subscribe and unsubscribe on it from anywhere in your application.

import { createPubSubContext, PubSubProvider } from '@cactuslab/usepubsub'

const myContext = createPubSubContext()

myContext.subscribe('ALERT_CHANNEL', function(message) {
  alert(message)
})

const App = () => {
  return (
    <PubSubProvider context={myContext}>
      ...
    </PubSubProvider>
  )
}

API Reference

type Handler = (message: unknown) => void

interface PubSubContext {
  publish: (channel: string, message: unknown) => void
  subscribe: (channel: string, handler: Handler) => () => void
  unsubscribe: (channel: string, handler: Handler) => void
}

/* Functions */
function createPubSubContext(): PubSubContext

/* Hooks */
function usePubSub(): PubSubContext

/* Components */
<PubSubProvider />
<PubSubProvider context={PubSubContext} />

License

This hook is created using create-react-hook.

Usage no npm install needed!