broadcast service

startup

npm start (npm start -- -p 9898 -d 1000) to start the server.

• websocket http://localhost:3000 to subscribe/push events

CLI parameters

• port / p
• delay / d - minimum delay of each response/broadcast (milliseconds)

Client connection

Start with following code on client side:

markup

<script src="http://localhost:3000/socket.io/socket.io.js"></script>

client logic

const socket = io('http://localhost:3000')

socket.on('state', (data) => {
	console.log('state received once', data)
})

socket.on('data', (data) => {
	console.log('data received on each client action', data)
})

Check client/client.js file for more examples, including emitting events. Adapt the code into your client application.

server logic

You may want to adjust the server, by providing a custom reducer that updates the server state, just as the clients send events. Modify lib/state.js.

Commands

state (request event + response event)

Sent once initially, and then on demand. Includes initial state and currrent client ID.

Requesting on demand: socket.emit('state') (request event). Needs to subscribe for state as well (response event).

data (request event + response event)

Clients may send data event to notify the server about a change. It is then processed via the reducer and current state is updated (also available via state events). data events are broadcasted to all other clients.