Server IO Emit
Video Lecture
![Server IO Emit](/img/yt_btn_sm.gif)
Description
Emit a message to all connected sockets.
Used most often when a server level event occurs. E.g., a timer event occurred, and you want to send a message to all clients.
![img/server-io-broadcast-emit.jpg](../img/server-io-broadcast-emit.jpg)
./src/server/server.ts
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35 | import { createServer } from 'http'
import { Server } from 'socket.io'
import * as express from 'express'
import * as path from 'path'
const port = 3000
const app = express()
app.use(express.static(path.join(__dirname, '../client')))
const server = createServer(app)
const io = new Server(server)
io.on('connection', (socket) => {
console.log('a user connected : ' + socket.id)
socket.emit('message', 'Hello ' + socket.id)
socket.broadcast.emit('message', 'Everybody, say hello to ' + socket.id)
socket.on('disconnect', () => {
console.log('socket disconnected : ' + socket.id)
socket.broadcast.emit('message', socket.id + ' has left the building')
})
})
server.listen(port, () => {
console.log('Server listening on port ' + port)
})
setInterval(() => {
io.emit('message', Math.floor(Math.random() * 100))
}, 1000)
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./src/client/client.ts
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12 | import { io } from 'socket.io-client'
const socket = io()
socket.on('connect', () => {
document.body.innerText = 'Connected : ' + socket.id
})
socket.on('message', (message) => {
document.body.innerHTML += '<p>' + message + '</p>'
window.scrollTo({ top: document.body.scrollHeight, behavior: 'smooth' })
})
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