# Socket.IO Quick Reference

• Server Side
  • Emitting events
• Client Side
  • Broadcasting (TBD)

# Server Side

npm install socket.io

You need to explicitly enable Cross-Origin Resource Sharing

import { Server } from 'socket.io';
import http from 'http';

const server = http.createServer(app);      // Create an HTTP server instance
const io = new Server(server, {             // Create a Socket.IO server instance
    cors: {
        origin: ['http://localhost:4200', 'https://example.com'],
        methods: ['GET', 'POST'],
    },
});

# Emitting events

io.on('connection', (socket) => {
    socket.emit('fish', 'This is the fish event');
});

io.on('connection', (socket) => {
    socket.on('chat message', (msg) => {
        console.log('message: ' + msg);
    });
});

io.on('connection', (socket) => { socket.emit('fish', 'This is the fish event'); socket.emit('message', 'This is the message event'); socket.on('message', (msg) => { console.log('message: ' + msg); }); });

# Client Side

npm install socket.io-client

# Broadcasting (TBD)