socket.io

Overview

• socket.io is a JS library for real-time web applications (ie: messengers, push notifications, online games)
• It allows for two way communication between web clients and servers

Getting started

const app = require('express')();
const http = require('http').Server(app);
const io = require('socket.io')(http); // Creates new socket instance connected to the http server

• use socket.emit method to create a custom event
• use io.socket.emit method to broadcast an event to all clients
• namespace = path or endpoint

var nsp = io.of('/my-namespace');
nsp.on('connection', function(socket) {
console.log('someone connected');
nsp.emit('hi', 'Hello everyone!');
});

• use join method to connect a socket to a channel
• best way to debug: DEBUG=* node app.js