We have to begin this application with a bit of server-side code. We will use Express as our primary server; however, we also want to use Socket.IO, so we have to set it up. Copy the template to start the new project. Then, in the project directory, go ahead and install all our packages and then Socket.IO with npm as follows:
npm install npm install socket.io --save
Now, to get Express and Socket.IO to play together nicely, we need to do things a bit differently in our server.js file. First, we require the http library of Node.js and socket.io. Here's how:
var http = require('http');
var socketio = require('socket.io');Then, we have to wrap our Express application (the app object) in a Node.js server object as follows:
var server = http.createServer(app);
Now we have a server. The final step to getting things working with Socket.IO is to create a Socket.IO instance that listens to our server. We do that this way:
var io = socketio.listen(server);
Currently in the server...