Socket.io - Introduction SOCKET.IO

The first goal is to setup a simple HTML webpage that serves out a form and a list of messages. We’re going to use the Node.JS web framework express to this end. Make sure Node.JS is installed.

First, let’s create a package.json manifest file that describes our project. I recommend you place it in a dedicated empty directory (I’ll call mine chat-example).

{
  "name": "socket-chat-example",
  "version": "0.0.1",
  "description": "my first socket.io app",
  "dependencies": {}
}

Now, in order to easily populate the dependencies property with the things we need, we’ll use npm install:

npm install express@4.15.2

Now that express is installed we can create an index.js file that will setup our application.

var app = require('express')();
var http = require('http').createServer(app);

app.get('/', function(req, res){
  res.send('<h1>Hello world</h1>');
});

http.listen(3000, function(){
  console.log('listening on *:3000');
});

This translates into the following:

• Express initializes app to be a function handler that you can supply to an HTTP server (as seen on line 2).
• We define a route handler / that gets called when we hit our website home.
• We make the http server listen on port 3000.

If you run node index.js you should see the following:

And if you point your browser to https://localhost:3000: