Making real-time updates with Ajax Push

Comet is a web model in which a long-held HTTP request allows the server to "push" data from the server to the browser without the need for the browser to make a request explicitly. Comet is known in many different names, Ajax Push, Server Push, Reverse Ajax two-way-web, and so on. In this recipe, we are going to create a simple server that sends or "pushes" its current time to client.

Getting ready

For this example, we will use Node.js and a library called Socket.IO (http://socket.io/). The dependency can be included in the package.json file or directly installed from npm.

How to do it...

Let's get started.

1. First, we will start with the server side, where we will add the needed require statements for Socket.IO, HTTP, and filesystem:

   var app = require('http').createServer(requestHandler),
       io = require('socket.io').listen(app),
       fs = require('fs')

2. The server is initialized with requestHandler, where we will just serve an index.html file placed in...