Book Image

HTML5 Data and Services Cookbook

Book Image

HTML5 Data and Services Cookbook

Overview of this book

HTML5 is everywhere. From PCs to tablets to smartphones and even TVs, the web is the most ubiquitous application platform and information medium bar. Its becoming a first class citizen in established operating systems such as Microsoft Windows 8 as well as the primary platform of new operating systems such as Google Chrome OS. "HTML5 Data and Services Cookbook" contains over 100 recipes explaining how to utilize modern features and techniques when building websites or web applications. This book will help you to explore the full power of HTML5 - from number rounding to advanced graphics to real-time data binding. "HTML5 Data and Services Cookbook" starts with the display of text and related data. Then you will be guided through graphs and animated visualizations followed by input and input controls. Data serialization, validation and communication with the server as well as modern frameworks with advanced features like automatic data binding and server communication will also be covered in detail.This book covers a fast track into new libraries and features that are part of HTML5!
Table of Contents (21 chapters)
HTML5 Data and Services Cookbook
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

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...