Book Image

Getting Started with HTML5 WebSocket Programming

By : Vangos Pterneas
Book Image

Getting Started with HTML5 WebSocket Programming

By: Vangos Pterneas

Overview of this book

<p>WebSockets are capable of bi-directional, full-duplex communication over a persistent TCP connection They provide many benefits compared to the alternatives (for example, long-polling or Comet), such as lower overhead, persistent connections, and low latency. In short, it is the most technically challenging HTML5 feature to implement, but for truly interactive websites, it's a technology worth learning.</p> <p>Getting Started with HTML5 WebSocket Programming gives you the true power of bi-directional communication, implemented by using the brand new HTML5 WebSocket API. You’ll learn how to configure the server and clients, how to transmit different types of data and how to secure the whole system.</p> <p>This book will introduce you to the WebSocket world. We start by introducing the WebSocket API, and continue with practical, real-world examples until we can determine how to build multi-functional web apps for any type of device.</p> <p>You will learn how to configure a web client and a web server that will help you send messages to others using easy-to-use mechanisms. We will also find out how different data types, such as images and videos, can be transferred with little effort. We present additional fallback techniques and solutions for older browsers too. Finally, we will secure our clients from malicious attacks and other threats.</p>
Table of Contents (15 chapters)

Error handling


When it comes to error handling, you have to take both internal and external parameters into account. Internal parameters include errors that can be generated because of the bugs in your code, or an unexpected user behavior. External errors have nothing to do with the application; rather, they are related to parameters you have no control on. The most important one is the network connectivity. Any interactive bidirectional web application requires, well, an active Internet connection.

Checking network availability

Imagine that your users are enjoying your web app, when suddenly the network connection becomes unresponsive in the middle of their task. In modern native desktop and mobile applications, it is a common task to check for network availability. The most common way of doing so is simply making an HTTP request to a website that is supposed to be up (for example, http://www.google.com). If the request succeeds, the desktop or mobile device knows there is active connectivity...