HTML5 and CSS3, Second Edition

Tip 32

Tip 32. Chatting with Web Sockets

Web developers have been pursuing real-time interaction with users for many

years, but most of the implementations have involved using JavaScript to

periodically hit the remote server to check for changes. HTTP is a stateless

protocol, so a web browser makes a connection to a server, gets a response,

and disconnects. Doing any kind of real-time work over a stateless protocol

can be quite rough. The HTML5 specification introduced web sockets, which

let the browser make a stateful connection to a remote server.^6 We can use

web sockets to build all kinds of great applications. One of the best ways to

get a feel for how they work is to write a chat client—which, coincidentally,

AwesomeCo wants for its support site.

AwesomeCo wants to create a simple web-based chat interface on its support

site that will let geographically dispersed members of the support staff com-

municate internally. See the following figure.

Figure 34—Our chat interface

6. Web sockets have been spun off into their own specification, which you can find at
   http://www.w3.org/TR/websockets/.

report erratum • discuss

Chatting with Web Sockets • 219

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