Professional XML

Chapter 22. REST

In the Web Services family, SOAP is the "cool kid" that gets all the attention, but REST is the child that gets work done quietly in the background. REpresentational State Transfer (REST) is the Web Service for the rest of us. Apart from the fact that the acronym needs work (it was coined for a PhD dissertation), REST is really just a description of how the Web works: by moving (transferring) from page to page (the state). Each page you visit is the representation of that state. REST is all about simple links and using simple messages and query strings to get the job done.

Although the process of REST may not be obvious with the general Web pages you visit, think about a shopping site. You browse through a list of products, changing the state of the application and the representation of that state in your browser. Finally, you find the item you've been dreaming of for so long, and you click the link to buy it. State is added to an invisible shopping cart. Viewing the cart's contents is another click away. Increasing the quantity of items purchased is a matter of setting the number, and clicking an Update button. Deleting is just as easy. Everything is managed through simple GET and POST requests. You get many of the benefits of SOAP without having to build SOAP requests, understand WS-something-or-other, or process WSDL. Instead, you define the XML you'd like to pass between client and server.

Introducing the Basics of REST

Some users accept this fairly strict definition ...