Chapter 8. Ajax Using XML and XMLHttpRequest

Unlike the previous chapter, which was sort of "mad scientist stuff" with training wheels, here the training wheels come off. We're free to either fly like the wind or remove large amounts of skin from various body parts. Based upon my personal experience as a web developer, we'll probably do some of both. From this chapter forward, nobody, regardless of their personal feelings, can deny that what we do in this chapter falls under the definition of Ajax.

Up to this point, the only part of Ajax that we've really seen is the JavaScript. Feels like a rip-off, doesn't it?

Don't worry, we're building up to it. It would not do to have the monster rise off the slab in the beginning of Chapter 1, would it? Alright, I, too have a tendency to fast-forward to the good parts. For example, I don't care how SG-1 got to Antarctica; I just want to see the ship-to-ship battle over the pole and the battle in space. Come to think of it, Stargate SG-1 should be required watching for mad scientists because two of the regular characters could be classified as mad scientists themselves.

The mad scientist stuff covered in this chapter is the basic building block of Ajax applications, the XMLHttpRequest object and how to determine what's actually going on. Along with this object is XML, including how to deal with it on the client and some of the ways to deal with it, such as SOAP (basically, a way to package XML for transport to and from the server). The final item covered is what to do with the XML on the client, such as put it in an XML Data Island. To skip ahead a little, because mad scientists like to describe their diabolical plans, XML Data Islands are one of the methods that can be used to both embed and bind HTML controls and data. The best part is, if you change one, the other changes.