Head First Ajax

Chapter 2. Designing Ajax Applications: Thinking Ajaxian

Welcome to Ajax apps—it’s a whole new web world.

So you’ve built your first Ajax app, and you’re already thinking about how to change all your web apps to make requests asynchronously. But that’s not all there is to Ajax programming. You’ve got to think about your applications differently. Just because you’re making asynchronous requests, doesn’t mean your application is user-friendly. It’s up to you to help your users avoid making mistakes, and that means rethinking your entire application’s design.

Mike’s traditional web site

Note

Note from HR: Can we use a less offensive term? How about “consistently annoys every one of Mike’s users”?

Mike’s got the hippest movie reviews going, and he’s taking his popular opinions online. Unfortunately, he’s having problems with his registration page. Users visit his site, select a username, type in a few other details, and submit their information to get access to the review site.

The problem is that if the username’s taken, the server responds with the initial page again, an error message... and none of the information the user already entered. Worse, users are annoyed that after waiting for a new page, they get nothing back but an error message. They want movie reviews!

Note

Users shouldn’t have ...