Part IV. Functionality and Usability Patterns
Ajax is fundamentally about delivering value to users and their organizations. The previous parts have mostly covered technical issues that support developers, and now it’s time to consider the user experience: how Ajax user interfaces will look, and what users will be able to do with them.
Many of the patterns combine display manipulation with the web remoting capability of Ajax. Others, such as Slider and Rich Text Editor, can be used in the absence of remoting, and still make an important contribution to the richness of Ajax interfaces. Most of the patterns here have been seen before in a desktop context and even on the Web in Flash or Java form; the point of documenting them here is to explore what works with standard browser technology and explain how these ideas can be implemented the Ajax way.
The first three chapters are all about user interface. Widgets (Chapter 14) introduces a number of widgets that are being woven into many Ajax interfaces. A higher-level perspective is taken by Page Architecture (Chapter 15), where the focus is on page layout, content breakdown, and techniques for exposing server-side content. With the popularity of Ajax, the Web is undergoing a rise in visual effects somewhat unprecedented on conventional desktop systems; the most common effects are described in Visual Effects (Chapter 16).
The stack of Ajax technologies opens up several possibilities that haven’t been fully explored in a web context. The patterns in Functionality (Chapter 17) are a little more speculative than those in other sections, but more and more real-world usages for them are emerging. They are worth looking at as they might let you build things in a way you hadn’t considered before.