Universal Design for Web Applications

Chapter 8. Scripting

We know what happened the first time HTML was stretched beyond its limits: spacer GIFs, nested layout tables, font tags, “best viewed in my browser” badges, and fragmented standards. And worst of all, poorly trained content creators, whose limited knowledge of how things ought to be continues to plague us almost 15 years later.

What we have learned is that no language will be ideal for all possible uses. HTML is a fantastic format for rich-text documents. And we’ve learned how to layer it with CSS and script to make it a pretty good platform for application frontends. We’ve even added an object called XmlHttpRequest, named the combination Ajax, and its phenomenal spread is the topic of dozens of books of its own.

Ajax is just one of a growing number of pretty good UI platforms, each of them well-suited to the modern Web. They’re fast, functional, and cross-platform.

Now, here’s the catch: whether you’re developing with Ajax, Adobe’s Flash and Flex, Microsoft’s Silverlight, or any other web-based platform, your responsibilities go beyond web accessibility and into the world of software accessibility. Some of the rules change when dealing with software, and in the next two chapters, we explain what these new rules entail. We also show you what rules from HTML still apply.

Building on a Solid Foundation

Progressive enhancement uses web technologies in a layered fashion that allows everyone to access the basic content and functionality of a web page, using any browser ...