Lesson 15. Creating Applications with Dynamic HTML and AJAX

Dynamic HTML offers you something unique: the capability to make changes in web pages on the fly. Using conventional HTML, web pages are loaded by a browser and just sit there until you click a link or interact with forms. That's pretty simple, but it can be static and boring.

People have improved upon static web pages by using a variety of technologies outside the realm of HTML. Any number of platforms are available for creating server-side web applications. You can embed Shockwave and Flash in your pages to add animation and interactivity, and use Java applets to provide application-like functions. However, these methods rely on browser plug-ins or virtual machines (which can be messy), and can lead to longer download times.

Dynamic HTML is different. DHTML, as it is commonly known, enables you to create web pages that look, feel, and act a lot like the other programs you use on your computerusing the web browser as an interfacewithout having to rely on external programming solutions. AJAX takes that one step further, and allows you to actually exchange data with the server from within your web page, without submitting a form or clicking on a link.

In this Lesson

Today's lesson is a full plate of information, so let's get right to it. In this lesson, you will learn about the following:

• Defining Dynamic HTML and the technologies that make it possible

• Understanding the Document Object Model (DOM)

• Creating cross-browser routines with DHTML by testing browser capabilities

• Examples of using DHTML to manipulate elements on a page