电子书免费下载 Build Your Own AJAX Web Applications

In the ten years or so since I made my first static web page, it’s been amazing to see the evolution of the Web as a platform—first for the exchange of information,and then for actual applications, running right in the browser. And now the AJAX explosion is taking web development to the next level. Using the power of AJAX-style development, you can create applications that rival desktop apps in their power and responsiveness and, best of all, you don’t have to rely on ugly hacks and kludges to get there.

What is AJAX? The acronym originally stood for “Asynchronous JavaScript and

XML ”—quite a mouthful—but it has since come to refer to a style of development

that uses web technologies like XML, DOM, CSS, and JavaScript to create uber-

interactive web documents that behave like full-blown applications. None of

these AJAX technologies are actually all that new (even the AJAX “secret sauce,”

XMLHttpRequest, has been around for years), but not a lot of people really knew

how to use them to the fullest. Now, with the proliferation of “Web 2.0” applic-

ations that push the web-app envelope, and its cool, easy-to-remember name,

the AJAX style of development is really starting to take off.

In the early days, web apps used server-side scripting like CGI, as well as simple web forms and image rollovers in the browser. Now we’re seeing developers take major steps forward to enhance the user experience with the ability to update the UI in pieces, instead of requiring a single, enormous redraw, and client-side functionality like drag-and-drop and edit-in-place. Today’s web applications are more interconnected as well, and are sometimes made up of data from multiple services or sources. A browser-based AJAX app is a fantastic platform for providing this kind of super-interactive, networked app experience to users. And the best part is that the AJAX revolution is still just getting started, so now’s a great time to jump in.

This book gives me a chance to show some cool ways in which you can use AJAX

techniques to add real power and responsiveness to your web applications while

supporting accessibility and backward compatibility . The beauty of AJAX is that

it lets you do all this using straightforward, standards-based code, so you won’t be seeing weird hacks or browser-specific code in this book. So, roll up your sleeves—I hope you’re ready to get your hands dirty in some AJAX code!