Building PHP Applications with Symfony™, CakePHP, and Zend® Framework

Chapter 10. AJAX

It was a joke, okay? If we thought it would actually be used, we wouldn't have written it!

—Mark Andreessen, speaking of the HTML TAG BLINK

WHAT'S IN THIS CHAPTER?

• Introducing AJAX

• Including autocomplete feature into your text fields

• Using pop-up windows

• Making an AJAX chat

In Greek mythology, Ajax was a Titan who supported the heavens on his back. This applies to AJAX as well, but instead of the heavens, this technology supports the whole world of modern interactive websites. (Well, OK, the Titan's name was Atlas, but it doesn't really matter as long as the trope is valid, right? Just look at what AJAX is capable of!)

In many ways, AJAX has become a hallmark of modern web applications. Users expect autocomplete, updating content without reloading, and other AJAX goodies. And sometimes they get angry with a web page that doesn't provide it.

AJAX, which stands for Asynchronous JavaScript and XML, is a web development technique that provides web developers with the capability to create dynamic and interactive web applications. Applications developed using AJAX perform all the operations on the client side and can communicate with a server to retrieve data that results from running various scripts and database queries. Data retrieved from a server using the XMLHttpRequest object can be used to update website content without the necessity of reloading the entire page or influencing the application's behavior.

Note

There is also another similar technique: Asynchronous HTML and ...