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Internet scripting technology has come along at a very brisk pace. While its roots are lodged in text-based displays (due to very limited amounts of storage space and memory), over the years it has rapidly evolved into a visual and highly functional medium. As it grows, so do the tools necessary to maintain, produce, and develop for it. As developers continue to stretch the boundaries of what they can accomplish with this rapidly advancing technology, they have begun to request increasingly robust development tools.

An interesting misconception regarding Ajax is that, given all the cool features it has to offer, the JavaScript code must be extremely difficult to implement and maintain. The truth is, however, that beginning your experimentation with the technology could not be simpler. The structure of an Ajax-based server request is quite easy to understand and invoke. You must simply create an object of the XMLHttpRequest type, validate that it has been created successfully, point where it will go and where the result will be displayed, and then send it. That’s really all there is to it.

While the concept of Ajax contains a handy set of functionality for creating actions on the fly, if you are not making use of its ability to connect to the server, you are really just using basic JavaScript. Not that there is anything truly wrong with that, but the real power lies in joining the client-side functionality of JavaScript with the server-side processing of the PHP language using the concept of Ajax.

Now that you have a basic understanding of how to use PHP with Ajax to accomplish some dynamic and functional goals, it’s time to start tying in some of the more complicated and powerful functionality available to PHP. The advantage to using a robust server-side language such as PHP with Ajax-sculptured JavaScript is that you can use it to accomplish tasks that are not easily accomplished (if at all) with JavaScript. One such set of core functionality is that of database storage and retrieval.

In the last chapter, you learned how to retrieve data from a MySQL database. Now, it is one thing to draw information from a database and perform dynamic queries on differing tables, but it is quite another to actually pass information to be dynamically saved to said database.

I suppose that it goes without saying that one of the more annoying, yet necessary, aspects of browsing a web site using a slow Internet connection is waiting for images to load. While text-based web sites can display instantaneously (or seemingly so) on any Internet connection, images must be downloaded in order to be viewable. With the advent of high-speed Internet, this issue has become less of a problem, but images still require time to display. Nonetheless, images are indispensable to the user experience, and therefore, as web developers, we’re tasked with minimizing the negative aspects of image loading.

In order to obtain a complete understanding of what goes into making Ajax-based applications, it makes sense that you should build one from scratch. In order to illustrate that process, I will lead you through the process of creating an Ajax-based photo gallery. The photo gallery is a fairly common web application that is popular among professional web developers and hobbyists alike.

For years, web developers have been stuck with the notion of what a web page can and cannot do. This mindset is based around technical limitations rather than lack of imagination; but over time this limitation has made many web developers become set in their ways.

Before Ajax became all the rage, web services was the talk of the town. How could it not be, really? Web services is a very exciting concept, both for those wishing to allow use of their custom code and information sets, and those eager to make use of such functionality. Basically, web services provide an interface for developers to perform certain operations on a computer external to the script calling the function. Site owners who wish to provide external access to information in their databases can look to web services to take care of business.

One of the great aspects of this wonderfully massive World Wide Web is that communities of similarly located individuals are able to come together with a common goal.