Web Development

XML – Where does it FIT?

November 24, 2008 November 24, 2008 As part of the learning process, I've heard a lot of interest in where some of the different technologies we teach "fit in" to the big picture. We try to go over it in each class, but with many subjects representing their own technologies, the specific value may not always be clear. Here are some real-world examples of where a deep understanding of XML fits in to the web developer world. Its obvious application is with Web Services. And, by the way, it is the X in AJAX. But here are some more applications of why a developer needs to know XML in-depth. Example: Facebook.com What differentiates you from a web designer? Well, first, you know what lives under the covers. In the case of Facebook.com, how would you like to create applications that are so extremely popular? Think that's a marketable skill? Facebook's Developer Site Their entire framework is built on FBML, or FaceBook Markup Language. Like XML or XHTML you'll notice the use of markup language. An easy example of FBML FBML markup to use when logged in as user 1160: <fb:name subjectid="219770" uid="219770" /> = himself <fb:name subjectid="219770" uid="1160" /> = you <fb:name subjectid="1160" uid="219770" /> = Josh Gibson <fb:name subjectid="1160" uid="1160" /> = yourself <fb:name uid="profileowner" useyou="true" possessive="true" reflexive="true" /> = your own Notice how the FBML is valid XML, meaning the tag opens and closes. It has attributes, and it uses the fb namespace. These are all important concepts that you should all know now. The use of attributes makes FBML incredibly powerful because you can get all sorts of different results depending what you set in the attributes. This is merely one of 50+ tags. Spend some time looking at the examples within the Documentation to get a sense of how much more you know about the development world you'll soon encounter as certified individuals. Example: XUL (XML User Interface) Do you use FireFox? Have you ever downloaded an add-on? Of course you have. A major component to those add-ons is XUL – again XML-based. To avoid duplicating their well written content, I'll leave it to you to read through their site and if you're feeling adventurous you can follow their step-by-step tutorial about building a "Hello World" extension. Suffice it to say, understanding XML will help you in numerous avenues as you continue your web development career.