Tuesday, June 26, 2012
What is XML DOM?
I find myself longing for the old days, when I could design a web site in 5 minutes on a Sunday and then go play golf for the rest of the afternoon, and still collect a full chinese hair week of salary for services rendered.That was back in 1996, when the internet was still new. Websites were created exclusively with HTML. The client would email me the content for their website, which I would upload to FrontPage, then insert some tags and a template for formatting and layout, add some graphics, and that was it.Nowadays, I find myself working up to 10 hours per day designing web sites. I have to use so many different programming languages and specifications when creating a site that it makes me dizzy. I can barely type this article because my brain literally hurts from all the different programming languages I have swirling around in my head. You might be wondering why my job has become so complicated in recent years. Well, it started with the wireless revolution, which made cyberspace a darn mess. Now, every wireless gadget is equipped with access to the internet and email. Cell phones, palm tops, laptops, even computer screens in automobiles have web browsers. These gadgets have platforms and web browsers that are very full lace wigs different from what is installed on an ordinary desktop PC. These new web browsers are not compatible with many elements of the HTML programming language. As a result, websites created purely with HTML are often invisible or inaccessible to the wireless internet user. New languages and specifications such as XHTML, XSL, and XML were created to conform to these new web browsers. XML was probably the most important innovation of them all. XML enabled web designers to define data without telling the browser how to display the data, unlike HTML, which both defines the data and tells the browser how to display it. XML data can be viewed on any platform or browser because it is a simple text file with no predefined tags, allowing the programmer to define data any number of ways. XHTML and XSL were created to convert XML files into actual web pages that had style and structure and could be viewed across all platforms and browsers.Now that you understand how and why programming was changed, you are ready for a brief introduction to the main topic of this article, XML DOM. DOM stands for Document Object Model. XML DOM is both platform and language independent, and sets forth several document objects for XML, as well as the means for accessing and changing XML documents.You should think of XML DOM as something that turns an XML document into a tree. Certain elements, or tags, become the branches, and other elements lace front wigs within those elements and their corresponding attributes are like the twigs attached to each individual branch. The elements can all be modified through this DOM tree. The Microsoft XML Parser is used if the programmer wants to modify the tree by inserting and deleting some of the branches and twigs, and then convert the branches and twigs back to XML.