Easy XML to Connect Content to Web Page
XML(Extensible Markup Language) is latest rage in programmer land, but it's
actual implementation on the Web is proceeding at a snail's pace. That's
because it's way more complicated than html, and nobody is explaining it in
plain, simple English. Your typical book on XML starts out by explaining that
XML is a "meta" language.
Nobody cares if it's a meta language or a "potato" language. What people want is
a simple, clear "hands-on" explanation of how to use XML. Unfortunately learning
XML is like learning mathematics. You can't learn it top-down. You have to learn
it from the bottom-up.
The real power of XML comes when it's teamed up with SXL and/or SOAP. Your
typical book on XML makes you dog through every detail of XML syntax, and
sometimes XSL and SOAP too, before you get any practical hands-on experience.
XSL (Extensible Stylesheet Language) allows you to display the same XML data
by applying different XSL style sheets to it. A server can detect the parameters
of the device you are using to view the data, and apply the appropriate style sheet
to make it look nice. SOAP (Simple Object Access Protocol) allows you communicate
with Web services using messages written in text (XML text to be specific).
This is all very amazing, but programmers learn by writing some code and watching
it work. You can't learn all the syntax of XML and XSL and SOAP all at once, and
you don't have to. You can write some XML code and make it do something useful by
What I am going to present here is an example that lets you store your website's
content in text files separate from your web pages. The web pages and the
content are combined using XML. You will learn some basic XML, including how to
write a DTD (Document Type Defintion) and how to use "external XML Entites".
This is going to be mind-blowingly simple. I stated that you can make XML do
something useful by combinig it with a bit Java Script. If you don't know Java
Script, you should learn. It's a fun and easy to use language. But you don't
need to know any Java Script for this example. Below is the entire Java Script
that will be used in this example.
rootElem = pageContent.documentElement;
for(i = 0; i < rootElem.childNodes.length; i++)
childnode = rootElem.childNodes.item(i);
Just paste this into a text file and save it with the file name drawpage.js.
You will "include" this code in webpage(s) by placing the line shown below
in the HEAD section of your webpage(s).