what are the real utilities of xml?
 

can someone explai nwhat the real utilities of xml are. i have found loads of tutorials on how to write xml but i haven seen what it is used for! thanx for the enlightenment

-the whackaxe

The ability to use data cross platform to its full potential. For example, i could create a contact book on windows, and then move it straight to my palm/mobile/macintosh/server and it'd look and act the same no matter what!

Jee

Well, to see some of the benefits of XML you have to have a particular language written in XML to see.

For instance, XHTML is HTML reformulated as XML. It's an XML language for marking up text with links, pictures, emphasis, etc.

SVG is a graphics language written in XML.

XSLT lets you transform one language into another.

The list goes on and on. The key question is what sort of data you want to store.

i can create my own language?!

Not quite - you can create your own data structure:

<address>
<name>John Doe</name>
<street>123 Elvis St.</street>
<city>New York</city>
<state>New York</state>
</address>

Notice how the tags describe what content they are holding - this is opposed to:

<table>
<tbody>
<tr><td>John Doe</td></tr>
<tr><td>123 Elvis St.</td></tr>
<tr><td>New York</td></tr>
<tr><td>New York</td></tr>
</tbody>
</table>

Which tells you nothing about the information it contains.

Since the tags are descriptive, you can easily use XSLT to transform the <address> document into the XHTML document shown above, use XSLFO is present it however you want, use CSS to style the text, or dynamically import it client-side or server-side and extract information from it using SAX or DOM.

Yep; the point of XML is to describe, structure and record data in a uniform way, so it can be exchanged easily and produced and used in a variety of environments. Applications are thought to transform this data into an environment-specific form and present it, if so desired.

I use xml files as my databases instead of connecting to databases. They can be accessed and modified client or server side.

oh ok then thanks for explaining that to me. i dont really think ill be using it for a while to be honest.

-the whackaxe