Xslt

alexd181 · #1 (**permalink**) 01-16-2008, 03:23 PM

XSLT - does anyone here use it? I am learning about how to use it, but so far I'm not sure why you'd use it. What are the main applications?

chrishirst · #2 (**permalink**) 01-17-2008, 01:39 AM

Making XML look pretty

alexd181 · #3 (**permalink**) 01-17-2008, 02:02 AM

I know, but what is XML normally used for? Eg. I know it can be used for external sitemaps etc. but what would a webdesigner use it for typically? Do you use it?

Quote:

And how can we win, when fools can be kings

Don't waste your time or time will waste you.

chrishirst · #4 (**permalink**) 01-17-2008, 10:17 AM

XML is the "adjective" of programming languages. It's a "describing" language.

It is used to describe the data it holds. So to use for a record library as an example;

Code:

<?xml version="1.0" encoding="ISO-8859-1"?>
<collection>
	<album>
		<artist>Muse</artist>
		<title>Black Holes and Revelations</title>
		<tracklist>
			<track>
				<name>Take a Bow</name>
				<time>4:39</time>
			</track>
			<track>
				<name>Starlight</name>
				<time>3:57</time>
			<track>
				<name>Supermassive Black Hole</name>
				<time>3:29</time>
			<track>
				<name>Map of the Problematique</name>
				<time>4:23</time>
			</track>
			<track>
				<name>Soldier’s Poem</name>
				<time>2:10</time>
			</track>
			<track>
				<name>Invincible</name>
				<time>4:54</time>
			</track>
			<track>
				<name>Assassin</name>
				<time>3:34</time>
			</track>
			<track>
				<name>Exo-Politics</name>
				<time>3:53</time>
			</track>
			<track>
				<name>City of Delusion</name>
				<time>4:48</time>
			</track>
			<track>
				<name>Hoodoo</name>
				<time>3:42</time>
			</track>
			<track>
				<name>Knights of Cydonia</name>
				<time>6:03</time>
			</track>
			<track>
				<name>Glorious" (bonus track)</name>
				<time>4:38</time>
			</track>
		</tracklist>
		<formats>
			<format>CD</format>
			<format>MiniDisc</format>
			<format>MP3</format>
		</formats>
	</album>

	<album>
	.
	.
	.
	</album>
</collection>

could be a node format for holding the data.

You could then write a XSL Style Sheet that told the browser/viewer exactly how you wanted the information to look.

So, instead of writing an application in a server side language to store the data in a database, extract it and display it, the whole process could be compressed into a couple of text files, which is totally self contained and, more importantly, doesn't need a web server to run on.

I don't use XML/XSLT for web apps very much, but I frequently use XML as a data storage medium.

alexd181 · #5 (**permalink**) 01-17-2008, 11:15 AM

That makes a lot of sense with the music example. However it sounds like XML cannot be updated dynamically, where as a database can. I don't see how you could add an entry later without editing the code which makes mysql seem favorable. Can XML be used with mysql or does that defeat the purpose?

chrishirst · #6 (**permalink**) 01-17-2008, 01:37 PM

XML can be updated dynamically by any application that can handle XML obviously you need to know the document structure.
RSS feeds are simply an XML document with a defined and controlled node structure, they can be updated "on the fly" by code.

Yes, XML can be used with databases. SQL 2005 has direct support for output as XML rather than needing a third party app.

If you want to make a snapshot of data available (RSS feeds for example) to external consumers you can export the db data to a XML file.