This isn't Gilligan's Island, but it's close

To a developer, an XML data island is pretty straightforward, but to a network or systems administrator? It might be a bit confusing.

An XML island is a piece of XML embedded within an HTML document that can be used to associate data with an HTML object, such as a list box or text field. This is not new, Internet Explorer has had this capability for several years and many a developer has used this feature on the client as it is very similar to its ADO functionality.

What's interesting is that XAML, Microsoft's new interface markup language, also offers similar functionality, though it's not really an island as the language is all XML anyway.  

Now, before you get crazy with the XML island idea, you have to understand that it is a Microsoft specific extension and isn't directly supported by browsers like Firefox. Yeah, I know, they're cool and you want it to be cross-browser, but right now the best you can do is emulate XML data islands in Firefox.

Will they ever be supported in Firefox? Well, the XMLHTTPRequest object was once a Microsoft only extension and look at it now - it's a stock object in all browsers and even has a W3C working group hovering over a specification. So it could happen, depending on how much demand there is for them. I suspect that this feature, which has been available for quite some time in IE (since 5.5 at least), will finally start to garner more interest as Web 2.0 and AJAX picks up steam and that demand will rise accordingly. Eventually we'll see it in Firefox and then look out world!

Anyway, back to the discussion. So an XML island makes it possible (in IE) to bind xml data embedded in a web page to specific components (or elements, if you're thinking of a web page as XHTML). 

<xml id="location" async="false">
       <city>Easton</city>
       <state>Pennsylvania</state>
</xml>
<input type=”text” datasrc=”#location” datafld=”city” />
<input type=”text” datasrc=”#location” datafld=”state” /> 

The result would appear (in IE) as:

What's even cooler is that binding XML to a table in IE results in a dynamically generated table containing all the data. I know, right? That's awesome. Especially when you combine that with the XMLHTTPRequest object and can grab XML to easily replace the "location" xml without much effort, updating the fields on the fly.

Yes, there are some security risks, there always is when you start tossing XML back and forth between the client and the server. But that's a discussion for another day.

Imbibing: Coffee