XMLHttpRequest

Tuesday, December 14th, 2004

I’ve heard about XMLHttpRequest before, but never really gave it much attention. Which means I didn’t even know what it was supposed to do, and therefor never looked into it further.

Turns out it’s pretty neat though. If you’re a webdeveloper, you must know how we deal with stuff like changing the values in a dropdown box depending on a chosen value in another dropdown box? You either send all possible information with the page when you construct it and then use Javascript to fill in the information on demand. Or you submit a form when something is chosen by the user and fill in the information server-side.

XMLHttpRequests let’s you retrieve information from the server using a client-side Javascript XML object without requiring a page reload. In essance, it’s a mixture between the two hacky methods mentioned above.

For more information, check out this article. An example is also present. While that example is nice, I like this one better.

I only had time to quickly skim through the article, so I’m still left with some more researching to do:

• What about security? Can we XML request over a secure connection?
• Do we have to transfer server-side session ID’s manually?
• Any complete frameworks available where have a XMLHttpRequest enabled front-end (client side) which queries a bunch of server-side pages which in their turn query the database (or stored XML information) and return information in XML?
• Can this be a nice platform for three-tire webapplications?

_{(Thanks to Joel On Software for posting about this)}