For Let’s Mix and a leading spirits brand I’ve developed a Facebook app to be displayed in a Facebook fan page tab.

A fun assignment, that turned out to be somewhat frustrating when I started to realize the limits of the Facebook API.

A Facebook app using FBML can include IFrames, and the app can also display the whole content in an IFrame if desired. The IFrame versions of the new and fancy social functionality can therefore easily be included, but put that same app in a tab on a fan page and this is no longer an option. All of a sudden the IFrames are gone.

Turns out that apps displayed in tabs can only use old style FBML. This is only the case for the specific combination of apps in tabs, but is still very frustrating when that’s exactly what you need to build. There are workarounds, through for example JavaScript, but to execute anything in JavaScript in this environment the user has to actively click something. No actions on load allowed. I hope that this is fixed by Facebook soon!

I haven’t had any reason to develop a full Facebook app yet, but since I was curious about their API I’ve been playing around with it. The SATS app was originally something I built years ago for my own webpage when I was a member of SATS (the gym). SATS’ search for classes didn’t have the interface I wanted, so I rearranged the search results a bit more to my liking. (It’s all ugly hacking, stripping data from an HTML result.) To my surprise, they haven’t changed their search functionality since then, so I ported the search to a Facebook app as an experiment. The app resides on my server and I rebuilt the whole front-end to return a JSON object with the data to show, then displaying it with FBML. I’d like to implement more of the existing search functionality, but as this has the status of being an ugly hack depending on SATS not rebuilding their search, I don’t think it’s worth the effort. Oh, and I think the app is buggy in IE at the moment.

After writing the SATS app I got curious about Google App Engine and wanted to do some sort of Hello World to test connecting GAE to a Facebook app. I built a very simple function just to display your friend list as an XML file.

The reason for this is that many of my friends complained about not being able to trace the people disappearing from their friend lists. This is also a convenient way to get the user ids for your friends if you’re developing an application and need test data. I’m not allowed to save versions of friend lists due to Facebook API user terms, but this way the users can save versions of their list to compare.