Facebook Application Reference

For the last few weeks I (along with some friends) have been developing some Facebook applications. Our first release: Christmas Fun! has been fantastic, growing incredibly fast in just the first week and a half. We are working on getting our second app done and are hoping to push it out by the end of the week.

During all this time, we came across a few things that we hope might help other developers:

• Store Facebook UIDs if you want to do profile updates - there doesn't appear to be a simple way of getting all of the users of your app, so storing them is the easiest way we could find to do mass updates
• Notifications.send & feed.publishTemplatizedAction - Here's what we found: notifications.send() is basically telling user A that user B did something to them. It also sends an email if configured (an extra parameter). feed.publishTemplatizedAction() is a way of telling all of user A's friends that user A did such-and-such. It also appears to be able to do aggregation of news stories, but we aren't 100% sure. As well, make sure to read the docs on the usage of the tag in the notifications (ie: if you don't place one at the start of your notification, one will be prepended)
  
• Images need absolute URLs - or Facebook will yell at you. And make sure the URLs are back to your host and not through Facebook. We recommend having a variable that stores your host in case you ever need to move hosts.
• Javascript - This is a big one...there's a few things to note here: 1) Facebook proxies your Javascript, so if you get errors using Firebug (or another tool) don't get freaked out if you see "app7291713u1241204901231_foo()" as a function. 2) If your code doesn't work as you thought, double check the FBJS DOM - Facebook likes to give a few different Javascript functions for handling properties.

We'll be sure to add in some more findings as we come across them.