At Terralever we have been building some Facebook applications, and have started shifting a lot of effort into building more.

I have to say they are a challenge, but a fun challenge. One of the developers, Justin and I were chatting today about this one new app we are working on and we both realized that we are learning so much about Facebook applications during every piece of function we write. Funny. But awesome too. There is so much to learn about the platform and how to use it, its so powerful.

One of the cool things that I found out today was collecting information about a user when they uninstall an application. I have never really wanted to collect any info on the users before, but the client we are building for right now wanted to collect a bunch of info about the users when they uninstall their app.

What we really wanted was the uid from that user. So, in the facebook documentation Post-Remove URL, they list all the POST variables. But I was having a hard time getting that info. Even watching with fiddler, I could not get the fb_sig_user. Finally, we just had to believe it was there, and sure enough it was.

uid = Convert.ToInt64(Request.Form["fb_sig_user"]);

There it is the C# used in the Post-Remove page. Awesome, I wish all facebook stuff was that easy.

Next up, the Fb:dialog. YAY.