That title was a mouthful! This post is a simple bug fix for an IE 7/8 issue that I couldn't find any solution for on the interwebs. The bug is as follows: if you use the Facebook JavaScript SDK to send apprequests (the invites that show up in the Facebook notifications jewel) and you're doing so through the FB.ui() method, the default settings will not work in Internet Explorer 7 and 8.
FB.ui() requests use Facebook Dialogs to render the modal. In your FB.ui() call you can reference the way in which you want Facebook Dialogs to render the modal. The options are 'page', 'popup', and 'iframe'. The Facebook documentation states that 'page' is the default, but for FB.ui({method: 'apprequests'}) calls, 'popup' is the default - which looks great in Chrome/FireFox/Safari; however, in IE, the modal never appears. So for IE users you need to set the display method to 'iframe' and it will work fine.
All you have to do is write some simple JavaScript browser detection code to toggle the display method. Here is my CoffeeScript to do this:
In case you're not a CoffeeScript fan, here is the equivalent to the above in JavaScript.