How can I tell if a user clicked “Don't allow” on a <fb:login-button> initiated dialog?

Question

I have a FB login button on my site. I'd like to analyze how many people click the button, but do not proceed with the login process (ie close the dialog, or click "Don't Allow").

Any ideas?

Answer 1

You cannot. Fb doesn't provide any callback for that.

Answer 2

I figured another way to solve this, though not so perfect. I can add an onClick to the fb:login-button tag and track event using Google Analytics. This tracks the event and doesn't interfere with Facebook login process. While it doesn't give an accurate answer to the question how many people clicked "Don't Allow", it does show how many people clicked the button which is a good start. If they didn't ended up signing up, its enough for me to consider them as those who click "Don't Allow".