Facebook app without prompted authentication

I've been trying to figure out a way to have my iframe Facebook app (built in PHP) work without requiring separate authentication methods. I am already logged into Facebook, but for some reason I still see all these Oauth notices from the example in the PHP SDK.

The only data I need is publicly available even without them "adding" my app. I am looking to collect their Facebook ID (since this is a contest, we need a unique ID for tracking), their name and (optionally) their email address as well.

The problem is, I cannot use the API to fetch the public information unless I already know their Facebook username. Any ideas on how I might be able to get their logged-in username or public handle so I can then fetch the rest of the information?

For whatever reason, Oauth is driving me completely insane with Facebook today.

Sidenote:

I did ma开发者_如何学JAVAnage to technically get the Javascript SDK operational, which fed some information to PHP for use. The only issue there is that once I login, I don't see the data. If I refresh...then it shows up. Unsure why the refresh is required, as I wouldn't expect a user to actually have to hit refresh in order to proceed with the app.

I guess you are a bit confused here, Facebook will NOT share the username, id, full name or email without the user explicitly authorizing/allowing your application (and in the case of the email, requesting the email permission!).

Read the official Canvas Tutorial for more information:

In order to gain access to all the user information available to your app by default (like the user's Facebook ID), the user must authorize your app.