How to create a Facebook App with "Like it" confirmation?

i'm a totally newbie in Facebook App coding and i would like to creat a simple app that give the main content only after a "Like it" confirmation?

The example: http://www.facebook.com/RelapseRecords?ref=ts&sk=app_162097493835692

(You only see the download links after "Like it")

Where i ca开发者_运维百科n find a how-to for that?

Thanks in advise, reevex

Actually, it is possible. Facebook recently introduced the „Signed Request” parameter which can be used to obtain what you need. After you decode this parameter you will have a JSON object. One of its field is called page. This is another JSON object containing among other params the liked boolean if the user has liked the page. This is only available if your app is an iframe loaded in a Page tab.

Based on this boolean value you can choose which content to display to the user.

Good luck!