I'm having a problem with app_data. I post a feed in my timeline with a link. This link is my app url with app_data aka:
http://apps.facebook.com/mfanpage/app_123456?app_data=my-very-important-data-here
When the user clicks in the link, he is directed to my app and Facebook ask for some permissions. If user accept all conditions, he is redirected to the app AND my app_data becomes EMPTY!
What can I do? Please HELP!
Its because when the user authorizes you're app, Facebook redirects the user to the redirect_uri that is provided by default by you're which basically does not include the app_data which is appended to the url, when the user clicks on the link. So you need to store the app_data some how, that when the user authorizes you're app, you can retrieve it again. Maybe go with the cookies or HTML5 localstorage for storing it temporarily so that you can retrieve it again.