Question

I want to send a link to my friend wall post though a fb app , if he/she clicks on the link then they will be send to a internal page of my fb app. If the user has not joined the app, then will the user will be automatically send to the inner page of my app if they joins the app.If not , then how i need to do it.

Answer 1

Add a parameter name app_data in the url like http://www.facebook.com/test?sk=app_1234&app_data=1 you can get the parameter in signed request of fb object.

If you call the function $fb->getUser() and that function return 0, it means user has not joined the app.