IOS Facebook login but not connect?

Question

Today I have a tough question, what causes me some problems.

I am starting to introduce, first of all in my life, Facebook Login / Connect in my iOS application.

What is strange? So far, nothing but the fact that I want users to ONLY be able to enter the application with Facebook Login, and not register. I explain better: only users who are already registered on my site can use Facebook Login to login.

• Website: Users can subscribe to Facebook Connect.
• IOS app: Users can only use Facebook Connect if they are already connected to the website using Facebook Connect.

Is this possible or an illusion? For example, if there is a way to get the facebook uuid of a registered user before showing the permission popup, it would be great because I check this uuid in my database and, if it exists, I will allow the user to connect.

Answer 1

On the side of the site

Your user logs in and then allows you to use your application. Once it is authorized, add your user ID to your database.

IOS side

Your user is logged in. Once she logs in, you have access to her user ID. So, before displaying the main screen of the application, a graphic download file will be displayed. Send the request with the user ID to your server. The server replies that it is authorized, and you proceed to display the main screen of the application. OR, the server responds that it is not authorized, and you proceed to display an error message that instructs the user to log in to the website first (perhaps there should be a redo button on this screen).

Answer 2

if I get your question .. you can create Api_service on your website through it, you can send a user’s email from the application and check if this letter is registered on your site .. so before creating a user on Facebook you create ask to call this api> you returned the value to your application, tell you that the user is registered on your site or not .. so that you can only allow the user you want to log in to fb.