iOS Facebook登录但不连接？

Question

today I've an hard question that it causes me some problems.

I'm beginning to implement, for the first in my life, the Facebook Login/Connect in my iOS application.

What's strange? Nothing so far, except I want that the users can ONLY login in the app with Facebook Login, not signup. I explain better: only the users that are already registered in my website can use Facebook Login for logging in.

• Website: users can signup with Facebook Connect
• iOS app: users can use Facebook Connect only if they're already connected in the website with Facebook Connect.

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

Answer 1

On the website side

Your user logs in, then authorizes to use your app. As soon as she is authorized, add her user id to your database.

On iOS side

Your user logs in. As soon as she logs in you have access to her user id. So, before showing the main app screen display a loading graphic. Send a request with the user id to your server. The server replies that she is authorized and you proceed to show your main app screen. OR, the server replies that she is not authorized and you proceed to show an error message that instructs the user to first authorize on the website (maybe this screen should have a retry button).

Answer 2

如果我得到你的问题..你可以通过它在你的网站上建立一个Api_service你可以从应用程序发送用户的电子邮件，并检查这个邮件是否在你的网站上注册..所以在用户登录Facebook之前你请求打电话这个api>你给你的应用程序返回了一个值告诉你用户是否在你的网站上注册了..那么你就可以只允许用户登录fb了。