Firebase Facebook login check if user exist

Question

I have an facebook login system which works with firebase but I want to check if user exist on my firebase (i don\'t want to add it, just want to make sure if he exist becau

Answer 1

You can use reauthenticateWithCredential method to check user is exist or not.

Check this Doc. , section -> Re-authenticate a user

let user = FIRAuth.auth()?.currentUser
var credential: FIRAuthCredential

// Prompt the user to re-provide their sign-in credentials

user?.reauthenticateWithCredential(credential) { error in
  if let error = error {
    // An error happened.
  } else {
    // User re-authenticated.
  }
}

If user re-authenticated successfully that means user is existed...