Firebase Not Capturing Email/Phone from Facebook - ios

Question

When a user logs into the app using Facebook, I am able to capture and display their full name; however, neither email nor phone number is coming across. I have tried both the "One account per email address" as well as "Multiple accounts per email". I have tested it with an account whose email address is definitely not already registered in Firebase. What am I missing such that email/phone are not being captured? This all does work with Google accounts.
let name = Auth.auth().currentUser?.displayName // works!
let email = Auth.auth().currentUser?.email // nil- why?
let phone = Auth.auth().currentUser?.phoneNumber // nil -why?
The login process, which is standard Firebase w/ Facebook, looks like this:
func loginButton(_ loginButton: FBSDKLoginButton!, didCompleteWith result: FBSDKLoginManagerLoginResult!, error: Error!)
{
if let error = error
{
print(error.localizedDescription)
}
else
{
if FBSDKAccessToken.current() != nil
{
let credential = FacebookAuthProvider.credential(withAccessToken: FBSDKAccessToken.current().tokenString)
Auth.auth().signIn(with: credential) { (user, error) in
if let error = error
{
print (error.localizedDescription)
}
}
}
}
}
To update based on comments below. The following also produces a nil email and phone when inspecting the contents of userInfo. I understand the phone might just be that way, but it seems the email was supposed to work.
let userInfo = Auth.auth().currentUser?.providerData

Answer 1

The top level phoneNumber currentUser.phoneNumber is only for Firebase verified phone numbers. If you have that Facebook phone number, you can use the currentUser.updatePhoneNumber API to verify that number (you will need to go through the whole flow). Otherwise, you can wait for the upcoming Admin node.js API to set phone numbers with Admin privileges on existing users: https://github.com/firebase/firebase-admin-node/commit/68563c4b2c8128fbc45fc65bad3f6730d320b539
As for the email, in the case of "multiple accounts per email" you need to set it yourself via currentUser.updateEmail. You can get the Facebook email from currentUser.providerData which contains the Facebook provider data.