Firebase does not create a Facebook account User UID using the Facebook App User ID

Question

I am developing an iOS app in swift that requires a user to create an account by connecting their Facebook account. A month ago, when I was testing by signing up with my own Facebook account, the User UID created by Firebase was in the format "facebook:(facebook app id)". This was what I wanted.

However, lately whenever a user creates a new acconut by connecting their Facebook account with my app, Firebase creates a User UID using a random string. For example: "E9FaL87wRmOKfhen2S6yszhCwtx1". Could this be because of the new Firebase update? Should I go through the migration process?

Here is my code for account creation:

@IBAction func facebookAuthAction(sender: AnyObject) {
    let facebookLogin = FBSDKLoginManager()

    facebookLogin.logInWithReadPermissions(nil, fromViewController: nil, handler: {(facebookResult, facebookError) -> Void in

        if facebookError != nil {
            print("Facebook login failed. Error \(facebookError)")
        } else if facebookResult.isCancelled {
            print("Facebook login was cancelled.")
        } else {
            let accessToken = FBSDKAccessToken.currentAccessToken().tokenString

            FIREBASE_REF.authWithOAuthProvider("facebook", token: accessToken, withCompletionBlock: { error, authData in

                    if error != nil {
                        print("Login failed. \(error)")
                    } else {
                        print("Logged in! \(authData)")
                        NSUserDefaults.standardUserDefaults().setValue(authData.uid, forKey: "uid")

                        FIREBASE_REF.childByAppendingPath("users").observeEventType(.Value, withBlock: {snapshot in
                            if snapshot.hasChild(authData.uid) == false {
                                self.createNewFBUser(authData.uid)
                            }
                        })

                        self.performSegueWithIdentifier("loginSegue", sender: self)
                    }
            })
        }
    })
}

func createNewFBUser(uid: String) {
    var emailAddress:String = ""
    var firstName:String = ""
    var lastName:String = ""
    var pictureURL:String = ""

    let parameters = ["fields": "email, first_name, last_name, picture.type(large)"]
    FBSDKGraphRequest(graphPath: "me", parameters: parameters).startWithCompletionHandler {(connection, result, error) -> Void in

        if error != nil {
            print(error)
            return
        }

        if let email = result["email"] as? String {
            emailAddress = email
        }
        if let first_name = result["first_name"] as? String {
            firstName = first_name
        }
        if let last_name = result["last_name"] as? String {
            lastName = last_name
        }
        if let picture = result["picture"] as? NSDictionary, data = picture["data"] as? NSDictionary, url = data["url"] as? String {
            pictureURL = url
        }

        let newUser = [
            "provider": "facebook",
            "firstName": firstName,
            "lastName": lastName,
            "email": emailAddress,
            "picture": pictureURL
        ]
        FIREBASE_REF.childByAppendingPath("users").childByAppendingPath(uid).setValue(newUser)
    }
}

Answer 1

When you upgrade your project to the new Firebase Console, your users are migrated to the new authentication back-end.

Newly created users after the upgrade will get a uid in the new format. See this post on the firebase-talk group for more information about the change and when it will also be applied to existing (non-upgraded) Firebase apps.

Note that Firebase has recommended against depending on the format of the uid for years. It is best to treat it as an opaque string that identifies the user.