Detect Firebase Auth Provider for Loged in User

Question

How can i check that my user Loged in to my app Using which Auth Provider ? I wanted to detect that did my user loged in to my app using Facebook auth provider or using Email Provider or by using Google auth provider . I have searched this in Firebase Docs but i couldnt find any proper answer ,

Answer 1

You can always check the list of providers as Malik pointed out. However, as you can have multiple providers linked to the same user, to get the sign in method of the current User with multiple providers, you have to check the ID token. You need to check firebase.sign_in_provider claim in the token. That will give you the sign in method used to get the ID token. To get it on the client, you need to getIdToken and then parse the returned JWT with some JWT parser.

Answer 2

FirebaseUser firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
if (firebaseUser.getProviderData().size() > 0) {
            //Prints Out google.com for Google Sign In, prints facebook.com for Facebook
            e("TOM", "Provider: " + firebaseUser.getProviderData().get(firebaseUser.getProviderData().size() - 1).getProviderId());

        }

Answer 3

您可以使用方法getIdTokenResult()用户对象（的firebase.User ），以获得IdTokenResult对象，其signInProvider属性，你可以用它来检测登入登录的用户的方法。

Answer 4

I have been puzzled over this problem and couldnt find an appropriate solution for a long time as well. The solution turns out to be short:

String strProvider = FirebaseAuth.getInstance().
         getAccessToken(false).getResult().getSignInProvider();

So, if (strProvider.equals("password")) then the authentication is by Email + Password,
if (strProvider.equals("google.com")) then the authentication is via Google,
if (strProvider.equals("facebook.com")) then the authentication is via Facebook.

Addition

However, with this one-liner you can get an exception wchich can be prevented by adding OnSuccessListener like so:

mAuth = FirebaseAuth.getInstance();
mAuth.getAccessToken(false).addOnSuccessListener(new OnSuccessListener<GetTokenResult>() {
                @Override
                public void onSuccess(GetTokenResult getTokenResult) {
                    strProvider = getTokenResult.getSignInProvider();
                }
            });

Answer 5

Reached here for same issue, unable to find the provider that user used to login.
I am working on react-js app using react-firebaseui lib for readymade UI.
After a lil struggle, I simply analysed the "user" object returned by auth and in that we receive an array "providerData".

Without further analysis I decided to use:

  const signinProvider = user.providerData[0].providerId;

In my case, we use only 2 providers google & password.
I get the user from "onAuthStateChanged" function as below:

import { fbAuth } from "./firebase";

fbAuth.onAuthStateChanged(function (user) {
    if (user) {
      console.log("authStateChanged:=====", user);
      useItFurther(user);
    } else {
      console.log("authStateChanged: no user logged in.");
      cleanUpAuthDetailsIfApplicable();
    }
  });

CAUTION : I haven't researched why is providerData an array and what more can be there in that array, what could be the sequence when there are more than 1 objects in that array, etc.
In my case, we had to add a condition for email validation based on provider. Like, for a particular domain email address, force user to use a specific provider.

Answer 6

Alternative

The getProviders() method list is sorted by the most recent provider used to sign in. So the first element in getProviderData() is the method that the user used to sign in.

Also the reason why FirebaseAuth.getInstance().getCurrentUser().getProviderId() returns firebase is because a backing Firebase Account is always created irrespective of how the user signs in. This helps with linking and unlinking of accounts where users may want to attach more than one credential (however your view of the FirebaseUser has not changed).

as mention this post .