dual_auth_firebase_demo

You can allow users to sign in to your app using email ?& phone both by linking auth provider credentials with same token Id.

Before you begin

• Create your firebase account
• Add your json file into your app
• In firebase Authentication enable for two authentication providers to your app.
  • Email Auth Provider
  • Phone Auth provider
• Choose realtime database to store auth data
• Add all needed dependencies into build.gradle

To link auth provider credentials to an existing user account:

• Sign in the user using email method.

• Complete the sign-in flow for the new authentication provider up to FirebaseAuth.signInWith methods.

• Pass the Credential object to the signed-in user's linkWithCredential method:

     mAuth.getCurrentUser().linkWithCredential(credential)
    .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
        @Override
        public void onComplete(@NonNull Task<AuthResult> task) {
            if (task.isSuccessful()) {
                Log.d(TAG, "linkWithCredential:success");
                FirebaseUser user = task.getResult().getUser();
                updateUI(user);
            } else {
                Log.w(TAG, "linkWithCredential:failure", task.getException());
                Toast.makeText(AnonymousAuthActivity.this, "Authentication failed.",
                        Toast.LENGTH_SHORT).show();
                updateUI(null);
            }
        }
    });