Register authenticated users with Facebook in Firebase Database

Question

Good night! Guys, I’m using Facebook login in my app and would like to register the user information in the database or firestore Realtime, as the name and email for example, I’ve recovered the logged in user information, I’ve already done the authentication, but I don’t know how to save this data, I can easily save when I use the email and password method, but with facebook the login method is different. What is the best way for me to save this data ?

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {

    callbackManager.onActivityResult(requestCode, resultCode, data);
    super.onActivityResult(requestCode, resultCode, data);

}

private void firebaseAutenticacaoFacebook(AccessToken accessToken) {

    AuthCredential credential = FacebookAuthProvider.getCredential(accessToken.getToken());
    mAuth.signInWithCredential( credential )
            .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                @Override
                public void onComplete(@NonNull Task<AuthResult> task) {
                    if (task.isSuccessful()) {

                        FirebaseUser user = mAuth.getCurrentUser();
                        
                        Usuario usuario = new Usuario();
                        
                        usuario.setEmail( user.getEmail() );
                        usuario.setNome ( user.getDisplayName());
                        usuario.setFoto ( user.getPhotoUrl().toString());


                        MainScreen();

                    } else {

                        String excecao = "";

                        try
                        {
                            throw task.getException();

                        }catch (FirebaseAuthUserCollisionException e)
                        {
                            excecao = "Este email ja foi cadastrado!";

                        }catch (Exception e)
                        {
                            excecao = "Erro ao logar usuário!" + e.getMessage();
                        }

                        Toast.makeText(getApplicationContext(), excecao , Toast.LENGTH_SHORT).show();

                    }
                }
            });
}

 public void MainScreen(){

    Intent i = new Intent(LoginActivity.this, MainActivity.class);
    startActivity(i);
    finish();
}

Answer 1

as the documentation in Read and write data on android

Have the instance:

private DatabaseReference mDatabase;
// ...
mDatabase = FirebaseDatabase.getInstance().getReference();

the User class

@IgnoreExtraProperties
public class User {

    public String username;
    public String email;

    public User() {
        // Default constructor required for calls to DataSnapshot.getValue(User.class)
    }

    public User(String username, String email) {
        this.username = username;
        this.email = email;
    }

}

and the function that will save to firebase:

private void writeNewUser(String userId, String name, String email) {
    User user = new User(name, email);

    mDatabase.child("users").child(userId).setValue(user);
}

by sample of your code, you can do:

//...
FirebaseUser user = mAuth.getCurrentUser();

writeNewUser(user.getUid(), user.getDisplayName(), user.getEmail());
//...