Agfdhyk

I am trying to implement google sign-in feature in my app. I have followed this documentation, problem is - if I use previously used google account, it is not showing an error like "the e-mail is already registered in this app". As a result, previously stored data with the account are deleted & the google account is registered again. Here is my code :

private void firebaseAuthWithGoogle(GoogleSignInAccount acct) {

    Log.d(TAG, "firebaseAuthWithGoogle:" + acct.getId());



    AuthCredential credential = GoogleAuthProvider.getCredential(acct.getIdToken(), null);

    mAuth.signInWithCredential(credential)

            .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {

                @Override

                public void onComplete(@NonNull Task<AuthResult> task) {

                    if (task.isSuccessful()) {

                        // Sign in success, update UI with the signed-in user's information

                        Log.d(TAG, "signInWithCredential:success");

                        FirebaseUser user = mAuth.getCurrentUser();

                        int coins = 100;

                        String name, email;

                        name = user.getDisplayName();

                        email = user.getEmail();

                        //updateUI(user);

                        storeUserCredentials(name, email, coins);

                    } else {

                        // If sign in fails, display a message to the user.

                        Log.w(TAG, "signInWithCredential:failure", task.getException());

                        Toast.makeText(SignUpActivity.this, "Error : " + task.getException().getMessage(), Toast.LENGTH_SHORT).show();

                    }

                }

            });

}



public void storeUserCredentials(String name, String email, int coins){

    progressBar.setVisibility(View.VISIBLE);

    User user = new User(name, email, coins);



    mDatabase.getReference("Users")

            .child(mAuth.getCurrentUser().getUid())

            .setValue(user)

            .addOnCompleteListener(new OnCompleteListener<Void>() {

                @Override

                public void onComplete(@NonNull Task<Void> task) {

                    progressBar.setVisibility(View.GONE);

                    if (task.isSuccessful()){

                        Toast.makeText(SignUpActivity.this, "Registration Successful!", Toast.LENGTH_SHORT).show();

                        startActivity(new Intent(SignUpActivity.this, MainActivity.class));

                        finish();

                    } else {

                        if (task.getException() instanceof FirebaseAuthUserCollisionException){

                            Toast.makeText(SignUpActivity.this, "The email is already used", Toast.LENGTH_SHORT).show();

                        } else {

                            Toast.makeText(SignUpActivity.this, task.getException().getMessage(), Toast.LENGTH_SHORT).show();

                        }



                    }

                }

            });

}

What is wrong with my code, please explain.

When you call signInWithCredential the SDK returns a task that successfully completes when the user is signed in. Since you call storeUserCredentials on that condition, it will get called each time the user is signed in. This is actually a quite normal flow.

If you want to detect if this account is new to Firebase Authentication, you can check the creation time of the user. See Firebase Auth, how to know new user signed up, rather than existing user sign in?

If you want to detect whether you've already seen the user before, you'll want to check in the database before calling storeUserCredentials. But what you now have is a pretty idiomatic flow, since it for example ensures you store the up-to-date display name each time you ask the user to sign in.