GitHub Authentication for Android Through Firebase

Question

Hello I want to know how can I access user email while authenticating a user through Github in my android App. I am using firebase and android studio. Please note that I cannot use user.getEmail in onSuccesslistner because I am also using Google authentication, which throws exception that email already exist and pending task method works for first time only. Basically I want to use setScopes to retrieve the user Email. I have to get Email and check if user exist in my database in simply logged in user.

Here is my Code:

    public void git_login(View view)
        {
            SignInWithGithubProvider(
                    OAuthProvider.newBuilder("github.com")
                            .setScopes(
                                   new ArrayList<String>()
                                    {
                                        {
                                            add("user:email");
                                        }
                                    }).build()
            );
        }
    
        private void SignInWithGithubProvider(OAuthProvider login)
        {
            Task<AuthResult> pendingResultTask= mAuth.getPendingAuthResult();
            if (pendingResultTask!=null)
            {
                // There's something already here! Finish the sign-in for your user.
                pendingResultTask
                        .addOnSuccessListener(
                                new OnSuccessListener<AuthResult>() {
                                    @Override
                                    public void onSuccess(AuthResult authResult) {
                                        Toast.makeText(getApplicationContext(), "User Exist" + authResult, Toast.LENGTH_SHORT).show();
                                        // User is signed in.
                                        // IdP data available in
                                        // authResult.getAdditionalUserInfo().getProfile().
                                        // The OAuth access token can also be retrieved:
                                        // authResult.getCredential().getAccessToken().
                                    }
                                })
                        .addOnFailureListener(
                                new OnFailureListener() {
                                    @Override
                                    public void onFailure(@NonNull Exception e) {
                                        // Handle failure.
                                    }
                                });
            }
            else {
                // There's no pending result so you need to start the sign-in flow.
                // See below.
                mAuth.startActivityForSignInWithProvider(this , login).addOnFailureListener(new OnFailureListener() {
                    @Override
                    public void onFailure(@NonNull Exception e)
                    {
    
                        if (e.toString().equals("com.google.firebase.auth.FirebaseAuthUserCollisionException: An account already exists with the same email address but different sign-in credentials. Sign in using a provider associated with this email address."))
                        {
                            showDialogAlert();
                        }
                    }
                }).addOnSuccessListener(new OnSuccessListener<AuthResult>() {
                    @Override
                    public void onSuccess(AuthResult authResult) {
                        FirebaseUser user = mAuth.getCurrentUser();
                        Toast.makeText(getApplicationContext(), "Login" + user.getUid() +"\n"+user.getEmail(), Toast.LENGTH_SHORT).show();
                        userNameForDb = user.getDisplayName();
                        userImageForDb = String.valueOf(user.getPhotoUrl());
                        userEmailForDb = user.getEmail();
                        Toast.makeText(CreateNewAccountActivity.this, "Account added to Firebase: " +userNameForDb+"\n"+userEmailForDb+"\n"+userTokenForDb, Toast.LENGTH_SHORT).show();
                        saveDataToDb(userNameForDb , userEmailForDb , userTokenForDb);
                    }
                });
    
            }
        }
```

Answer 1

I want to know how can I access user email while authenticating a user through Github

The simplest solution I can think of is once you are successfully authenticated, you can get the email address from the "userInfo" object like in the following lines of code:

FirebaseUser firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
if (firebaseUser != null) {
    for (UserInfo userInfo : firebaseUser.getProviderData()) {
        if (userInfo.getProviderId().equals("github.com")) {
            Log.d(TAG, "User is signed in with Github");
            Log.d(TAG, "email: " + userInfo.getEmail());
        }
    }
}

The output in the logcat will be the email address that was used by the user for the authentication process.

Edit:

It's true, if the user is already registered with a Gmail account, you'll get an Exception that says that such an account is already there. So you need to use for authentication Google credentials.

I actually want to get the user id in this case and want to check it in my database which is my local server that this email exists or not.

There is no need for that because you can handle the Exception, and indicate to the user that a Google account is already there, and then simply use Google credentials for authentication. If there is no Exception, is obvious that the user doesn't exist yet.