How to properly sign out of Facebook on Android with Firebase?

Question

So I figured out how to properly signout with Google. Cool. Now, what about Facebook?

When I get an error signing in to Facebook, such as an error indicating I already have a Firebase account with the same credentials but a different social provider, I get the "Log out of facebook" button. To be more clear:

I try logging into Facebook, then I get an error ( this isn't my problem! ), but the problem is, Facebook's button is now on "Log out". When it should still be "Sign In With Facebook" . I know why this is happening; it's because the error is with Firebase and Facebook thinks I'm signed in.

But the real question is , how do I properly sign out of Facebook? FirebaseAuth.getInstance().signout() doesn't seem to logout of Facebook itself.

Here's my current logout() method:

static void logOut(final Context context) {
    new SweetAlertDialog(context, SweetAlertDialog.WARNING_TYPE)
        .showCancelButton(true)
        .setTitleText(context.getString(R.string.areYouSure))
        .setContentText(context.getString(R.string.logoutMSG))
        .setCancelText(context.getString(android.R.string.no))
        .setCancelClickListener(new SweetAlertDialog.OnSweetClickListener() {
            @Override
            public void onClick(SweetAlertDialog sweetAlertDialog) {
                sweetAlertDialog.dismiss();
            }
        })
        .setConfirmText(context.getString(R.string.yes))
        .setConfirmClickListener(new SweetAlertDialog.OnSweetClickListener() {
            @Override
            public void onClick(final SweetAlertDialog sweetAlertDialog) {
                //region Google
                GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                    .requestIdToken(context.getString(R.string.default_web_client_id))
                    .requestEmail()
                    .build();
                final GoogleApiClient mGoogleApiClient = new GoogleApiClient.Builder(context)
                    .enableAutoManage((FragmentActivity) context, new GoogleApiClient.OnConnectionFailedListener() {
                        @Override
                        public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
                            FirebaseCrash.log(connectionResult.getErrorMessage());
                            Toast.makeText(context, context.getString(R.string.error), Toast.LENGTH_SHORT).show();
                        }
                    })
                    .addApi(Auth.GOOGLE_SIGN_IN_API, gso)
                    .build();
                mGoogleApiClient.registerConnectionCallbacks(new GoogleApiClient.ConnectionCallbacks() {@
                    Override
                    public void onConnected(@Nullable Bundle bundle) {

                        FirebaseAuth.getInstance().signOut();
                        if (mGoogleApiClient.isConnected()) {
                            Auth.GoogleSignInApi.signOut(mGoogleApiClient).setResultCallback(new ResultCallback < Status > () {@
                                Override
                                public void onResult(@NonNull Status status) {
                                    if (status.isSuccess()) {
                                        FirebaseAuth.getInstance().signOut();
                                        sweetAlertDialog.dismiss();
                                        Log.d(TAG, "User Logged out");
                                        Intent intent = new Intent(context, SignUp.class);
                                        context.startActivity(intent);
                                        ((FragmentActivity) context).finish();
                                    } else
                                        Toast.makeText(context, context.getString(R.string.error), Toast.LENGTH_SHORT).show();
                                }
                            });
                        }
                    }

                    @
                    Override
                    public void onConnectionSuspended(int i) {
                        Log.e(TAG, "Google API Client Connection Suspended");
                    }
                });
                //endregion
            }
        }).show();
}

Answer 1

I had a similar problem and got it solved using both the firebase Auth instance and the facebook LoginManager instance

FirebaseAuth.getInstance().signOut();
LoginManager.getInstance().logOut();

My Question

Answer 2

3 Sign Out methods for Firebase itself, Google and Facebook .

//LOG_OUT
    public static void signOut(Activity activity) {
        if (mAuth == null)
            mAuth = FirebaseAuth.getInstance();

        //Firebase SignOut
        mAuth.signOut();

        //Google SignOut
        SignInWithGoogle signInWithGoogle = new SignInWithGoogle(activity);
        signInWithGoogle.getGoogleSignInClient().signOut()
                .addOnCompleteListener(activity, new OnCompleteListener<Void>() {
            @Override
            public void onComplete(@NonNull Task<Void> task) {
                Log.d(TAG, "Google Sign Out!!! ");
            }
        });

        //Facebook SignOut
        LoginManager.getInstance().logOut();
    }