gistfile1.txt

VIEWMODEL

public class ViewModelUsers extends AndroidViewModel {

    public boolean
        UNAUTHENTICATED,        // Initial state, the user needs to authenticate
        AUTHENTICATED,          // The user has authenticated successfully
        INVALID_AUTHENTICATION;  // Authentication failed


    private RepoUsers repoUsers;
    private LiveData<List<TableUsers>> verifyUserLogin;
    private String email, password;
    private boolean validated;
    private SharedPreferences mLoginPrefs;
    private SharedPreferences.Editor mEditor;


    public ViewModelUsers(@NonNull Application application) {
        super(application);
        repoUsers = new RepoUsers(application);
        mLoginPrefs = getApplication().getSharedPreferences(LOGIN_PREF, Context.MODE_PRIVATE);
        mEditor = mLoginPrefs.edit();
        verifyUserLogin = repoUsers.verifyUserLogin(email, password);
    }

    public LiveData<List<TableUsers>> verifyUserLogin(String email, String password) {
        MediatorLiveData mediator = new MediatorLiveData();
        mediator.addSource(repoUsers.verifyUserLogin(email, password), new Observer<List<TableUsers>>() {
            @Override
            public void onChanged(List<TableUsers> tableUsers) {
                for (TableUsers ut : tableUsers) {
                    // If the users details match whats in the Room Database the login success boolean is set to true and the user can progress.
                    if (ut.getEmail().equals(email) && ut.getPassword().equals(password)) {
                        mEditor.putString("fName", ut.getFirstName());
                        mEditor.putString("lName", ut.getLastName());
                        mEditor.putString("email", ut.getEmail());
                        mEditor.putLong("userId", ut.getPkUserId());
                        mEditor.apply();
                        mEditor.commit();
                        AUTHENTICATED = true;
                        authenticate();
                    }
                }
                mediator.removeSource(repoUsers.verifyUserLogin(email, password));
            }
        });

        return mediator;

    }

    public boolean authenticate() {
        return AUTHENTICATED;
    }
    
    
    
    
    
    
    
    public class LoginFragment extends BaseFragment implements TextWatcher, CompoundButton.OnCheckedChangeListener, View.OnClickListener {

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view =inflater.inflate(R.layout.fragment_login, container, false);

        // Initialises the View model.
        mViewModelUsers = new ViewModelProvider(requireActivity()).get(ViewModelUsers.class);

        return view;
    }
    
     @Override
    public void onClick(View view) {

        switch (view.getId()) {

 case R.id.btnLogin:
                // Checks if the username and password is valid.
                if (!validateEmail() | !validatePassword()) {
                    return;
                }

                strEmailInput = etEmail.getText().toString();
                strPasswordInput = etPassword.getText().toString();

                // Checks the users inputted username & password against the information stored in the Room Database
                mViewModelUsers.verifyUserLogin(strEmailInput, strPasswordInput).observe(getViewLifecycleOwner(), new Observer<List<TableUsers>>() {
                    @Override
                    public void onChanged(List<TableUsers> tableUsers) {

                        AUTHENTICATED = mViewModelUsers.authenticate();
                        if (AUTHENTICATED) {
                            loginSettings();
                        } else{
                            Snackbar.make(view,
                                    "Invalid login",
                                    Snackbar.LENGTH_SHORT
                            ).show();
                        }
                    }
                });

                break;
        }
    }
    
    }