I am using the riverpod_generator, and the AsyncNotifier in riverpod
part 'auth_controller.g.dart';
// 3. annotate
#riverpod
// 4. extend like this
class AuthController extends _$AuthController {
// 5. override the [build] method to return a [FutureOr]
#override
FutureOr<void> build() {
// 6. return a value (or do nothing if the return type is void)
}
Future<void> signIn({
required String email,
required String password,
}) async {
final authRepository = ref.read(authRepositoryProvider);
state = const AsyncLoading();
state = await AsyncValue.guard(
() async => await authRepository.signIn(email, password));
}
Future<void> logout() async {
state = const AsyncLoading();
state = await AsyncValue.guard(() async {
await FirebaseAuth.instance.signOut();
});
}
}
So when I am trying to logout the error will be occur it said
Future already completed
How to solve this?
I solve this problem, actually I listen to the changes of FirebaseAuth currentUser, then it will automatically redirect either homepage (if logged in) or login page (if logout), therefore the error will be occurred because I subscribe to the changes of FirebaseAuth
Related
Note: I've seen similar questions all over Stackoverflow, but none of them exactly answer this.
Context:
I have an authentication cubit that has a variety of user states:
/// User exists, includes user's access and refresh tokens.
class User extends AuthenticationState {
final Tokens? tokens;
final bool justRegistered;
final bool tokensAvailable;
User({
required this.tokens,
this.justRegistered = false,
this.tokensAvailable = true,
});
#override
List<Object?> get props => [tokens, justRegistered, tokensAvailable];
}
/// No authenticated user exists.
class NoUser extends AuthenticationState {}
/// User is currently being registered or signed in.
class UserLoading extends AuthenticationState {}
Problem:
I have a Posts Cubit that needs to manage API calls and pass in the current user's access token to them in order to work. However, this access token is only stored inside the Authentication Cubit's state (in the User state, inside the tokens variable).
Is there a (good practice) way to get this token from the Authentication Cubit's User state inside the Post Cubit so I can use it to send API requests that require tokens for authentication to return posts?
Thanks!
You can create a class something like API Provider and authenticateService, pass and use in your Cubit to call API :
For example:
Future<Response<dynamic>> _callAndRetryDelete(
String url, {
int validStatus,
int retries,
}) async =>
retry(
() async {
final Map<String, String> authHeaders = await _authenticationService.getAuthHeaders;
if (authHeaders == null) {
throw ApiError('Could not get authorization', endpoint: url, method: HTTPMethod.Delete);
}
_client.options = _options(success: validStatus, authHeaders: authHeaders);
try {
return await _client.delete(url);
} on DioError catch (error) {
final String message = _error(error);
throw ApiError(message, endpoint: url, method: HTTPMethod.Delete);
}
},
maxAttempts: retries,
);
AuthenticaionService.class
Future<void> _doLogin(Map<String, dynamic> params) async {
final Response<Map<String, dynamic>> response =
await _handler.post(_loginEndpoint, body: params,
validStatus: 200);
final Map<String, String> res =
response?.data?.map((String key, dynamic value) => MapEntry<String, String>(key, value.toString()));
final Authentication authentication = Authentication.parse(res);
await _parseAndStore(authentication);
return authentication;}
AuthCubit:
Future<void> signIn() async => cubitAction(
action: () async {
emit(AuthenticationLoading());
await _authenticationService.signIn(payload);
emit(AuthenticationDone);
}
);
final loginProvider =
FutureProvider.family<bool, LoginParam>((ref, param) async {
if (param.sgId == '' || param.password == '') {
return false;
}
final http.Response response =
await APIClient().login(param.sgId, param.password);
if (response.statusCode == 200) {
await APIClient().saveTokens(response);
UserDefaultEntity entity =
await ref.watch(userDefaultsProvider(param.sgId).future);
//ref.state = AsyncValue.data(true);
return true;
} else {
throw Exception(jsonDecode(response.body)['message'] ?? 'Unknown Error');
}
});
void login(String userName, String password) async {
state = AsyncValue.loading();
AsyncValue<bool> result;
try {
result = await ref.refresh(loginProvider(LoginParam(userName, password)));
state = result;
} catch (e) {
state = AsyncError(e);
}
}
I'm trying to throw an custom exception inside riverpod future provider and catch the exception in other state notifier classes, but the catch block is not triggered.
Is there any other way to handle exceptions that future provider throw.
First of all, you won't have to manually catch errors inside a FutureProvider, it will do that for you. Refer this example.
Generally, the operations that happen after certain "user interaction" like a button click (in this case, login operation), are not meant to be written in FutureProvider. Scenarios where you'd be using FutureProvider are as follows:
Fetching some data over HTTP/HTTPS.
Performing operations like reading a file or a local database.
So your use case of login can be achieved using a StateNotifier.
// auth_provider.dart
import 'package:hooks_riverpod/hooks_riverpod.dart';
// Always prefer some strongly typed object to
// know current status of authentication.
enum AuthState {
unauthenticated,
authenticated,
authenticating,
failed,
}
// StateNotifier is recommended to encapsulate all your business
// logic into a single class and use it from there.
class AuthStateNotifier extends StateNotifier<AuthState> {
// Initialize with the default state of "unauthenticated".
const AuthStateNotifier() : super(AuthState.unauthenticated);
Future<void> login(LoginParam params) async {
if (param.sgId.isEmpty || param.password.isEmpty) {
state = AuthState.failed;
return;
}
final http.Response response = await APIClient().login(param.sgId, param.password);
if (response.statusCode == 200) {
await APIClient().saveTokens(response);
UserDefaultEntity entity = await ref.watch(userDefaultsProvider(param.sgId).future);
state = AuthState.authenticated;
return;
} else {
state = AuthState.failed;
throw Exception(jsonDecode(response.body)['message'] ?? 'Unknown Error');
}
}
}
// Finally, create a provider that can be consumed in the presentation layer (UI).
final authProvider = StateNotifierProvider<AuthStateNotifier, AuthState>((ref) => const AuthStateNotifier());
Then, in your UI part, usually in the onTap / onPressed event handler of button, you can use it as follows. Please note that, we have created a button widget that extends the ConsumerWidget to access the ref.
// login.dart
import 'auth_provider.dart';
class LoginButton extends ConsumerWidget {
final LoginParam params;
const LoginButton({
Key? key,
required this.params,
}) : super(key: key);
#override
Widget build(BuildContext context, WidgetRef ref) {
void login() {
try {
await ref.read(authProvider.notifier).login(params);
} catch (e) {
// Handle error here.
}
}
return ElevatedButton(
child: Text('Login'),
// Call the handler here.
onPressed: login,
);
}
}
When i run the app and log-in / or already logged in before closed app => "Null check operator used on a null value" error pops up and it goes away just in a second. I guess user going to page before data came up.
If i sign-out and log in with another acc. Red screen wont came up but the last users data appears just for a second then current users data comes after. Could you please help me about this.
My primitiv Sign-in method
Future signIn() async {
try {
await FirebaseAuth.instance.signInWithEmailAndPassword(
email: emailController.text.trim(),
password: passwordController.text.trim(),
);
print('Signed In');
} on FirebaseAuthException catch (e) {
print (e);
Utils.showSnackBar(e.message);
}}}
User Provider
class UserProvider with ChangeNotifier {
User? _user;
final AuthMethods _authMethods = AuthMethods();
User get getUser => _user!;
Future<void> refreshUser() async {
User user = await _authMethods.getUserDetails();
_user = user;
notifyListeners();}}
The code i use refresh User welcomepage level
class _welcomePageState extends State<welcomePage> {
void initState() {
super.initState();
addData();
}
addData() async{
UserProvider _userProvider = Provider.of(context,listen: false);
await _userProvider.refreshUser();
}
#override
if that codes not enough to solve i can share all could you please help me to solve this problem.
You are force-unwrapping here :
User get getUser => _user!;
which means when you hot-reload the app it is null and the crash appears until it is null, you should make it optional and provide a default value so it doesn't crash.
I am trying to refactor my code and use a separate class object to register users and then send them to the correct page which is either the awaiting for email confirmation screen(if they haven't confirmed their email address) or the actual chat screen in the app.
I pass the Navigator.pushNamed object from the Flutter material build to the separate class object, but the Navigator.pushNamed doesn't work when it is sent as a parameter to the class object. It only worked when it is in the main build.
This is the main section that collects the parameters and sends them to the class
Widget build(BuildContext context) {...
Registration(
email: email,
password: password,
awaitingEmailConfPage:
() async {
await Navigator.pushNamed(context, EmailConfirmation.id);
},
confirmedEmailConfPage: () async {
await Navigator.pushNamed(context, ChatScreen.id);
}
).registerNewUser();
This is the class object that receives the Navigator.pushNamed but doesn't want to allow it to work and send users to the correct screen.
class Registration {
Registration(
{required this.awaitingEmailConfPage,
required this.confirmedEmailConfPage});
final _auth = FirebaseAuth.instance;
Future Function() awaitingEmailConfPage;
Future Function() confirmedEmailConfPage;
void registerNewUser() async {
try {
User? user = _auth.currentUser;
if (user!.emailVerified) {
await awaitingEmailConfPage;
} else {
await confirmedEmailConfPage;
}
}
}
If you want to call a function that receive as parameter you need to use call() method:
if (user!.emailVerified) {
await awaitingEmailConfPage.call();
} else {
await confirmedEmailConfPage.call();
}
I'm trying to use riverpod for login with a laravel backend. Right now I'm just returning true or false from the repository. I've set a form that accepts email and password. The isLoading variable is just to show a circle indicator. I've run the code and it works but not sure if I'm using riverpod correctly. Is there a better way to do it ?
auth_provider.dart
class Auth{
final bool isLogin;
Auth(this.isLogin);
}
class AuthNotifier extends StateNotifier<Auth>{
AuthNotifier() : super(Auth(false));
void isLogin(bool data){
state = new Auth(data);
}
}
final authProvider = StateNotifierProvider((ref) => new AuthNotifier());
auth_repository.dart
class AuthRepository{
static String url = "http://10.0.2.2:8000/api/";
final Dio _dio = Dio();
Future<bool> login(data) async {
try {
Response response = await _dio.post(url+'sanctum/token',data:json.encode(data));
return true;
} catch (error) {
return false;
}
}
}
login_screen.dart
void login() async{
if(formKey.currentState.validate()){
setState((){this.isLoading = true;});
var data = {
'email':this.email,
'password':this.password,
'device_name':'mobile_phone'
};
var result = await AuthRepository().login(data);
if(result){
context.read(authProvider).isLogin(true);
setState((){this.isLoading = false;});
}else
setState((){this.isLoading = false;});
}
}
Since I'm not coming from mobile background and just recently use flutter+riverpod in my recent project, I cannot say this is the best practice. But there are some points I'd like to note:
Use interface such IAuthRepository for repository. Riverpod can act as a dependency injection.
final authRepository = Provider<IAuthRepository>((ref) => AuthRepository());
Build data to send in repository. You should separate presentation, business logic, and explicit implementation for external resource if possible.
Future<bool> login(String email, String password) async {
try {
var data = {
'email': email,
'password': password,
'device_name':'mobile_phone'
};
Response response = await _dio.post(url+'sanctum/token',data:json.encode(data));
return true;
} catch (error) {
return false;
}
}
Do not call repository directly from presentation/screen. You can use the provider for your logic, which call the repository
class AuthNotifier extends StateNotifier<Auth>{
final ProviderReference ref;
IAuthRepository _authRepository;
AuthNotifier(this.ref) : super(Auth(false)) {
_authRepository = ref.watch(authRepository);
}
Future<void> login(String email, String password) async {
final loginResult = await_authRepository.login(email, password);
state = Auth(loginResult);
}
}
final authProvider = StateNotifierProvider((ref) => new AuthNotifier(ref));
On screen, you can call provider's login method
login() {
context.read(authProvider).login(this.email, this.password);
}
Use Consumer or ConsumerWidget to watch the state and decide what to build.
It also helps that instead of Auth with isLogin for the state, you can create some other state. At the very least, I usually create an abstract BaseAuthState, which derives to AuthInitialState, AuthLoadingState, AuthLoginState, AuthErrorState, etc.
class AuthNotifier extends StateNotifier<BaseAuthState>{
...
AuthNotifier(this.ref) : super(AuthInitialState()) { ... }
...
}
Consumer(builder: (context, watch, child) {
final state = watch(authProvider.state);
if (state is AuthLoginState) ...
else if (state is AuthLoadingState) ...
...
})
Instead of using a bool, I like to use enums or class for auth state
enum AuthState { initialize, authenticated, unauthenticated }
and for login state
enum LoginStatus { initialize, loading, success, failed }