Flutter unable to login after create new account - flutter

Question

After building the app, if I try to login it's working fine, but if I create a new account then try to login again, login is not working. I have seen after debugging that I'm getting token in _authenticate method. I think notifyListeners not working here but I don't know why?
I'm using the provider package in my flutter app. I have an Auth provider class where I'm saving data in firebase and also login by firebase. Below it's my provider class.
class Auth with ChangeNotifier {
String? _token;
late DateTime _expiryDate = DateTime.now();
late String _userId;
bool get isAuth {
return token != null;
}
String? get token {
if ((_expiryDate).isAfter(DateTime.now())) {
return _token;
}
return null;
}
Future _authenticate(String email, String password, String urlSegment) async {
var urlParse = Uri.parse(urlSegment);
try {
final response = await http.post(urlParse,
body: jsonEncode({
'email': email,
'password': password,
'returnSecureToken': true
})
);
final responseData = jsonDecode(response.body);
if (responseData['error'] != null) {
throw HttpException(responseData['error']['message']);
}
// set token and user id from firebase response
_token = responseData['idToken'];
_userId = responseData['localId'];
_expiryDate = DateTime.now()
.add(Duration(seconds: int.parse(responseData['expiresIn'])));
notifyListeners();
return responseData['idToken'];
} catch (error) {
rethrow;
}
}
Future login(String email, String password) async {
print(email);
String url = Constants.firebaseLoginUrl;
return _authenticate(email, password, url);
}
Future signup(String email, String password) async {
String url = Constants.firebaseSignupUrl;
return _authenticate(email, password, url);
}
}
In signUp page I have tried below code to create a new user
Future<void> signUpSubmit() async {
if (_formKey.currentState!.validate()) {
await Provider.of<Auth>(context, listen: false).signup(_email.text, _pass.text);
}
I have checked new data is saving perfectly.
In signUp page there has a login button, after click on login button I have redirect in login page,
TextButton(
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => const LoginPage()
),
);
},
child: const Text('Log in to access'),
)
After click on login I have redirect in login page, then tried login again but it's not working. In debug I'm getting token if I print(token) in _authenticate method.
In main.dart my consumer is looks like
child: Consumer<Auth>(
builder: (ctx,auth, _) => MaterialApp(
home: auth.isAuth ? const HomePage():const LoginPage(),
)
After create account if I rebuild app again then login is working? How I will solve this problem?

Answer 1

See you are redirecting directly in loginPage rather than via the main page ! Just redirect the login button to main page, in your main page there has condition
home: auth.isAuth ? const HomePage(): const LoginPage()
So, if it is auth false it will always redirect to the login page.
Change
MaterialPageRoute( builder: (context) => const LoginPage() ),
To
MaterialPageRoute( builder: (context) => const MainPage() ),