CODEWITHSUNDEEP
androidflutter
abrev
abrev

Reputation: 325

Flutter: Calling different pages deppending on the situation (logged or not logged user)

I'm having a problem with my app.

The situation is: i have a very simple login system on the app and i save the logged user using SharedPreferences. But if the user leaves the app and then return it will open the login screen again, so i want to skip the login screen if the user is logged.

So in my main i put a function to check if there is login information, if yes it would redirect right to the app page or to the login page if not. But when i try to call the app page it always calls the page setted on the Home part.

How can i solve this? Is there any way to make it ignore the Home? Is there a way to make the "if" part on the home? Would be the better solution but its not possible.

Also i know i'm not using the best way to make this control, but it works (despite of this problem i have now, sure) and if you have any tips on making it better i would appreciate.

Heres my code:


class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

void main() => runApp(new MyApp());

class _MyAppState extends State<MyApp> {
  Future<void> verificaLogin() async {
    print("running ok"); //just to test if the function runs
    final prefs = await SharedPreferences.getInstance();
    final key = 'usuario';
    final value = prefs.getString(key);
    print('saved tester $value');
    String usu = value; /

    if (usu.isEmpty) {
      BuildContext context;
      Navigator.push(
        context,
        MaterialPageRoute(builder: (context) => LoginScreen()), //sends to loginscreen if not logged
      );
    }
    if (usu.isNotEmpty) {
      BuildContext context;
      Navigator.of(context)
          .pushReplacement(MaterialPageRoute(builder: (context) => Pedidos())); //sends to main (not main.dart) app page
    }
  }

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) => verificaLogin());
  }

  Widget build(BuildContext context) {
    return BotToastInit(
      child: MaterialApp(
        navigatorObservers: [BotToastNavigatorObserver()],
        title: "Test App",
        theme: ThemeData(
          primarySwatch: Colors.green,
        ),
        debugShowCheckedModeBanner: false,
        home: LoginScreen(), //i'm calling the loginscreen, it ignores the function on the top
      ),
    );
  }
}

Upvotes: 0

Views: 92

Answers (2)

Erika Valdes
Erika Valdes

Reputation: 66

Hi you can use a FutureBuilder at vefiricaLoigin, and then Material App at home use verificaLogin, https://api.flutter.dev/flutter/widgets/FutureBuilder-class.html

verificaLogin() {
    return FutureBuilder<Widget>(
     future: SharedPreferences.getInstance(),
     builder: (BuildContext context, prefs) {
      final key = 'usuario';
      final value = prefs.getString(key);
      String usu = value;
      if (usu.isEmpty) {
       return LoginScreen()l
      } else {
      return Pedidos();
    }
  );
}     

     Widget build(BuildContext context) {
        return MaterialApp(
            title: "Test App",
            theme: ThemeData(
              primarySwatch: Colors.green,
            ),
            debugShowCheckedModeBanner: false,
            home: verificaLogin()
        );
      }

Upvotes: 0

Jaimil Patel
Jaimil Patel

Reputation: 1347

Please make one SplashScreen like below it resolves your issue..
and call this as home: SplashScreen(),

class SplashScreen extends StatefulWidget {
  @override
  _SplashScreenState createState() => _SplashScreenState();
}

class _SplashScreenState extends State<SplashScreen> {
  String loginData = "";

  SharedPreferences sharedPreferences;
  void initState() {
    super.initState();
    readFromStorage();
  }

  void readFromStorage() async {
    sharedPreferences = await SharedPreferences.getInstance();
    final key = 'usuario';
    loginData = sharedPreferences.getString(key);

    if (loginData.isNotEmpty) {
      Future.delayed(const Duration(milliseconds: 3000), () {
        setState(() {
          Navigator.of(context)
      .pushReplacement(MaterialPageRoute(builder: (context) => Pedidos()));
        });
      });
    } else {
      Future.delayed(const Duration(milliseconds: 3000), () {
        setState(() {
           Navigator.push(
    context,
    MaterialPageRoute(builder: (context) => LoginScreen()),);
        });
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
          child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
          FlutterLogo(
            size: 100.0,
          ),
        ],
      )),
    );
  }
}

Upvotes: 1

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