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Why I can't see the result of "print()" statement in my Flutter code?

Time:11-23

I am trying to write a simple signup/login page. The following codes are the main.dart, screen page for the view and the auth_controller for the control page of the project.

main.dart:

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MultiProvider(
      providers: [
        ChangeNotifierProvider.value(
          value: Auth(),
        ),

      ],
      child: Consumer<Auth>(
        builder: (ctx, auth, _) => MaterialApp(
          title: 'MyShop',
          theme: ThemeData(
            primarySwatch: Colors.purple,
            accentColor: Colors.deepOrange,
            fontFamily: 'Lato',

          ),
          home: auth.isAuth
              ? MapScreen()
              : FutureBuilder(
                  future: auth.tryAutoLogin(),
                  builder: (ctx, authResultSnapshot) =>
                      authResultSnapshot.connectionState ==
                              ConnectionState.waiting
                          ? SplashScreen()
                          : AuthScreen(),
                ),
          routes: {
            MapScreen.routeName: (ctx) => MapScreen(),

          },
        ),
      ),
    );
  }
}

auth_screen.dart:

enum AuthMode { Signup, Login }

class AuthScreen extends StatelessWidget {
  static const routeName = '/auth';

  @override
  Widget build(BuildContext context) {
    final deviceSize = MediaQuery.of(context).size;
    // final transformConfig = Matrix4.rotationZ(-8 * pi / 180);
    // transformConfig.translate(-10.0);
    return Scaffold(
      // resizeToAvoidBottomInset: false,
      body: Stack(
        children: <Widget>[
          Container(
            decoration: BoxDecoration(
              gradient: LinearGradient(
                colors: [
                  const Color.fromRGBO(215, 117, 255, 1).withOpacity(0.5),
                  const Color.fromRGBO(255, 188, 117, 1).withOpacity(0.9),
                ],
                begin: Alignment.topLeft,
                end: Alignment.bottomRight,
                stops: const [0, 1],
              ),
            ),
          ),
          SingleChildScrollView(
            child: Container(
              height: deviceSize.height,
              width: deviceSize.width,
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                crossAxisAlignment: CrossAxisAlignment.center,
                children: <Widget>[
                  Flexible(
                    child: Container(
                      margin: const EdgeInsets.only(bottom: 20.0),
                      padding: const EdgeInsets.symmetric(
                          vertical: 8.0, horizontal: 94.0),
                      transform: Matrix4.rotationZ(-8 * pi / 180)
                        ..translate(-10.0),
                      // ..translate(-10.0),
                      decoration: BoxDecoration(
                        borderRadius: BorderRadius.circular(20),
                        color: Colors.deepOrange.shade900,
                        boxShadow: const [
                          BoxShadow(
                            blurRadius: 8,
                            color: Colors.black26,
                            offset: Offset(0, 2),
                          )
                        ],
                      ),
                      child: Text(
                        'USmobile',
                        style: TextStyle(
                          color: Theme.of(context)
                              .textSelectionTheme
                              .selectionColor,
                          fontSize: 50,
                          fontFamily: 'Anton',
                          fontWeight: FontWeight.normal,
                        ),
                      ),
                    ),
                  ),
                  Flexible(
                    flex: deviceSize.width > 600 ? 2 : 1,
                    child: const AuthCard(),
                  ),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }
}

class AuthCard extends StatefulWidget {
  const AuthCard({
    Key? key,
  }) : super(key: key);

  @override
  _AuthCardState createState() => _AuthCardState();
}

class _AuthCardState extends State<AuthCard>
    with SingleTickerProviderStateMixin {
  final GlobalKey<FormState> _formKey = GlobalKey();
  AuthMode _authMode = AuthMode.Login;
  Map<String, String> _authData = {
    'email': '',
    'password': '',
  };
  var _isLoading = false;
  final _passwordController = TextEditingController();
  AnimationController? _controller;
  Animation<Offset>? _slideAnimation;
  Animation<double>? _opacityAnimation;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
      vsync: this,
      duration: const Duration(
        milliseconds: 300,
      ),
    );
    _slideAnimation = Tween<Offset>(
      begin: const Offset(0, -1.5),
      end: const Offset(0, 0),
    ).animate(
      CurvedAnimation(
        parent: _controller as Animation<double>,
        curve: Curves.fastOutSlowIn,
      ),
    );
    _opacityAnimation = Tween(begin: 0.0, end: 1.0).animate(
      CurvedAnimation(
        parent: _controller as Animation<double>,
        curve: Curves.easeIn,
      ),
    );
    // _heightAnimation.addListener(() => setState(() {}));
  }

  @override
  void dispose() {
    super.dispose();
    _controller!.dispose();
  }

  void _showErrorDialog(String message) {
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('An Error Occurred!'),
        content: Text(message),
        actions: <Widget>[
          TextButton(
            child: const Text('Okay'),
            onPressed: () {
              Navigator.of(ctx).pop();
            },
          )
        ],
      ),
    );
  }

  Future<void> _submit() async {
    if (!_formKey.currentState!.validate()) {
      // Invalid!
      return;
    }
    _formKey.currentState!.save();
    setState(() {
      _isLoading = true;
    });
    try {
      if (_authMode == AuthMode.Login) {
        // Log user in
        await Provider.of<Auth>(context, listen: false).login(
          _authData['email'] as String,
          _authData['password'] as String,
        );
      } else {
        // Sign user up
        await Provider.of<Auth>(context, listen: false).signup(
          _authData['email'] as String,
          _authData['password'] as String,
        );
      }
      // } on HttpException catch (error) {
      //   var errorMessage = 'Authentication failed';
      //   print("this is the auth data");
      //   print(_authData);
      //   if (error.toString().contains('EMAIL_EXISTS')) {
      //     errorMessage = 'This email address is already in use.';
      //   } else if (error.toString().contains('INVALID_EMAIL')) {
      //     errorMessage = 'This is not a valid email address';
      //   } else if (error.toString().contains('WEAK_PASSWORD')) {
      //     errorMessage = 'This password is too weak.';
      //   } else if (error.toString().contains('EMAIL_NOT_FOUND')) {
      //     errorMessage = 'Could not find a user with that email.';
      //   } else if (error.toString().contains('INVALID_PASSWORD')) {
      //     errorMessage = 'Invalid password.';
      //   }
      //   _showErrorDialog(errorMessage);
    } catch (error) {
      var errorMessage = 'Could not authenticate you. Please try again later.'  
          error.toString();
      _showErrorDialog(errorMessage);
    }

    setState(() {
      _isLoading = false;
    });
  }

  void _switchAuthMode() {
    if (_authMode == AuthMode.Login) {
      setState(() {
        _authMode = AuthMode.Signup;
      });
      _controller!.forward();
    } else {
      setState(() {
        _authMode = AuthMode.Login;
      });
      _controller!.reverse();
    }
  }

  @override
  Widget build(BuildContext context) {
    final deviceSize = MediaQuery.of(context).size;
    return Card(
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(10.0),
      ),
      elevation: 8.0,
      child: AnimatedContainer(
        duration: const Duration(milliseconds: 300),
        curve: Curves.easeIn,
        height: _authMode == AuthMode.Signup ? 320 : 260,
        // height: _heightAnimation.value.height,
        constraints:
            BoxConstraints(minHeight: _authMode == AuthMode.Signup ? 320 : 260),
        width: deviceSize.width * 0.75,
        padding: const EdgeInsets.all(16.0),
        child: Form(
          key: _formKey,
          child: SingleChildScrollView(
            child: Column(
              children: <Widget>[
                TextFormField(
                  decoration: const InputDecoration(labelText: 'E-Mail'),
                  keyboardType: TextInputType.emailAddress,
                  validator: (value) {
                    if (value!.isEmpty || !value.contains('@')) {
                      return 'Invalid email!';
                    }
                  },
                  onSaved: (value) {
                    _authData['email'] = value as String;
                  },
                ),
                TextFormField(
                  decoration: const InputDecoration(labelText: 'Password'),
                  obscureText: true,
                  controller: _passwordController,
                  validator: (value) {
                    if (value!.isEmpty || value.length < 5) {
                      return 'Password is too short!';
                    }
                  },
                  onSaved: (value) {
                    _authData['password'] = value as String;
                  },
                ),
                AnimatedContainer(
                  constraints: BoxConstraints(
                    minHeight: _authMode == AuthMode.Signup ? 60 : 0,
                    maxHeight: _authMode == AuthMode.Signup ? 120 : 0,
                  ),
                  duration: const Duration(milliseconds: 300),
                  curve: Curves.easeIn,
                  child: FadeTransition(
                    opacity: _opacityAnimation as Animation<double>,
                    child: SlideTransition(
                      position: _slideAnimation as Animation<Offset>,
                      child: TextFormField(
                        enabled: _authMode == AuthMode.Signup,
                        decoration: const InputDecoration(
                            labelText: 'Confirm Password'),
                        obscureText: true,
                        validator: _authMode == AuthMode.Signup
                            ? (value) {
                                if (value != _passwordController.text) {
                                  return 'Passwords do not match!';
                                }
                              }
                            : null,
                      ),
                    ),
                  ),
                ),
                const SizedBox(
                  height: 20,
                ),
                if (_isLoading)
                  const CircularProgressIndicator()
                else
                  ElevatedButton(
                    child:
                        Text(_authMode == AuthMode.Login ? 'LOGIN' : 'SIGN UP'),
                    onPressed: _submit,
                    style: ElevatedButton.styleFrom(
                      shape: RoundedRectangleBorder(
                        borderRadius: BorderRadius.circular(30),
                      ),
                      primary: Theme.of(context).primaryColor,
                      padding: const EdgeInsets.symmetric(
                          horizontal: 30.0, vertical: 8.0),
                      onPrimary:
                          Theme.of(context).primaryTextTheme.button!.color,
                    ),
                  ),
                TextButton(
                  child: Text(
                      '${_authMode == AuthMode.Login ? 'SIGNUP' : 'LOGIN'} '),
                  onPressed: _switchAuthMode,
                  style: TextButton.styleFrom(
                    padding: const EdgeInsets.symmetric(
                        horizontal: 30.0, vertical: 4),
                    tapTargetSize: MaterialTapTargetSize.shrinkWrap,
                    textStyle: TextStyle(color: Theme.of(context).primaryColor),
                  ),
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}

auth_controller.dart:

class Auth with ChangeNotifier {
  String? _token;
  DateTime? _expiryDate;
  String? _userId;
  Timer? _authTimer;

  bool get isAuth {
    return token != null;
  }

  String? get token {
    if (_expiryDate != null &&
        _expiryDate!.isAfter(DateTime.now()) &&
        _token != null) {
      return _token;
    }
    return null;
  }

  String? get userId {
    return _userId;
  }

  Future<void> _authenticate(
      String email, String password, String urlSegment) async {
    final url = Uri.parse('http://10.0.2.2:8000/api/$urlSegment');
    try {
      final http.Response response = await http.post(
        url,
        headers: {"Content-Type": "application/json"},
        body: json.encode(
          {
            'email': email,
            'password': password,

            //'returnSecureToken': true,
          },
        ),
      );
      print("This is response.body");
      print(response.body);
      print("This is response.body.runtimeType");
      print(response.body.runtimeType);
      final responseData = json.decode(response.body);
      print("this is responseData");
      print(responseData);
      print("this is responseData['error']");
      print(responseData['error']);
      if (responseData['error'] != null) {
        throw HttpException(responseData['error']['message']);
      } else {
        print("There wasn't error here!");
      }
      _token = responseData['idToken'];
      print("This is the token");
      print(_token);
      _userId = responseData['id'];
      print("This is userId");
      print(_userId);
      print("This is expiryDate");
      print(responseData['expiresIn']);
      _expiryDate = DateTime.now().add(
        Duration(
          seconds: int.parse(
            responseData['expiresIn'],
          ),
        ),
      );
      print("I can no see thiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiis");

      _autoLogout();
      notifyListeners();
      final prefs = await SharedPreferences.getInstance();
      final userData = json.encode(
        {
          'token': _token,
          'userId': _userId,
          'expiryDate': _expiryDate!.toIso8601String(),
        },
      );

      prefs.setString('userData', userData);
    } catch (error) {
      throw error;
    }
  }

  Future<void> signup(String email, String password) async {
    return _authenticate(email, password, 'register');
  }

  Future<void> login(String email, String password) async {
    return _authenticate(email, password, 'verifyPassword');
  }

  Future<bool> tryAutoLogin() async {
    final prefs = await SharedPreferences.getInstance();
    if (!prefs.containsKey('userData')) {
      return false;
    }
    final extractedUserData = json.decode(prefs.getString('userData') as String)
        as Map<String, Object>;
    final expiryDate =
        DateTime.parse(extractedUserData['expiryDate'] as String);

    if (expiryDate.isBefore(DateTime.now())) {
      return false;
    }
    _token = extractedUserData['token'] as String;
    _userId = extractedUserData['userId'] as String;
    _expiryDate = expiryDate;
    notifyListeners();
    _autoLogout();
    return true;
  }

  Future<void> logout() async {
    _token = null;
    _userId = null;
    _expiryDate = null;
    if (_authTimer != null) {
      _authTimer!.cancel();
      _authTimer = null;
    }
    notifyListeners();
    final prefs = await SharedPreferences.getInstance();
    // prefs.remove('userData');
    prefs.clear();
  }

  void _autoLogout() {
    if (_authTimer != null) {
      _authTimer!.cancel();
    }
    final timeToExpiry = _expiryDate!.difference(DateTime.now()).inSeconds;
    _authTimer = Timer(Duration(seconds: timeToExpiry), logout);
  }
}

I know the backend part works fine and the following is the result I do get while running my app and try to register a new user through the Android Emulator:

I/flutter ( 6814): This is response.body
I/flutter ( 6814): {"id":"619c5141e08b15bf9173ab06","name":"","email":"[email protected]","password":"$2a$10$yYUtDS1PrSAgpQBxoVm7Ae7O8ujR33ONz4gM5t7iHWt6e907pjFrq","idToken":"eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJ0ZXN0QHRlc3RpbmcuY29tIiwiZXhwIjoxNjM5Mjc1NjAzNzQzfQ.LgrlwFNrLhGr5UfHikL83e2tBjbqMyN4OKG6Fz816AeOs6ezfnhvQoXBDAsV2pIt4CWuBVf8qGbBYSXCQxgarw","expiresIn":1639275603743}
I/flutter ( 6814): This is response.body.runtimeType
I/flutter ( 6814): String
I/flutter ( 6814): this is responseData
I/flutter ( 6814): {id: 619c5141e08b15bf9173ab06, name: , email: test@testing.com, password: $2a$10$yYUtDS1PrSAgpQBxoVm7Ae7O8ujR33ONz4gM5t7iHWt6e907pjFrq, idToken: eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJ0ZXN0QHRlc3RpbmcuY29tIiwiZXhwIjoxNjM5Mjc1NjAzNzQzfQ.LgrlwFNrLhGr5UfHikL83e2tBjbqMyN4OKG6Fz816AeOs6ezfnhvQoXBDAsV2pIt4CWuBVf8qGbBYSXCQxgarw, expiresIn: 1639275603743}
I/flutter ( 6814): this is responseData['error']
I/flutter ( 6814): null
I/flutter ( 6814): There wasn't error here!
I/flutter ( 6814): This is the token
I/flutter ( 6814): eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJ0ZXN0QHRlc3RpbmcuY29tIiwiZXhwIjoxNjM5Mjc1NjAzNzQzfQ.LgrlwFNrLhGr5UfHikL83e2tBjbqMyN4OKG6Fz816AeOs6ezfnhvQoXBDAsV2pIt4CWuBVf8qGbBYSXCQxgarw
I/flutter ( 6814): This is userId
I/flutter ( 6814): 619c5141e08b15bf9173ab06
I/flutter ( 6814): This is expiryDate
I/flutter ( 6814): 1639275603743

I see all the print() statements work except this:

print("I can no see thiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiis");

I don't know why? I also see the following error message in my Android Emulator that I can't understand the reason?

type 'int' is not a subtype of type 'String'

I also know the error occures in this part of the code in auth_controller.dart file:

} catch (error) {
  print(error);
  throw error;
}

CodePudding user response:

    int.parse(
        responseData['expiresIn'],
    )

For the above code to work responseData['expiresIn'] should be a String. But in the response, this comes as an int value. Make sure this is a String.

Or you can just use it like this,

    Duration(
        seconds: responseData['expiresIn'],
    ),
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