AsyncError<Benutzer?>(Fehler: Nullprüfoperator für einen Nullwert verwendet, stackTrace: #0 currentUserDetailsProvider.< ⇐ Android

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Zunächst wird „Benutzer N/A“ und „AsyncError“ angezeigt (Fehler: Nullprüfoperator für einen Nullwert verwendet, StackTrace: #0 currentUserDetailsProvider. Fehler, aber nach einem Warmstart funktioniert es einwandfrei. Warum?

Code: Select all

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:appwrite/models.dart' as model;
import '../apis/auth_api.dart';
import '../apis/user_api.dart';
import '../models/user_model.dart';
import '../widgets/snack_bar.dart';

final authControllerProvider =
StateNotifierProvider((ref) {
return AuthController(
authAPI: ref.watch(authAPIProvider),
userAPI: ref.watch(userAPIProvider),
);
});

final currentUserDetailsProvider = FutureProvider((ref) async {
final currentUserId = ref.watch(currentUserAccountProvider).value!.$id;
final userDetails = ref.watch(userDetailsProvider(currentUserId));
return userDetails.value;
});

final userDetailsProvider = FutureProvider.family((ref, String uid) async {
final authController = ref.watch(authControllerProvider.notifier);
return authController.getUserData(uid);
});

final currentUserAccountProvider = FutureProvider((ref) async {
final authController = ref.watch(authControllerProvider.notifier);
return authController.currentUser();
});

class AuthController extends StateNotifier {
final AuthAPI _authAPI;
final UserAPI _userAPI;
AuthController({required AuthAPI authAPI, required UserAPI userAPI})
: _authAPI = authAPI,
_userAPI = userAPI,
super(false);

Future currentUser() => _authAPI.currentUserAccount();

void signUp({
required String email,
required String password,
required BuildContext context,
}) async {
state = true;
final res = await _authAPI.signUp(email: email, password: password);

res.fold((failure) {
print('Sign up failed: ${failure.message}');
showSnackBar(context, failure.message);
}, (user) async {
User userModel = User(
email: email,
name: getNameFromEmail(email),
uid: user.$id,
patientName: '',
patientAge: 18,
patientGender: '--',
disorderName: '',
phoneNumber: '',
emotion: '',
sessionId: '');

final res2 = await _userAPI.saveUserData(userModel);
res2.fold((failure) {
print('Failed to save user data: ${failure.message}');
showSnackBar(context, 'Database creation failed: ${failure.message}');
}, (r) {
showSnackBar(context, 'Account Created Successfully!');
login(email: email, password: password, context: context);
});
});

state = false;
}

void login({
required String email,
required String password,
required BuildContext context,
}) async {
state = true;
final res = await _authAPI.login(email: email, password: password);
state = false;
res.fold(((l) {
showSnackBar(context, l.message);
}), (r) => Navigator.pushNamed(context, '/home'));
}

Future getUserData(String uid) async {
final document = await _userAPI.getUserData(uid);
final updatedUser = User.fromMap(document.data);
return updatedUser;
}

void update({required BuildContext context, required User userData}) async {
state = true;
final res = await _userAPI.updateUserData(userData.uid, userData);
state = false;
res.fold(
(l) => {showSnackBar(context, l.message)},
(r) =>
{showSnackBar(context, 'Patient details updated successfully!')});
}

Future  updateUserSession({
required BuildContext context,
required User? updatedUser,
}) async {
state = true;
final currentUserId = await currentUser();
if (currentUserId == null) {
state = false;
showSnackBar(context, 'No user logged in.');
return;
}
try {
final res = await _userAPI.updateUserData(currentUserId.$id, updatedUser!);
res.fold(
(failure) {
showSnackBar(context, 'error occured: ${failure.message}');
},
(success) {
showSnackBar(context, 'Session updated successfully.');
},
);
} catch (e) {
print(e);
showSnackBar(context, 'Error updating session: $e');
}
state = false;
}

void logout(BuildContext context) async {
state = true;
final res = await _authAPI.logout();
state = false;
res.fold(
(l) => showSnackBar(context, l.message),
(r) => Navigator.pushNamedAndRemoveUntil(
context,
'/landing',
(route) => false,
),
);
}
}

Es funktioniert nach einem Warmstart. Wie passiert das?

Code: Select all

import 'package:appwrite/appwrite.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'appwrite.dart';

final appwriteClientProvider = Provider((ref) {
Client client = Client();
return client
.setEndpoint(AppWrite.endPoint)
.setProject(AppWrite.projectId)
.setSelfSigned(status: true);
});

final appwriteAccountProvider = Provider((ref) {
final client = ref.watch(appwriteClientProvider);
return Account(client);
});

final appwriteDatabseProvider = Provider((ref) {
final client = ref.watch(appwriteClientProvider);
return Databases(client);
});

Code: Select all

import 'package:caregiver_app/widgets/loading_page.dart';
import 'package:caregiver_app/widgets/snack_bar.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:flutter/services.dart';
import '../constants/auth_controller.dart';

class ProfileScreen extends ConsumerWidget {
const ProfileScreen({Key? key}) : super(key: key);

@override
Widget build(BuildContext context, WidgetRef ref) {
final currentUser = ref.watch(currentUserDetailsProvider);
print(currentUser);
return currentUser == null
? Loader()
: Scaffold(
body: Column(
children: [
const Expanded(flex: 2, child: TopPortion()),
Expanded(
flex: 3,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Column(
children: [
currentUser.when(
data: (user) {
if (user == null) {
return Text('User: N/A');
}
return Text(
'name: ${user.name}',
style: TextStyle(
fontSize: 20, fontStyle: FontStyle.italic),
);
},
error: (e, st) {
print('Error occurred: $e');
print('Stack trace: $st');
return Center(child: Text('User: N/A'));
},
loading: () =>
Center(child: CircularProgressIndicator()),
),
const SizedBox(height: 16),
currentUser.when(
data: (user) {
return Text(
'name: ${user?.email}',
style: TextStyle(
fontSize: 20, fontStyle: FontStyle.italic),
);
},
error: (e, st) => Center(child: Text('User: N/A')),
loading: () =>
Center(child: CircularProgressIndicator())),
const SizedBox(height: 16),
Row(
children: [
Expanded(
child: currentUser.when(
data: (user) {
return Text(
'name: ${user?.uid}',
style: TextStyle(
fontSize: 20,
fontStyle: FontStyle.italic),
);
},
error: (e, st) =>
Center(child: Text('User: N/A')),
loading: () =>  Center(
child: CircularProgressIndicator())),
),
IconButton(
icon: const Icon(Icons.copy),
onPressed: () {
if (currentUser != null) {
Clipboard.setData(ClipboardData(
text: currentUser.value?.uid));
ScaffoldMessenger.of(context).showSnackBar(
const SnackBar(
content:
Text('UID copied to clipboard!')),
);
}
},
),
],
),
const SizedBox(height: 16),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
FloatingActionButton.extended(
onPressed: () {
Navigator.pushNamed(context, '/patient');
},
heroTag: 'Patient Data',
elevation: 0,
backgroundColor: Color(0xff0043ba),
label: const Text('Patient Data',
style: TextStyle(color: Colors.white)),
icon: const Icon(Icons.person_add_alt_1,
color: Colors.white),
),
const SizedBox(width: 16.0),
FloatingActionButton.extended(
onPressed: () {},
heroTag: 'chat',
elevation: 0,
backgroundColor: Color(0xff0043ba),
label: const Text('Chat',
style: TextStyle(color: Colors.white)),
icon: const Icon(Icons.message_rounded,
color: Colors.white),
),
],
),
const SizedBox(height: 16),
const ProfileInfoRow()
],
),
),
),
],
),
);
}
}

class ProfileInfoRow extends StatelessWidget {
const ProfileInfoRow({Key? key}) : super(key: key);

final List
 _items = const [
ProfileInfoItem('Days', 900),
ProfileInfoItem('active', 120),
ProfileInfoItem('status', 200),
];

@override
Widget build(BuildContext context) {
return SizedBox(
height: 80,
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: _items.map((item) {
final index = _items.indexOf(item);
return Expanded(
child: Row(
children: [
if (index != 0) const VerticalDivider(),
Expanded(child: singleItem(context, item)),
],
),
);
}).toList(),
),
);
}

Widget singleItem(BuildContext context, ProfileInfoItem item) =>  Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Padding(
padding: const EdgeInsets.all(8.0),
child: Text(
item.value.toString(),
style: const TextStyle(
fontWeight: FontWeight.bold,
fontSize: 20,
),
),
),
Text(
item.title,
style: Theme.of(context).textTheme.caption,
)
],
);
}

class ProfileInfoItem {
final String title;
final int value;
const ProfileInfoItem(this.title, this.value);
}

class TopPortion extends StatelessWidget {
const TopPortion({Key? key}) : super(key: key);

@override
Widget build(BuildContext context) {
return Stack(
fit: StackFit.expand,
children: [
Container(
margin: const EdgeInsets.only(bottom: 50),
decoration: const BoxDecoration(
gradient: LinearGradient(
begin: Alignment.bottomCenter,
end: Alignment.topCenter,
colors: [Color(0xff0043ba), Color(0xff006df1)]),
borderRadius: BorderRadius.only(
bottomLeft: Radius.circular(50),
bottomRight: Radius.circular(50),
)),
),
Align(
alignment: Alignment.bottomCenter,
child: SizedBox(
width: 150,
height: 150,
child: Stack(
fit: StackFit.expand,
children: [
Container(
decoration: const BoxDecoration(
color: Colors.black,
shape: BoxShape.circle,
image: DecorationImage(
fit: BoxFit.cover,
image: AssetImage('assets/images/medical_team.png'),
),
)),
],
),
),
)
],
);
}
}

Wie kann dafür gesorgt werden, dass es ordnungsgemäß funktioniert, ohne dass ein Neustart erforderlich ist? Kennt jemand die Lösung? Bitte helfen Sie!