[My code] . When I use User user = Provider.of(context, listen: false).user; => user null
My code here
class UserController extends ChangeNotifier {
User _user;
User get user => _user;
Future<void> getUser() async {
String token = await AppValue.getToken();
Uri uri = Uri.parse('http://20.89.111.129/api/user/getProfileUser');
Map<String, String> headers = {'Authorization': 'Bearer $token'};
try {
final response = await http.get(
uri,
headers: headers,
);
final data = jsonDecode(response.body);
User newUser = new User(
address: (data['address'] == null) ? '' : data['address'],
birthday: (data['birthday'] == null) ? '' : data['birthday'],
email: (data['email'] == null) ? '' : data['email'],
fullName: (data['fullName'] == null) ? '' : data['fullName'],
);
_user = newUser; // _user is not null
notifyListeners();
} catch (error) {
log('ST WRONG!');
throw (error);
}
}
}
// When I use User user = Provider.of(context, listen: false).user; => user null
I think you need to tell the provider the exact class you want to act on,
//so instead of this;
User user = Provider.of(context, listen: false).user;
// do this
User user = Provider.of< UserController>(context, listen: false).user;
Related
I built the google signin and email password signup app using flutter,
I want when user log to application then user's "uid" and "email" save in shared preference.
In google login I built when login then pass the boolean value and pass uid and email to shared preference. Then when users close app and when reopen then login in home screen and can get uid and email.
But when user signup or login using email password then can not pass the boolean value and uid and email to google login shared preference. In below I'll mentioned google login method and email password method.
googlelogin method
// handling google sigin in
Future handleGoogleSignIn() async {
final sp = context.read<SignInProvider>();
final ip = context.read<InternetProvider>();
await ip.checkInternetConnection();
if (ip.hasInternet == false) {
openSnackbar(context, 'Check your Internet connection', Colors.red);
googleController.reset();
} else {
await sp.signInWithGoogle().then((value) {
if (sp.hasError == true) {
openSnackbar(context, sp.errorCode.toString(), Colors.white);
googleController.reset();
} else {
// checking whether user exists or not
sp.checkUserExists().then((value) async {
if (value == true) {
// user exists
await sp.getUserDataFromFirestore(sp.uid).then((value) => sp
.saveDataToSharedPreferences()
.then((value) => sp.setSignIn().then((value) {
googleController.success();
handleAfterSignIn();
})));
} else {
// user does not exist
sp.saveDataToFirestore().then((value) => sp
.saveDataToSharedPreferences()
.then((value) => sp.setSignIn().then((value) {
googleController.success();
handleAfterSignIn();
})));
}
});
}
});
}
//login function
}
saveDataToSharedPreferences method and setSignIn boolean value (it has in a siginprovider class in another file)
class SignInProvider extends ChangeNotifier {
//instantiate of firebaseAuth, facebook and google
final FirebaseAuth firebaseAuth = FirebaseAuth.instance;
final GoogleSignIn googleSignIn = GoogleSignIn();
bool _isSignedIn = false;
bool get isSignedIn => _isSignedIn;
//hasError, errorCode, provider,uid,email,name,imageUrl
bool _hasError = false;
bool get hasError => _hasError;
String? _errorCode;
String? get errorCode => _errorCode;
String? _uid;
String? get uid => _uid;
String? _email;
String? get email => _email;
SignInProvider() {
checkSignInUser();
}
Future checkSignInUser() async {
final SharedPreferences s = await SharedPreferences.getInstance();
_isSignedIn = s.getBool('signed_in') ?? false;
notifyListeners();
}
Future setSignIn() async {
final SharedPreferences s = await SharedPreferences.getInstance();
s.setBool('signed_in', true);
_isSignedIn = true;
notifyListeners();
}
Future saveDataToSharedPreferences() async {
final SharedPreferences s = await SharedPreferences.getInstance();
await s.setString('email', _email!);
await s.setString('uid', _uid!);
notifyListeners();
}
Future getDataFromSharedPreferences() async {
final SharedPreferences s = await SharedPreferences.getInstance();
_email = s.getString('email');
_uid = s.getString('uid');
notifyListeners();
}
}
**email password signup**
void signUp(String email, String password) async {
if (_formkey.currentState!.validate()) {
await _auth
.createUserWithEmailAndPassword(email: email, password: password)
.saveDataToSharedPreferences()
.sp.setSignIn()
.then((value) => {postDetailsToFirestore()})
.catchError((e) {
Fluttertoast.showToast(msg: e!.message);
});
}
}
in email password signup has postDetailsToFirestore method
postDetailsToFirestore() async {
// calling our fireStore
//calling our user model
// sending these values
FirebaseFirestore firebaseFirestore = FirebaseFirestore.instance;
User? user = _auth.currentUser;
UserModel userModel = UserModel();
if (user != null) {
//writing all the values
userModel.email = user?.email;
userModel.uid = user?.uid;
await firebaseFirestore
.collection("users")
.doc(user?.uid)
.set(userModel.toMap());
Fluttertoast.showToast(msg: "Account created successfully ");
Navigator.pushAndRemoveUntil(
(context),
MaterialPageRoute(builder: (context) => HomeScreen()),
(route) => false);
}
}
in email password signup I called
these 2 methods but show this error
when signup how to pass uid and emaill to saveDataToSharedPreferences method and pass sp.setSignIn() boolean like as in google signing?
You are trying to use method saveDataToSharedPreferences from Future class, not from auth. For fix this issue, call prefs from main object:
final result = await _auth.createUserWithEmailAndPassword(
email: email,
password: password,
);
result.saveDataToSharedPreferences()
.sp.setSignIn()
// etc.
I have an application and I created a legin and logout page... and when I click on my application's logout button, I get an error like this " Null check operator used on a null value"*and when I point to the error, it tells me [1] :
https://i.stack.imgur.com/n0uJ8.pngentrez
import 'dart:async';
import 'dart:convert';
import 'dart:async';
import 'dart:convert';
import 'dart:math';
import 'package:flutter/material.dart';
import 'package:http/http.dart';
import 'package:logger/logger.dart';
import '../db/db_auth_shared_preference.dart';
import '../network/app_urls.dart';
import '../models/auth.dart';
enum Status {
notLoggedIn,
loggedIn,
authenticating,
loggedOut,
notReet,
reseted,
resetting
}
//Help display the logs
var logger = Logger();
class AuthProvider with ChangeNotifier {
Auth? _auth;
Auth get auth => _auth!;
void setAuth(Auth auth) {
_auth = auth;
notifyListeners();
}
bool isAuth() {
if (_auth == null || auth.token == '') {
return false;
}
return true;
}
// Time before the token expires
Timer? _authTimer;
DateTime? _expiryDate;
String? username;
String? password;
// Set the status of the user to Not Logged In at the start of the app
Status _status = Status.notLoggedIn;
Status get status => _status;
// Change the status of the user
set status(Status value) {
_status = value;
notifyListeners();
}
// Log In the user
Future<Map<String, dynamic>> login(String email, String password) async {
Map<String, Object> results;
final Map<String, dynamic> loginData = {
'email': email,
'password': password
};
status = Status.authenticating;
logger.d("--- Authentication ---");
try {
Response response = await post(
Uri.parse(
"${AppUrl.login}? username=${loginData['email']}&password=${loginData['password']}"
),
);
logger.d('Login response : ${response.statusCode}');
// The Request Succeded
if (response.statusCode == 200) {
final Map<String, dynamic> responseData =
json.decode(utf8.decode(response.bodyBytes));
var requestStatus = responseData["status"];
if (requestStatus != 0) {
status = Status.notLoggedIn;
results = {'status': false, 'message': "La Connexion a échoué"};
} else {
// Get the status code of the request
Map<String, dynamic> authData = responseData["utilisateurJson"];
logger.d(authData);
_expiryDate = DateTime.now().add(const Duration(seconds: 3500));
//store user shared pref
Auth authUser = Auth.fromMap(authData,
timeToExpire: _expiryDate,
username: loginData['email'],
password: loginData['password']);
_expiryDate = authUser.expiryDate;
logger.wtf(_expiryDate);
//clear session data
AuthPreferences().removeAuth();
//store User session
AuthPreferences().saveAuth(authUser);
setAuth(authUser);
status = Status.loggedIn;
username = loginData["email"];
password = loginData["password"];
results = {
'status': true,
'message': 'Successful login',
'auth': authUser,
};
autoLogOut();
}
} else {
status = Status.notLoggedIn;
results = {'status': false, 'message': 'La Connexion a échoué'};
}
return results;
} catch (e) {
logger.e(e);
status = Status.notLoggedIn;
results = {
'status': false,
'message': "La Connexion avec le serveur a échoué"
};
return results;
} }
void autoLogOut() {
if (_authTimer != null) {
_authTimer!.cancel();
}
final timeToExpiry = _expiryDate!.difference(DateTime.now()).inSeconds;
_authTimer = Timer(Duration(seconds: timeToExpiry),
() async => await login(username!, password!));
}
// Log Out the User
void logOut() {
logger.d("--- User Logging Out ---");
AuthPreferences().removeAuth();
status = Status.loggedOut;
_expiryDate = null;
_auth = null;
logger.d("--- User Logged Out ---");
}
Future<Auth?> tryAutoLogin() async {
final authSession = await AuthPreferences().getAuth();
if (authSession == null) {
return null;
}
logger.d("The expiry time is : ${authSession.expiryDate}");
if (authSession.expiryDate.isBefore(DateTime.now())) {
login(authSession.username, authSession.password);
return authSession;
}
_expiryDate = authSession.expiryDate;
setAuth(authSession);
logger.d("SETTING THE USER");
autoLogOut();
return authSession;
}
}
Error Explanation: Bang operator(!) means that in flutter, when you use this operator, you are completely sure that variable is not going to be null in any case.
There are two ways to resolve it -
Use if conditional to confirm that variable is not null
Use null-aware or if-null operator ?? like
Auth get auth => _auth ?? Auth();
Since you didn't provide any error logs; based on attached image and as your cursor on line no 29, _auth variable is null. So before using ! make sure your variable is not null.
How to dynamically auth users and save tokens in shared pref?
I understood how to save token in sharedprefernces, but can't understand how to take it dynamically by login/password and pass token from it to sharedpref dynamically in loginWithToken(); beacuse I use this function for auth in
final httpConnectionOptions = HttpConnectionOptions(
accessTokenFactory: () => SharedPreferenceService().loginWithToken(),
and it is required only String
My code now is like that:
Here is request where I am making request to get token:
Future<String?> getToken(String password, String login) async {
String _email = "admin";
String _password = "123";
Map<String, String> headers = {
'Content-Type': 'application/json',
'accept': ' */*'
};
final body = {
'username': _email,
'password': _password,
};
var response = await http.post(
Uri.parse("http://mylink/login"),
headers: headers,
body: jsonEncode(body),
);
if (response.statusCode == 200) {
var value = jsonEncode(response.body);
return value;
}
return null;
}
here is I created logging logic:
final TextEditingController _loginController = TextEditingController();
final TextEditingController _passwordController = TextEditingController();
ElevatedButton(
onPressed: () async {
var username = _loginController.text;
var password = _passwordController.text;
var jwt = await ProviderService()
.getToken(password, username);
if (jwt != null) {
SharedPreferenceService().setToken(jwt);
Navigator.pushNamed(
context, '/mainPageAdmin');
} else {
displayDialog(context);
}
},
here is my shared pref. I can't understand how to put new token value in that string, after paaword and login was sent.
String tokens = 'dhjwhdwdwkjdhdkje';
Future<bool> getSharedPreferencesInstance() async {
_prefs = await SharedPreferences.getInstance().catchError((e) {
print("shared preferences error : $e");
return false;
});
return true;
}
Future setToken(String token) async {
await _prefs?.setString('token', token);
}
Future clearToken() async {
await _prefs?.clear();
}
Future<String> get token async => _prefs?.getString('token') ?? '';
Future<String> loginWithToken() async {
bool value = await getSharedPreferencesInstance();
if (value == true) {
setToken("Bearer $tokens");
// print(tokens);
}
return tokens;
}
Api Responce:
{
"$id": "1",
"token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJodHRwOi8vc2NoZW1hcy54bWxzb2FwLm9yZ",
"user": {
"$id": "2"
}
}
Auth class I parsed:
Auth authFromJson(String str) => Auth.fromJson(json.decode(str));
String authToJson(Auth data) => json.encode(data.toJson());
class Auth {
Auth({
this.token,
this.user,
});
final String? token;
final User? user;
factory Auth.fromJson(Map<String, dynamic> json) => Auth(
token: json["token"],
user: User.fromJson(json["user"]),
);
Map<String, dynamic> toJson() => {
"token": token,
"user": user!.toJson(),
};
}
In your getToken function do this:
if (response.statusCode == 200) {
var value = jsonEncode(response.body) as Map<String, dynamic>;
await setToken(value['token']);
return value;
}
I'm trying to use Riverpod stateNotifier to track the changes of an enum during user authentication to determine the appropriate screen to be displayed. Eg SignUp, SignIn, Homepage or the Authenticating screen but I get this error back in my named constructor:
The superclass 'StateNotifier' doesn't have a zero argument constructor.
Try declaring a zero argument constructor in 'StateNotifier', or explicitly invoking a different constructor in 'StateNotifier'.
I know that there something i don't understand here but i can't figure it out.
Here is my code:
enum Status {
unInitialized,
unauthenticated,
authenticating,
authenticated,
processing
}
class AuthWithEmailPassword extends StateNotifier<Status> {
AuthWithEmailPassword() : super(Status.authenticated);
Status _status = Status.authenticated;
// AuthWithEmailPassword();
UserServices _userServices = UserServices();
FirebaseAuth _auth;
UserModel _userModel;
User _user;
Status get status => _status;
User get user => _user;
UserModel get userModel => _userModel;
//Name consturctor of this class
#override
AuthWithEmailPassword.initialize()
: _auth = FirebaseAuth.instance{
_status = Status.unInitialized;
_auth.authStateChanges().listen((User value) async {
_status = Status.unInitialized;
if (value == null) {
_status = Status.unauthenticated;
print('user is signed out');
} else {
_userModel = await _userServices.getUserByUid(id: value.uid);
_status = Status.authenticated;
_user = value;
print('user signed in');
}
});
}}
Instead of using a named constructor, you could create an initialize function and call it in your StateNotifierProvider.
For example:
class AuthWithEmailPassword extends StateNotifier<Status> {
AuthWithEmailPassword() : super(Status.authenticated);
Status _status = Status.authenticated;
Status get status => _status;
final FirebaseAuth _auth = FirebaseAuth.instance;
User _user;
User get user => _user;
UserModel _userModel;
UserModel get userModel => _userModel;
bool _init = false;
late StreamSubscription _sub;
void initialize() {
if (_init) return;
_status = Status.unInitialized;
_sub = _auth.authStateChanges().listen(_listener);
_init = true;
}
#override
void dispose() {
_sub.cancel();
super.dispose();
}
Future<void> _listener(User? value) async {
_status = Status.unInitialized;
if (value == null) {
_status = Status.unauthenticated;
print('user is signed out');
} else {
_userModel = await _userServices.getUserByUid(id: value.uid);
_status = Status.authenticated;
_user = value;
print('user signed in');
}
}
}
final authWithEmailPasswordProvider = StateNotifierProvider.autoDispose<AuthWithEmailPassword, Status>((_) {
return AuthWithEmailPassword()..initialize();
});
Thanks to Alex Hartford who helped me with a solution when i was desperate on this issue. I have finally been able to figure out another solution also and maybe someone might like it.
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter_ecom/controle/userServices.dart';
import 'package:flutter_ecom/models/userModel.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
enum Status {
unInitialized,
unauthenticated,
authenticating,
authenticated,
}
final authStatus = StateNotifierProvider<AuthWithEmailPassword, Status>(
(ref) => AuthWithEmailPassword.initialize());
class AuthWithEmailPassword extends StateNotifier<Status> {
FirebaseFirestore firestore = FirebaseFirestore.instance;
UserServices _userServices = UserServices();
// Status state = Status.unInitialized;
FirebaseAuth _auth;
UserModel _userModel;
User _user;
// Status get status => _status;
User get user => _user;
UserModel get userModel => _userModel;
String _error;
String get error => _error;
//Name consturctor of this class
AuthWithEmailPassword.initialize()
: _auth = FirebaseAuth.instance,
super(Status.unInitialized) {
_auth.authStateChanges().listen((User value) async {
await Future.delayed(
const Duration(milliseconds: 4000),
);
if (value == null) {
state = Status.unauthenticated;
print('user is signed out');
} else {
_userModel = await _userServices.getUserByUid(id: value.uid);
state = Status.authenticated;
_user = value;
print('user signed in');
}
});
}
Register Screen On Pressed method given, I believe there is a problem with calling Firebase user = result.user
onPressed: () async {
if(_formKey.currentState.validate()){
setState(() => loading = true);
dynamic result = await _auth.registerWithEmailAndPassword(email, password);
FirebaseUser user = result.user;
await DatabaseService(uid: user.uid).newUserInfo(
_nameC.text,
_cityC.text,
_contactnoC.toString()
);
if(result == null) {
setState(() {
error = 'Please supply a valid email';
loading = false;
});
}}},
// Database backend
class DatabaseService {
final String uid;
DatabaseService ({this.uid});
final CollectionReference userdata2 = Firestore.instance.collection('UserData');
Future newUserInfo(String name, String city, String contactno) async {
return await userdata2.document(uid).setData({
'name' : name,
'city' : city,
'contactno' : contactno
});
}}
// authentication backend
// register with email and password
Future registerWithEmailAndPassword(String email, String password) async {
try {
AuthResult result = await _auth.createUserWithEmailAndPassword(email: email, password: password);
FirebaseUser user = result.user;
DatabaseService(uid: user.uid);
return _userFromFirebaseUser(user);
} catch (error) {
print(error.toString());
return null;
} }
// user.dart
class User {
final String uid;
User({this.uid});
}