i am developing a flutter app. App has onboarding screen. I want to store that the user first open. I am using sharedpreferences for this. Below codes, always open OnBoardingScreen. Whats my fault ? please help me.
save bool method
saveBool(bool isOk) async {
final prefs = await SharedPreferences.getInstance();
prefs.setBool('firstOpen', isOk);
}
check bool method
checkFirstOpen() async {
SharedPreferences prefs = await SharedPreferences.getInstance();
bool checkValue = prefs.containsKey('firstOpen');
return checkValue;
}
}
And here i decide to route
main.dart
home: checkFirstOpen() == true ? MyHomePage() : OnboardingScreen());
I save bool in setState.
onTap: (){
var route = new MaterialPageRoute(
builder: (BuildContext context) =>
new MyHomePage(),
);
Navigator.of(context).push(route);
setState(() {
saveBool(true);
});
},
You are simply checking if you the key is present or not.
Remove this line
prefs.containsKey("firstOpen");
Instead, access the value using
prefs.getBool("firstOpen") ?? true
Related
I'm trying to save a value in the shared preferences in flutter then get it. But it's always returning null. The value is being retrieved from an API that is working fine in the backend.
Here is my code:
Method in which i'm getting the data from the api:
List<LastOrder>? lastOrders;
var isLoaded3 = false;
int od_id = 0;
getLastOrderMethod() async {
lastOrders = await RemoteService().getLastOrder(2);
if (lastOrders != null) {
setState(() {
isLoaded = true;
});
return ListView.builder(
itemCount: 1,
itemBuilder: (BuildContext context, int index) {
setState(() {
od_id = lastOrders![0].id;
print('getLastOrderMethod: $od_id');
saveIdOrder(od_id);
});
return;
});
}
}
Method in which i'm trying to save the variable value in the shared preferences:
Future<bool> saveIdOrder(value) async {
SharedPreferences sharedPreferences = await SharedPreferences.getInstance();
print('save: $od_id');
return await sharedPreferences.setInt('order_id', value);
}
Method in which i'm trying to get the variable value in the shared preferences:
static Future getIdOrder() async {
SharedPreferences sharedPreferences = await SharedPreferences.getInstance();
final x = sharedPreferences.getInt('order_id');
print('get: $x');
return x;
}
#override
void initState() {
// TODO: implement initState
print('intial ${od_id}'); => 0
getIdOrder(); => null
getLastOrderMethod();
super.initState();
}
I'd be glad for any kind of help!
getIdOrder() is a future method, it will take some time to fetch the data. While initState cant be async method, you can use .then and inside it call setState to update the ui. but Using FutureBuilder will be best option.
late final future = getIdOrder();
#override
Widget build(BuildContext context) {
return Scaffold(
body: FutureBuilder(
future: future,
builder: (context, snapshot) {
if (snapshot.hasData) {
return Text("${snapshot.data}"); // your widget
}
return CircularProgressIndicator();
},
),
floatingActionButton: FloatingActionButton(onPressed: () {}),
);
}
More about using FutureBuilder
Solved the issue by doing all the logic inside the listView.builder(), then updated the variable value inside a setState()
I need to redirect user to login page when he clicks on logout button from drawer (wherever he is). The problem is that when I click on the logout button, the screen remains the same.
According to this post: Flutter provider state management, logout concept
I have:
void main() async {
runApp(
MultiProvider(
providers: [
ChangeNotifierProvider<Profile>(
create: (final BuildContext context) {
return Profile();
},
)
],
child: MyApp(),
),
);
}
MyApp:
class _MyAppState extends State<MyApp> {
#override
void initState() {
super.initState();
initPlatformState();
}
/// Platform messages are asynchronous, so we initialize in an async method.
Future<void> initPlatformState() async {
if (!mounted) return;
}
#override
Widget build(BuildContext context) {
return new MaterialApp(
initialRoute: '/',
navigatorKey: navigatorKey,
// ...
home: Consumer<Profile>(
builder: (context, profile, child){
return profile.isAuthenticated ? SplashScreen() : AuthScreen();
}
)
);
}
}
The part of the drawer where there is the logout button:
ListTile(
leading: Icon(Icons.logout),
title: Text(AppLocalizations.of(context)!.logout),
onTap: () async {
SharedPreferences preferences =
await SharedPreferences.getInstance();
await preferences.clear();
final Profile profile =
Provider.of<Profile>(context, listen: false);
profile.isAuthenticated = false;
}),
As I said, when I click on the logout button from the drawer, the user is correctly logged out, but the screen remains the same.
UPDATE
This is the profile class:
class Profile with ChangeNotifier {
bool _isAuthenticated = false;
bool get isAuthenticated {
return this._isAuthenticated;
}
set isAuthenticated(bool newVal) {
this._isAuthenticated = newVal;
this.notifyListeners();
}
}
I think you are using provider class incorrectly.
use your profile class like this.
class Profile with ChangeNotifier {
bool _isAuthenticated = true;
bool get getIsAuthenticated => _isAuthenticated;
set setIsAuthenticated(bool isAuthenticated) {
_isAuthenticated = isAuthenticated;
notifyListeners();//you must call this method to inform lisners
}
}
in set method call notifyListners();
in your listTile
replace profile.isAuthenticated = false to profile.isAuthenticated = false;
Always use getters and setters for best practice.
I hope this is what you were looking for.
Add Navigator.of(context).pushReplacementNamed("/routeName") in LogOut onTap() Section.
For more information : https://api.flutter.dev/flutter/widgets/Navigator/pushReplacementNamed.html
Make sure to have logout route set in MyApp file, and i'd edit logout button file as such:
ListTile(
leading: Icon(Icons.logout),
title: Text(AppLocalizations.of(context)!.logout),
onTap: () async {
SharedPreferences preferences =
await SharedPreferences.getInstance();
await preferences.clear();
final Profile profile =
Provider.of<Profile>(context, listen: false);
profile.isAuthenticated = false;
// add login file route here using Navigator.pushReplacementNamed() ;
}),
Navigator push named -> logout route?
I have two asynchronous functions, one returns a popup, the other makes a permission request. I call them in the init method. But they are called simultaneously, i.e. the first window appears and immediately the second. How do I fix this?
class _MyAppState extends State<MyApp> {
final keyIsFirstLoaded = 'is_first_loaded';
#override
void initState() {
super.initState();
WidgetsBinding.instance.addPostFrameCallback((_) async {
final context = MyApp.navKey.currentState.overlay.context;
await showDialogIfFirstLoaded(context);
await initPlatformState();
});
}
showDialogIfFirstLoaded(BuildContext context, prefs) async {
SharedPreferences prefs = await SharedPreferences.getInstance();
bool isFirstLoaded = prefs.getBool(keyIsFirstLoaded);
if (isFirstLoaded == null) {
showDialog(
context: context,
builder: (BuildContext context) {
// return object of type Dialog
return new AlertDialog(
// title: new Text("title"),
content: new Text("//"),
actions: <Widget>[
new FlatButton(
child: new Text(".."),
onPressed: () {
Navigator.of(context).pop();
prefs.setBool(keyIsFirstLoaded, false);
},
),
],
);
},
);
}
}
initPlatformState() async {
print('Initializing...');
await BackgroundLocator.initialize();
print('Initialization done');
final _isRunning = await BackgroundLocator.isRegisterLocationUpdate();
setState(() {
isRunning = _isRunning;
});
onStart();
print('Running ${isRunning.toString()}');
}
add return to showDialog statement, you're not returning a Future so await isn't doing anything
Personal advice: always specify return types, cause if you don't, you get dynamic return type. If you do specify it, the IDE/dart analysis server will help you with problems such as this one.
I want to implement Auto Login with Shared preferences.
What I want to implement is that as soon as 'LoginPage' starts, it goes to the next page without rendering LoginPage according to the Flag value stored in Shared preferences.
However, there is a problem in not becoming Navigate even though implementing these functions and calling them from initstate. What is the problem?
//Login Page
void autoLogIn() async {
final SharedPreferences prefs = await SharedPreferences.getInstance();
final String userId = prefs.getString('username');
print("ddddddddddddddd");
SocketProvider provider = Provider.of<SocketProvider>(context);
Future.delayed(Duration(milliseconds: 100)).then((_) {**//I tried giving Delay but it still didn't work.**
Navigator.of(context).pushNamedAndRemoveUntil("/MainPage", (route) => false);
});
}
#override
void initState() {
// TODO: implement initState
loginBloc = BlocProvider.of<LoginBloc>(context);
if(!kReleaseMode){
_idController.text = "TESTTEST";
_passwordController.text = "1234123";
}
initBadgeList();
autoLogIn();**//This is the function in question.**
super.initState();
print("1111111111111111");
}
I don't think you should show LoginPage widget if user is already logged in and then navigate to main page.
I suggest you to use FutureBuilder and show either splash screen or loader while performing await SharedPreferences.getInstance(). In this case your App widget should look like this:
class App extends MaterialApp {
App()
: super(
title: 'MyApp',
...
home: FutureBuilder(
future: SharedPreferences.getInstance(),
builder: (context, snapshot) {
if (snapshot.data != null) {
final SharedPreferences prefs = snapshot.data;
final userId = prefs.getString('username');
...
return userId == null ?? LoginPage() : MainPage();
} else {
return SplashScreenOrLoader();
}
}));
}
But if you still want to show LoginPage first, just replace SplashScreenOrLoader() with LoginPage() in code above.
I use SharedPreferences to keep login status. its works fine.
but after close my app when I open this. it's showing all my screen like flash screen then its stay on its right screen.
but I don't want this and this not good.
I want when apps check login status its shows a loading screen or anything then after completing its show apps right screen.
how can I do this?
Here is my login status check code
checkLoginStatus() async {
sharedPreferences = await SharedPreferences.getInstance();
if (sharedPreferences.getString("empid") == null) {
Navigator.of(context).pushAndRemoveUntil(
MaterialPageRoute(builder: (BuildContext context) => Home()),
(Route<dynamic> route) => false);
}
}
Snippet
void main async {
bool isUserLogin = await User.isUserLogin();
if (isUserLogin) { // wait untill user details load
await User.currentUser.loadPastUserDetails();
}
runApp(MyApp(isUserLogin));
}
and
class MyApp extends StatelessWidget {
bool isUserLogin;
MyApp(this.isUserLogin);
#override
Widget build(BuildContext context) {
var defaultRoot = isUserLogin ? HomePage() : LoginScreen();
final material = MaterialApp(
debugShowCheckedModeBanner: false,
home: defaultRoot,
);
return material;
}
}
Hope this helps!
Personnally I like to use a variable _isLoading which I set to true at the beginning of my login method using a setState. Then using this bool you just have to change what is displayed in your Scaffold.
bool _isLoading = false;
checkLoginStatus() async {
setState() => _isLoading = true;
sharedPreferences = await SharedPreferences.getInstance();
if (sharedPreferences.getString("empid") == null) {
Navigator.of(context).pushAndRemoveUntil(
MaterialPageRoute(builder: (BuildContext context) => Home()),
(Route<dynamic> route) => false);
} else {
setState() => _isLoading = false;
}
}
EDIT: In your case this might be more relevant:
#override
Widget build(BuildContext context) {
switch (currentUser.status) {
case AuthStatus.notSignedIn:
return LoginPage();
case AuthStatus.signedIn:
return HomePage();
default:
return LoadingPage();
}
}
My currentUser is just a class that I've created containing an enum AuthStatus which can have the value notSignedIn or signedIn. If you set the status to null while loading you can display your loading screen.