Hey I have this simple code for didChangeAppLifecycleState that triggers a function that updates a Firestore record of when user was online last time
#override
void didChangeAppLifecycleState(AppLifecycleState state) {
super.didChangeAppLifecycleState(state);
final authServiceProvider =
Provider.of<AuthServiceProvider>(context, listen: false);
if (state == AppLifecycleState.resumed) {
} else {
authServiceProvider.updateUserLastOnline();
}
}
It works fine in a separate page but how I make it work for the whole app not copying this code to every single page?
I just converted my main widget in main.dart into Stateful widget with WidgetsBindingObserver and added the same code
#override
void didChangeAppLifecycleState(AppLifecycleState state) {
super.didChangeAppLifecycleState(state);
final authServiceProvider =
Provider.of<AuthServiceProvider>(context, listen: false);
if (state == AppLifecycleState.resumed) {
} else {
authServiceProvider.updateUserLastOnline();
}
}
Now it works for the whole app.
Related
I'm using a Cubit in my app and I'm struggling to understand one behavior.
I have a list of products and when I open the product detail screen I want to have a "blank" screen with a loading indicator until receiving the data to populate the layout, but the loading indicator is not being triggered in the listener (only in this first call, when making a refresh in the screen it shows the loader).
I'm using a BlocConsumer and i'm making the request in the builder when catching the ApplicationInitialState (first state), in cubit I'm emitting the ApplicationLoadingState(), but this state transition is not being caught in the listener, only when the SuccessState is emitted the listener triggers and tries to remove the loader.
I know the listener does not catch the first State emitted but I was expecting it to catch the first state transition.
UI
#override
void initState() {
super.initState();
WidgetsBinding.instance.addObserver(this);
}
#override
Widget build(BuildContext context) {
_l10n = AppLocalizations.of(context);
return _buildConsumer();
}
_buildConsumer() {
return BlocConsumer<ProductCubit, ApplicationState>(
bloc: _productCubit,
builder: (context, state) {
if (state is ApplicationInitialState) {
_getProductDetail();
}
return Scaffold(
appBar: _buildAppbar(state),
body: _buildBodyState(state),
);
},
listener: (previous, current) async {
if (current is ApplicationLoadingState) {
_loadingIndicator.show(context);
} else {
_loadingIndicator.close(context);
}
},
);
}
Cubit
class ProductCubit extends Cubit<ApplicationState> with ErrorHandler {
final ProductUseCase _useCase;
ProductCubit({
required ProductUseCase useCase,
}) : _useCase = useCase,
super(const ApplicationInitialState());
void getProductDetail(String id) async {
try {
emit(const ApplicationLoadingState());
final Product = await _useCase.getProductDetail(id);
emit(CSDetailSuccessState(
detail: ProductDetailMapper.getDetail(Product),
));
} catch (exception) {
emit(getErrorState(exception));
}
}
}
ApplicationLoadingState
abstract class ApplicationState extends Equatable {
const ApplicationState();
#override
List<Object> get props => [];
}
class ApplicationLoadingState extends ApplicationState {
const ApplicationLoadingState();
}
On my first screen, I fill out the form and then click the next button it added SubmitDataEvent() to the bloc. Then, the BolcListner listing and when it comes to SuccessSate it navigate to the next screen.
on the second screen, when I click the back button it navigates to the previous screen. After that, when I change the user-input data on the form and again click the next button now SubmitDataEvent() is not added.
I preferred some resources related to this and I understand the problem is that the state is in SuccessSate and it doesn't change to InitialState. So in dispose() I used bloc.close();
#override
void dispose() {
bloc.close();
super.dispose();
}
But still, it's not working. Also, I try with this code
#override
void dispose() {
bloc.emit(InitialState);
bloc.close();
super.dispose();
}
still, it's not working.
I used this to navigate between screens:
Navigator.popAndPushNamed()
What I want to do is:
On the first screen, when clicking on the next button SubmitDataEvent() added to the bloc and it in SuccessState it navigate to the next screen. When I click the back button on the second page it navigates again to the first screen. Now when I click the next button on the first screen I want to run all bloc process again.
There are no dependencies with the first and second screens.
first screen code:
...
#override
void initState() {
super.initState();
bloc = injection<SubmitPersonalDetailsBloc>();
EasyLoading.addStatusCallback((status) {
print('EasyLoading Status $status');
if (status == EasyLoadingStatus.dismiss) {
_timer?.cancel();
}
});
}
#override
void dispose() {
_scrollController.dispose();
bloc.close();
super.dispose();
}
#override
Widget buildView(BuildContext context) {
return Scaffold(
body: BlocProvider<SubmitPersonalDetailsBloc>(
create: (_) => bloc,
child: BlocListener<SubmitPersonalDetailsBloc,
BaseState<PersonalDetailsState>>(
listener: (context, state) {
if (state is LoadingSubmitPersonalDetailsState) {
EasyLoading.show(status: 'Submitting Data');
}
if (state is SubmitPersonalDetailsSuccessState) {
setState(() {
submitPersonalDetailsResponseEntity =
state.submitPersonalDetailsResponseEntity;
});
if (submitPersonalDetailsResponseEntity!.responseCode == "00") {
EasyLoading.showSuccess('Done!');
//Navigate next screen
EasyLoading.dismiss();
}
} else if (state is SubmitPersonalDetailsFailedState) {
EasyLoading.showError(state.error); }
},
....
The problem is on Dependency Injection, Once it creates an instance the parameters don't change. So when navigating to the next screen have to reset that instance.
#override
void dispose() {
_scrollController.dispose();
bloc.close();
injection.resetLazySingleton<SubmitPersonalDetailsBloc>(); // here reset the instance
super.dispose();
}
You can try with this snippet
if (result.responseCode == APIResponse.RESPONSE_SUCCESS) {
yield SubmitPersonalDetailsSuccessState(
submitPersonalDetailsResponseEntity: r);
} else
yield SubmitPersonalDetailsFailedState(error: r.responseMsg);
}
I'm getting an error like the one in the picture. I'm confused because I'm not setting up GlobalKey on every page. I just made a GlobalKey on main.dart for this:
class _MyAppState extends State<MyApp> with WidgetsBindingObserver {
StreamController<bool> _showLockScreenStream = StreamController();
StreamSubscription _showLockScreenSubs;
GlobalKey<NavigatorState> _navigatorKey = GlobalKey();
#override
void initState() {
super.initState();
WidgetsBinding.instance.addObserver(this);
_showLockScreenSubs = _showLockScreenStream.stream.listen((bool show){
if (mounted && show) {
_showLockScreenDialog();
}
});
}
#override
void dispose() {
WidgetsBinding.instance.removeObserver(this);
_showLockScreenSubs?.cancel();
super.dispose();
}
// Listen for when the app enter in background or foreground state.
#override
void didChangeAppLifecycleState(AppLifecycleState state) {
if (state == AppLifecycleState.resumed) {
// user returned to our app, we push an event to the stream
_showLockScreenStream.add(true);
} else if (state == AppLifecycleState.inactive) {
// app is inactive
} else if (state == AppLifecycleState.paused) {
// user is about quit our app temporally
} else if (state == AppLifecycleState.suspending) {
// app suspended (not used in iOS)
}
}
#override
Widget build(BuildContext context) {
return MaterialApp(
navigatorKey: _navigatorKey,
...
);
}
void _showLockScreenDialog() {
_navigatorKey.currentState.
.pushReplacement(new MaterialPageRoute(builder: (BuildContext context) {
return PassCodeScreen();
}));
}
}
I've tried to remove the GlobalKey _navigatorKey but the error still appears.
The error appears when switching pages. Is there anyone who can help me?
There are many kinds of Keys. But the GlobalKey allows access to the state of a widget (if it's a StatefulWigdet).
Then, if you use the same GlobalKey for many of them, there is a conflict with their States.
In addition, they must be of the same type due to its specification:
abstract class GlobalKey<T extends State<StatefulWidget>> extends Key {
// ...
void _register(Element element) {
assert(() {
if (_registry.containsKey(this)) {
assert(element.widget != null);
final Element oldElement = _registry[this]!;
assert(oldElement.widget != null);
assert(element.widget.runtimeType != oldElement.widget.runtimeType);
_debugIllFatedElements.add(oldElement);
}
return true;
}());
_registry[this] = element;
}
// ...
}
This fragment of code shows that in debug mode, there is an assertion for ensuring that there isn't any other GlobalState of the same type previously registered.
In my app, I am playing music (local) in a loop, which plays continuously unless the user stops it. I am using audioplayers package.
Future playLoop(String filePath) async {
player.stop();
player = await cache.loop(filePath);
}
Currently, when app is minimised, the music is not getting stoped. The feature I want to implement is that when the app is minimised, it should stop playing music in the background.
Thanks in advance.
Solutions :
#override
void didChangeAppLifecycleState(AppLifecycleState state) {
if (state == AppLifecycleState.paused) {
//stop your audio player
}else{
print(state.toString());
}
}
#override
void initState() {
super.initState();
WidgetsBinding.instance.addObserver(this);
}
There are mainly 4 states for it:
resumed: The application is visible and responding to user input.
inactive: The application is in an inactive state and is not receiving
user input.
paused: The application is not currently visible to the user, not
responding user input, and running in the background.
detached: The application is still hosted on a flutter engine but is
detached from any host views.
The solution above is correct, but some steps are needed before to get it
1 add WidgetsBindingObserver to your class
class AnyClass extends StatefulWidgets {
_AnyClassState createState() => _AnyClassState();
}
class _AnyClassState extends State<AnyClass> with
WidgetsBindingObserver {
Widget build(BuildContext context) {
return ...
}
}
2 Now it will work, we can added the methods inside class
class _AnyClassState extends State<AnyClass> with
WidgetsBindingObserver {
// ADD THIS AppLifecycleState VARIABLE
late AppLifecycleState appLifecycle;
// ADD THIS FUNCTION WITH A AppLifecycleState PARAMETER
didChangeAppLifecycleState(AppLifecycleState state) {
appLifecycle = state;
setStae(() {});
if(state == AppLifecycle.paused) {
// IF YOUT APP IS IN BACKGROUND...
// YOU CAN ADDED THE ACTION HERE
print('My app is in background');
}
}
// CREATE INITSTATE AND DISPOSE METHODS
initState() {
super.initState();
WidgetsBinding.instance.addObserver(this);
}
dispose() {
WidgetsBinding.instance.removeObserver(this);
super.dispose();
}
Widget build(BuildContext context) {
return ...
}
}
NOW IT WILL WORK FINE!
I'm programming a flutter application in which a user is presented with a PageView widget that allows him/her to navigate between 3 "pages" by swiping.
I'm following the setup used in https://medium.com/flutter-community/flutter-app-architecture-101-vanilla-scoped-model-bloc-7eff7b2baf7e, where I use a single class to load data into my model, which should reflect the corresponding state change (IsLoadingData/HasData).
I have a main page that holds all ViewPage widgets. The pages are constructed in the MainPageState object like this:
#override
void initState() {
_setBloc = SetBloc(widget._repository);
_notificationBloc = NotificationBloc(widget._repository);
leftWidget = NotificationPage(_notificationBloc);
middleWidget = SetPage(_setBloc);
currentPage = middleWidget;
super.initState();
}
If we go into the NotificationPage, then the first thing it does is attempt to load data:
NotificationPage(this._notificationBloc) {
_notificationBloc.loadNotificationData();
}
which should be reflected in the build function when a user directs the application to it:
//TODO: Consider if state management is correct
#override
Widget build(BuildContext context) {
return StreamBuilder<NotificationState>(
stream: _notificationBloc.notification.asBroadcastStream(),
//initialData might be problematic
initialData: NotificationLoadingState(),
builder: (context, snapshot) {
if (snapshot.data is NotificationLoadingState) {
return _buildLoading();
}
if (snapshot.data is NotificationDataState) {
NotificationDataState state = snapshot.data;
return buildBody(context, state.notification);
} else {
return Container();
}
},
);
}
What happens is that the screen will always hit "NotificationLoadingState" even when data has been loaded, which happens in the repository:
void loadNotificationData() {
_setStreamController.sink.add(NotificationState._notificationLoading());
_repository.getNotificationTime().then((notification) {
_setStreamController.sink
.add(NotificationState._notificationData(notification));
print(notification);
});
}
The notification is printed whilst on another page that is not the notification page.
What am i doing wrong?
//....
class _SomeState extends State<SomeWidget> {
//....
Stream<int> notificationStream;
//....
#override
void initState() {
//....
notificationStream = _notificationBloc.notification.asBroadcastStream()
super.initState();
}
//....
Widget build(BuildContext context) {
return StreamBuilder<NotificationState>(
stream: notificationStream,
//....
Save your Stream somewhere and stop initialising it every time.
I suspect that the build method is called multiple times and therefore you create a new stream (initState is called once).
Please try let me know if this helped.