how can i set state in static method? i get an error which is 'instanceFactory != null': Object/factory

[yakupbaser]

hi to all. i use foreground_service plugin & stacked(state management lib) & get_it and foreground_service needs a static periodicfunction that i use a static service class in it. But when i use static class with stacked plugin, the app is working but i cant manage the state which in my static class. So how to manage state in static class, how can i use get_it & static class & states together?

my static service class is:

 @lazySingleton
class IlanService with ReactiveServiceMixin {
  static IlanService _ilanService;
  factory IlanService() {
    if (_ilanService == null) {
      _ilanService = IlanService._internal();
      return _ilanService;
    } else {
      return _ilanService;
    }
  }
  Ilan _ilan = Ilan();
  Ilan get ilan => _ilan;
  Future<void> updateIlan() async {
  _ilan = await databaseHelper.getIlan(mazagaService.magazaID);
  notifyListeners();
}

locator.dart:

import 'package:get_it/get_it.dart';
import 'package:injectable/injectable.dart';
import 'locator.config.dart';
final getIt = GetIt.instance;
@InjectableInit(
  initializerName: r'$initGetIt', // default
  preferRelativeImports: true, // default
  asExtension: false, // default
)
void configureDependencies() => $initGetIt(getIt);

main.dart:

void main() async{
  configureDependencies();
  WidgetsFlutterBinding.ensureInitialized();
  runApp(MyApp());
}

myview.dart which has the periodic function fore foreground_service:

.
..
...
import 'package:buybox/app/services/ilan_service.dart';
import 'package:flutter/material.dart';
import 'package:flutter_foreground_service_plugin/flutter_foreground_service_plugin.dart';
import 'package:stacked/stacked.dart';
import 'package:buybox/datamodels/ilan_model.dart';
IlanService ilanService = IlanService();
/* if i try final ilanService = getIt<IlanService>(); then i get an error:
[ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: 'package:get_it/get_it_impl.dart': Failed assertion: line 298 pos 9: 'instanceFactory != null': Object/factory with  type IlanService is not registered inside GetIt.
E/flutter (26306): (Did you accidentally do  GetIt sl=GetIt.instance(); instead of GetIt sl=GetIt.instance;
E/flutter (26306): Did you forget to register it?)
*/
void periodicTaskFun() {
  FlutterForegroundServicePlugin.executeTask(() async {
  ..
  ..
  ...
  await ilanService.updateIlan();
  await FlutterForegroundServicePlugin.refreshForegroundServiceContent(
    notificationContent: NotificationContent(
      iconName: 'ic_launcher',
      titleText: 'Title Text',
      bodyText: '${DateTime.now()}',
      subText: 'subText',
      color: Colors.red,
    ),
  );
});

and lastly i added locator.config.dart:

// GENERATED CODE - DO NOT MODIFY BY HAND
// **************************************************************************
// InjectableConfigGenerator
// **************************************************************************
import 'package:stacked_services/stacked_services.dart';
import 'package:get_it/get_it.dart';
import 'package:injectable/injectable.dart';
import 'services/fiyat_service.dart';
import 'services/third_party_services_module.dart';
/// adds generated dependencies
/// to the provided [GetIt] instance
GetIt $initGetIt(
  GetIt get, {
  String environment,
  EnvironmentFilter environmentFilter,
}) {
  final gh = GetItHelper(get, environment, environmentFilter);
  final thirdPartyServicesModule = _$ThirdPartyServicesModule();
  gh.lazySingleton<IlanService>(() => IlanService());
  // Eager singletons must be registered in the right order
  gh.singleton<DialogService>(thirdPartyServicesModule.dialogService);
  return get;
}
class _$ThirdPartyServicesModule extends ThirdPartyServicesModule {
  @override
  DialogService get dialogService => DialogService();
}

so how can i use final ilanService = getIt(); instead of IlanService ilanService = IlanService(); Bcoz i have to set state in it :( (edited)

[escamoteur]

My guess is that you call

final ilanService = getIt<IlanService>();

before your registration is finished.
is final ilanService a global variable?

[yakupbaser]

yes it is global variable

[escamoteur]

Yeah there is the problem. Why do you use a global variable here and not access get_it when you need it?

[yakupbaser]

bcoz periodicTaskFun need it?

[escamoteur]

you can call Getit inside a static function

[yakupbaser]

so should i register service class in static function whith getIt?

[escamoteur]

Why registering in the static function? just use it in there with getIt<IlanService>()

[yakupbaser]

i made your said but i get same error:

`void periodicTaskFun() {

FlutterForegroundServicePlugin.executeTask(() async {

final staticIlanService = getIt<IlanService>()

dbIlanList = await staticIlanService.getIlanListWithoutRender();

.
..
...
await FlutterForegroundServicePlugin.refreshForegroundServiceContent(
  notificationContent: NotificationContent(
    iconName: 'ic_launcher',
    titleText: 'Title Text',
    bodyText: '${DateTime.now()}',
    subText: 'subText',
    color: Colors.red,
  ),
);

});`

error is:

[ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: 'package:get_it/get_it_impl.dart': Failed assertion: line 298 pos 9: 'instanceFactory != null': Object/factory with type DatabaseHelper is not registered inside GetIt. E/flutter (15573): (Did you accidentally do GetIt sl=GetIt.instance(); instead of GetIt sl=GetIt.instance; E/flutter (15573): Did you forget to register it?)

[escamoteur]

could I clone your project and have a closer look?

[yakupbaser]

i created a clear project for this issue. There is a counter text in the form. When i click the Increase State From HomeViewModal its success. But When i click the Start ForeGround Service; it doesnt set the Text widget and if i use getit i get same error:

final newExampleService = getIt<ExampleService>();

https://github.com/yakupbaser/demogetit

[escamoteur]

It didn't crash here. can you push the version that crashes?

[yakupbaser]

yes it did not crash becoz i use ExampleService newExampleService = ExampleService(); in periodicTaskFun of home_view.dart. if you try final newExampleService = getIt<ExampleService>(); then you can see the crash

//i pushed crashed build repo

[escamoteur]

Ok, it has nothing to do with the ststic method, the problem is that your periodic function is called from a different Isolate which has its own global variables, which means there also is a GetIt but it's a different instance than theone you register your objects in.

Do you need to have this running on a different Isolate? would a normal Timer not be enough?

I also doubt that you need that static stuff in your example service. Important is for this plugin that your periodic function is either gloibal or static.

[yakupbaser]

periodicTaskFun of foreground service is working when app is closed but timer is not :(

[escamoteur]

ah, I see. Then I fear you have to instanciate your Objects there manually. It doesn't look like you can pass over any data to the functionthat is called.

[yakupbaser]

even so thanks for your helps :)

[escamoteur]

Thanks, spread the word about get_it, check out get_it_mixin and I'm always happy of a nice tweet @thomasburkhartb