Hello I'm currently building a Over Complicated Todo flutter app and I came across this error:

E/flutter (25502): [ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: 'package:get_it/get_it_impl.dart': Failed assertion: line 372 pos 7: 'instanceFactory != null': Object/factory with type DataServiceManager is not registered inside GetIt.

E/flutter (25502): (Did you accidentally do GetIt sl=GetIt.instance(); instead of GetIt sl=GetIt.instance;

E/flutter (25502): Did you forget to register it?)

but I clearly registered DataServiceManager in main.dart.

void main() {
WidgetsFlutterBinding.ensureInitialized();

void lazySingletonSetup() {
 myLocator.registerLazySingletonAsync<TodoDatasource>(
     () async => DataServiceManager()); // <<--------------- in question
}


lazySingletonSetup();

runApp(ChangeNotifierProvider(
 create: (context) => TodoList(),
 child: const TodoApp(),
));
} 

I also tried using GetIt.I but error still persists.

also to take note my other files just in case:

DataServiceManager

class DataServiceManager implements TodoDatasource {
  late final TodoDatasource _local;
  final TodoDatasource _remote = RemoteApiDatasource();

  DataServiceManager() {
    if (kIsWeb) {
      _local = LocalHiveDatasource();
    } else {
      _local = LocalSQLiteDatasource();
    }
  }
  // TODO: REMOVE ALL COMMENTED BLOCKS OF CODE

  // Future<bool> _checkConnectivity() async {
  //   // bool? result = html.window.navigator.onLine;
  //   // if ((kIsWeb && html.window.navigator.onLine == false) ||
  //   if (kIsWeb || await Connectivity().checkConnectivity() == ConnectivityResult.none) {
  //     return false;
  //   }
  //   return true;
  // }

  @override
  Future<bool> addTodo(Todo t) async {
    // return await _checkConnectivity()
    //     ? await _remote.addTodo(t)
    //     : await _local.addTodo(t);
    return _local.addTodo(t);
  }

  @override
  Future<bool> updateTodo(Todo t) async {
    // return await _checkConnectivity()
    //     ? await _remote.updateTodo(t)
    //     : await _local.updateTodo(t);
    return _local.updateTodo(t);
  }

  @override
  Future<bool> deleteTodo(Todo t) async {
    // return await _checkConnectivity()
    //     ? await _remote.deleteTodo(t)
    //     : await _local.deleteTodo(t);
    return _local.deleteTodo(t);
  }
  @override
  Future<List<Todo>> getAllTodo() async {
    // return await _checkConnectivity()
    //     ? await _remote.getAllTodo()
    //     : await _local.getAllTodo();
    return _local.getAllTodo();

  }

  @override
  Future<List<Map<String, Object?>>> getId(int i) {
    // return await _checkConnectivity()
    //     ? await _remote.getAllTodo()
    //     : await _local.getAllTodo();
    return _local.getId(i);
  }
}

TodoDatasource

import 'package:todo_list1/models/todo.dart';

abstract class TodoDatasource {
  Future<List<Todo>> getAllTodo();
  Future<bool> addTodo(Todo t);
  Future<bool> deleteTodo(Todo t);
  Future<List<Map<String, Object?>>> getId(int i);
  // Future<Todo> getTodo(int i);
  Future<bool> updateTodo(Todo t);
}

any help will be appreciated thank you.

CodePudding user response：

I have found the culprit. definitely the

myLocator.registerLazySingletonAsync<TodoDatasource>(() async => DataServiceManager());

is working but one of my provider class (TodoList) is looking for the registered GetIt, which is not registered. here's the sample codeblock:

class TodoList extends ChangeNotifier {
  // This is our data model. which holds our data which is a list of To_do’s
  List<Todo> _todos = [];

  // This is an immutable returned list for presenting in the UI
  UnmodifiableListView<Todo> get todos => UnmodifiableListView(_todos);

  // constructor for the refresh method
  TodoList() {
    refresh();
  }

  // a total or court property getter
  int get todoCount {
    return _todos.length;
  }

  // GetIt method refresh
  Future<void> refresh() async {
    _todos = await GetIt.I<DataServiceManager>().getAllTodo();
    notifyListeners();

silly me.

CodePudding user response：

If you are not passing an async factory function to registerLazySingletonAsync use registerLazySingleton instead.

void lazySingletonSetup() {
  myLocator.registerLazySingleton<TodoDatasource>(() => DataServiceManager());
}