[Feature Request] Distinguish factories and singletons

[crtl]

Currently there is no way to distinguish factories from singletons.

Use Case: I am using getIt to manage services / blocs that are available globally, most of them are singletons but some require factories. When a widget/component creates a bloc it is responsible for disposing it. Due to the nature of GetIt there is currently no way to distinguish if the retrieved object was created using a factory or singleton which in turn directly ties the container to the code because you have to know what instances are instantiated in what way.

// container.dart

getIt.registerLazySingleton<Test>(() => Test());

getIt.registerFactory<Test2>(() => Test2());


// my_widget.dart

/* ... */

initState() {
  super.initState();

  final test = getIt<Test>();

  // How to know that Test2 was created using a factory to dispose resource when widget disposes?
  final test2 = getIt<Test2>();
}

dispose() {
  test2.dispose();
  super.dispose();
}

Solution

Solution would be to add a method like T Function() GetIt.getFactory<T>() or T GetIt.fromFactory<T>(). This would only be syntactic sugar because of BC we cannot change T GetIt.get<T>() so the method would just show the consumer what happens behind the curtain.

/// Returns an instance [T] 
T fromFactory<T>({String? instanceName}) => get<T>(instanceName: instanceName);

/// Returns factory function for [T]
T Function() getFactory<T>({String? instanceName}) => () => get<T>(instanceName: instanceName);

// Usage

final test2 = getIt.fromFactory<Test2>(); // Now we now test2 is created using a factory and we are responsible for disposing it

[escamoteur]

Not sure if is a responsebility of get_it. In you case I would add a field bool disposeManually that is set to true by the factory and that you can check in the dispose function. @esDotDev what do you think?

[esDotDev]

Ya even a simple mixin Factory {} works?

if(test2 is Factory){
  test2.dispose();
}