guys, I have some doubts about how longer lives a ...

# koin

[rg]

guys, I have some doubts about how longer lives a single instance and the result of a factory instances.
I already understand that single=bean=a lazy instance that can be reused anytime that it’s needed, and factory is a factory of these beans = singles.
My main doubt is, if I have a factory of usecases/interactors, how long will live usecase1, usecase2 etc? Is this always engaged with application scope? Or should I define a new scope to make my usecase lives until viewmodel.onCleared(e.g)?

[arnaud.giuliani]

a single is a singleton instance

[arnaud.giuliani]

a factory create an instance for you each time your request the definition

[arnaud.giuliani]

You can inject a factory definition into your `ViewModel`’s constructor as it will just request it the first time

[arnaud.giuliani]

I uses factory to declare my usecases classes

[arnaud.giuliani]

if you don’t inject the factory definition elsewhere, you will just have one instance created

[rg]

if I don’t inject my factory into my viewmodels, my usecases instances will be engaged with the application lifecycle right?

[rg]

and about a factory create an instance for you each time your request the definition, and how long lives each instance that was created each time to request the definition?

[rg]

thanks in advance @arnaud.giuliani

[arnaud.giuliani]

in Koin, everything is lazy - and then nothing is created until you ask for it

[arnaud.giuliani]

for a factory definition, Koin create it each time you request it. But Koin won’t hold it for you:

[arnaud.giuliani]

you factory instance will be hold by the component that requested it

[arnaud.giuliani]

class MyUseCase
class MyViewModel(val myUseCase : MyUseCase) : ViewModel()

module {
  factory { MyUseCase() }
  viewModel { MyViewModel(get())}
}

[arnaud.giuliani]

the MyViewModel instance will keep the MyUseCase instance until it is destroyed

[rg]

👍 ok thanks