Hello fellow koiners :wave: This is regarding mult...

# koin

[Joaquim Ley]

Hello fellow koiners 👋
This is regarding multiplatform, as anyone managed to do constructor injection on the Swift/iOS part? So for my specific use case, I want to inject a executor/usecase into a Swift class. The issue is this executor has a dependency and so on and forth, on Android is quite simple as we just need to declare the modules and use by viewModel() or wtv it suits you, you could even inject() but on Swift seems like we don't have access to Koin's sugar.
--
Summarising:
View wants to create a ViewModel <- UseCase <- Repository <- RemoteApi
Note: '<-' Depends on

[Joaquim Ley]

For some context, this is somewhat what’s happening here:
• https://github.com/joreilly/PeopleInSpace/blob/master/common/src/commonMain/kotlin/com/surrus/common/repository/PeopleInSpaceRepository.kt#L30-L31
But I really wanted to do constructor injection

[streetsofboston]

We simplified the dependency injection. We don’t use the viewModel() function.

We have an expect ViewModel in the commonMain and the androidMain’s actual of this extends the the jetpack ViewModel, the iosMain just makes a simple actual out of it.

Then we have in the commonMain a bunch of ViewModelFactories that act as an assisted-inject. E.g. MyScreenViewModel has a MyScreenViewModelFactory and this factory is configured through Koin (in commonMain) with the necessary dependencies. These dependencies are then used to create a MyScreenViewModel (this is much like the Assisted-Inject of Dagger).

In Android app:

class MyActivity : BaseActivityAndKoinComponent() {
    val factory: MyScreenViewModelFactory = inject()
    val viewModel by lazy { factory.create() }
    ...
}

In iOS:

... 
let factory = MyScreenViewModelFactory.get()
....
let viewModel = factory.create()

To make this happen, iOS has the following extensions:

protocol KoinInjectable: AnyObject {
    static func get(parameter: Any, qualifier: Koin_coreQualifier?) -> Self
}

extension KoinInjectable {
    /// Creates and returns an instance of `Self`
    ///
    /// If `Self` has not been registered with Koin, this will fail with an uncaught Kotlin exception.
    static func get(parameter: Any = "", qualifier: Koin_coreQualifier? = nil) -> Self {
        KoinIOS().get(objCClass: Self.self, qualifier: qualifier, parameter: parameter) as! Self
    }
}
...
extension MyScreenViewModelFactory: KoinInjectable {}

and iosMain has the kotlin function get defined for object KoinOS.

[zalewski.se]

You could use actual/expect for defying koin modules. Then in Android you can provide it with viewModel and in iOS by using factory

[Joaquim Ley]

Thank you both for your time and clarification, you did give me the pointers I need, thanks 🙏