[🚀] Add Koin Integration

[Nek-12]

Description (required)

• Koin scopes tied to the store's lifecycle
• Automatically closing scopes
• Koin Containers
• Koin Scopes for stores (take from the sample app?)
• StoreViewModel injection from the sample app - can also make it multiplatform?

[y9vad9]

it would be perfect, sometimes I don't want to provide anything explicitly, but still use it, for example, in the plugin with dependency that provided somewhere at the top.

In brief, my case is the following:
I want to handle authorization exception and navigate users to login page, when UnauthorizedException is happened. I use Koin for the DI and it would perfectly match my need. I can handle exceptions within plugin system and another integration with Koin will help a lot.

[Nek-12]

Thanks for the feedback, unfortunately koin did not make it to 3.0, but yeah, I'm thinking of exactly the same use-case. It's going to be worked on next after I add some more docs.

But your use-case is already possible with existing tools.

You could grab the setup from docs or the sample app and create a plugin:

fun <S: MVIState, I: MVIIntent, A: MVIAction> authOnErrorPlugin(
    onSignInNeeded: suspend () -> Unit
) = plugin<S, I, A> {
    onException { e -> 
       if (e !is UnauthorizedException) return@onException e
       onSignInNeeded()
       null
    }
}

In onSignInNeeded, you can send an event to a container that will handle navigation events, something like AppEventContainer, call your navigator callback, or just request another user (it depends on your stack). I personally like the approach with a separate container for events like this.

An even better approach would be to observe the current user object in whileSubscribed and redirect if the user is null for example.

[y9vad9]

Your way seems reasonable, but I just don't like singletons (and at the same time, I don't want to provide to every screen component this handler). For now I think about some way around Decompose to provide such handler from the top (but a bit busy with university at the moment).