I would be also interested in sharing the same ViewModel ins

Question

I would be also interested in sharing the same ViewModel instance between a composable or multiple composables and host Fragment Activity My use case is that I have click callbacks in the composables which trigger events in the viewmodel Then host Fragment subscribes to this event to show snackbar or trigger navigation

Moritz Post · Answer

You could create a custom Scope and pass in a session object so that each view model gets the same instance

Lukasz Kalnik · Answer

But then every time I navigate away I would have to destroy the scope

Moritz Post · Answer

The scope can be given to each view model

Lukasz Kalnik · Answer

Yes but I want to have a new viewmodel once I navigate to the same screen with new data

Moritz Post · Answer

That would mean you create a new session

Moritz Post · Answer

eg if you have screens like A gt B gt C you would create a new shard session object when starting A and pass that shared object to B and C

Lukasz Kalnik · Answer

So then I would need to create destroy the session as part of my navigation right

Moritz Post · Answer

Actually not as part of the navigation but automatically in your koin module declaration

Lukasz Kalnik · Answer

So I just have to do `getKoin createScope ` But when will the session be finished Will it be automatically finished when I leave the starting fragment

Moritz Post · Answer

In that case that would be up to the screen ViewModel that the session is tied to

Moritz Post · Answer

Example

Lukasz Kalnik · Answer

Ok that sounds like a good idea to try out

Moritz Post · Answer

you create a module with a Session ``` private val myModule = module scope lt Session gt scoped MySession ```

Moritz Post · Answer

and another which would create your ViewModels ``` private var mySessionScope Scope = null private val viewModelModule = module viewModel mySessionScope = getKoin createScope lt Session gt with requireNotNull mySessionScope ScreenAViewModel get get apply addCloseable close viewModel with requireNotNull mySessionScope ScreenBViewModel get viewModel with requireNotNull mySessionScope ScreenCViewModel get ```

Moritz Post · Answer

Here you can saee that ScreenA is used to close the mySessionScope scope

Moritz Post · Answer

the `get ` calls would be able to resolve the shared `MySession`

Lukasz Kalnik · Answer

Interesting I didn t see that `addCloseable` before

Moritz Post · Answer

That is from androidx lifecycle ViewModel

Moritz Post · Answer

it would than be able to close the session

Moritz Post · Answer

The solution is not 100 nice because the sessionScope is held in a separate var instead of getting from the koin object each time

Lukasz Kalnik · Answer

I see that s new in 2 5 0

Lukasz Kalnik · Answer

Thanks for your suggestions do you know any resource article which goes in more depth into scoped viewmodels in Koin I find that the documentation is missing some of the more specific use cases

Moritz Post · Answer

yeah i agree i pieced it together from the docs and various repos i think

Moritz Post · Answer

no immediate pointers

Lukasz Kalnik · Answer

Ok thanks so much for your help this is really cool

Moritz Post · Answer

you are welcome Good Luck