Hi, I'm trying to use Compose alongside ViewModels...

# kodein

[kluck]

Hi, I'm trying to use Compose alongside ViewModels, but I'm pretty new to both. I'm using version 7.7.0 of kodein, and have a basic App :

class App : Application(), DIAware {
    val homeModule: (app: App) -> DI.Module = { app ->

        DI.Module("homeModule") {
            bindProvider { HomeViewModel(app) }
        }
    }

    override val di: DI by DI.lazy {
        import(homeModule(this@App))
    }
[...]
}

ViewModel:

class HomeViewModel(app: App) : AndroidViewModel(app), DIAware {

    override val di by closestDI()
    private val initializingUseCase: InitializingUseCase by instance()

    private val _status: MutableStateFlow<String> = MutableStateFlow("")
    val status: StateFlow<String> = _status.asStateFlow()

[...]
}

Home Composable:

@Composable
fun Home() {
    val di = androidContextDI()
    val viewModel by di.instance() // -> This doesn't work
    val status by getLifecycleAwareState(flow = viewModel.status, initialValue = "")
    StatelessHome(status = status)
}

I can't find the correct way to instanciate my viewModel. The extensions from kodein-di-framework-android-x-viewmodel I found are based on AppCompatActivity

[romainbsl]

Hi. using DI module for android-x could help

[romainbsl]

with the following dependencies

implementation 'org.kodein.di:kodein-di-framework-compose:7.7.0'
    implementation 'org.kodein.di:kodein-di-framework-android-x:7.7.0'
    implementation 'org.kodein.di:kodein-di-framework-android-x-viewmodel:7.7.0'

[romainbsl]

here is a working example
https://gist.github.com/romainbsl/a95712f3ad9bd7747ac6cc2ee85981d4

[kluck]

Thanks a lot, I'll check it out

[kluck]

@romainbsl I've played around with your gist, but can't get it to work the way I want: I keep getting a brand new instance of homeViewModel whenever there's a Compose refresh. Here's my modified gist: https://gist.github.com/lucmazon/90644bce6b7215092356285c5dbcdf90
Any idea why that happens?

[romainbsl]

because we use a bindProvider {} that is invoked each time we call rememberInstance

[romainbsl]

1. Using a bindSingleton might work

[romainbsl]

2. We miss a rememberViewModel based on the viewModel delegate from kodein-di-framework-android-x-viewmodel

[romainbsl]

it handles its own storage of the viewmodel based on the lifecycle owner

[kluck]

Yes, that was what I was looking for

[romainbsl]

Going with the 1. just work ATM, until a better integration with Compose

[kluck]

Alright, will do, thanks for your help

[kluck]

Should I report this somewhere?

[romainbsl]

you can create an issue on Github as a reminder, not sure I'll be able to do it right now

[romainbsl]

thanks 🙏

[romainbsl]

I add a rememberViewModel @Composable function

[romainbsl]

you can try it as a SNAPSHOT
maven { url = "<https://oss.sonatype.org/content/repositories/snapshots>" }

[romainbsl]

org.kodein.di:kodein-di-framework-compose:7.9.0-master-SNAPSHOT

[kluck]

It does work perfectly! I'm curious about what you did, but can't see any commit in here: https://github.com/Kodein-Framework/Kodein-DI-Compose . Is it on another repository?

[romainbsl]

Oups this project is not what you think. its a playground

[romainbsl]

here https://github.com/Kodein-Framework/Kodein-DI/commit/2932c4359fcbd7a0ded88d6e9a478fbb2381ea78

[kluck]

aaah, that explains it ^^. So my issue is in the wrong place…

[romainbsl]

That is why I never saw it 😅