Hello. I'm using Rick's `KMMViewModel` library and...

# multiplatform

[AndreiBogdan]

Hello. I'm using Rick's KMMViewModel library and I've defined a view model in KMM but I'd like to subclass that viewModel on Android's side and add some more stuff to it. Problem is that I have no idea how to properly instantiate the view model.

NativeViewModel -> CustomKMMViewModel -> Rick'sKMMViewModel

Android Native -> KMM -> KMM

Using val mViewModel: NativeViewModel by viewModels() does not work ... ideas on how this can be done ?!

It shows a:
Type mismatch.
Required: NativeViewModel
Found: ViewModel

[William Walker]

Should be able to. Try explicitly denoting the class name:
val viewModel by lazy { ViewModelProvider(this).get(NativeViewModel::class.java) as NativeViewModel }

[hfhbd]

@William Walker can you please do not send you answers to the channel too?

[AndreiBogdan]

image.png

[AndreiBogdan]

So it doesn't see the SubscribeViewModel as a ViewModel ?!?! it's extending a SubscribeViewModel class in KMM which in return extends KMMViewModel ...

[AndreiBogdan]

Android:

class SubscribeViewModel : SubscribeViewModel() {

KMM

open class SubscribeViewModel :
    BaseViewModel<SubscribeViewModel.UiState, SubscribeViewModel.RedirectType>(

also KMM

open class BaseViewModel<U : Any, R> internal constructor(
    uiStateDefault: U,
    private val redirectTypeDefault: R
) : KMMViewModel() {

[William Walker]

It is trying to infer the mViewModel as a regular androidx viewmodel. You need to explicitly denote it as SubscribeViewModel

[William Walker]

You might also need to drop the lazy part- that delegate may only work for regular androidx viewmodels

[AndreiBogdan]

Yeah ... no clue how to do that. I tried a couple of things with not luck. Any ideas?

[William Walker]

val mViewmodel: SubscribeViewmodel = …

[William Walker]

does that work?

[William Walker]

Is rick’s viewmodel exposed as an api dependency by your kotlin multiplatform project?

[William Walker]

If it’s implementation only, it won’t be able to be consumed by your android viewmodel

[AndreiBogdan]

@Rick Clephas ? am I doing something wrong by any chance ?! I'm literally out of ideas.

[William Walker]

Did you expose Rick’s kmm vm as an api dependency?

[AndreiBogdan]

api("com.rickclephas.kmm:kmm-viewmodel-core:1.0.0-ALPHA-19")

i got this in commonMain

[William Walker]

@AndreiBogdan try updating your androidx viewmodel dependency it was just updated for KMP support and now takes Kclasses as parameters for viewmodel instantiation: https://developer.android.com/jetpack/androidx/releases/lifecycle

[Rick Clephas]

This seems to be a linting issue. Using a small “helper” function removes the error:

inline fun <reified VM : KMMViewModel> Fragment.viewModels(
    noinline ownerProducer: () -> ViewModelStoreOwner = { this },
    noinline extrasProducer: (() -> CreationExtras)? = null,
    noinline factoryProducer: (() -> ViewModelProvider.Factory)? = null
): Lazy<VM> = viewModels(ownerProducer, extrasProducer, factoryProducer)

[AndreiBogdan]

image.png

[AndreiBogdan]

hmm ... 🤔 ideas ?

[Rick Clephas]

What exactly is the full error message?

[AndreiBogdan]

image.png

[AndreiBogdan]

aaah

[AndreiBogdan]

wait

[AndreiBogdan]

:))

[AndreiBogdan]

i just noticed, yeah

[AndreiBogdan]

Inline function 'public inline fun <reified VM : KMMViewModel> Fragment.viewModels(noinline ownerProducer: () -> ViewModelStoreOwner = ..., noinline extrasProducer: (() -> CreationExtras)? = ..., noinline factoryProducer: (() -> ViewModelProvider.Factory)? = ...): Lazy<VM> defined in com.pickatale.bookshelf.onboarding in file SubscribeFragment.kt' cannot be recursive

[AndreiBogdan]

ah, well that explains it then :))

[AndreiBogdan]

i've renamed the extension

[AndreiBogdan]

image.png

[Rick Clephas]

Ah the viewModel function should be the one from AndroidX

[AndreiBogdan]

image.png

[Rick Clephas]

Hmm maybe the signature has changed. The idea is to define the exact same inline function but restrict the generic to the KMMViewModel class

[AndreiBogdan]

maybe i've got an older version of androidX ... ?

[Rick Clephas]

Yeah could be. You can update it with the correct parameters

[AndreiBogdan]

Done! I finally got what you intended on doing. 😄 Looking good, no more compile errors. Thank you !