hey guys does anybody use moko viewModel with koin...

# moko

[deviant]

hey guys
does anybody use moko viewModel with koin di? how you declare your viewModels modules in common code? koin viewModel helper factory available only for android projects. so we use the factory extension temporarily. but it recreates viewModel each time.

[wbertan]

We have created our own:
In common we have a BaseViewModel

expect abstract class BaseViewModel()

And we create an actual for Android and another for iOS:
Android:

actual abstract class BaseViewModel : ViewModel()

Which the Android extends androidx.lifecycle.ViewModel, which will work nicely with the Lifecycles.
And the iOS just the simple one:

actual abstract class BaseViewModel

[deviant]

but moko mvvm already provides the common vm (which uses android vm for android). the problem is with providing via koin di. probably i should asj this question in the #koin 🙂

[wbertan]

We are also using Koin, so for Android we have the viewModel method, but for iOS we had to make it a factory .

[deviant]

i get it. so you use platform specific modules. interesting. probably we gonna do the same

[wbertan]

So for Koin, we have our own method too
In common:

expect inline fun <reified T : BaseViewModel<*, *>> Module.viewModelDefinition(
    qualifier: Qualifier? = null,
    noinline definition: Definition<T>
): Pair<Module, InstanceFactory<T>>

While then for Android the implementation will call the Koin `viewModel`:

actual inline fun <reified T : BaseViewModel<*, *>> Module.viewModelDefinition(
    qualifier: Qualifier?,
    noinline definition: Definition<T>,
): Pair<Module, InstanceFactory<T>> = viewModel(qualifier = qualifier, definition = definition)

And for iOS will use a `factory`:

actual inline fun <reified T : BaseViewModel<*, *>> Module.viewModelDefinition(
    qualifier: Qualifier?,
    noinline definition: Definition<T>,
): Pair<Module, InstanceFactory<T>> = factory(qualifier = qualifier, definition = definition)

[deviant]

thanks!

[Vladimir Vasic]

Hello @wbertan, I'm having trouble implementing these extensions in my KMM project, I'm getting error message when trying to implement actual viewModelDefinition for android.
Error message: Module.viewModel(Qualifier? = ...) where T = TypeVariable(T) for inline fun <reified T : ViewModel> Module.viewModel(qualifier: Qualifier? = ...): Pair<Module, InstanceFactory<T>> defined in org.koin.androidx.viewmodel.dsl
Module.viewModel(Qualifier? = ..., Definition<TypeVariable(T)>

My implementation:

actual inline fun <reified T : BaseViewModel> Module.viewModelDefinition(
    qualifier: Qualifier?,
    noinline definition: Definition<T>,
): Pair<Module, InstanceFactory<T>> = viewModel(qualifier = qualifier, definition = definition)

Also when I want to use this inside a fragment, how am I calling it?

[Vladimir Vasic]

Thank you 🙂

[wbertan]

🤔 how it is your BaseViewModel ? Do you have any generics there as well?
In the fragment we just do

private val viewModel: MyViewModel by viewModel()

That viewModel is from Koin:

import org.koin.androidx.viewmodel.ext.android.viewModel

[Vladimir Vasic]

This is my BaseViewModel

open class BaseViewModel : ViewModel() {

    open fun onViewCreated() {}

    open fun onViewResumed() {}

    open fun onViewPaused() {}

    open fun onViewStopped() {}
}

I use no generics.
Soo I still use the same implementation with koin in module right?

val loginModule = module {
    viewModel {
        LoginViewModel(get())
    }
}

[wbertan]

Sorry, did the test and forgot to post here, for me this is compiling fine:

open class Asas : ViewModel() {

    open fun onViewCreated() {}

    open fun onViewResumed() {}

    open fun onViewPaused() {}

    open fun onViewStopped() {}
}

inline fun <reified T : Asas> Module.viewModelDefinition(
    qualifier: Qualifier?,
    noinline definition: Definition<T>
): Pair<Module, InstanceFactory<T>> = viewModel(qualifier = qualifier, definition = definition)

In the Koin Module, you should then not use the viewModel, but instead that viewModelDefinition

val loginModule = module {
    viewModelDefinition {
        MyViewModel()
    }
}

[wbertan]

By the way, I'm using latest Canary Electric Eel, Versions:

koin = "3.2.0"
    const val agp = "7.2.1"
    const val kotlin = "1.7.0"

[Vladimir Vasic]

I guess my IDE was messed up, sorry for late response but it is working like a charm 🙂. Thank you very much for your help 🙂