Dagger can not inject ViewModel with KClass - mvvm

Question

I am moving my project java to kotlin, but got some confusion about KClass and Class
Here is my BaseActivity
abstract class BaseActivity<DB : ViewDataBinding, VM : BaseViewModel> : DaggerAppCompatActivity() {
private lateinit var mCustomDialog: CustomDialog
private lateinit var mViewDataBinding: DB
private lateinit var mViewModel : VM
#Inject
lateinit var viewModelFactory: ViewModelFactory
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
// Set Custom Dialog
mCustomDialog = CustomDialog(this, R.style.LoadingDialogStyle)
// Set ViewModel
mViewModel = ViewModelProviders.of(this, viewModelFactory).get(getViewModelClass().java)
// Set DataBinding
mViewDataBinding = DataBindingUtil.setContentView(this, getLayoutId())
mViewDataBinding.lifecycleOwner = this
mViewDataBinding.setVariable(getBindingVariable(), mViewModel)
mViewDataBinding.executePendingBindings()
// Initialize UI
prepareView(savedInstanceState)
}
#LayoutRes
abstract fun getLayoutId(): Int
protected abstract fun getViewModelClass(): KClass<VM>
abstract fun getBindingVariable(): Int
fun getViewModel(): VM {
return mViewModel
}
fun getViewDataBinding() : DB {
return mViewDataBinding
}
I am using protected abstract fun getViewModelClass(): KClass<VM> function for initializing ViewModel class in the function below
ViewModelProviders.of(this, viewModelFactory).get(getViewModelClass().java)
I use ViewModel in activities by this way
class SplashActivity : BaseActivity<ActivitySplashBinding, SplashViewModel>() {
override fun getViewModelClass(): KClass<SplashViewModel> {
return SplashViewModel::class
}
override fun getLayoutId(): Int {
return R.layout.activity_splash
}
override fun getBindingVariable(): Int {
return BR.vm
}
override fun prepareView(savedInstanceState: Bundle?) {
getViewModel().testLog()
}
}
But when I run the project, I got this error
error: [Dagger/MissingBinding] java.util.Map<java.lang.Class<? extends androidx.lifecycle.ViewModel>,javax.inject.Provider<androidx.lifecycle.ViewModel>> cannot be provided without an #Provides-annotated method.
public abstract interface AppComponent extends dagger.android.AndroidInjector<com.example.example.MyApp> {
^
java.util.Map<java.lang.Class<? extends androidx.lifecycle.ViewModel>,javax.inject.Provider<androidx.lifecycle.ViewModel>> is injected at
com.example.example.utils.ViewModelFactory(viewModels)
com.example.example.utils.ViewModelFactory is injected at
com.example.example.base.BaseActivity.viewModelFactory
com.example.example.ui.splash.SplashActivity is injected at
dagger.android.AndroidInjector.inject(T) [com.example.example.di.AppComponent ? com.example.example.di.ActivityBindingsModule_SplashActivityInjector$app_debug.SplashActivitySubcomponent]
So I made some research and find out it is about KClass in my ViewModelKey
Here is ViewModelKey
#Target(AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY_GETTER, AnnotationTarget.PROPERTY_SETTER)
#Retention(AnnotationRetention.RUNTIME)
#MapKey
annotation class ViewModelKey(val value: KClass<out ViewModel>)
If I do not change my code to Kotlin and use old Java class like this it works properly
#Target(ElementType.METHOD)
#Retention(RetentionPolicy.RUNTIME)
#MapKey
public #interface ViewModelKey {
Class<? extends ViewModel> value();
}
This is my ViewModelFactory class
#Suppress("UNCHECKED_CAST")
class ViewModelFactory #Inject
constructor(private val viewModels: MutableMap<Class<out ViewModel>, #JvmSuppressWildcards Provider<ViewModel>>) : ViewModelProvider.Factory {
override fun <T : ViewModel> create(modelClass: Class<T>): T {
val creator = viewModels[modelClass]
?: viewModels.asIterable().firstOrNull { modelClass.isAssignableFrom(it.key) }?.value
?: throw IllegalArgumentException("unknown model class $modelClass")
return try {
creator.get() as T
} catch (e: Exception) {
throw RuntimeException(e)
}
}
}
My SplashActivityModule
#Module
abstract class SplashActivityModule {
#Binds
#IntoMap
#ViewModelKey(SplashViewModel::class)
internal abstract fun provideSplashViewModel(splashViewModel: SplashViewModel) : ViewModel
}
So how can I use ViewModelKey properly with Kotlin and what is main cause of this error, any help will be appreciated

Answer 1

Your ViewModelKey be like
#MustBeDocumented
#kotlin.annotation.Target(AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY_GETTER, AnnotationTarget.PROPERTY_SETTER)
#kotlin.annotation.Retention(AnnotationRetention.RUNTIME)
#MapKey
internal annotation class ViewModelKey(val value: KClass<out ViewModel>)

Answer 2

As mentioned this question problem is related to Kotlin version. Using higher than 1.3.30 version solves the problem.