Parameters in by inject() are not lazy

After playing around a little bit with the new parameters i came accross another issue.

class MyFragment : Fragment() {
   val presenter: MyPresenter by inject(parameters = mapOf("activity" to activity!!)
   // or since support lib 27.1.0 we can call
   val presenter: MyPresenter by inject(parameters = mapOf("activity" to requiredActivity())
}

if you instantiate this fragment the presenter gets created instantly and not on his first call. this leads to the following exception

Caused by: java.lang.IllegalStateException: Fragment MyFragment{3833b34} not attached to an activity.

currently a workaround is to inject the presenter like this

class MyFragment : Fragment() {
   val presenter: MyPresenter by lazy { (StandAloneContext.koinContext as KoinContext).get<MyPresenter>("",  mapOf("activity" to activity!!)) }
}

this works and the presenter gets only created after the first call

i think it would be great if by inject() has the same functionality as by lazy or if you will not change this direct instantiation you could provide another by injectLazy() function or so…

I am looking forward for your feedback

[arnaudgiuliani]

Ok. Fixed.

I migrate all params to be functional. Koin has now a very nice syntax to supply dynamic params (lambda directly opened for parameters):

val presenter: MyPresenter by inject { mapOf("key" to myKey) }

Just migrate my MVP sample: https://github.com/Ekito/koin-samples/blob/0.9.1/samples/android-weatherapp/app/src/main/kotlin/org/koin/sampleapp/view/search/SearchActivity.kt#L23

You can play with Koin 0.9.1-alpha-5 👍

[fredy-mederos]

The same with viewModel()… I try with @Bodo1981 solution and it works

inline fun <reified T : ViewModel> LifecycleOwner.viewModel(
    fromActivity: Boolean = true,
    key: String? = null,
    name: String? = null,
    noinline paramsFunc: () -> ParameterMap = { emptyMap() }
): Lazy<T> {
    return viewModelByClass(fromActivity, T::class, key, name, paramsFunc)
}

fun <T : ViewModel> LifecycleOwner.viewModelByClass(fromActivity: Boolean = true, clazz: KClass<T>, key: String? = null, name: String? = null, paramsFunc: () -> ParameterMap = { emptyMap() }): Lazy<T> {
    return lazy { getViewModelByClass(fromActivity, clazz, key, name, paramsFunc()) }
}