Hello folks, I am seeing a weird behaviour by Koin-Android Viewmodel. I have a main Activity with bottom navigation. The bottom navigation tabs

replaces

Fragments. I have created global instances of fragments in the activity (in order not to re-instantiate the fragments again on tab change). Now once a fragment is loaded and replaced (on tab change),its complete lifecycle is called (from

onAttach()

to

onDestroy()

and

onDetach()

). So I expected the viewmodel of the fragment to also get destroyed and

onCleared()

called once the

onDestroy()

of the fragment is called. Also new viewmodel should be instantiated when fragments is created again. But it is not happening as expected. The viewmodel is only created once and

onCleared()

is only called the first time

onDestroy()

of the fragment is called. I tested it using the following code :

class HomeViewModel : ViewModel() {

    init {
        Log.d("Fragment_Checker","Viewmodel_INIT")
    }

    private var counter = 1


    fun getCounter():Int{
        counter++
        return counter
    }

    override fun onCleared() {
        Log.d("Fragment_Checker","ViewModel_Destroyed")
        super.onCleared()
    }
}

/*Fragment class */

class HomeFragment : androidx.fragment.app.Fragment() {

    val viewModel: HomeViewModel by viewModel()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        Log.d("Fragment_Checker","onCreate")
 
    }
    override fun onResume() {
        super.onResume()
        Log.d("Fragment_Checker","Counter "+viewModel.getCounter())
    }

    override fun onDetach() {
        super.onDetach()
        Log.d("Fragment_Checker","onDetach")
    }
    override fun onDestroy() {
        super.onDestroy()
        Log.d("Fragment_Checker","onDestroy")
    }

The log output looks like : onCreate Viewmodel_INIT Counter 2 //tab changed ViewModel_Destroyed onDestroy onDetach //move back to home tab onCreate Counter 3 //tab changed onDestroy onDetach

Do I need the

koin-ktor

package? What does it add over

koin-core

?

Hi @arnaud.giuliani, do you know wether

ViewModel

can have another ViewModel as constructor dependency ? Something like this

viewModel { BasketViewModel(get()) }
viewModel { SelectProductViewModell(get(),  basketViewModel) }

How can I make koin compatible with instant reloading on Android? I have the module definition in the

onCreated

of my Activity right now, and it errors due to re-declaration of singles

Hello ! how to use same dependency "single" for a few modules?

I’ve created a small example using #koin and #vertx, let me know what you think https://github.com/vert-x3/vertx-examples/pull/326

Hi guys! Using the following module declaration val module = module{ viewModel { MyModule(get()) } // MyModule extends ViewModule } The MyModule object gets created every time it is injected even when I rotate the device. It also doesn’t follow the activity lifecycle, did I do any mistake during the configuration?

I have a problem using koin, mockito and android studio: I am doing something very similar to this example: https://github.com/InsertKoinIO/getting-started-koin-core/blob/master/src/test/kotlin/org/koin/sample/HelloMockTest.kt but the declareMock() function is unresolved (even when using the full qualified name) and the "by inject" keep asking for a clazz parameter. I m using org.koin:koin-test:1.0.2 and org.koin:koin-android:1.0.1 and org.koin:koin-java:1.0.0-RC-1 (for legacy Java code)

new website updates 👉 https://beta.insert-koin.io/

@arnaud.giuliani hi! how safe is it using beta version on production?

How is Koin handling viewmodels? when does the viewmodel initialized and destroyed?

Hi all is it possible to register shutdown hooks on beans created by koin? During my application shutdown I'd like to some of my beans to have a method invoke to clean up resources

Hi ! Having troubles with koin on generic declaration, for example :

single<BaseCmsMapper<OnClickHodor?, OnClick>>(name = "onClickMapper") {
        OnClickMapper(errorDispatcher = get(), templateMapper = get("templateMapper"))
    }

onClickMapper dependency is used just below like :

single<BaseCmsMapper<SeasonHodor, Season>>(name = "seasonMapper") {
        SeasonMapper(errorDispatcher = get(), onClickMapper = get("onClickMapper"))
    }

returned error is :

2019-02-06 12:26:02.392 18700-18700/? E/KOIN: [ERROR] - Error while resolving instance for class 'com.canal.android.mycanalpoc.cms.common.BaseCmsMapper' - error: org.koin.error.NoBeanDefFoundException: No compatible definition found. Check your module definition 
2019-02-06 12:26:02.395 18700-18700/? E/KOIN: [ERROR] - Error while resolving instance for class 'com.canal.android.mycanalpoc.cms.common.BaseCmsMapper' - error: org.koin.error.BeanInstanceCreationException: Can't create definition for 'Single [name='onClickMapper',class='com.canal.android.mycanalpoc.cms.common.BaseCmsMapper']' due to error :No compatible definition found. Check your module definition

Any idea?

yeah, generic types are not handled. Prefer go with some holder type instead

certainly caught me out before, do you think registration of generics could be made illegal?

Hi guys. I have a question regarding reloading of modules. In my app I have a base module where the application class is located which starts koin. Than I have a couple of (feature) modules depending on the base module but do not know anything about each other. Now I have a library with where the users login is handled (in a singleton class). I need the same instance in both feature modules but when I try to load the same module twice, koin is telling me, that the definitions already exists and the app crashes. So the question is, how can I (re)load this "account" module without crashing the app? (To declare the modules in the base module is no option for me)

but Android Studio (3.4 or 3.5) can't find the class or package

did you checked: https://beta.insert-koin.io/docs/2.0/quick-references/koin-for-android/#extended-scope-api-for-android-koin-android-scope-or-koin-androidx-scope-projects

👋 hello, i'm migrating my application from dagger to koin and I am thinking is there a similar solution to dagger Provider<T>? Basically injecting a factory which can create T objects with it's dependencies provided by koin.

Good morning@arnaud.giuliani, Some weeks ago I updated Koin to the beta version and it's incredible. It's really fast creating instances, congrats!!

Hi, I am testing my modules like this

class ModulesTest : KoinTest {

    @Test
    fun checkAllModules() {
        koinApplication { modules(listOf(coreModule, appModule, roomModule, moshiModule)) }.checkModules()
    }
}

but I am getting the following error:

org.koin.core.error.NoBeanDefFoundException: No definition found for 'android.content.Context' has been found

I know it is because my room module is using

androidApplication()

but I don't know how to fix it. Any ideas please??

also, we are having some discussions on the office whether we should use Koin or Dagger2 for a new project. We have started with Koin and I would like to stick to it, but some of my workmates think it won't escalate well on big projects. Has somebody tried Koin on big projects? Could somebody provide some insights on this escalation problems? thanks!

@arnaud.giuliani, can you help me with this issue?

very simple sample

in the Koin declaration, it's initialized like this: single { MutableLiveData<LoginState>() }

FYI, When doing Koin JUnit tests, I found that I had to call stopKoin() before startKoin(). startKoin is called from the @Setup of the unit tests. Otherwise, it'd complain that the koin application is already started when startKoin() is called. Don't see this mentioned in the docs anywhere...

Hello, how can i do this example with koin? https://github.com/googlesamples/android-architecture/blob/todo-mvp-clean/todoapp/app/src/main/java/com/example/android/architecture/blueprints/todoapp/taskdetail/TaskDetailActivity.java How can i inject the string extra

EXTRA_TASK_ID

with koin?

problem is that ON_DESTROY is not send when opening next Activity

@arnaud.giuliani I'm trying to build master, to make a PR actually and there seems to be a build error on koin-ktor