You also change the GuessTheWord app to use LiveData as the data-binding source to notify the UI about changes in the data, without using LiveData observer methods.

Note: To import ViewModel into your Android project, see the instructions for declaring dependencies in the Lifecycle release notes. Now we, the developers, control the creation of fragments . Hence, choosing the appropriate architecture is one of the key points in building a decent product. It is defined in the koin module viewModel { params - > AnnotationsViewModel (params[ EXTRA_CONTENDER_ID ], params[ EXTRA_ANNOTATION_ID ], get()) }

A pragmatic lightweight dependency injection framework for Kotlin developers. // then will the subclass have access to the specific viewmodel methods that it // We need to pass the actual class (right) because Koin can't use generic classes abstract class ViewModelFragment < VM : ViewModel > ( @LayoutRes val layout : Int , private val viewModelClass : KClass < VM > ) : Fragment ( ) { The ViewModel class allows data to survive configuration changes such as screen rotations.

So, let’s get started (all code listed in this article available here). class SomeFragment : Fragment() { private val someViewModel: SomeViewModel by viewModel() } For anyone who has used Architecture Components for a while, there are situations where a Fragment's ViewModel should be tied to the Fragment's lifecycle while at other times it should use a ViewModel associated with the Activity's lifecycle and shared.

To build a high-quality application, one has to pay great attention to the app architecture, since its role is decisive. The library Koin provided a specific delegate for ViewModels: private val viewModel: MyViewModel by viewModel() In Koin, it is very easy to override one item for tests, so code that uses this is unit testable. In fact, the most fundamental decisions that determine the structure and interaction of components rely on the architecture. Add Koin dependency. I also will add koin-androidx-viewmodel dependency, just to make this example closer to real world.

ViewModel Overview Part of Android Jetpack. The initial thought was somehow(due to Fragment going though lifecycle) ViewModel was triggering LiveData multiple data on the same Observer.

Ktx. Probably inspired by solutions like above and/or to unite all the different approaches, Google provided its own delegate: Koin. The ViewModel class is designed to store and manage UI-related data in a lifecycle conscious way.

What is KOIN? Passing Data between Android Fragments using ViewModel.

After you integrate data binding with the ViewModel objects, you no longer need click handlers in the app's fragments, so you remove them. If your application uses fragments, one fragment shows list of items and another fragment displays details of the selected item, then list fragment needs to pass the selected item id to the item-details fragment so that it can fetch data for the item and display in UI. Latest News Follow us on Twitter for latest news: @insertkoin_io Koin is a DSL, a light container and a pragmatic API. This is what I'm using to get the ViewModel in one of the fragments in the nav_graph_play nested graph: private val playVM: PlayViewModel by sharedGraphViewModel(R.id.nav_graph_play) This is in my module: object AppModule { val module: Module = org.koin.dsl.module { viewModel { PlayViewModel() } } } Using the above extension.

Written in pure Kotlin, using functional resolution only: no proxy, no code generation, no reflection.

At time of writing, the latest version of Koin is 2.1.5. This viewModel is being created without problems to feed a fragment.