The state of MVI on Android - MVIKotlin - PostListStoreFactory

MVIKotlin-PostListStoreFactory.kt

internal class PostListStoreFactory(
    private val storeFactory: StoreFactory,
    private val postRepository: PostRepository,
    val stateKeeper: StateKeeper<PostListState>
) {

    fun create() = object : Store<PostListIntent, PostListState, NavigationEvent> by storeFactory.create(
        name = "PostListStore",
        initialState = stateKeeper.consume() ?: PostListState(),
        bootstrapper = SimpleBootstrapper(Unit),
        executorFactory = ::createExecutorFactory,
        reducer = ReducerImpl
    ) {}

    private fun createExecutorFactory() = ExecutorImpl(postRepository)

    private class ExecutorImpl(
        private val postRepository: PostRepository
    ) : SuspendExecutor<PostListIntent, Unit, PostListState, List<PostOverview>, NavigationEvent>() {

        // Only one Action triggered on create so using Unit
        override suspend fun executeAction(action: Unit, getState: () -> PostListState) = loadOverviews()

        // Split the intent object back out again
        override suspend fun executeIntent(intent: PostListIntent, getState: () -> PostListState) = when (intent) {
            is PostListIntent.PostClicked -> postClicked(intent.post)
        }

        private fun postClicked(post: PostOverview) {
            // Triggering a side effect
            publish(OpenPostNavigationEvent(post))
        }

        // Load the overviews
        private suspend fun loadOverviews() {
            val overviews = withContext(Dispatchers.Default) {
                postRepository.getOverviews()
            }
            // Dispatch the Result
            dispatch(overviews)
        }
    }

    private object ReducerImpl : Reducer<PostListState, List<PostOverview>> {
        // Combine State and Result
        override fun PostListState.reduce(result: List<PostOverview>): PostListState = copy(overviews = result)
    }
}