Android Room Database IS updating, but is not sending updates upon returning to a Fragment

Question

FIXED

SEE BELOW

If a picture is worth 1,000 words, a video is worth, like, a lot of words. Here's a video explanation of the issue.

I've included a video as it makes things much clearer. The problem: When I first load up the fragment containing the list of items with state I need to toggle, I can toggle that state just fine. I send the update to the Room database and the changes are emitted back to my ViewModel, who then dispatches them to the Fragment.

However, when I leave the fragment and come back, the changes are no longer dispatched. I don't know if I'm doing something incredibly stupid or if this is a bug.

I'm also using the Jetpack Navigation components if that's relevant. I'll include code below.

Please let me know if you need to see any other code referenced below and I'll add it to the question.

Thank you very much for your time and consideration.

ShowsFragment

class ShowsFragment : Fragment(), ShowClickListener, Observer<Resource<List<ShowDomainModel>>> {  

    @Inject  
    lateinit var factory: ViewModelFactory  
    @Inject  
    lateinit var adapter: ShowsAdapter  

    private lateinit var showsViewModel: ShowsViewModel  

    override fun onAttach(context: Context) {  
        super.onAttach(context)  

        AndroidSupportInjection.inject(this)  
        showsViewModel = ViewModelProviders.of(this, factory).get(ShowsViewModel::class.java)  
    }  

    override fun onCreateView(  
        inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?  
    ) = inflater.inflate(R.layout.fragment_shows, container, false)!!  

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {  
        super.onViewCreated(view, savedInstanceState)  

        adapter.clickListener = this  
        shows.adapter = adapter  
        val shows = showsViewModel.getShows()  
        shows.observe(this, this)  
    }  

    override fun onChanged(resource: Resource<List<ShowDomainModel>>) {  
        Timber.d("onChanged")  
        when (resource.state) {  
            State.SUCCESS -> {  
                adapter.shows = resource.data!!  
                adapter.notifyDataSetChanged()  
            }  
            State.LOADING -> Unit  
            State.ERROR -> TODO("Handle error state in ShowsFragment")  
        }  
    }  

    override fun onShowFavoriteClicked(show: ShowDomainModel) {  

        if (show.favorite) {  
            showsViewModel.unfavoriteShow(show.playlistId)  
        } else {  
            showsViewModel.favoriteShow(show.playlistId)  
        }  
    }  

    override fun onShowClicked(show: ShowDomainModel) {  
        findNavController().navigate(  
            ShowsFragmentDirections.showEpisodes(show.name, show.playlistId)  
        )  
    }  
}

ShowsDao

@Dao  
abstract class ShowsDao {  

    @Query("SELECT * FROM $TABLE_NAME")  
    abstract fun getShows(): Observable<List<ShowCacheModel>>  

    @Insert(onConflict = OnConflictStrategy.IGNORE)  
    abstract fun insertShows(shows: List<ShowCacheModel>)  

    @Query("SELECT * from $TABLE_NAME WHERE favorite = 1")  
    abstract fun getFavoriteShows(): Observable<List<ShowCacheModel>>  

    @Query("UPDATE $TABLE_NAME SET favorite = :favorite WHERE $COLUMN_SHOW_ID = :showId")  
    abstract fun setFavorite(showId: String, favorite: Boolean)  
}

ShowsViewModel

@Singleton  
class ShowsViewModel @Inject constructor(  
    private val getShows: GetShows,  
    private val addShowToFavorites: AddShowToFavorites,  
    private val removeShowFromFavorites: RemoveShowFromFavorites  
) : ViewModel() {  

    private val shows: MutableLiveData<Resource<List<ShowDomainModel>>> = MutableLiveData()  

    init {  
        shows.postValue(Resource.loading())  
        getShows.execute(GetShowsObserver())
    }  

    override fun onCleared() {  
        getShows.dispose()  
        super.onCleared()  
    }  

    fun getShows(): LiveData<Resource<List<ShowDomainModel>>> = shows  

    fun favoriteShow(id: String) = addShowToFavorites.execute(  
        AddShowToFavoritesObserver(),  
        AddShowToFavorites.Params.forShow(id)  
    )  

    fun unfavoriteShow(id: String) = removeShowFromFavorites.execute(  
        RemoveShowFromFavoritesObserver(),  
        RemoveShowFromFavorites.Params.forShow(id)  
    )

    inner class GetShowsObserver : DisposableObserver<List<ShowDomainModel>>() {  
        override fun onComplete() {  
            Log.d("ShowsViewModel","onComplete")  
            throw RuntimeException("GetShows should not complete, should be observing changes to data.")  
        }  

        override fun onNext(showList: List<ShowDomainModel>) {
            shows.postValue(Resource.success(showList))  
        }  

        override fun onError(e: Throwable) {  
            shows.postValue(Resource.error(e.localizedMessage))  
        }  
    }  

    inner class AddShowToFavoritesObserver : DisposableCompletableObserver() {  
        override fun onComplete() = Unit  

        override fun onError(e: Throwable) =  
            shows.postValue(Resource.error(e.localizedMessage))  
    }  

    inner class RemoveShowFromFavoritesObserver : DisposableCompletableObserver() {  
        override fun onComplete() = Unit  

        override fun onError(e: Throwable) =  
            shows.postValue(Resource.error(e.localizedMessage))  
    }  
}

Answer 1

Turns out the fix is very simple. I just needed to use the Activity as the lifecycle that was passed to the ViewModel.

ShowsFragment

    // ...
    override fun onAttach(context: Context) {  
        super.onAttach(context)  

        AndroidSupportInjection.inject(this)
        // CHANGED ONE LINE AND IT WORKS
        // (changed this to activity!!)  
        // CHANGED ONE LINE AND IT WORKS
        showsViewModel = ViewModelProviders.of(activity!!, factory).get(ShowsViewModel::class.java)  
    } 
    // ...

}