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Firestore with StateFlow real time change is observed in repo and view model, but adapter is not being updated

As a developer one needs to adapt to change, I read somewhere it says:
If you don’t choose the right architecture for your Android project, you will have a hard time maintaining it as your codebase grows and your team expands.
I wanted to implement Clean Architecture with MVVM
My app data flow will look like this:
Model class
data class Note(
val title: String? = null,
val timestamp: String? = null
)
Dtos
data class NoteRequest(
val title: String? = null,
val timestamp: String? = null
)
and
data class NoteResponse(
val id: String? = null,
val title: String? = null,
val timestamp: String? = null
)
Repository layer is
interface INoteRepository {
fun getNoteListSuccessListener(success: (List<NoteResponse>) -> Unit)
fun deleteNoteSuccessListener(success: (List<NoteResponse>) -> Unit)
fun getNoteList()
fun deleteNoteById(noteId: String)
}
NoteRepositoryImpl is:
class NoteRepositoryImpl: INoteRepository {
private val mFirebaseFirestore = Firebase.firestore
private val mNotesCollectionReference = mFirebaseFirestore.collection(COLLECTION_NOTES)
private val noteList = mutableListOf<NoteResponse>()
private var getNoteListSuccessListener: ((List<NoteResponse>) -> Unit)? = null
private var deleteNoteSuccessListener: ((List<NoteResponse>) -> Unit)? = null
override fun getNoteListSuccessListener(success: (List<NoteResponse>) -> Unit) {
getNoteListSuccessListener = success
}
override fun deleteNoteSuccessListener(success: (List<NoteResponse>) -> Unit) {
deleteNoteSuccessListener = success
}
override fun getNoteList() {
mNotesCollectionReference
.addSnapshotListener { value, _ ->
noteList.clear()
if (value != null) {
for (item in value) {
noteList
.add(item.toNoteResponse())
}
getNoteListSuccessListener?.invoke(noteList)
}
Log.e("NOTE_REPO", "$noteList")
}
}
override fun deleteNoteById(noteId: String) {
mNotesCollectionReference.document(noteId)
.delete()
.addOnSuccessListener {
deleteNoteSuccessListener?.invoke(noteList)
}
}
}
ViewModel layer is:
interface INoteViewModel {
val noteListStateFlow: StateFlow<List<NoteResponse>>
val noteDeletedStateFlow: StateFlow<List<NoteResponse>>
fun getNoteList()
fun deleteNoteById(noteId: String)
}
NoteViewModelImpl is:
class NoteViewModelImpl: ViewModel(), INoteViewModel {
private val mNoteRepository: INoteRepository = NoteRepositoryImpl()
private val _noteListStateFlow = MutableStateFlow<List<NoteResponse>>(mutableListOf())
override val noteListStateFlow: StateFlow<List<NoteResponse>>
get() = _noteListStateFlow.asStateFlow()
private val _noteDeletedStateFlow = MutableStateFlow<List<NoteResponse>>(mutableListOf())
override val noteDeletedStateFlow: StateFlow<List<NoteResponse>>
get() = _noteDeletedStateFlow.asStateFlow()
init {
// getNoteListSuccessListener
mNoteRepository
.getNoteListSuccessListener {
viewModelScope
.launch {
_noteListStateFlow.emit(it)
Log.e("NOTE_G_VM", "$it")
}
}
// deleteNoteSuccessListener
mNoteRepository
.deleteNoteSuccessListener {
viewModelScope
.launch {
_noteDeletedStateFlow.emit(it)
Log.e("NOTE_D_VM", "$it")
}
}
}
override fun getNoteList() {
// Get all notes
mNoteRepository.getNoteList()
}
override fun deleteNoteById(noteId: String) {
mNoteRepository.deleteNoteById(noteId = noteId)
}
}
and last but not least Fragment is:
class HomeFragment : Fragment() {
private lateinit var binding: FragmentHomeBinding
private val viewModel: INoteViewModel by viewModels<NoteViewModelImpl>()
private lateinit var adapter: NoteAdapter
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View {
binding = FragmentHomeBinding.inflate(inflater, container, false)
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
val recyclerView = binding.recyclerViewNotes
recyclerView.addOnScrollListener(
ExFABScrollListener(binding.fab)
)
adapter = NoteAdapter{itemView, noteId ->
if (noteId != null) {
showMenu(itemView, noteId)
}
}
recyclerView.adapter = adapter
// initView()
fetchFirestoreData()
binding.fab.setOnClickListener {
val action = HomeFragmentDirections.actionFirstFragmentToSecondFragment()
findNavController().navigate(action)
}
}
private fun fetchFirestoreData() {
// Get note list
viewModel
.getNoteList()
// Create list object
val noteList:MutableList<NoteResponse> = mutableListOf()
// Impose StateFlow
viewModel
.noteListStateFlow
.onEach { data ->
data.forEach {noteResponse ->
noteList.add(noteResponse)
adapter.submitList(noteList)
Log.e("NOTE_H_FRAG", "$noteResponse")
}
}.launchIn(viewLifecycleOwner.lifecycleScope)
}
//In the showMenu function from the previous example:
#SuppressLint("RestrictedApi")
private fun showMenu(v: View, noteId: String) {
val menuBuilder = MenuBuilder(requireContext())
SupportMenuInflater(requireContext()).inflate(R.menu.menu_note_options, menuBuilder)
menuBuilder.setCallback(object : MenuBuilder.Callback {
override fun onMenuItemSelected(menu: MenuBuilder, item: MenuItem): Boolean {
return when(item.itemId){
R.id.option_edit -> {
val action = HomeFragmentDirections.actionFirstFragmentToSecondFragment(noteId = noteId)
findNavController().navigate(action)
true
}
R.id.option_delete -> {
viewModel
.deleteNoteById(noteId = noteId)
// Create list object
val noteList:MutableList<NoteResponse> = mutableListOf()
viewModel
.noteDeletedStateFlow
.onEach {data ->
data.forEach {noteResponse ->
noteList.add(noteResponse)
adapter.submitList(noteList)
Log.e("NOTE_H_FRAG", "$noteResponse")
}
}.launchIn(viewLifecycleOwner.lifecycleScope)
true
} else -> false
}
}
override fun onMenuModeChange(menu: MenuBuilder) {}
})
val menuHelper = MenuPopupHelper(requireContext(), menuBuilder, v)
menuHelper.setForceShowIcon(true) // show icons!!!!!!!!
menuHelper.show()
}
}
With all the above logic I'm facing TWO issues
issue - 1
As mentioned here, I have added SnapshotListener on collection as:
override fun getNoteList() {
mNotesCollectionReference
.addSnapshotListener { value, _ ->
noteList.clear()
if (value != null) {
for (item in value) {
noteList
.add(item.toNoteResponse())
}
getNoteListSuccessListener?.invoke(noteList)
}
Log.e("NOTE_REPO", "$noteList")
}
}
with it if I change values of a document from Firebase Console, I get updated values in Repository and ViewModel, but list of notes is not being updated which is passed to adapter, so all the items are same.
issue - 2
If I delete any item from list/recyclerview using:
R.id.option_delete -> {
viewModel
.deleteNoteById(noteId = noteId)
// Create list object
val noteList:MutableList<NoteResponse> = mutableListOf()
viewModel
.noteDeletedStateFlow
.onEach {data ->
data.forEach {noteResponse ->
noteList.add(noteResponse)
adapter.submitList(noteList)
Log.e("NOTE_H_FRAG", "$noteResponse")
}
}.launchIn(viewLifecycleOwner.lifecycleScope)
still I get updated list(i.e new list of notes excluding deleted note) in Repository and ViewModel, but list of notes is not being updated which is passed to adapter, so all the items are same, no and exclusion of deleted item.
Question Where exactly I'm making mistake to initialize/update adapter? because ViewModel and Repository are working fine.

Make following changes:
In init{} block of NoteViewModelImpl :
// getNoteListSuccessListener
mNoteRepository
.getNoteListSuccessListener{noteResponseList ->
viewModelScope.launch{
_noteListStateFlow.emit(it.toList())
}
}
you must add .toList() if you want to emit list in StateFlow to get notified about updates, and in HomeFragment
private fun fetchFirestoreData() {
// Get note list
viewModel
.getNoteList()
// Impose StateFlow
lifecycleScope.launch {
viewModel.noteListStateFlow.collect { list ->
adapter.submitList(list.toMutableList())
}
}
}
That's it, I hope it works fine.

Try to remove additional lists of items in the fetchFirestoreData() and showMenu() (for item R.id.option_delete) methods of the HomeFragment fragment and see if it works:
// remove `val noteList:MutableList<NoteResponse>` in `fetchFirestoreData()` method
private fun fetchFirestoreData() {
...
// remove this line
val noteList:MutableList<NoteResponse> = mutableListOf()
// Impose StateFlow
viewModel
.noteListStateFlow
.onEach { data ->
adapter.submitList(data)
}.launchIn(viewLifecycleOwner.lifecycleScope)
}
And the same for the delete menu item (R.id.option_delete).

How to use different classes with only one LiveData list?

I have this interface and 2 classes, I know it's not the best approach here, but that's not the point now.
interface FilterItem {
val id: String
val name: String
val isChecked: ObservableField<Boolean>
fun reset()
}
data class Technology(
override val id: String,
override val name: String,
override val isChecked: ObservableField<Boolean> = ObservableField(),
) : FilterItem {
override fun reset() {
isChecked.set(false)
}
}
data class Project(
override val id: String,
override val name: String,
override val isChecked: ObservableField<Boolean> = ObservableField(),
) : FilterItem {
override fun reset() {
isChecked.set(false)
}
}
And then I have a ViewModel
private val _filterList = MutableLiveData<List<FilterItem>>().apply {
viewModelScope.launch {
value = loadSkills()
}
}
val filterList: LiveData<List<FilterItem>>
get() = _filterList
private fun loadSkills(): MutableList<FilterItem> {
val technologiesList: MutableList<FilterItem> = mutableListOf()
technologiesList.add(Technology("1", "Android"))
technologiesList.add(Technology("2", "Kotlin"))
return technologiesList
}
private fun loadProjects(): MutableList<FilterItem> {
val projectsList: MutableList<FilterItem> = mutableListOf()
projectsList.add(Project("1", "Project 1"))
projectsList.add(Project("2", "Project 2"))
return projectsList
}
I want to use the filterList so that is holds a list of Technologies or a list of Projects, depending on what BottomSheetDialog I'm opening.
showSkillsButton.setOnClickListener {
showFilterModal(filterViewModel.filterList, SKILLS)
}
showProjectsButton.setOnClickListener {
showFilterModal(filterViewModel.projects, PROJECTS)
}
I want to somehow use filterList only(I had 2 lists for skills and projects, but it would be nice if I could replace them with only 1 filterList).
Is there any way to do this? Or what would be the best approach?

How to implement multiple queries with room database?

Im creating an android app using room database with MVVM pattern, the problem is that i cant use multiple queries when fetching data. I can fetch data once, but then i cant do it anymore.
DAO interface:
#Dao
interface StockDao {
#Insert
suspend fun insert(stock:Stock)
#Update
suspend fun update(stock:Stock)
#Delete
suspend fun delete(stock:Stock)
#Query("DELETE FROM stock_table")
suspend fun deleteAll()
#Query("SELECT * FROM stock_table")
fun selectAll():Flow<List<Stock>>
#Query("SELECT * FROM stock_table WHERE isFinished = 0")
fun selectAllUnfinished(): Flow<List<Stock>>
#Query("SELECT * FROM stock_table WHERE isFinished = 1")
fun selectAllFinished():Flow<List<Stock>>
#Query("SELECT * FROM stock_table ORDER BY totalSpent DESC")
fun selectAllOrderByDesc():Flow<List<Stock>>
#Query("SELECT * FROM stock_table ORDER BY totalSpent ASC")
fun selectAllOrderByAsc():Flow<List<Stock>>
}
Repository:
class StockRepository(private val stockDao: StockDao) {
private lateinit var allStock: Flow<List<Stock>>
suspend fun insert(stock: Stock) {
stockDao.insert(stock)
}
suspend fun update(stock: Stock) {
stockDao.update(stock)
}
suspend fun delete(stock: Stock) {
stockDao.delete(stock)
}
suspend fun deleteAll() {
stockDao.deleteAll()
}
fun selectAll(): Flow<List<Stock>> {
allStock = stockDao.selectAll()
return allStock
}
fun selectAllOrderByDesc(): Flow<List<Stock>> {
allStock = stockDao.selectAllOrderByAsc()
return allStock
}
fun selectAllOrderByAsc(): Flow<List<Stock>> {
allStock = stockDao.selectAllOrderByAsc()
return allStock
}
fun selectAllFinished(): Flow<List<Stock>> {
allStock = stockDao.selectAllFinished()
return allStock
}
fun selectAllUnfinished(): Flow<List<Stock>> {
allStock = stockDao.selectAllUnfinished()
return allStock
}
}
Viewmodel class:
class StockViewModel(private val repo: StockRepository) : ViewModel() {
companion object {
const val ALL = 0
const val ORDER_BY_DESC = 1
const val ORDER_BY_ASC = 2
const val FINISHED = 3
const val UNFINISHED = 4
}
var allStocks = repo.selectAll().asLiveData()
fun insert(stock: Stock) = viewModelScope.launch {
repo.insert(stock)
}
fun update(stock: Stock) = viewModelScope.launch {
repo.update(stock)
}
fun delete(stock: Stock) = viewModelScope.launch {
repo.delete(stock)
}
fun deleteAll() = viewModelScope.launch {
repo.deleteAll()
}
fun selectAllStockWithFilter(filter: Int): LiveData<List<Stock>> {
when (filter) {
ALL -> allStocks = repo.selectAll().asLiveData()
ORDER_BY_DESC -> allStocks = repo.selectAllOrderByDesc().asLiveData()
ORDER_BY_ASC -> allStocks = repo.selectAllOrderByAsc().asLiveData()
FINISHED -> allStocks = repo.selectAllFinished().asLiveData()
UNFINISHED -> allStocks = repo.selectAllUnfinished().asLiveData()
}
return allStocks
}
class StockViewModelFactory(private val repo: StockRepository) : ViewModelProvider.Factory {
override fun <T : ViewModel?> create(modelClass: Class<T>): T {
if (modelClass.isAssignableFrom(StockViewModel::class.java)) {
#Suppress("UNCHECKED_CAST")
return StockViewModel(repo) as T
}
throw IllegalArgumentException("Unknown viewModel class")
}
}
}
Application class:
class FinanceApplication :Application(){
private val database by lazy { FinanceDatabase.getInstance(this)}
val stockRepository by lazy { StockRepository(database.stockDao()) }
}
Activity using this viewmodel :
class StocksActivity : AppCompatActivity() {
//Layout components
private lateinit var binder: ActivityStocksBinding
private lateinit var recyclerView: RecyclerView
private lateinit var recyclerViewAdapter: StockAdapter
//ViewModel
private val viewModel: StockViewModel by viewModels {
StockViewModel.StockViewModelFactory((application as FinanceApplication).stockRepository)
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binder = ActivityStocksBinding.inflate(layoutInflater)
setContentView(binder.root)
fetchStocks()
}
private fun fetchStocks() {
viewModel.allStocks.observe(this) {
recyclerViewAdapter.submitList(it)
}
}
private fun initRecyclerViewLayout() {
val recyclerViewLayoutBinder = binder.includedLayout
recyclerView = recyclerViewLayoutBinder.stocksRecyclerView
recyclerViewAdapter = StockAdapter(this)
recyclerView.adapter = recyclerViewAdapter
recyclerView.layoutManager = LinearLayoutManager(this)
recyclerView.setHasFixedSize(true)
}
override fun onCreateOptionsMenu(menu: Menu?): Boolean {
menuInflater.inflate(R.menu.menu_stock_toolbar, menu)
return true
}
override fun onOptionsItemSelected(item: MenuItem): Boolean {
when (item.itemId) {
R.id.menu_stock_toolbar_filter_all -> viewModel.selectAllStockWithFilter(StockViewModel.ALL)
R.id.menu_stock_toolbar_filter_maior_menor -> viewModel.selectAllStockWithFilter(StockViewModel.ORDER_BY_DESC)
R.id.menu_stock_toolbar_filter_menor_maior -> viewModel.selectAllStockWithFilter(StockViewModel.ORDER_BY_ASC)
R.id.menu_stock_toolbar_filter_finalized -> viewModel.selectAllStockWithFilter(StockViewModel.FINISHED)
R.id.menu_stock_toolbar_filter_opened -> viewModel.selectAllStockWithFilter(StockViewModel.UNFINISHED)
}
return true
//NOTHIN HAPPENS AFTER CHOOSING ONE
}
}
When i enter the activity, all the data is fetched normally, but when i click on a menu item to apply some filter on it, nothing happens, the data doesnt change. How can i fix this?

allStocks may seem dynamic because it's LiveData, but remember that it's still a reference to an object in memory. When StocksActivity is created, it observes allStocks in it's initial state. For the sake of simplicity, let's say allStocks is pointing to an object in memory with the address of "A". When selectAllStockWithFilter() is eventually invoked, the allStocks handle is updated to point to a new instance of LiveData living in memory at address "B". The problem you're facing is that StocksActivity is still observing "A". Nothing communicated that the allStocks handle itself has been changed.
One way to resolve this would be to change allStocks into an instance of MutableLiveData. Subsequently, whenever the contents of this allStocks should be updated, instead of reassigning allStocks, you would update it's internal "value". This allows the ViewModel to pump new/updated values through the same LiveData object instance that StocksActivity is observing.
Something like this:
class StockViewModel(private val repo: StockRepository) : ViewModel() {
...
val allStocks = MutableLiveData<List<Stock>>().apply { value = repo.selectAll() }
...
fun selectAllStockWithFilter(filter: Int) {
when (filter) {
ALL -> allStocks.postValue(repo.selectAll())
ORDER_BY_DESC -> allStocks.postValue(repo.selectAllOrderByDesc())
ORDER_BY_ASC -> allStocks.postValue(repo.selectAllOrderByAsc())
FINISHED -> allStocks.postValue(repo.selectAllFinished())
UNFINISHED -> allStocks.postValue(repo.selectAllUnfinished())
}
}
...
}

Room SQLite query doesn't return any results, even though there are rows in the database that match

I am using this command to get data from a Room database:
select * from location_search_results where searchQuery = "wilmington"
Here is what the database looks like:
And here are the search results:
I have verified that the name of the table is correct and everything, and there's no spelling errors that I can find, so why would this query not return any of the three rows that it should match?
EDIT for code:
The source code is publicly available here, I am working in the mvvm branch, so if you pull it, make sure you're there. Below are the relevant classes:
LocationSearchResponse.kt:
#Entity(tableName = "location_search_results")
class LocationSearchResponse(
#ColumnInfo(name = "type")
val type: String,
#TypeConverters(DataConverter::class)
#SerializedName("query")
val searchQuery: List<String>,
#TypeConverters(DataConverter::class)
val features: List<Feature>,
#ColumnInfo(name = "attribution")
val attribution: String
) {
#PrimaryKey(autoGenerate = true)
var id: Int = 0
}
LocationSearchRepositoryImpl.kt:
class LocationSearchRepositoryImpl (
private val locationResponseDao: LocationResponseDao,
private val locationNetworkDataSource: LocationNetworkDataSource
): LocationSearchRepository {
init {
locationNetworkDataSource.downloadedLocationSearchResults.observeForever { locationResults ->
persistFetchedLocations(locationResults)
}
}
// update search data in db if necessary, then return the data that was searched for.
override suspend fun searchForLocation(query: String): LiveData<out LocationSearchResponse> {
return withContext(Dispatchers.IO) {
initSearch(query)
return#withContext locationResponseDao.searchForLocation(query)
}
}
// if a fetch is necessary (query has not already been searched), fetch search results
private suspend fun initSearch(query: String) {
if (isFetchLocationResultsNeeded(query))
fetchLocationResults(query)
}
private fun isFetchLocationResultsNeeded(query: String) : Boolean {
// get the cached results. If it's null, return true because it needs to be updated
val cachedResults = locationResponseDao.searchForLocationNonLive(query.toLowerCase())
if (cachedResults == null) return true
// if the results are empty, it needs to be fetched, else it doesn't
return cachedResults.features.isEmpty()
}
private suspend fun fetchLocationResults(query: String) {
locationNetworkDataSource.fetchLocationSearchResults("mapbox.places", query)
}
private fun persistFetchedLocations(fetchedLocationResults: LocationSearchResponse) {
GlobalScope.launch(Dispatchers.IO) {
locationResponseDao.upsert(fetchedLocationResults)
}
}
}
LocationResponseDao.kt:
#Dao
interface LocationResponseDao {
// update or insert existing entry if there is a conflict when adding to db
#Insert(onConflict = OnConflictStrategy.REPLACE)
fun upsert(locationResults: LocationSearchResponse)
#Query("select * from location_search_results WHERE searchQuery = :query")
fun searchForLocation(query: String): LiveData<LocationSearchResponse>
#Query("select * from location_search_results WHERE searchQuery = :query")
fun searchForLocationNonLive(query: String): LocationSearchResponse?
#Query("delete from location_search_results")
fun nukeTable()
}
and ChooseCityFragment.kt:
class ChooseCityFragment : ScopedFragment(), KodeinAware {
override val kodein by closestKodein()
private val locationViewModelFactory: LocationResponseViewModelFactory by instance()
private val weatherResponseViewModelFactory: WeatherResponseViewModelFactory by instance()
private lateinit var locationViewModel: LocationResponseViewModel
private lateinit var weatherViewModel: WeatherResponseViewModel
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
setupViews()
// Inflate the layout for this fragment
return inflater.inflate(R.layout.choose_city_fragment, container, false)
}
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
locationViewModel = ViewModelProviders.of(this, locationViewModelFactory)
.get(LocationResponseViewModel::class.java)
weatherViewModel = ViewModelProviders.of(this, weatherResponseViewModelFactory)
.get(WeatherResponseViewModel::class.java)
updateToolbar()
}
fun updateToolbar() {
(activity as? AppCompatActivity)?.supportActionBar?.title = "Choose Location"
(activity as? AppCompatActivity)?.supportActionBar?.subtitle = null
}
fun bindUI() = launch {
val locationResults = locationViewModel.locationResponse
val owner = viewLifecycleOwner
locationResults.observe(owner, Observer {
if (it == null) return#Observer
// TODO: set loading icon to GONE
initRecyclerView(it.features.toLocationSearchResultListItem())
})
}
fun setupViews() = launch {
search_button.setOnClickListener {
searchLocations()
search_results_rv.adapter?.notifyDataSetChanged()
}
}
// TODO: search text can not be more than 20 words or more than 256 characters. Need to account for this
fun searchLocations() = launch {
val searchText = search_box.text.toString()
if (searchText != "") {
locationViewModel.searchLocation(search_box.text.toString())
bindUI()
} else
Toast.makeText(context?.applicationContext, "Please enter a search term", Toast.LENGTH_SHORT).show()
}
private fun List<Feature>.toLocationSearchResultListItem() : List<LocationSearchResultListItem> {
return this.map {
LocationSearchResultListItem(it)
}
}
private fun initRecyclerView(items: List<LocationSearchResultListItem>) {
val groupAdapter = GroupAdapter<ViewHolder>().apply {
addAll(items)
}
groupAdapter.notifyDataSetChanged()
search_results_rv.apply {
layoutManager = LinearLayoutManager(this#ChooseCityFragment.context)
adapter = groupAdapter
}
groupAdapter.setOnItemClickListener { item, view ->
(item as? LocationSearchResultListItem)?.let {
refreshWeather(it.feature.coordinates[0], it.feature.coordinates[1])
}
}
}
private fun refreshWeather(latitude: Double, longitude: Double) = launch {
weatherViewModel.refreshWeatherWithCoordinates(latitude, longitude)
}
}

It turns out there was a space being added to the end of the searchQuery that I wasn't able to see. Once I figured out where my code was adding that space, I removed it and now everything looks good.

try something like this
it`s a dao interface example
use big letters in your query
#Query("SELECT * FROM person WHERE favoriteColor LIKE :color")
List<Person> getAllPeopleWithFavoriteColor(String color);
more info here

Could not complete scheduled request to refresh entries. ClientErrorCode: 3 Android Kotlin

Let me get straight to the point here the error in the logcat is:
Could not complete scheduled request to refresh entries. ClientErrorCode: 3
I have tested the Realm() part of the code and it fetched the right data. Basically, the app just crashes when it loads that Activity. All Im trying to do right now is post the itemName in each cell. If you guys need the logcat, just say so and I'll post it. Any other details needed too.
This is the code for my Activity with a recyclerView with just an ImageView and a TextView in each cell.:
class EssentialsActivity : AppCompatActivity() {
var category: String? = null
val realmtypeFunctions = RealmTypeFunctions()
var realmResults: RealmResults<ChattRItem>? = null
var chattRItemList = mutableListOf<ChattRItem>()
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_essentials)
//init realm
Realm.init(this)
category = "People"
recyclerView_Essentials.setBackgroundColor(Color.CYAN)
recyclerView_Essentials.layoutManager = GridLayoutManager(this, 3)
// AsyncTask.execute {
category?.let {
loadFromRealm(it)
}
// }
this.runOnUiThread {
recyclerView_Essentials.adapter = EssentialsAdapter(chattRItemList)
}
}
override fun onCreateOptionsMenu(menu: Menu?): Boolean {
val inflater = menuInflater
inflater.inflate(R.menu.categories, menu )
return super.onCreateOptionsMenu(menu)
}
override fun onOptionsItemSelected(item: MenuItem?): Boolean {
val intent: Intent?
intent = Intent(this, AddItemActivity::class.java)
intent.putExtra("category", category)
startActivity(intent)
// when (item?.itemId) {
// R.id.essentials_menu_item -> {
// intent = Intent(this, EssentialsActivity::class.java)
// startActivity(intent)
// }
// R.id.addItem_menu_item -> {
// intent = Intent(this, AddItemActivity::class.java)
// startActivity(intent)
// }
// else -> return false
// }
return super.onOptionsItemSelected(item)
}
private fun loadFromRealm(category: String){
val realm = Realm.getDefaultInstance()
try {
val query: RealmQuery<ChattRItem>? = realm.where(ChattRItem::class.java).equalTo("itemCategory", category)
val result: RealmResults<ChattRItem>? = query?.findAll()
result?.let {
for (i in it) {
println(i.itemName)
chattRItemList.add(i)
}
println(chattRItemList.count())
}
} finally {
realm.close()
}
}
}
class EssentialsAdapter(private val chattRItemList: List<ChattRItem>): RecyclerView.Adapter<CustomViewHolder>(){
//realm class variable here to be displayed
/* var essentials = array of realm essential item */
// var essentialsActivity = EssentialsActivity()
//number of items
override fun getItemCount(): Int {
// return 12 //return realm items count
return this.chattRItemList.size
}
override fun onBindViewHolder(holder: CustomViewHolder, position: Int) {
// holder.itemView.textView_essentials_name.text = "Essentials Item"
val chattRItem = chattRItemList.get(position)
// holder.itemView.textView_essentials_name.text = chattRItem.itemName
holder.bind(chattRItem)
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CustomViewHolder{
// how do we create a cell view
val layoutInflater = LayoutInflater.from(parent.context)
val cellForRow = layoutInflater.inflate(R.layout.essentials_cells_layout, parent, false)
return CustomViewHolder(view = cellForRow)
}
}
class CustomViewHolder(view: View): RecyclerView.ViewHolder(view) {
fun bind(chattRitem: ChattRItem) {
itemView.textView_essentials_name.text = chattRitem.itemName
}
}

So basically I figured it out. This was not the right error from LogCat. There was another set of errors from Logcat many lines above this. The error was the result list was a #Realm object. My recyclerView was asking for a non RealmClass object. So i had to make a similar object except not a RealmClass.
#RealmClass
open class ChattRItem: RealmModel {
#PrimaryKey var itemId: String = ""
var itemName: String = ""
var itemCategory: String = ""
var itemImageFileName: String = ""
var itemAudioFileName: String = ""
}
class ChattRBoxItems(val itemId: String, val itemName: String, val itemCategory: String, val itemImageFileName: String, val itemAudioFileName: String)
then I mapped the result into this new class then applied it to my recyclerView.