Develop Reference

How do I retrieve a value from a list of objects in Kotlin?

I've been spinning my wheels on this for a while. I have made my api call and successfully returned the data I'm looking for. I have taken this data and inserted it into a database. I've verified all of the info I need is in the database through the database inspector. Now I am looking to retrieve the data from the database, and populate a spinner with that data. Specifically I'm looking to retrieve a list of colors from SeedColors
#Entity(tableName = "colors")
data class SeedColors(
#PrimaryKey
val colorSeedID: String,
val color: String,
val timeCreated: String,
val timeUpdated: String,
val type: String
)
Here is my dao interface
interface DogColorDao {
#Query("SELECT * FROM colors")
fun getAll(): Flow<List<SeedColors>>
#Query("SELECT * FROM colors")
fun getAllColors(): List<SeedColors>
#Query("SELECT * FROM colors WHERE colorSeedID = :colorID")
fun getColorById(colorID: Int): SeedColors
#Insert(onConflict = OnConflictStrategy.REPLACE)
fun insertDogColors(dogColor: List<SeedColors>)
#Delete
fun deleteAll(colors: SeedColors)
Repository:
val db: DogColorDatabase = DogColorDatabase.getDatabase(MatchbreedApp.ctx)
val allColors: Flow<List<SeedColors>> = db.dogColorDao().getAll()
ViewModel:
class SeedViewModel(private val repo: SeedRepo): ViewModel() {
val errorData: MutableLiveData<ErrorObject> = MutableLiveData()
// access room here
val allColors: LiveData<List<SeedColors>> = repo.allColors.asLiveData()
val allBreeds: LiveData<List<SeedBreed>> = repo.allBreeds.asLiveData()
val elbows: LiveData<List<Elbow>> = repo.elbows.asLiveData()
val heart: LiveData<List<Heart>> = repo.heart.asLiveData()
val hips: LiveData<List<Hip>> = repo.hips.asLiveData()
val temperament: LiveData<List<Temperament>> = repo.temperament.asLiveData()
val policies: LiveData<List<SeedPolicies>> = repo.policies.asLiveData()
val externalLinks: LiveData<List<ExternalLinks>> = repo.externalLinks.asLiveData()
val titles: LiveData<List<SeedTitle>> = repo.titles.asLiveData()
fun getSeeds() {
repo.getSeeds("all", getStringPref(PREF_TOKEN), "", errorData)
}
custom spinner adapter:
class MBColorSpinnerAdapter(var context: Context, var colorList: List<SeedColors>): BaseAdapter() {
override fun getCount(): Int {
return colorList.size
}
override fun getItem(i: Int): Any {
return i
}
override fun getItemId(i: Int): Long {
return i.toLong()
}
override fun getView(i: Int, convertView: View?, parent: ViewGroup?): View {
val view: View
val inflater = LayoutInflater.from(context)
//LayoutInflater.from(context).inflate(R.layout.mb_spinner_item, parent, false)
view = inflater.inflate(R.layout.mb_spinner_item, parent, false)
val viewHolder: MBColorSpinnerAdapter.ItemHolder = ItemHolder(view)
view?.tag = viewHolder
viewHolder.color.text = colorList[i].color
return view
}
override fun getDropDownView(position: Int, convertView: View?, parent: ViewGroup?): View {
val view: View = super.getDropDownView(position, convertView, parent)
val textView: TextView = view as TextView
if (position == 0) {
textView.text = ""
}
return view
}
override fun isEnabled(position: Int): Boolean {
return position != 0
}
fun updateColorList(colors: List<SeedColors>) {
this.colorList = colors
notifyDataSetChanged()
}
inner class ItemHolder(view: View?) {
var color: TextView = view?.findViewById(R.id.spinner_drop_down) as TextView
}
}
And in my fragment, I am observing changes to the database and updating the adapter
initializing the adapter with an empty arrayList
private fun initSpinners() {
breedSpinner = _binding.sBreed
colorSpinner = _binding.sColor
colorAdapter = MBColorSpinnerAdapter(requireContext(), dogColorList)
breedAdapter = MBSpinnerAdapter(
requireContext(),
breedList
)
if (seedViewModel.allColors.hasActiveObservers()) {
seedViewModel.allColors.observe(viewLifecycleOwner, colorObserver)
colorAdapter.notifyDataSetChanged()
}
and here is my observer
private val colorObserver: Observer<List<SeedColors>> = Observer {
if (it != null) {
colorAdapter.updateColorList(it)
}
}
what I think is happening is that I am setting the adapter to the whole SeedColor object, and it doesn't know what to choose - color, type, colorSeedID, etc. I'm trying to figure out a way to get the object values that I want (color) into a list and populate my adapter with that instead of a List. But I'm not sure how to do that. I've seen a lot of
var color: List<String> = allColors.map {
it.color
}
but that isn't working because it's still in a list. I can do
var color: List<String> = allColors.map {
it[0].color
}
but this only gives me 1 color, and there's over 100. any ideas??
thanks!!

Currently retrieving information just like it should. Would be helpful if I set my adapter. that was the issue why nothing was populating the spinner.
colorSpinner.adapter = colorAdapter

Room Data doesn't show in the RecyclerList

It's first time using Room Data while also using MVVM pattern. The aim is that I want my data to appeard on the RecyclerList but it's doesn't shut down nor shows me any error it's just appears empty.
Here is my Database class:
#Database(entities = [Plant::class, Plant_Category::class], version = 1)
abstract class PlantDatabase:RoomDatabase() {
abstract fun plantDao(): PlantOperations
abstract fun plantCategoryDao(): PlantCategoryOperations
companion object {
private var INSTANCE: PlantDatabase? = null
fun getDatabase(context: Context): PlantDatabase {
if (INSTANCE == null) {
INSTANCE = Room.databaseBuilder(
context.applicationContext,
PlantDatabase::class.java, DB_NAME // contains directory of sqlite database
)
.fallbackToDestructiveMigration()
.build()
}
return INSTANCE!!
}
}
}
My dao class:
#Dao
interface PlantOperations {
#Query("SELECT * FROM Plant")
fun getAll(): Flow<List<Plant>>
#Insert
fun insertPlant( plant: Plant)
#Delete
fun delete(plant:Plant)
#Update
fun updatePlant(plant:Plant)}
This is my repository class:
class PlantRepository(application:Application){
private var allPlants = MutableLiveData<List<Plant>>()
private val plantDAO = PlantDatabase.getDatabase(application).plantDao()
init {
CoroutineScope(Dispatchers.IO).launch {
val plantData = plantDAO.getAll()
plantData.collect{
allPlants.postValue(it)
}
}
}
fun getAllPlants(): MutableLiveData<List<Plant>> {
return allPlants
}
}
My Viewmodel class:
class PlantViewModel(
application: Application
): AndroidViewModel(application) {
private var repository = PlantRepository(application)
private var _allPlants = repository.getAllPlants()
val allPlants: MutableLiveData<List<Plant>>
get() = _allPlants
}
My Recycler in Fragment:
override fun onCreateView(inflater: LayoutInflater,
container: ViewGroup?, savedInstanceState: Bundle?): View? {
lateinit var photoAdapter: Photo_Adapter
lateinit var plantViewModel: PlantViewModel
val view: View = inflater.inflate(R.layout.fragment_edit__form, container, false)
val fab = view.findViewById(R.id.floatingActionButton) as FloatingActionButton
val recyclerView = view.findViewById(R.id.recyclerView) as RecyclerView
recyclerView.layoutManager = GridLayoutManager(context, 2)
photoAdapter = Photo_Adapter(context)
recyclerView.adapter = photoAdapter
plantViewModel = ViewModelProvider(this).get(PlantViewModel::class.java)
plantViewModel.allPlants.observe(viewLifecycleOwner, androidx.lifecycle.Observer {
photoAdapter.setDataList(it)
})
// photoAdapter.setDataList(dataList)
//Floating button that opens the Form in order to add plant
fab?.setOnClickListener {
val intent = Intent(view.context, Edit_Form::class.java)
startActivity(intent);
}
return view
}
This is my adapter class:
class Photo_Adapter(var context: Context?) : RecyclerView.Adapter<Photo_Adapter.ViewHolder>() {
var dataList = emptyList<Plant>()
internal fun setDataList(dataList: List<Plant>) {
this.dataList = dataList
notifyDataSetChanged()
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
// Get the data model based on position
var data = dataList[position]
holder.title.text = data.name
holder.desc.text = data.type.toString()
holder.image.setImageResource(data.image)
holder.relativeLayout.setOnClickListener { view -> //Toast.makeText(view.getContext(),"click on item: "+model.getTitle(),Toast.LENGTH_LONG).show();
val intent = Intent(view.context, PlantDetails::class.java)
intent.putExtra("plant_name", data.name)
intent.putExtra("plant_image",data.image)
intent.putExtra("plant_type", data.type.type)
intent.putExtra("plant_water", data.type.water_time)
intent.putExtra("plant_details", data.type.details)
view.context.startActivity(intent)
}
}
// Provide a direct reference to each of the views with data items
class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
var image: ImageView
var title: TextView
var desc: TextView
var relativeLayout: CardView
init {
image = itemView.findViewById(R.id.image)
title = itemView.findViewById(R.id.title)
desc = itemView.findViewById(R.id.desc)
relativeLayout = itemView.findViewById<View>(R.id.relativeLayout) as CardView
}
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): Photo_Adapter.ViewHolder {
// Inflate the custom layout
var view = LayoutInflater.from(parent.context).inflate(R.layout.photo_layout, parent, false)
return ViewHolder(view)
}
// total count of items in the list
override fun getItemCount() = dataList.size
}
Perhaps I forgot to add something? In Anyway I will be grateful for your help.

You should not observe data on your repository, your activity/view should observe this data. Take a look at this:
First, add this dependency to your gradle:
implementation "androidx.lifecycle:lifecycle-livedata-ktx:2.3.1"
Then in your repository
class PlantRepository(application:Application){
private val plantDAO = PlantDatabase.getDatabase(application).plantDao()
fun getAllPlants(): Flow<List<Plant>> = plantDAO.getAll()
}
In your view model:
class PlantViewModel(
application: Application
): AndroidViewModel(application) {
private var repository = PlantRepository(application)
val allPlants = repository.getAllPlants()
.flowOn(Dispatchers.IO)
.asLiveData()
}
And your activity is fine, but check your adapter, make sure that you're notifing your adapter that your list has changed.
You can also work (collect) flows on your view, but this depends on you

A list of 10+ items are retrieved from firebase database, after 9th item 10th item is affecting 1st and 11th item is affecting 2nd item and so on

I'm retrieving a list of items from the firebase database and displaying them using RecyclerView in my android app. The problem is when I'm retrieving more than 9 items and updating some data in the 1st item (while running) as you can see in the image below the 10th item also got affected and vice-versa same with 2nd and 11th item and so on.
Like when I'm adding and fixing the quantity of the 1st item , the same happens with the 10th item (the 10th item also get added with the same quantity as of 1st item).
MenuFragment.kt
class MenuFragment : Fragment() {
private var dishList: MutableList<DishModel> = mutableListOf()
private lateinit var myRef: DatabaseReference
lateinit var list: RecyclerView
lateinit var proceedToCartLayout: RelativeLayout
lateinit var addToCartBtn: Button
private var selectedCategory = ""
companion object {
fun newInstance(): Fragment {
return MenuFragment()
}
}
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val view = inflater.inflate(R.layout.fragment_menu, container, false)
//retrieve id
val bundle = this.arguments
selectedCategory = bundle!!.getString("CATEGORY_ID")!!
list = view.findViewById(R.id.recyclerMenu)
myRef = FirebaseDatabase.getInstance().getReference("Category")
proceedToCartLayout = view.findViewById(R.id.ProceedToCart)
addToCartBtn = view.findViewById(R.id.btn_cart)
return view
}
override fun onResume() {
if (ConnectionManager().checkConnectivity(activity as Context)) {
fetchMenu()
} else {
val alterDialog = androidx.appcompat.app.AlertDialog.Builder(activity as
Context)
alterDialog.setTitle("No Internet")
alterDialog.setMessage("Connect to internet to continue")
alterDialog.setIcon(R.drawable.nointernet)
alterDialog.setPositiveButton("Open Settings") { _, _ ->
val settingsIntent = Intent(Settings.ACTION_SETTINGS)//open wifi settings
startActivity(settingsIntent)
}
alterDialog.setNegativeButton("Exit") { _, _ ->
ActivityCompat.finishAffinity(activity as Activity)
}
alterDialog.setCancelable(false)
alterDialog.create()
alterDialog.show()
}
super.onResume()
}
private fun fetchMenu() {
myRef.child(selectedCategory).addValueEventListener(object : ValueEventListener {
override fun onCancelled(p0: DatabaseError) {
Toast.makeText(context, "$p0", Toast.LENGTH_SHORT).show()
}
override fun onDataChange(p0: DataSnapshot) {
if (p0.exists()) {
dishList.clear()
for (i in p0.children) {
val plan = i.getValue(DishModel::class.java)
dishList.add(plan!!)
}
val adapter = MenuAdapter(
context!!,
R.layout.menu_list_item,
dishList,
proceedToCartLayout,
addToCartBtn, selectedCategory
)
list.adapter = adapter
}
}
})
}
}
MenuAdapter.kt
class MenuAdapter(
private val ctx: Context,
private val layoutResId: Int,
private val dishList:
List<DishModel>,
private val proceedToCartPassed: RelativeLayout,
private val buttonProceedToCart: Button,
private val categoryName: String
) : RecyclerView.Adapter<MenuAdapter.MyViewHolder>() {
private lateinit var proceedToCart: RelativeLayout
private var itemSelectedCount: Int = 0
private var itemsSelectedId = arrayListOf<String>()
private var itemList = arrayListOf<DishModel>()
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MenuAdapter.MyViewHolder {
val layoutInflater: LayoutInflater = LayoutInflater.from(ctx)
val view: View = layoutInflater.inflate(layoutResId, null)
return MyViewHolder(view)
}
override fun onBindViewHolder(holder: MenuAdapter.MyViewHolder, position: Int) {
var btnClick = false
var no = 0
val range = 1..5
val dish = dishList[position]
holder.dishName.text = dish.dishName
holder.dishPrice.text = "Rs " + dish.cost + " /-"
Picasso.get().load(dish.image).error(R.drawable.defaultdish).into(holder.dishImage)
holder.increaseBtn.setOnClickListener {
if (btnClick) {
no += 1
if (no in range) {
holder.quantity.text = no.toString()
dish.qty = no
}
}
}
holder.decreaseBtn.setOnClickListener {
if (btnClick) {
no -= 1
if (no in range) {
holder.quantity.text = no.toString()
dish.qty = no
}
}
}
proceedToCart = proceedToCartPassed
buttonProceedToCart.setOnClickListener {
val intent = Intent(ctx, CartActivity::class.java)
intent.putExtra(
"categoryId",
categoryName
)
intent.putExtra(
"selectedItemsId",
itemsSelectedId
)
intent.putExtra("itemList", itemList)
ctx.startActivity(intent)
}
holder.buttonAddToCart.setOnClickListener {
if (holder.buttonAddToCart.text.toString() == "Remove") {
itemSelectedCount--//unselected
itemsSelectedId.remove(holder.buttonAddToCart.tag.toString())
itemList.remove(dish)
holder.buttonAddToCart.text = "Add"
holder.buttonAddToCart.setBackgroundResource(R.drawable.rounded_corners)
btnClick = false
no = 0
dish.qty = no
holder.quantity.text = no.toString()
} else {
itemSelectedCount++//selected
itemsSelectedId.add(holder.buttonAddToCart.tag.toString())
itemList.add(dish)
holder.buttonAddToCart.text = "Remove"
holder.buttonAddToCart.setBackgroundResource(R.drawable.rounded_corners_yellow)
btnClick = true
no = 1
dish.qty = no
holder.quantity.text = no.toString()
}
if (itemSelectedCount > 0) {
proceedToCart.visibility = View.VISIBLE
} else {
proceedToCart.visibility = View.GONE
}
}
holder.buttonAddToCart.tag = dishList.indexOf(dish) + 1
}
override fun getItemCount(): Int {
return dishList.size
}
inner class MyViewHolder(view: View) : RecyclerView.ViewHolder(view) {
val dishName: TextView = view.findViewById(R.id.txtDishName)
val dishPrice: TextView = view.findViewById(R.id.txtDishPrice)
val dishImage: ImageView = view.findViewById(R.id.dishImage)
val buttonAddToCart: Button = view.findViewById(R.id.add_dish)
val increaseBtn: Button = view.findViewById(R.id.increase)
val decreaseBtn: Button = view.findViewById(R.id.decrease)
val quantity: TextView = view.findViewById(R.id.quantity)
}
}

Please Add
holder.quantity.text = dish.qty.toString() after or before as you wish Picasso.get().load(dish.image).error(R.drawable.defaultdish).into(holder.dishImage)
Something like below.
Picasso.get().load(dish.image).error(R.drawable.defaultdish).into(holder.dishImage)
holder.quantity.text = dish.qty.toString()
holder.increaseBtn.setOnClickListener
Because I can see you are not setting holder.quantity.text thinking your recyclerview item view have the default as 0 but as you know in recyclerview the views are been reused and when they. are been reused the default value is not 0 for that but the value last view which is going to be reused, which in your case is every 10th item.
The golden rule if you are working with recylerview and thinking of using default value of any view from the XML view itself, so you will be surprised when you start scrolling you will notice that that is not the case and the default value is something other than that.
Always set the default value in onBind so next time the view been reused it takes the default value you want
if you are having an if condition to update something do write it's else as well because the same caching will make you wonder why your items are behaving differently.
Important point, make sure your setting default value in 1st point is outside any clicklistener or any view listener you set up because we have to make sure the setter gets executed every time the onBind is getting called
I have my fair share of experience working with checkbox, edittext , radio button etc in items and giving me surprising result on scrolling hence I always make sure to follow the above points when working with recylerviews.

I added the below code in my adapter (override getItemViewType) and it worked !
override fun getItemViewType(position: Int): Int {
return position
}

Input validation with MVVM and Data binding

I try to learn the MVVM Architecture by implementing a very simple app that takes three inputs from the user and stores them in a Room Database then display the data in a RecyclerView.
From the first try it seems to work well, then the app crashes if one of the inputs is left empty. Now, I want to add some input validations (for now the validations must just check for empty string), but I can't figure it out. I found many answers on stackoverflow and some libraries that validates the inputs, but I couldn't integrate those solutions in my app (most probably it is due to my poor implementation of the MVVM).
This is the code of my ViewModel:
class MetricPointViewModel(private val repo: MetricPointRepo): ViewModel(), Observable {
val points = repo.points
#Bindable
val inputDesignation = MutableLiveData<String>()
#Bindable
val inputX = MutableLiveData<String>()
#Bindable
val inputY = MutableLiveData<String>()
fun addPoint(){
val id = inputDesignation.value!!.trim()
val x = inputX.value!!.trim().toFloat()
val y = inputY.value!!.trim().toFloat()
insert(MetricPoint(id, x , y))
inputDesignation.value = null
inputX.value = null
inputY.value = null
}
private fun insert(point: MetricPoint) = viewModelScope.launch { repo.insert(point) }
fun update(point: MetricPoint) = viewModelScope.launch { repo.update(point) }
fun delete(point: MetricPoint) = viewModelScope.launch { repo.delete(point) }
override fun addOnPropertyChangedCallback(callback: Observable.OnPropertyChangedCallback?) {
}
override fun removeOnPropertyChangedCallback(callback: Observable.OnPropertyChangedCallback?) {
}
}
and this is the fragment where everything happens:
class FragmentList : Fragment() {
// TODO: Rename and change types of parameters
private var param1: String? = null
private var param2: String? = null
//Binding object
private lateinit var binding: FragmentListBinding
//Reference to the ViewModel
private lateinit var metricPointVm: MetricPointViewModel
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
arguments?.let {
param1 = it.getString(ARG_PARAM1)
param2 = it.getString(ARG_PARAM2)
}
}
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
//Setting up the database
val metricPointDao = MetricPointDB.getInstance(container!!.context).metricCoordDao
val repo = MetricPointRepo(metricPointDao)
val factory = MetricPointViewModelFactory(repo)
metricPointVm = ViewModelProvider(this, factory).get(MetricPointViewModel::class.java)
// Inflate the layout for this fragment
binding = FragmentListBinding.inflate(inflater, container, false)
binding.apply {
lifecycleOwner = viewLifecycleOwner
myViewModel = metricPointVm
}
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
initRecyclerview()
}
private fun displayPoints(){
metricPointVm.points.observe(viewLifecycleOwner, Observer {
binding.pointsRecyclerview.adapter = MyRecyclerViewAdapter(it) { selecteItem: MetricPoint -> listItemClicked(selecteItem) }
})
}
private fun initRecyclerview(){
binding.pointsRecyclerview.layoutManager = LinearLayoutManager(context)
displayPoints()
}
private fun listItemClicked(point: MetricPoint){
Toast.makeText(context, "Point: ${point._id}", Toast.LENGTH_SHORT).show()
}
companion object {
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment FragmentList.
*/
// TODO: Rename and change types and number of parameters
#JvmStatic
fun newInstance(param1: String, param2: String) =
FragmentList().apply {
arguments = Bundle().apply {
putString(ARG_PARAM1, param1)
putString(ARG_PARAM2, param2)
}
}
}
}
I'm planning also to add a long click to the recyclerview and display a context menu in order to delete items from the database. Any help would be appreciated.
My recycler view adapter implementation:
class MyRecyclerViewAdapter(private val pointsList: List<MetricPoint>,
private val clickListener: (MetricPoint) -> Unit): RecyclerView.Adapter<MyViewHolder>(){
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
val layoutInflater = LayoutInflater.from(parent.context)
val binding: RecyclerviewItemBinding = DataBindingUtil.inflate(layoutInflater, R.layout.recyclerview_item, parent, false)
return MyViewHolder(binding)
}
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
holder.bind(pointsList[position], clickListener)
}
override fun getItemCount(): Int {
return pointsList.size
}
}
class MyViewHolder(private val binding: RecyclerviewItemBinding): RecyclerView.ViewHolder(binding.root){
fun bind(point: MetricPoint, clickListener: (MetricPoint) -> Unit){
binding.idTv.text = point._id
binding.xTv.text = point.x.toString()
binding.yTv.text = point.y.toString()
binding.listItemLayout.setOnClickListener{
clickListener(point)
}
}
}

Try the following,
fun addPoint(){
val id = inputDesignation.value!!.trim()
if(inputX.value == null)
return
val x = inputX.value!!.trim().toFloat()
if(inputY.value == null)
return
val y = inputY.value!!.trim().toFloat()
insert(MetricPoint(id, x , y))
inputDesignation.value = null
inputX.value = null
inputY.value = null
}
Edit:
you can try the following as well if you wish to let the user know that the value a value is expected
ViewModel
private val _isEmpty = MutableLiveData<Boolean>()
val isEmpty : LiveData<Boolean>
get() = _isEmpty
fun addPoint(){
val id = inputDesignation.value!!.trim()
if(inputX.value == null){
_isEmpty.value = true
return
}
val x = inputX.value!!.trim().toFloat()
if(inputY.value == null){
_isEmpty.value = true
return
}
val y = inputY.value!!.trim().toFloat()
insert(MetricPoint(id, x , y))
inputDesignation.value = null
inputX.value = null
inputY.value = null
}
//since showing a error message is an event and not a state, reset it once its done
fun resetError(){
_isEmpty.value = null
}
Fragment Class
metricPointVm.isEmpty.observe(viewLifecycleOwner){ isEmpty ->
isEmpty?.apply{
if(it){
// make a Toast
metricPointVm.resetError()
}
}
}

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.