What i want to achive is
Call IndexList API and display the responded list in a spinner -> Click on Spinner item i want to call 3 api in parallel using .zip operator and display in DetailViewModel
I am using flatmap for calling api in sequence
In first flatmap i am calling IndexList api and i am passing IndexList response to call 3 multiple api in parallel using Observable.zip operator but i am not able
to achive the second part of calling 3 API in parallel and display in view model
Code Snippet:
Spinner Click :
spinner_index_list?.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
//Performing action onItemSelected and onNothing selected
override fun onItemSelected(parent: AdapterView<*>, view: View, pos: Int, id: Long) {
mRecyclerView?.visibility = View.GONE
//Select item from spinner calling API
val symbolDefaultGroup = SymbolForDefaultGroup(indexExchangeSegmentList[pos], parent.getItemAtPosition(pos).toString())
grpIndexViewModel.getSearchSymbol(symbolDefaultGroup)?.observe(this#FragmentWatchlist, Observer { instrumentByIdResponse ->
mDataProvider = ExpandableDataProvider(instrumentByIdResponse)
mRecyclerView?.visibility = View.VISIBLE
if (instrumentByIdResponse != null)
initRecyclerView(savedInstanceState)
})
}
ViewModel :
fun getSearchSymbol(symbolForDefaultGroup: SymbolForDefaultGroup): LiveData<List<InstrumentByIdResponse>>? {
instrumentByIdResponse = null
instrumentByIdResponse = MutableLiveData<List<InstrumentByIdResponse>>()
instrumentByIdResponse = groupRepository.getSearchSymbol(symbolForDefaultGroup)
L.d("get symbol for default group method")
return instrumentByIdResponse
}
Repository:
override fun getSearchSymbol(symbolForDefaultGroup: SymbolForDefaultGroup): LiveData<List<InstrumentByIdResponse>> {
val mutableLiveData = MutableLiveData<List<InstrumentByIdResponse>>()
val instrumentsIdList = ArrayList<Instrument>()
val marketDataQuotesList = ArrayList<QuotesList>()
val subscriptionList = ArrayList<SubscriptionList>()
val symbolFroDefaultGroup: Observable<BaseResponse<SymbolForDefaultGroupResponse>> = remoteServices.requestSymbolForDefaultGroup(symbolForDefaultGroup)
symbolFroDefaultGroup
.flatMap { response ->
for (i in 0 until response.result!!.instruments.size) {
instrumentsIdList.add(Instrument(EnumConfig.getExchangeSegment(response.result.exchangeSegment)!!.toInt(), response.result.instruments[i].toInt()))
marketDataQuotesList.add(QuotesList(EnumConfig.getExchangeSegment(response.result.exchangeSegment)!!.toInt(), response.result.instruments[i].toInt()))
subscriptionList.add(SubscriptionList(EnumConfig.getExchangeSegment(response.result.exchangeSegment)!!.toInt(), response.result.instruments[i].toInt()))
}
val instrumentByIdResult = InstrumentById(instrumentsIdList)
val marketDataQuotes = MarketDataQuotes("ABC", "ABC", marketDataQuotesList, 1111)
val subscriptionList = Subscribe("ABC", "ABC", "Mobile", subscriptionList, 1111)
return#flatMap getDetails(instrumentByIdResult, marketDataQuotes, subscriptionList)
}
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribeWith(object : ErrorCallBack<BaseResponse<List<InstrumentByIdResponse>>>() {
override fun onSuccess(t: BaseResponse<List<InstrumentByIdResponse>>) {
L.d("Success of Search Instrument")
mutableLiveData.value = transform1(t)
}
})
return mutableLiveData
}
private fun transform1(response: BaseResponse<List<InstrumentByIdResponse>>?): List<InstrumentByIdResponse>? {
return response!!.result!!.toList()
}
fun getDetails(instrumentById: InstrumentById, marketDataQuotes: MarketDataQuotes, subscription: Subscribe): Observable<DetailsModel> {
return Observable.zip(
remoteServices.requestInstrumentById(instrumentById),
remoteServices.requestMarketDataQuotes(marketDataQuotes),
remoteServices.requestSubscribe(subscription),
/*Observable.fromArray(remoteServices.requestInstrumentById(instrumentById)),
Observable.fromArray(remoteServices.requestMarketDataQuotes(marketDataQuotes)),
Observable.fromArray(remoteServices.requestSubscribe(subscription)),*/
Function3<List<InstrumentByIdResponse>, MarketDataQuotesResponse, SubscribeResult, DetailsModel>
{ instrumentByIdResponse, marketDataQuotesResponse, subscribeResponse ->
createDetailsModel(instrumentByIdResponse, marketDataQuotesResponse, subscribeResponse)
})
}
private fun createDetailsModel(instrumentByIdResponse: List<InstrumentByIdResponse>, marketDataQuotesResponse: MarketDataQuotesResponse, subscribeResult: SubscribeResult): DetailsModel {
return DetailsModel(instrumentByIdResponse, marketDataQuotesResponse, subscribeResult)
}
data class DetailsModel(
val instrument: List<InstrumentByIdResponse>,
val marketDataQuotes: MarketDataQuotesResponse,
val subscribe: SubscribeResult)
RemoteService :
fun requestInstrumentById(instrumentById: InstrumentById) = ApiService.requestInstrumentById(instrumentById)
APIService :
#Headers("Content-Type: application/json")
#POST("search/instrumentsbyid")
fun requestInstrumentById(#Body instrumentById: InstrumentById): Observable<BaseResponse<List<InstrumentByIdResponse>>>
API Structure
Error that i get on Zip Operator
Related
i'm facing hard times updating list of Orders in real time from firestore using stateflow !!
class RepositoryImp : Repository {
private fun Query.snapshotFlow(): Flow<QuerySnapshot> = callbackFlow {
val snapshott = addSnapshotListener { value, error ->
if (error != null) {
close()
return#addSnapshotListener
}
if (value != null)
trySend(value)
}
awaitClose {
snapshott.remove()
}
}
override fun getAllOrders() = flow<State<List<OrderModel>>> {
emit(State.loading())
val snapshot = ORDER_COLLECTION_REF.snapshotFlow()
.mapNotNull { it.toObjects(OrderModel::class.java) }
emit(State.success(snapshot)) // **HERE** !!!!!!
}.catch {
emit(State.failed(it.message.toString()))
}.flowOn(Dispatchers.IO)
}
i'm receiving the error from // emit(State.success(snapshot)) that says :
Type mismatch: inferred type is Flow<(Mutable)List<OrderModel!>> but List< OrderModel> was expected
sealed class State <T> {
class Loading <T> : State<T>()
data class Success <T> (val data: T) : State <T>()
data class Failed <T> (val message: String) : State <T>()
companion object {
fun <T> loading() = Loading <T>()
fun <T> success(data: T) = Success(data)
fun <T> failed(message: String) = Failed<T>(message)
}
}
My fun to LoadOrders :
private suspend fun loadOrders() {
viewModel.getAllOrders().collect { state ->
when (state) {
is State.Loading -> {
showToast("Loading")
}
is State.Success -> {
adapter.submitList(state.data)
}
is State.Failed -> showToast("Failed! ${state.message}")
}
}
}
Your snapshot variable is a Flow of lists, not a single List. If you want to just fetch the current list, you shouldn't use a flow for that. Instead use get().await().
override fun getAllOrders() = flow<State<List<OrderModel>>> {
emit(State.loading())
val snapshot = ORDER_COLLECTION_REF.get().await()
.let { it.toObjects(OrderModel::class.java) }
emit(State.success(snapshot))
}.catch {
emit(State.failed(it.message.toString()))
}.flowOn(Dispatchers.IO)
The flowOn call is actually unnecessary because we aren't doing anything blocking. await() is a suspend function.
Based on comments discussion below, supposing we want to show a loading state only before the first item, then show a series of success states, and we want to show an error and stop emitting once there's an error, we could do:
override fun getAllOrders() = flow<State<List<OrderModel>>> {
emit(State.loading())
val snapshots = ORDER_COLLECTION_REF.snapshotFlow()
.mapNotNull { State.success(it.toObjects(OrderModel::class.java)) }
emitAll(snapshots)
}.catch {
emit(State.failed(it.message.toString()))
}
I have information in json and I retrieve it using retrofit2, everything works fine, I get the data in a List.
I need this information to fill elements in Jetpack Compose for which I use mutableStateOf to save the states.
My function that I use is the following:
fun jsonParsing(
dataRecox: MutableState<List<Event>>
) {
val TAG_LOGS = "Mariox"
val retrofit = Retrofit.Builder()
.baseUrl("http://myserversample.com/pGet/track/")
.addConverterFactory(GsonConverterFactory.create())
.build()
val retrofitAPI = retrofit.create(APIService1::class.java)
retrofitAPI.getRecolector().enqueue(object : Callback<List<Event>> {
override fun onResponse(
call: Call<List<Event>>,
response: Response<List<Event>>
) {
val data = response.body()
val mydata = data!!
dataRecox.value = mydata
Log.i(TAG_LOGS, Gson().toJson(data))
}
override fun onFailure(call: Call<List<Event>>, t: Throwable) {
t.printStackTrace()
}
})
}
Mymodel:
data class Event (
val deviceID : Int,
val statusCode : Int,
val accountID : String,
val speedKPH : Int,
.
.
.
}
My composable:
#Composable
fun Greeting(name: String) {
val dataRecox = remember {
mutableStateOf(emptyList<Event>())
}
jsonParsing(dataRecox)
println("======")
println(dataRecox) // ok data
println(dataRecox.value). // ok data
//Uncommenting println(dataRecox.value[0]) I get empty.
//println(dataRecox.value[0])
//Text(text = dataRecox.value[0].uniqueID)
}
When I do not use the information in the console, by calling Greeting("Android") all the data is printed correctly:
The problem comes when I want to use that information:
For example, if I want to print in console println(dataRecox.value[0]) here it returns empty. If I want to use it with a composable Text: Text(text = dataRecox.value[0].uniqueID) it also gives me empty.
Can someone explain to me why this happens, because when I start using the information the data becomes empty.
The way you're doing is totally different of the recommended way... here's my suggestion.
Define a class to represent the screen's state.
data class ScreenState(
val events: List<Event> = emptyList(),
val error: Throwable? = null
)
Use a ViewModel to perform the API request and keep the screen state.
class EventsViewModel : ViewModel()
private val _screenState = MutableStateFlow<ScreenState>(ScreenState())
val screenState = _screenState.asStateFlow()
init {
jsonParsing()
}
fun jsonParsing() {
val TAG_LOGS = "Mariox"
val retrofit = Retrofit.Builder()
.baseUrl("http://myserversample.com/pGet/track/")
.addConverterFactory(GsonConverterFactory.create())
.build()
val retrofitAPI = retrofit.create(APIService1::class.java)
retrofitAPI.getRecolector().enqueue(object : Callback<List<Event>> {
override fun onResponse(
call: Call<List<Event>>,
response: Response<List<Event>>
) {
val data = response.body()
Log.i(TAG_LOGS, Gson().toJson(data))
_screenState.update {
ScreenState(it.events)
}
}
override fun onFailure(call: Call<List<Event>>, t: Throwable) {
t.printStackTrace()
_screenState.update {
ScreenState(error = t)
}
}
})
}
}
Instantiate the ViewModel and use it in your screen...
#Composable
fun Greeting(name: String) {
val vm = viewModel<EventsViewModel>()
val screenState by vm.screenState.observeAsState()
LazyColumn(Modifier.fillMaxSize()) {
items(screenState.items) {
Text(it. accountID)
}
}
}
I have tried two different ways to access my spinner. Without success thus far.
I want to load the data for each driver as chosen.
To give an idea of my app.
Code for adapter:
class TableViewAdapter(var tripsheetlist: Tripsheetlist) : RecyclerView.Adapter<TableViewAdapter.RowViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RowViewHolder {
val itemView = LayoutInflater.from(parent.context).inflate(R.layout.table_list_item, parent, false)
return RowViewHolder(itemView) }
override fun getItemCount(): Int { return tripsheetlist.videos.size + 1 // one more to add header row
}
override fun onBindViewHolder(holder: RowViewHolder, position: Int) {
val rowPos = holder.adapterPosition
if (rowPos == 0) {
// Header Cells. Main Headings appear here
holder.itemView.apply {
setHeaderBg(txtWOrder)
setHeaderBg(txtDElNote)
setHeaderBg(txtCompany)
// setHeaderBg(txtAddress)
setHeaderBg(txtWeight)
setHeaderBg(txtbutton1)
setHeaderBg(txtbutton2)
setHeaderBg(txttvdone)
txtWOrder.text = "WOrder"
txtDElNote.text = "DElNote"
txtCompany.text = "Company"
// txtAddress.text = "Address"
txtWeight.text = "Weight"
txtbutton1.text = "Delivered"
txtbutton2.text = "Exception"
txttvdone.text = ""
}
} else {
val modal = tripsheetlist.videos[rowPos -1]
holder.itemView.apply {
setContentBg(txtWOrder)
setContentBg(txtDElNote)
setContentBg(txtCompany)
setContentBg(txtWeight)
setContentBg(txtbutton1)
setContentBg(txtbutton2)
setContentBg(txttvdone)
val list : MutableList<String> = ArrayList()
list.add("Deon")
list.add("Leon")
list.add("David")
list.add("Dick")
println(list)
val spinner : Spinner = findViewById(R.id.spnDriver)
spinner.onItemSelectedListener = object : AdapterView.OnItemSelectedListener{
override fun onItemSelected(p0: AdapterView<*>?, p1: View?, p2: Int, p3: Long) {
val item :String = list[p2]
if (item == "David")
{
txtWOrder.text = modal.WOrder.toString()
txtDElNote.text = modal.DElNote.toString()
txtCompany.text = modal.name.toString()
txtWeight.text = modal.id.toString()
}
}
override fun onNothingSelected(p0: AdapterView<*>?) {
}
}
I did it like this as a test for now. As I will get the drivers from my JSON. I don't have access to it yet so that is why the static values.
The problem I am getting now is: findViewById(R.id.spnDriver) must not be null
I first had my spinner class in my main activity and passed it over like this:
val list : MutableList<String> = ArrayList()
list.add("Deon")
list.add("Leon")
list.add("David")
list.add("Dick")
list.add("Jim")
list.add("Harry")
val adapter = ArrayAdapter( this, androidx.appcompat.R.layout.support_simple_spinner_dropdown_item, list)
val spinner: Spinner = findViewById(R.id.spnDriver)
spinner.adapter = adapter
spinner.onItemSelectedListener = object : AdapterView.OnItemSelectedListener{
override fun onItemSelected(p0: AdapterView<*>?, p1: View?, p2: Int, p3: Long) {
val item :String = list[p2]
Toast.makeText(this#MainActivity, "Driver $item selected", Toast.LENGTH_SHORT).show()
}
override fun onNothingSelected(p0: AdapterView<*>?) {
//empty
}
// insert code that activates data pull of tripsheet for driver= actifavte by method the class/object that activates the data pull. so datapuul(Driver)
}
limitDropDownHeight(spinner)
//drivers end
val btnLoadData: Button = findViewById(R.id.btnLoadData)
// weightsum(tvTotalweight, Tripsheetlist)
// totaldelNotes(tvTotaldelv,Tripsheetlist)
// setData(btnLoadData, Tripsheetlist )
fetchJson(spinner)
}
private fun fetchJson(spinner: Spinner) {
println("Attempting to Fetch JSON")
val url = "https://api.letsbuildthatapp.com/youtube/home_feed"
val request = Request.Builder().url(url).build()
val client = OkHttpClient()
client.newCall(request).enqueue(object: Callback {
override fun onFailure(call: Call, e: IOException) {
println("Failed to execute request") }
override fun onResponse(call: Call, response: Response) {
val body = response.body?.string()
println(body)
val gson = GsonBuilder().create()
val tripsheetlist = gson.fromJson(body, Tripsheetlist::class.java)
runOnUiThread {
recyclerViewTripsheetlist.adapter = TableViewAdapter(tripsheetlist, spinner)
}
}
})
}
In my Adapter class I then called it with : val spinner = spnDriver
This led to a different error: AppCompatSpinner.setOnItemSelectedListener(android.widget.AdapterView$OnItemSelectedListener)' on a null object reference
But seems like it passed the val spinner =spnDriver without a problem.
Thank you for all input and help.
I found a solution. What I did was to keep the spinner inside my MainActivity and then just pass the result of the spinner to the adapter - where I wanted to use it.
My app using room as a database and retrofit as a network calling api.
i am observing database only as a single source of truth. every thing is working fine. But i am not finding solution of one scenario.
Like for the first time when user open app it do following operations
fetch data from db
fetch data from server
because currently database is empty so it sends empty result to observer which hide progress bar . i want to discard that event and send result to observer when server dump data to database. even server result is empty. so progress bar should always hide once their is confirmation no data exists.
in other words application should always rely on database but if it empty then it should wait until server response and then notify observer.
this is my code
observer
viewModel.characters.observe(viewLifecycleOwner, Observer {
Log.e("status is ", "${it.message} at ${System.currentTimeMillis()}")
when (it.status) {
Resource.Status.SUCCESS -> {
binding.progressBar.visibility = View.GONE
if (!it.data.isNullOrEmpty()) adapter.setItems(ArrayList(it.data))
}
Resource.Status.ERROR -> {
Toast.makeText(requireContext(), it.message, Toast.LENGTH_SHORT).show()
binding.progressBar.visibility = View.GONE
}
Resource.Status.LOADING ->
binding.progressBar.visibility = View.VISIBLE
}
})
ViewModel
#HiltViewModel
class CharactersViewModel #Inject constructor(
private val repository: CharacterRepository
) : ViewModel() {
val characters = repository.getCharacters()
}
Repository
class CharacterRepository #Inject constructor(
private val remoteDataSource: CharacterRemoteDataSource,
private val localDataSource: CharacterDao
) {
fun getCharacters() : LiveData<Resource<List<Character>>> {
return performGetOperation(
databaseQuery = { localDataSource.getAllCharacters() },
networkCall = { remoteDataSource.getCharacters() },
saveCallResult = { localDataSource.insertAll(it.results) }
)
}
}
Utility function for all api and database handling
fun <T, A> performGetOperation(databaseQuery: () -> LiveData<T>,
countQuery: () -> Int,
networkCall: suspend () -> Resource<A>,
saveCallResult: suspend (A) -> Unit): LiveData<Resource<T>> =
liveData(Dispatchers.IO) {
emit(Resource.loading())
val source = databaseQuery().map { Resource.success(it,"database") }.distinctUntilChanged()
emitSource(source)
val responseStatus = networkCall()
if (responseStatus.status == SUCCESS) {
saveCallResult(responseStatus.data!!)
} else if (responseStatus.status == ERROR) {
emit(Resource.error(responseStatus.message!!))
}
}
LocalDataSource
#Dao
interface CharacterDao {
#Query("SELECT * FROM characters")
fun getAllCharacters() : LiveData<List<Character>>
#Insert(onConflict = OnConflictStrategy.REPLACE)
suspend fun insertAll(characters: List<Character>)
#Insert(onConflict = OnConflictStrategy.REPLACE)
suspend fun insert(character: Character)
}
DataSource
class CharacterRemoteDataSource #Inject constructor(
private val characterService: CharacterService
): BaseDataSource() {
suspend fun getCharacters() = getResult { characterService.getAllCharacters() }}
}
Base Data Source
abstract class BaseDataSource {
protected suspend fun <T> getResult(call: suspend () -> Response<T>): Resource<T> {
try {
Log.e("status is", "started")
val response = call()
if (response.isSuccessful) {
val body = response.body()
if (body != null) return Resource.success(body,"server")
}
return error(" ${response.code()} ${response.message()}")
} catch (e: Exception) {
return error(e.message ?: e.toString())
}
}
private fun <T> error(message: String): Resource<T> {
Timber.d(message)
return Resource.error("Network call has failed for a following reason: $message")
}
}
Character Service
interface CharacterService {
#GET("character")
suspend fun getAllCharacters() : Response<CharacterList>
}
Resource
data class Resource<out T>(val status: Status, val data: T?, val message: String?) {
enum class Status {
SUCCESS,
ERROR,
LOADING
}
companion object {
fun <T> success(data: T,message : String): Resource<T> {
return Resource(Status.SUCCESS, data, message)
}
fun <T> error(message: String, data: T? = null): Resource<T> {
return Resource(Status.ERROR, data, message)
}
fun <T> loading(data: T? = null): Resource<T> {
return Resource(Status.LOADING, data, "loading")
}
}
}
CharacterList
data class CharacterList(
val info: Info,
val results: List<Character>
)
What is the best way by that i ignore database if it is empty and wait for server response and then notify observer
I want to send some data to the server and show its response to the user.
I'm using MVVM so I created a repository like this:
class Repository {
fun getData(context: Context, word: String): LiveData<String> {
val result = MutableLiveData<String>()
val request = object : StringRequest(
Method.POST,
"https://.......",
Response.Listener {
result.value = it.toString()
},
Response.ErrorListener {
result.value = it.toString()
}) {
#Throws(AuthFailureError::class)
override fun getParams(): MutableMap<String, String> {
val params = HashMap<String, String>()
params["word"] = word
return params
}
}
val queue = Volley.newRequestQueue(context)
queue.add(request)
return result
}
}
which just sends 'word' to the server and get its response.
my view model class contains just a mutableLiveData and a function. it is like this:
class ViewModel(application: Application) : AndroidViewModel(application) {
var result = MutableLiveData<String>()
fun getData(word: String): LiveData<String> {
val repository = Repository()
result = repository.getData(getApplication(), word) as MutableLiveData<String>
return result
}
}
I set an observation for result in my main Activity, therefore it is my MainActivity codes:
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val model = ViewModelProviders.of(this).get(ViewModel::class.java)
submit.setOnClickListener {
model.getData(search_txt.text.toString())
}
model.result.observe(this, Observer {
Log.i("Log", "observe is :$it")
text.text = it
})
}
but it doesn't work! I get the user's input using an edit text and after pressing a button, I call getData function which is in my View Model class. but it returns always null and observation won't work.
I try to put observe the method in my button listener, in this way I get the result but it seems it's not a correct way because after I rotate my phone, all data ware gone and I need to fetch data from the server again while it shouldn't.