i am working on an online shopping application using retrofit, coroutine, livedata, mvvm,...
i want to show progress bar before fetching data from server for afew seconds
if i have one api request i can show that but in this app i have multiple request
what should i do in this situation how i should show progress bar??
Api Service
#GET("homeslider.php")
suspend fun getSliderImages(): Response<List<Model.Slider>>
#GET("amazingoffer.php")
suspend fun getAmazingProduct(): Response<List<Model.AmazingProduct>>
#GET("handsImages.php")
suspend fun getHandsFreeData(
#Query(
"handsfree_id"
) handsfree_id: Int
): Response<List<Model.HandsFreeImages>>
#GET("handsfreemoreinfo.php")
suspend fun gethandsfreemoreinfo(): Response<List<Model.HandsFreeMore>>
#GET("wristmetadata.php")
suspend fun getWristWatchMetaData(
#Query(
"wrist_id"
) wrist_id: Int
): Response<List<Model.WristWatch>>
repository
fun getSliderImages(): LiveData<List<Model.Slider>> {
val data = MutableLiveData<List<Model.Slider>>()
val job = Job()
applicationScope.launch(IO + job) {
val response = api.getSliderImages()
withContext(Main + SupervisorJob(job)) {
data.value = response.body()
}
job.complete()
job.cancel()
}
return data
}
fun getAmazingOffer(): LiveData<List<Model.AmazingProduct>> {
val data = MutableLiveData<List<Model.AmazingProduct>>()
val job = Job()
applicationScope.launch(IO + job) {
val response = api.getAmazingProduct()
withContext(Main + SupervisorJob(job)) {
data.value = response.body()
}
job.complete()
job.cancel()
}
return data
}
fun getHandsFreeData(handsree_id: Int): LiveData<List<Model.HandsFreeImages>> {
val dfData = MutableLiveData<List<Model.HandsFreeImages>>()
val job = Job()
applicationScope.launch(IO + job) {
val response = api.getHandsFreeData(handsree_id)
withContext(Main + SupervisorJob(job)) {
dfData.value = response.body()
}
job.complete()
job.cancel()
}
return dfData
}
fun getHandsFreeMore(): LiveData<List<Model.HandsFreeMore>> {
val data = MutableLiveData<List<Model.HandsFreeMore>>()
val job = Job()
applicationScope.launch(IO + job) {
val response = api.gethandsfreemoreinfo()
withContext(Main + SupervisorJob(job)) {
data.value = response.body()
}
job.complete()
job.cancel()
}
return data
}
VIEWMODEL
fun getSliderImages() = repository.getSliderImages()
fun getAmazingOffer() = repository.getAmazingOffer()
fun recieveAdvertise() = repository.recieveAdvertise()
fun dailyShoes(context: Context) = repository.getDailyShoes(context)
i will appreciate your help
I couldn't help but notice that your repository contains lots of repetitive code. first point to learn here is that all that logic in Repository, it usually goes in the ViewModel. second thing is that you are using applicationScope to launch your coroutines, which usually is done using viewModelScope(takes care of cancellation) object which is available in every viewModel.
So first we have to take care of that repetitive code and move it to ViewModel. So your viewModel would now look like
class YourViewModel: ViewModel() {
// Your other init code, repo creation etc
// Live data objects for progressBar and error, we will observe these in Fragment/Activity
val showProgress: MutableLiveData<Boolean> = MutableLiveData()
val errorMessage: MutableLiveData<String> = MutableLiveData()
/**
* A Generic api caller, which updates the given live data object with the api result
* and internally takes care of progress bar visibility. */
private fun <T> callApiAndPost(liveData: MutableLiveData<T>,
apiCall: () -> Response<T> ) = viewModelScope.launch {
try{
showProgress.postValue(true) // Show prgress bar when api call is active
if(result.code() == 200) { liveData.postValue(result.body()) }
else{ errorMessage.postValue("Network call failed, try again") }
showProgress.postValue(false)
}
catch (e: Exception){
errorMessage.postValue("Network call failed, try again")
showProgress.postValue(false)
}
}
/******** Now all your API call methods should be called as *************/
// First declare the live data object which will contain the api result
val sliderData: MutableLiveData<List<Model.Slider>> = MutableLiveData()
// Now call the API as
fun getSliderImages() = callApiAndPost(sliderData) {
repository.getSliderImages()
}
}
After that remove all the logic from Repository and make it simply call the network methods as
suspend fun getSliderImages() = api.getSliderImages() // simply delegate to network layer
And finally to display the progress bar, simply observe the showProgress LiveData object in your Activity/Fragment as
viewModel.showProgress.observer(this, Observer{
progressBar.visibility = if(it) View.VISIBLE else View.GONE
}
First create a enum class status:
enum class Status {
SUCCESS,
ERROR,
LOADING
}
Then create resource class like this:
data class Resource<out T>(val status: Status, val data: T?, val message: String?) {
companion object {
fun <T> success(data: T?): Resource<T> {
return Resource(Status.SUCCESS, data, null)
}
fun <T> error(msg: String, data: T?): Resource<T> {
return Resource(Status.ERROR, data, msg)
}
fun <T> loading(data: T?): Resource<T> {
return Resource(Status.LOADING, data, null)
}
}
}
Now add your request to a list of response:
var list = java.util.ArrayList<Response<*>>()
suspend fun getApis() = list.addAll(
listOf(
api.advertise(),
api.getAmazingProduct(),
api.dailyShoes(),
api.getSliderImages(),
.
.
.
)
)
In your viewmodel class:
private val _apis = MutableLiveData<Resource<*>>()
val apis: LiveData<Resource<*>>
get() = _apis
init {
getAllApi()
}
fun getAllApi() {
val job = Job()
viewModelScope.launch(IO + job) {
_apis.postValue(
Resource.loading(null)
)
delay(2000)
repository.getApis().let {
withContext(Main + SupervisorJob(job)) {
it.let {
if (it) {
_apis.postValue(Resource.success(it))
} else {
_apis.postValue(Resource.error("Unknown error eccured", null))
}
}
}
}
job.complete()
job.cancel()
}
}
Now you can use status to show progress like this . use this part in your target fragment:
private fun setProgress() {
viewModel.apis.observe(viewLifecycleOwner) {
when (it.status) {
Status.SUCCESS -> {
binding.apply {
progress.visibility = View.INVISIBLE
line1.visibility = View.VISIBLE
parentscroll.visibility = View.VISIBLE
}
}
Status.ERROR -> {
binding.apply {
progress.visibility = View.INVISIBLE
line1.visibility = View.INVISIBLE
parentscroll.visibility = View.INVISIBLE
}
}
Status.LOADING -> {
binding.apply {
progress.visibility = View.VISIBLE
line1.visibility = View.INVISIBLE
parentscroll.visibility = View.INVISIBLE
}
}
}
}
}
I hope you find it useful.
Related
I want to fetch data from the server using Retrofit but it shows me HTTP 500 server error I know it is due to a null value in parameters but I don't where is the null value comes from. I try my best to find the null value but can't find it. If any other reason then please tell me.
Here is my Fragment Code
#RequiresApi(Build.VERSION_CODES.M)
override fun inOnCreateView(mRootView: ViewGroup, savedInstanceState: Bundle?) {
val homeActivity = activity as HomeNavHostActivity
homeActivity.toolbar_id?.visibility = View.VISIBLE
homeActivity.toolbar_search_icon_id.visibility = View.VISIBLE
homeActivity.toolbar_add_icon_id.visibility = View.GONE
homeActivity.home_view_layout?.visibility = View.VISIBLE
homeActivity.bottom_layout?.visibility = View.VISIBLE
homeActivity.toolbar_title_tv.text = "Home"
homeActivity.toolbar_search_icon_id.setOnClickListener() {
showSearchDialog(mRootView)
}
homeActivity.cancel_text.setOnClickListener() {
homeActivity.search_layout.visibility = View.GONE
homeActivity.toolbar_title_tv.visibility = View.VISIBLE
homeActivity.search_view?.setQuery("", false)
homeActivity.search_view?.clearFocus()
}
val dialogHelper by inject<MaterialDialogHelper>()
setupProgressDialog(viewModel.showHideProgressDialog, dialogHelper)
if (isNetworkAvailable(requireContext())) {
var area:String = "20"
var zipcode:String = "WC2N5DU"
viewModel.getSkipFilterList(zipcode, area)
} else {
showAlertDialog(getString(R.string.no_internet))
}
attachViewModel()
}
Here is my ViewModel Code
var filterSkipList: MutableLiveData<SkipListResponse> = MutableLiveData()
fun getSkipFilterList(zipcode: String, area: String) {
viewModelScope.launch {
_showHideProgressDialog.value = true.wrapWithEvent()
sharedWebServices.getFilterSkip(zipcode, area).run {
onSuccess {
_showHideProgressDialog.value = false.wrapWithEvent()
if (it.code == VALID_STATUS_CODE) {
filterSkipList.value = it
}else {
showSnackbarMessage(it.message)
}
}
onFailure {
_showHideProgressDialog.value = false.wrapWithEvent()
it.message?.let { it1 -> showSnackbarMessage(it1) }
}
}
}
}
Here is my data class
#Serializable
data class SkipFilterList(
val zipcode:String,
val area:String
)
Here is my Post
#POST("search-skip")
suspend fun skipListing(
#Header("Authorization") token: String?,
#Body body: SkipFilterList): SkipListResponse
Here is My Repostry
suspend fun getFilterSkip(
zipcode: String,
area: String
) = withContext(dispatcher) {
val token = SharePrefrenceHelper.getInstance(app).getToken()
val body = SkipFilterList(zipcode, area)
safeApiCall {
Result.success(apiServices.skipListing("Bearer" + token, body))
}
}
By passing json object in the body this was solved.
val jsonObject = JsonObject()
jsonObject.addProperty("zipcode", zipcode)
jsonObject.addProperty("radius", area)
Context: I found few tutorials explaining how consume mutilple endpoints from Kotlin at same time but they are based on Android and in my case it is a backend application. I have some experience using CompleteableFuture but I assume I should use Coroutine since it is a Kotlin and there is no Spring dependency.
Following some suggestions, I reached
#Singleton
class PersonEndpoint()
{
#Inject
lateinit var employeClient: EmployeClient
override suspend fun getPersonDetails(request: PersonRequest): PersonResponse {
var combinedResult: String
GlobalScope.launch {
val resultA: String
val resultB: String
val employeesA = async{ employeClient.getEmployeesA()}
val employeesB = async{ employeClient.getEmployeesB()}
try{
combinedResult = employeesA.await() + employeesB.await()
print(combinedResult)
} catch (ex: Exception) {
ex.printStackTrace()
}
// ISSUE 1
if I try add return over here it is not allowed.
I understand it is working how it is designed to work: GlobalScope is running in different thread
}
// ISSUE 2
if I try return combinedResult over here combinedResult isn't initialized.
I understand it is working how it is designed to work: GlobalScope is running in different thread and I can
debug and see that return over here executes earlier than employeesA.await = employeesB.await
}
So, how can I execute combinedResult = employeesA.await() + employeesB.await() before returning to the client?
*** Edited after Denis/ answer
#Singleton
class CustomerEndpoint(){
fun serve(): Collection<Int> {
return runBlocking {
async {
getItemDouble(1)
}
async {
getItemTriple(1)
}
}.map { it.await() }
}
suspend fun getItemDouble(i: Int): Int {
delay(1000)
return i * 2
}
suspend fun getItemTriple(i: Int): Int {
delay(1000)
return i * 3
}
override suspend fun getPersonDetails(request: PersonRequest): PersonResponse {
val result = serve()
println("Got result $result")
...
}
import kotlinx.coroutines.async
import kotlinx.coroutines.delay
import kotlinx.coroutines.runBlocking
import kotlin.system.measureTimeMillis
fun main() {
val durationMs = measureTimeMillis {
val result = serve()
println("Got result $result")
}
println("The processing is done in $durationMs ms")
}
fun serve(): Collection<Int> {
return runBlocking {
(1..2).map {
async {
getItem(it)
}
}.map { it.await() }
}
}
suspend fun getItem(i: Int): Int {
delay(1000) // Emulate item retrieval work
return i * 2
}
Note that here we have two nested calls - getItem(1) and getItem(2). We can see that they are executed in parallel as overall running time is ~1 second.
Edited in August 05th 2021
private suspend fun myMethod(): List<Any> {
return runBlocking {
listOf(
async { method1() },
async { method2() }
).map { it.await() }
}
}
method1 and method2 are methods calling different endpoints.
loadSingle return Single object, if it fails I want to call getObservable(rsList) which return Observable.
I am trying with onErrorResumeNext but it needs Single object.
How can I call getObservable(rsList) on failure of loadSingle() ?
Thanks in advance!!
repo.loadSingle()
.subscribeOn(Schedulers.io())
.onErrorResumeNext {
repo.getObservable(rsList)
}
.flatMapObservable {
if (it != null && it.status == Status.SUCCESS) {
upRsList(it.data)
}
repo.getObservable(rsList)
}
({ //observable success
}, {
//observable error
})
Api interface
interface HomeApi{
fun getSingel():Single<List<String>>
fun getObservable():Observable<HomeResponse>
}
Dependencies
testImplementation("org.junit.jupiter:junit-jupiter-api:5.6.2")
testRuntimeOnly("org.junit.platform:junit-platform-launcher:1.6.2")
testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:5.6.2")
testRuntimeOnly("org.junit.vintage:junit-vintage-engine:5.6.2")
implementation "io.reactivex.rxjava3:rxjava:3.0.4"
implementation "io.reactivex.rxjava3:rxkotlin:3.0.0"
Required classes
internal interface Repo {
fun loadSingle(): Single<Result<List<String>>>
fun getObservable(list: List<String>): Observable<String>
}
internal class RepoImpl : Repo {
override fun loadSingle(): Single<Result<List<String>>> {
return Single.error(RuntimeException("fail"))
}
override fun getObservable(list: List<String>): Observable<String> {
if (list === emptyList<String>()) {
return Observable.just("42")
}
return Observable.just("success")
}
}
internal sealed class Result<T> {
data class Success<T>(val value: T) : Result<T>()
data class Failure<T>(private val failure: Throwable) : Result<T>()
}
Test
Wrap the error via #onErrorReturn into a default value, and handle the result accordingly.
class So64751341 {
#Test
fun `64751341`() {
val repo: Repo = RepoImpl()
val testScheduler = TestScheduler()
val flatMapObservable = repo.loadSingle()
.subscribeOn(testScheduler)
.onErrorReturn { failure -> Result.Failure(failure) }
.flatMapObservable { result ->
when (result) {
is Result.Success -> repo.getObservable(result.value)
is Result.Failure -> repo.getObservable(emptyList())
}
}
val test = flatMapObservable.test()
testScheduler.triggerActions()
test // return default value 42 onError
.assertValue("42")
}
}
Repo#loadSingle() throws exception synchronously
internal class RepoExceptionImpl : Repo {
override fun loadSingle(): Single<Result<List<String>>> {
throw java.lang.RuntimeException("whatever")
}
override fun getObservable(list: List<String>): Observable<String> {
if (list === emptyList<String>()) {
return Observable.just("42")
}
return Observable.just("success")
}
}
Test
Repo#loadSingle must be wrapped with Single#defer. Single#defer will catch the exception and emit it as #onError to the subscriber, which in turn will be handled by #onErrorReturn
#Test
fun `64751341_exception`() {
val repo: Repo = RepoExceptionImpl()
val testScheduler = TestScheduler()
val flatMapObservable = Single.defer {
repo.loadSingle()
}
.subscribeOn(testScheduler)
.onErrorReturn { failure -> Result.Failure(failure) }
.flatMapObservable { result ->
when (result) {
is Result.Success -> repo.getObservable(result.value)
is Result.Failure -> repo.getObservable(emptyList())
}
}
val test = flatMapObservable.test()
testScheduler.triggerActions()
test // return default value 42 onError
.assertValue("42")
}
I am using Exoplayer to play some videos. I have some .mpd live url's which comes from a backend. Normally if the broadcast is live, the seek bar is set to right end side and on the left end side live video cache time is stated with minus value like (-00.59.51). I want to achive that in my project. But by default, current position of the video stated on left side and video duration on right side.
There is two problem:
1.We have to detect if the video is live or not.
2.We need to set time values for live video.
private fun initializePlayerXml(currentXmlLink: String) {
if (player == null) {
val trackSelector = DefaultTrackSelector(this)
trackSelector.setParameters(
trackSelector.buildUponParameters().setMaxVideoSizeSd()
)
try {
player = SimpleExoPlayer.Builder(this)
.build()
} catch (e: Exception) {
}
}
if (player!!.bufferedPosition == 0L) {
playButton.setImageResource(R.drawable.ic_pause)
}
playButton.setOnClickListener {
if (player!!.isPlaying) {
player!!.pause()
playButton.setImageResource(R.drawable.ic_play)
} else {
player!!.play()
playButton.setImageResource(R.drawable.ic_pause)
}
}
val doubleClickForwardFun = DoubleClick(object : DoubleClickListener {
override fun onSingleClickEvent(view: View?) {
}
override fun onDoubleClickEvent(view: View?) {
val currentPosition = player!!.currentPosition
player!!.seekTo(currentPosition + 10000)
}
})
val doubleClickBackwardFun = DoubleClick(object : DoubleClickListener {
override fun onSingleClickEvent(view: View?) {
}
override fun onDoubleClickEvent(view: View?) {
val currentPosition = player!!.currentPosition
player!!.seekTo(currentPosition - 10000)
}
})
doubleClickBackward.setOnClickListener(doubleClickBackwardFun)
doubleClickForward.setOnClickListener(doubleClickForwardFun)
forwardButton.setOnClickListener {
val currentPosition = player!!.currentPosition
player!!.seekTo(currentPosition + 10000)
}
backwardButton.setOnClickListener {
val currentPosition = player!!.currentPosition
player!!.seekTo(currentPosition - 10000)
}
val mediaItem =
MediaItem.Builder()
.setUri(currentXmlLink)
.setMimeType(MimeTypes.APPLICATION_MPD)
.build()
player!!.addMediaItem(mediaItem)
playerView!!.player = player
player!!.playWhenReady = playWhenReady
player!!.seekTo(currentWindow, playbackPosition)
playbackStateListener.let { player!!.addListener(it) }
player!!.prepare()
}
I have already a question on Exoplayer/Issues, you can check here. Also my repo is here.
Currently, I use retrofit2 to call restful apis and get response. Because the response body can be multiple types, I wrote the code following.
//Interface
#FormUrlEncoded
#POST("payments/events/{id}")
fun postPayment(#Path("id") id: String): Call<Any>
//Api Manager
fun postPayment(id: String): Observable<Any> {
return Observable.create {
subscriber ->
val callResponse = api.postPayment(id)
val response = callResponse.execute()
if (response.isSuccessful) {
if (response.body() is MyClass1) {
// never success...
} else if (response.body() is MyClass2) {
// never success...
}
subscriber.onNext(response.body())
subscriber.onCompleted()
} else {
subscriber.onError(Throwable(response.message()))
}
}
}
So I'm not able to cast response.body() to MyClass1 or MyClass2.
response.body() as MyClass1 occurs error too.
MyClass1 and MyClass2 are normal template classes.
class MyClass1( val id: String, val data: String)
Is there any smart way to cast response body to my custom classes?
Small update for MyClass2
class MyClass2( val token: String, val url: String, val quantity: Int)
As mentioned by #Miha_x64, Retrofit doesn't know about your classes (MyClass1 and MyClass2) because your Call uses the Any type. Therefore, Retrofit is not creating an instance of MyClass1 or MyClass2, instead it is just creating an instance of the Any class.
The simplest solution would just be to combine the two classes:
data class MyClass(
val id: String?,
val data: String?,
val token: String?,
val url: String?,
val quantity: Int
)
Then you can specify the response type in your interface:
#FormUrlEncoded
#POST("payments/events/{id}")
fun postPayment(#Path("id") id: String): Call<MyClass>
In the case your response does not have an id or data element, they will just be null. Then you can check which type of response was received simply by checking which values are null:
if (response.body().id != null) {
// Handle type 1 response...
} else if (response.body().token != null) {
// Handle type 2 response...
}
A slightly more complex solution would be to write a wrapper for your two classes, and a type adapter to populate the wrapper. This would avoid the nullability of each of the fields, as well as keep your data structure separated.
This would differ based on the ConverterFactory you are using but if, for example, you are using Gson, it would look something like this:
data class ApiResponse(
val val1: MyClass1? = null,
val val2: MyClass2? = null
)
class ApiResponseAdapter : TypeAdapter<ApiResponse> {
#Throws(IOException::class)
override fun write(out: JsonWriter, value: ApiResponse?) {
if (value != null) {
out.beginObject()
value.val1?.id? let { out.name("id").value(it) }
value.val1?.data? let { out.name("data").value(it) }
value.val2?.token? let { out.name("token").value(it) }
value.val2?.url? let { out.name("url").value(it) }
value.val2?.quantity? let { out.name("quantity").value(it) }
out.endObject()
} else {
out.nullValue()
}
}
#Throws(IOException::class)
override fun read(in: JsonReader): ApiResponse {
reader.beginObject()
var id: String? = null
var data: String? = null
var token: String? = null
var url: String? = null
var quantity: Int = 0
while(in.hasNext()) {
val name = in.nextName()
if (name.equals("id", true)) {
id = in.nextString()
} else if (name.equals("data", true)) {
data = in.nextString()
} else if (name.equals("token", true)) {
token = in.nextString()
} else if (name.equals("url", true)) {
url = in.nextString()
} else if (name.equals("quantity", true)) {
quantity = in.nextInt()
}
}
reader.endObject()
if (id != null && data != null) {
return ApiResponse(MyClass1(id, data), null)
} else if (token != null && url != null) {
return ApiResponse(null, MyClass2(token, url, quantity))
} else {
return ApiResponse()
}
}
}
Then you can add this type adapter to your Gson instance:
val gson = GsonBuilder().registerTypeAdapter(ApiResponse::class.java, ApiResponseAdapter()).create()
Then replace the Call<Any> type with Call<ApiRepsone> and you can then check which response was received by checking which value is null:
if (response.body().val1 != null) {
// Handle MyClass1 response...
} else if (response.body().val2 != null) {
// Handle MyClass2 response...
}
First of all, thanks #Bryan for answer. Your answer was perfect but finally I did something tricky way.
...
if (response.isSuccessful) {
val jsonObject = JSONObject(response.body() as Map<*, *>)
val jsonString = jsonObject.toString()
if (jsonObject.has("id")) {
val myclass1Object = Gson().fromJson(jsonString, MyClass1::class.java)
...
} else {
val myclass2Object = Gson().fromJson(jsonString, MyClass2::class.java)
...
}
}
...