How can I prevent some code duplication for a feed handler - scala

I have a feed handler and I would like to prevent the data handle again if the value updated is same as previous value, so I have code like this
map.get(statisticsOpenAcronym).map { x =>
var open = x.asInstanceOf[Number].doubleValue();
if (statistics.open != open) {
statistics.open = open;
statistics.changed = true;
}
}
map.get(statisticsCloseAcronym).map { x =>
var close = x.asInstanceOf[Number].doubleValue();
if (statistics.close != close) {
statistics.close = close;
statistics.changed = true;
}
}
But then I need to have the [if xxx is difference, the update xxx and set change flag ] replicate again and again.
Just wonder, how can I prevent this?

You can compose functions (I had to change some things because I'm not sure of your types):
case class Statistic() {
var open = true
var close = !open
var changed = false
}
var statistics = Statistic()
def f(map: Map[String, String], statisticsOpenAcronym: String, statistic: Statistic, condition: Statistic => Boolean, exec: (Statistic, Boolean) => ()) = {
map.get(statisticsOpenAcronym).map { x =>
val close = x.asInstanceOf[Boolean]
if (condition(statistic)) {
exec(statistic, close)
}
}
}
def closeCondition(): Statistic => Boolean = { statistics: Statistic =>
statistics.close
}
def closeStatistic(): (Statistic, Boolean) => Unit = { (statistics: Statistic, close: Boolean) =>
statistics.close = close
statistics.changed = true;
}
f(Map.empty, "acronym", statistics, closeCondition(), closeStatistic())
Better yet you could make closeStatistics return a new statistic with the parameters you want instead of Unit.
The open case is analogue.

Related

Jetpack Compose Snackbar above Dialog

How can a Snackbar be shown above a Dialog or AlertDialog in Jetpack Compose? Everything I have tried has resulted in the snack bar being below the scrim of the dialog not to mention the dialog itself.
According to Can I display material design Snackbar in dialog? it is possible in non-Compose Android by using a custom or special (like getDialog().getWindow().getDecorView()) view, but that isn't accessible from Compose I believe (at least not without a lot of effort).
I came up with a solution that mostly works. It uses the built-in Snackbar() composable for the rendering but handles the role of SnackbarHost() with a new function SnackbarInDialogContainer().
Usage example:
var error by remember { mutableStateOf<String?>(null) }
AlertDialog(
...
text = {
...
if (error !== null) {
SnackbarInDialogContainer(error, dismiss = { error = null }) {
Snackbar(it, Modifier.padding(WindowInsets.ime.asPaddingValues()))
}
}
}
...
)
It has the following limitations:
Has to be used in place within the dialog instead of at the top level
There is no host to queue messages, instead that has to be handled elsewhere if desired
Dismissal is done with a callback (i.e. { error = null} above) instead of automatically
Actions currently do nothing at all, but that could be fixed (I had no use for them, the code do include everything necessary to render the actions I believe, but none of the interaction).
This has built-in support for avoiding the IME (software keyboard), but you may still need to follow https://stackoverflow.com/a/73889690/582298 to make it fully work.
Code for the Composable:
#Composable
fun SnackbarInDialogContainer(
text: String,
actionLabel: String? = null,
duration: SnackbarDuration =
if (actionLabel == null) SnackbarDuration.Short else SnackbarDuration.Indefinite,
dismiss: () -> Unit,
content: #Composable (SnackbarData) -> Unit
) {
val snackbarData = remember {
SnackbarDataImpl(
SnackbarVisualsImpl(text, actionLabel, true, duration),
dismiss
)
}
val dur = getDuration(duration, actionLabel)
if (dur != Long.MAX_VALUE) {
LaunchedEffect(snackbarData) {
delay(dur)
snackbarData.dismiss()
}
}
val popupPosProvider by imeMonitor()
Popup(
popupPositionProvider = popupPosProvider,
properties = PopupProperties(clippingEnabled = false),
) {
content(snackbarData)
}
}
#Composable
private fun getDuration(duration: SnackbarDuration, actionLabel: String?): Long {
val accessibilityManager = LocalAccessibilityManager.current
return remember(duration, actionLabel, accessibilityManager) {
val orig = when (duration) {
SnackbarDuration.Short -> 4000L
SnackbarDuration.Long -> 10000L
SnackbarDuration.Indefinite -> Long.MAX_VALUE
}
accessibilityManager?.calculateRecommendedTimeoutMillis(
orig, containsIcons = true, containsText = true, containsControls = actionLabel != null
) ?: orig
}
}
/**
* Monitors the size of the IME (software keyboard) and provides an updating
* PopupPositionProvider.
*/
#Composable
private fun imeMonitor(): State<PopupPositionProvider> {
val provider = remember { mutableStateOf(ImePopupPositionProvider(0)) }
val context = LocalContext.current
val decorView = remember(context) { context.getActivity()?.window?.decorView }
if (decorView != null) {
val ime = remember { WindowInsetsCompat.Type.ime() }
val bottom = remember { MutableStateFlow(0) }
LaunchedEffect(Unit) {
while (true) {
bottom.value = ViewCompat.getRootWindowInsets(decorView)?.getInsets(ime)?.bottom ?: 0
delay(33)
}
}
LaunchedEffect(Unit) {
bottom.collect { provider.value = ImePopupPositionProvider(it) }
}
}
return provider
}
/**
* Places the popup at the bottom of the screen but above the keyboard.
* This assumes that the anchor for the popup is in the middle of the screen.
*/
private data class ImePopupPositionProvider(val imeSize: Int): PopupPositionProvider {
override fun calculatePosition(
anchorBounds: IntRect, windowSize: IntSize,
layoutDirection: LayoutDirection, popupContentSize: IntSize
) = IntOffset(
anchorBounds.left + (anchorBounds.width - popupContentSize.width) / 2, // centered on screen
anchorBounds.top + (anchorBounds.height - popupContentSize.height) / 2 + // centered on screen
(windowSize.height - imeSize) / 2 // move to the bottom of the screen
)
}
private fun Context.getActivity(): Activity? {
var currentContext = this
while (currentContext is ContextWrapper) {
if (currentContext is Activity) {
return currentContext
}
currentContext = currentContext.baseContext
}
return null
}
private data class SnackbarDataImpl(
override val visuals: SnackbarVisuals,
val onDismiss: () -> Unit,
) : SnackbarData {
override fun performAction() { /* TODO() */ }
override fun dismiss() { onDismiss() }
}
private data class SnackbarVisualsImpl(
override val message: String,
override val actionLabel: String?,
override val withDismissAction: Boolean,
override val duration: SnackbarDuration
) : SnackbarVisuals

Play Framework - Respond with JSON after uploading a file (multipartFormData)

I am using this code to upload an image on server , that i get from this link play upload
def upload = Action(parse.multipartFormData) { request =>
request.body
.file("picture")
.map { picture =>
val dataParts = request.body.dataParts;
val filename = Paths.get(picture.filename).getFileName
val fileSize = picture.fileSize
val contentType = picture.contentType
val picturePaths =
picture.ref.copyTo(
Paths.get(
s"/opt/docker/images/$filename"
),
replace = true
)
if (dataParts.get("firstPoint") == None) {
val pointlocation = new Point_LocationModel(
dataParts.get("step").get(0),
dataParts.get("backgroundTargetName").get(0),
dataParts.get("x").get(0),
dataParts.get("y").get(0),
dataParts.get("z").get(0),
dataParts.get("rotation").get(0),
dataParts.get("note").get(0),
dataParts.get("tag").get(0),
dataParts.get("work_session_id").get(0),
(picturePaths).toString
)
point_LocationRepository.create(pointlocation).map { data =>
Created(Json.toJson(data._2))
}
} else {
val jValuefirstPoint =
Json.parse(dataParts.get("firstPoint").get(0)).as[PointModel]
val jValuesecondPoint =
Json.parse(dataParts.get("secondPoint").get(0)).as[PointModel]
val pointlocation = new Point_LocationModel(
dataParts.get("step").get(0),
dataParts.get("backgroundTargetName").get(0),
Some(jValuefirstPoint),
Some(jValuesecondPoint),
dataParts.get("rotation").get(0),
dataParts.get("note").get(0),
dataParts.get("tag").get(0),
dataParts.get("work_session_id").get(0),
(picturePaths).toString
)
point_LocationRepository.create(pointlocation).map { data =>
logger.info(s"repoResponse: ${data}");
Created(Json.toJson(data._2))
}
}
Ok(s"picturePaths ${picturePaths}")
}
.getOrElse(Ok("Invalid Format"))
}
This code works very well, but on the response I want to get the response from the repository. How can i await for the response of the repository to return this?
Can you give me any idea how can i do it?
Thanks in advance.
If we simplify your code to the essential bits, you have:
def upload = Action(parse.multipartFormData) { request =>
request.body
.file("picture")
.map { picture =>
if (someConditionA) {
someBusinessLogicA().map { data =>
Created(Json.toJson(data._2))
}
} else {
someBusinessLogicB().map { data =>
Created(Json.toJson(data._2))
}
}
Ok(s"picturePaths ${picturePaths}")
}
.getOrElse(Ok("Invalid Format"))
}
There are 2 problems:
the return of your if/else is swallowed by the Ok(s"picturePaths ${picturePaths}")
assuming your business logic returns Future[_] you need to "propagate" the Future everywhere
Something like this should work:
def upload = Action.async(parse.multipartFormData) { request =>
request.body
.file("picture")
.map { picture =>
if (someConditionA) {
someBusinessLogicA().map { data =>
Created(Json.toJson(data._2))
}
} else {
someBusinessLogicB().map { data =>
Created(Json.toJson(data._2))
}
}
}
.getOrElse(Future.successful(Ok("Invalid Format")))
}
Notice the Action.async and the Future in the getOrElse.

LIveData is observed more than twice everytime from acivity and emitting previous data

I follow MVVM Login API, with Retrofit ,My problem is livedata is observed more than twice and always emitting previous response when observed from activity, But inside Repository its giving correct response
I tried a lot of solutions from stackoverflow and other websites but still no luck, Tried removing observers also but still getting previous data ,so plz suggest a working solution, I will post my code below,
LoginActivity.kt
private lateinit var loginViewModel: LoginViewModel
loginViewModel = ViewModelProvider(this, ViewModelProvider.NewInstanceFactory()).get(
LoginViewModel::class.java
)
loginViewModel.login(userEmail, pwd)
loginViewModel.getLoginRepository().observe(this, Observer {
val loginResult = it ?: return#Observer
val accessToken = loginResult.user?.jwtToken.toString()
})
val statusMsgObserver = Observer<String> { statusMsg ->
showToast(statusMsg)
})
val errorMsgObserver = Observer<String> { errorMsg ->
// Update the UI
showToast(errorMsg)
})
loginViewModel.getStatusMessage()?.observe(this, statusMsgObserver)
loginViewModel.getErrorStatusMessage()?.observe(this, errorMsgObserver)
LoginViewModel.kt:
class LoginViewModel: ViewModel() {
private var loginRepository: LoginRepository? = null
private var _mutableLiveData = MutableLiveData<LoginAPIResponse?>()
val liveData: LiveData<LoginAPIResponse?> get() = _mutableLiveData
private var responseMsgLiveData:MutableLiveData<String>?= null
private var errorResponseMsgLiveData:MutableLiveData<String>?= null
fun login(username: String, password: String) {
loginRepository = LoginRepository.getInstance()!!
/* Query data from Repository */
//val _mutableLiveData: MutableLiveData<Response<LoginAPIResponse?>?>? = loginRepository?.doLogin(username, password)
_mutableLiveData = loginRepository?.doLogin(username, password)!!
responseMsgLiveData = loginRepository?.respMessage!!
errorResponseMsgLiveData = loginRepository?.loginResponseErrorData!!
}
fun getLoginRepository(): LiveData<LoginAPIResponse?> {
return liveData
}
fun getStatusMessage(): LiveData<String>? {
return responseMsgLiveData
}
fun getErrorStatusMessage(): LiveData<String>? {
return errorResponseMsgLiveData
}
}
LoginRepository.kt:
class LoginRepository {
private val loginApi: ApiEndpoints = RetrofitService.createService(ApiEndpoints::class.java)
val responseData = MutableLiveData<LoginAPIResponse?>()
var respMessage = MutableLiveData<String>()
var loginResponseErrorData = MutableLiveData<String>()
fun doLogin(username: String, password: String)
: MutableLiveData<LoginAPIResponse?> {
respMessage.value = null
loginResponseErrorData.value = null
val params = JsonObject()
params.addProperty("email", username)
params.addProperty("password",password)
val jsonParams = JsonObject()
jsonParams.add("user",params)
loginApi.loginToServer(jsonParams).enqueue(object : Callback<LoginAPIResponse?> {
override fun onResponse( call: Call<LoginAPIResponse?>, response: Response<LoginAPIResponse?> ) {
responseData.value = response.body()
respMessage.value = RetrofitService.handleError(response.code())
val error = response.errorBody()
if (!response.isSuccessful) {
val errorMsg = error?.charStream()?.readText()
println("Error Message: $errorMsg")
loginResponseErrorData.value = errorMsg
} else {
println("API Success -> Login, $username, ${response.body()?.user?.email.toString()}")
}
}
override fun onFailure(call: Call<LoginAPIResponse?>, t: Throwable) {
println("onFailure:(message) "+t.message)
loginResponseErrorData.value = t.message
responseData.value = null
}
})
return responseData
}
companion object {
private var loginRepository: LoginRepository? = null
internal fun getInstance(): LoginRepository? {
if (loginRepository == null) {
loginRepository = LoginRepository()
}
return loginRepository
}
}
}
In onDestroy(),I have removed the observers,
override fun onDestroy() {
super.onDestroy()
loginViewModel.getLoginRepository()?.removeObservers(this)
this.viewModelStore.clear()
}
In LoginActivity, when I observe loginResult it gives previous emitted accessToken first and then again called and giving current accessToken, Similarly observer is called more than twice everytime.
But inside repository,its giving recent data, plz check my code and suggest where I have to correct to get correct recent livedata
Finally i found the solution, In LoginRepository, I declared responseData outside doLogin(), It should be declared inside doLogin()
Since it was outside the method, it always gave previous data first and then current data,
Once I declare inside method problem was solved and now it is working Perfect!!!

Controlling (start/stop) IObservable through ToggleSwitch using ReactiveUI

I am trying to hook a stream (IObservable) to be controlled through ToggleSwitch in a UWP project. The expectation is that I start the streaming when the switch is in On state and stop when it is in Off state.
So the thought is to
1. Create two commands, one to start the stream and another to stop the stream.
2. Create two Observables that monitors the switch state and InvokeCommand when the condition is right.
ViewModel
public class MainPageViewModel : ViewModelBase
{
public ReactiveCommand<Unit, (long, float)> StreamCommand { get; }
public ReactiveCommand<Unit, Unit> StopCommand { get; }
public IObservable<(long, float)> FlowStream { get; set; }
private bool _isStreamOn;
public bool IsStreamOn
{
get => _isStreamOn;
set => this.RaiseAndSetIfChanged(ref _isStreamOn, value);
}
public MainPageViewModel()
{
var stream = GetStream();
var canSwitchOn = this.WhenAnyValue(x => x.IsStreamOn);
var canSwitchOff = this.WhenAnyValue(x => x.IsStreamOn, isOn => isOn != true);
FlowStream = StreamCommand = ReactiveCommand.CreateFromObservable(
() =>
{
stream.Start();
return Observable.FromEventPattern<StreamDataEventArgs<(long, INumeric, INumeric, INumeric)>>(
h => stream.DataAvailable += h,
h => stream.DataAvailable -= h)
.SelectMany(e => e.EventArgs.Data)
.Select(item => item));
}, canSwitchOn);
StopCommand = ReactiveCommand.Create(
() =>
{
stream.Stop();
IsStreamOn = false;
}, canSwitchOff);
canSwitchOff.InvokeCommand(StopCommand);
canSwitchOn.InvokeCommand(StreamCommand);
}
}
View
public sealed partial class MainPage : Page, IViewFor<MainPageViewModel>
{
public MainPage()
{
InitializeComponent();
NavigationCacheMode = Windows.UI.Xaml.Navigation.NavigationCacheMode.Enabled;
ViewModel = new MainPageViewModel();
this.WhenActivated(subscription =>
{
subscription(this.OneWayBind(this.ViewModel,
vm => vm.StreamCommand,
v => v.chart.SeriesCollection[0].Stream)); // Chart take care of displaying data
subscription(this.Bind(this.ViewModel,
vm => vm.IsStreamOn,
v => v.streamToggle.IsOn));
});
}
object IViewFor.ViewModel
{
get { return ViewModel; }
set { ViewModel = (MainPageViewModel)value; }
}
public MainPageViewModel ViewModel
{
get { return (MainPageViewModel)GetValue(ViewModelProperty); }
set { SetValue(ViewModelProperty, value); }
}
public static readonly DependencyProperty ViewModelProperty =
DependencyProperty.Register("ViewModel", typeof(MainPageViewModel), typeof(MainPage), null);
}
However, the InvokeCommand fails, as it requires the ReactiveCommands to take the bool, instead of Unit.
Any idea how I can invoke a command when certain conditions are met?
If you want to turn a stream (IObservable<(long, float)> FlowStream) on and off based on a IObservable<bool> IsStreamOn observable then you can do this:
IObservable<(long, float)> outputStream =
IsStreamOn
.Select(flag => flag ? FlowStream : Observable.Never<(long, float)>())
.Switch();
So each time IsStreamOn produces a true you start getting values from FlowStream, otherwise the values stop.
This assumes that FlowStream is hot. If not, do this:
IObservable<(long, float)> outputStream =
FlowStream
.Publish(fs =>
IsStreamOn
.Select(flag => flag ? fs : Observable.Never<(long, float)>())
.Switch());
Here's a simple test:
void Main()
{
IObservable<long> outputStream =
FlowStream
.Publish(fs =>
IsStreamOn
.Select(flag => flag ? fs : Observable.Never<long>())
.Switch());
using (outputStream.Subscribe(Console.WriteLine))
{
IsStreamOn.OnNext(true);
Thread.Sleep(TimeSpan.FromSeconds(2.5));
IsStreamOn.OnNext(false);
Thread.Sleep(TimeSpan.FromSeconds(3.0));
IsStreamOn.OnNext(true);
Thread.Sleep(TimeSpan.FromSeconds(3.0));
}
}
IObservable<long> FlowStream = Observable.Interval(TimeSpan.FromSeconds(1.0));
Subject<bool> IsStreamOn = new Subject<bool>();
This produces:
0
1
5
6
7
Given the comments re actually calling .Start() and .Stop() then try something like this:
IObservable<(long, float)> outputStream =
Observable
.Create<(long, float)>(o =>
{
var stream = GetStream();
return
FlowStream
.Publish(fs =>
IsStreamOn
.Do(flag => { if (flag) stream.Start(); else stream.Stop(); })
.Select(flag => flag ? fs : Observable.Never<(long, float)>())
.Switch())
.Subscribe(o);
});
In these scenarios with your observables I tend to do
var canSwitchOn = this.WhenAnyValue(x => x.IsStreamOn).Select(_ => Unit.Default);
That will allow you not to have the bool passed along to the command.
oh also you may want a where() clause in this cause if you want to trigger a command in the right condition.
eg.
var switchOn = this.WhenAnyValue(x => x.IsStreamOn).Where(x => x).Select(_ => Unit.Default);
var switchOff = this.WhenAnyValue(x => x.IsStreamOn).Where(x => !x).Select(_ => Unit.Default);

Setting state in ajax success in scalajs-react

I am trying to open one popup on successful submission of another in scalajs-react. My problem is on success state is not getting modified. Here is my addNewAgent method called as a callback on submission of first popup.
def addNewAgent(userModel: UserModel, addNewAgent: Boolean = false): Callback = {
println(addNewAgent)
if(addNewAgent){
createUser(userModel).onComplete {
case Success(s) =>
println(s.msgType)
if (s.msgType == ApiResponseMsg.CreateUserWaiting){
t.modState(s => s.copy(showNewAgentForm = false, showConfirmAccountCreation = true))
} else {
t.modState(s => s.copy(showNewAgentForm = false, showRegistrationFailed = true))
}
case Failure(s) =>
println(s)
t.modState(s => s.copy(showRegistrationFailed = true))
// now you need to refresh the UI
}
t.modState(s => s.copy(showNewAgentForm = false))
} else {
t.modState(s => s.copy(showNewAgentForm = false))
}
}
and component code is :
val component = ReactComponentB[Props]("AddNewAgent")
.initialState(State()) // initial state from TodoStore
.backend(new Backend(_))
.renderPS(($, P, S) => {
val B = $.backend
<.div()(
Button(Button.Props(B.addNewAgentForm(), CommonStyle.default, Seq(HeaderCSS.Style.SignUpBtn)),"Sign Up"),
if (S.showNewAgentForm) NewAgentForm(NewAgentForm.Props(B.addNewAgent))
else if (S.showConfirmAccountCreation ) ConfirmAccountCreation(ConfirmAccountCreation.Props(B.confirmAccountCreation))
else
Seq.empty[ReactElement]
)
})
// .componentDidMount(scope => scope.backend.mounted(scope.props))
.configure(OnUnmount.install)
.build
def apply(props: Props) = component(props)
For anyone looking for an answer to this problem what is happening here is that
the modState calls inside the future completion will never be really called
because they return a Callback that don't run. To solve this you need to add runNow() like t.modState(s => s.copy(showNewAgentForm = false, showRegistrationFailed = true)).runNow()