public SingleItemLoader()
{
itemState = currentLoader.flatMap(opt => {
discardPreviousRequest();
foreach (var bindingLoader in opt)
{
var(_request, assetFtr) = bindingLoader.loadASync();
request.value = _request.some();
return(assetFtr.toRxVal().map(csOpt => csOpt.toRight(new IsLoading(true))));
}
return(RxVal.cached(F.left <IsLoading, A>(new IsLoading(false))));
});
itemState.subscribe(tracker, e => {
if (e.isRight)
{
discardPreviousRequest();
}
});
currentLoader.zip(priority, request, (show, _priority, req) =>
F.t(show.isSome ? (_priority == LoadPriority.High ? PRIORITY_HIGH : PRIORITY_LOW) : PRIORITY_OFF, req)
).subscribe(tracker, tpl => {
var(_priority, req) = tpl;
foreach (var r in req)
{
r.priority = _priority;
}
});
}
// TODO: test
/// <summary>
/// Convert <see cref="IRxVal{A}"/> to <see cref="IObservable{B}"/>.
///
/// Useful for converting from <see cref="IRxVal{A}"/> to event source. For example:
///
/// <code><![CDATA[
/// someRxVal.map(_ => F.unit)
/// ]]></code>
///
/// would only emit one event, because the result of a map would be a <see cref="IRxVal{A}"/>
/// that has a <see cref="Unit"/> type, which by it's definition only has one value.
///
/// Thus we'd need to use
/// <code><![CDATA[
/// someRxVal.toEventSource(_ => F.unit)
/// ]]></code>
/// </summary>
public static IObservable <B> toEventSource <A, B>(
this IRxVal <A> rxVal, Fn <A, B> mapper
) => new Observable <B>(onEvent =>
rxVal.subscribe(NoOpDisposableTracker.instance, v => onEvent(mapper(v)))
);