public IObservable <IChangeSet <TObject, TKey> > Run()
{
return(Observable.Create <IChangeSet <TObject, TKey> >(observer =>
{
var allData = new Cache <TObject, TKey>();
var filteredData = new ChangeAwareCache <TObject, TKey>();
Func <TObject, bool> predicate = t => false;
var locker = new object();
var refresher = LatestPredicateObservable()
.Synchronize(locker)
.Select(p =>
{
//set the local predicate
predicate = p;
//reapply filter using all data from the cache
return filteredData.RefreshFilteredFrom(allData, predicate);
});
var dataChanged = _source
// .Finally(observer.OnCompleted)
.Synchronize(locker)
.Select(changes =>
{
//maintain all data [required to re-apply filter]
allData.Clone(changes);
//maintain filtered data
filteredData.FilterChanges(changes, predicate);
//get latest changes
return filteredData.CaptureChanges();
});
return refresher
.Merge(dataChanged)
.NotEmpty()
.SubscribeSafe(observer);
}));
}