/// <summary>
/// Returns a observable of cache changes preceeded with the initital cache state
/// </summary>
/// <param name="predicate">The result will be filtered using the specfied predicate.</param>
/// <returns></returns>
public IObservable <IChangeSet <TObject, TKey> > Connect(Func <TObject, bool> predicate = null)
{
return(Observable.Create <IChangeSet <TObject, TKey> >
(
observer =>
{
if (predicate == null)
{
return Observable.Return(_innerCache.AsInitialUpdates())
.Concat(_changes)
.SubscribeSafe(observer);
}
var updater = new FilteredUpdater <TObject, TKey>(new ChangeAwareCache <TObject, TKey>(), predicate);
var filtered = updater.Update(_innerCache.AsInitialUpdates(predicate));
if (filtered.Count != 0)
{
observer.OnNext(filtered);
}
return _changes
.Select(updater.Update)
.NotEmpty()
.SubscribeSafe(observer);
}));
}