private IObservable <RedundantCollection <TParam, TResult> > FetchDataAndJoin <TResult, TParam>(Func <IVideoItemsStoreReader, IEnumerable <TParam>, IObservable <IEnumerable <TResult> > > fetchData, Action <IVideoItemsStoreWriter, IEnumerable <TResult> > writeData, RedundantCollection <TParam, TResult> collection)
{
return(fetchData(_externalStoreReader, collection.OnlyNotJoined)
.Where(e => e != null)
.Do(e => writeData(_localStoreWriter, e))
.Select(e => collection.JoinIfEmpty(e)));
}
public static RedundantCollection <T, TOuter> JoinIfEmpty <T, TOuter>(this RedundantCollection <T, TOuter> redundantCollection, IEnumerable <TOuter> joinedCollection,
Func <T, TOuter, bool> joinPredicate = null)
{
redundantCollection.JoinIfEmpty(joinedCollection, joinPredicate);
return(redundantCollection);
}