NSFetchedResultsController custom sort not getting called

Question

I am currently trying to populate a UITableView in my project from Core Data using NSFetchedResultsController. I am using a custom search with a comparator (although I have

Answer 1

There are a couple of things I can think of. First, though this may not be your problem, you cannot sort on transient properties. But more likely is that when sorting in a model backed by a SQL store, the comparator gets "compiled" to a SQL query, and not all Objective-C functions are available. In this case, you'd need to sort in memory after the fetch is performed.

EDIT: See this doc, specifically the Fetch Predicates and Sort Descriptors section.