NSFetchRequest with predicate/sort function closures

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I am rebuilding my app's CoreData stack and going to use a unit of work/repository pattern with generics.

My set up is a BaseRepository<T:NSObject> generic class along with a CoreDataRepository<T:NSManagedObject> class that inherits from the base repository.

I have four methods for retrieval: getAll, getAllSorted, getAllFiltered, and lastly getAllFilteredSorted.

The CoreDataRepository will chain the first three get methods into the last one, passing in default values.

Here is the definition of the designated method:

func getAllFilteredSorted(predicate:(T) -> Bool, comparer:(T, T) -> Bool) -> T[]
    {
        let request = NSFetchRequest(entityName: entityName)
        let results = context.executeFetchRequest(request, error: nil)

        // TODO: Set predicate in Swift
        // TODO: Set sort descriptors in Swift

        return results as T[]
    }

However, I cannot find a way to create NSPredicate or NSSortDescriptors with these function closures. NSManagedObjectContext.executeFetchRequest(...) does not have an overload to take them either.

Any ideas on how to accomplish this? I don't mind if I can convert the closures to the proper objects, I just do not want to change my function's parameter definitions.

asked 19 secs ago

SiLo

1,774