I have 3 different view controllers that present same data. Basically they are presented one after another. They are presenting same entity that is fetched with NSFetchedResultsController.
I am now pondering since these are same NSFetchedResultsControllers, should I just optimize things and create one, that I pass between controllers? Is there any downside to this, or even better is this good practice?
Also just passing dataset wouldn't suffice since i want controllers to react to changes to database.
should I just optimize things and create one, that I pass between controllers?
Yes, minimising the overhead of performing a similar fetchRequest on init of every VC is a good practice.
A better alternate instead of passing the NSFetchedResultsControllers object between VCs would be -
To completely abstract out all FetchedResultsControllers initialisation & delegate function implementations to a helper class christened like:
@interface CoreDataHelper: NSObject < NSFetchedResultsControllerDelegate >
You'll need re-wiring of the delegate listeners & choose appropriate time for allocating & if required(not essential) deallocating of the CoreDataHelper instance
A singleton CoreDataHelper will serve you well enough to handle all Core Data interactions.
Segregating Model interactions away & independent from View components enables for creating loosely-coupled modules, making them reusable & succinct.