Change default NSManagedObjectContext of NSPersistentDocument

Question

Core data newbie here. I'm trying to change the default NSManagedObjectContext of an NSPersistentDocument, in order to initialise and use it with NSMainQueueConcurrencyType.

Currently I'm doing it in -windowControllerDidLoadNib: like this:

- (void)windowControllerDidLoadNib:(NSWindowController *)aController
{
    [super windowControllerDidLoadNib:aController];
    NSManagedObjectContext *newMOC = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
    [newMOC setPersistentStoreCoordinator:[self.managedObjectContext persistentStoreCoordinator]];
    [self setManagedObjectContext:newMOC];
}

This seemingly works fine. But I'm wondering if initialisation of the MOC in -windowControllerDidLoadNib: is the best thing to do, or whether it should be placed somewhere else and/or initialised in a different way.

Thanks for any help.

Answer 1

The preferred pattern is the "pass-the-baton" approach where you pass the managed object context down to the child view controllers. Give your controllers a managed object context attribute and simply pass it on when you present them.