nsmanagedobjectcontext

I am really confused by the following paragraph straight from the NSManagedObjectContext documentation : Setter methods on queue-based managed object contexts are thread-safe. You can invoke these methods directly on any thread. The big question is setters methods on the ManagedObjectContext but NOT in the ManagedObjects owned by this context? or is it on both?. Specifically if for a private queue MOC object something like this: [privateContext setPersistentStoreCoordinator:self.persistentStoreCoordinator]; Would be thread safe regardless of the thread executing this line but would something

Phew, sorry for the long title. I have a single Managed Object Context where I am storing songs derived from two different locations. I get some of the songs from the persistent storage on the phone (using Core Data), and I pull some of the songs from an online database. Both of the songs are of the same MananagedObject subclass. I would like both of these songs to be in a single context because I would like them both to show up on a table view connected with an NSFetchedResultsController. The problem occurs when I would like to save one of the songs. I don't want to save all of the songs that

I'm developing an application where I need to both calculate things (multiple seconds operations) and write things (sync data with a server) on a background thread. Because of this I use two NSManagedObjectContexts (MOC), a child and a parent, and these must always be in sync. To make sure they are in sync I always edit/add data to the child MOC so it gets pushed to the main MOC with the following pattern: [childMOC performBlock:^{ MyObject *myObject = *create new object in childMOC* [childMOC save:&error]; [mainMOC performBlock:^{ [mainMOC save:&error]; // Is this mandatory to make it work

I am using RestKit 0.20 to parse JSON data and save to database. THere is a mapped entity SchoolClass, which is handled by RestKit and saves fine. I have another entity called MyClass, which stores the classes I have selected. This one is only local on the device. Here is the code I create and save the MyClass entity NSManagedObjectContext *managedObjCtx = [RKManagedObjectStore defaultStore].mainQueueManagedObjectContext; MyClass* course = [managedObjCtx insertNewObjectForEntityForName:@"MyClass"]; .. set the data for course here NSError *executeError = nil; if(![managedObjCtx save:

I need to delete my persistent store (doing it object by object is not practical because I have over 100,000 objects). I've tried this: - (IBAction)resetDatabase:(id)sender { NSPersistentStore* store = [[__persistentStoreCoordinator persistentStores] lastObject]; NSError *error = nil; NSURL *storeURL = store.URL; // release context and model [__managedObjectContext release]; [__managedObjectModel release]; __managedObjectModel = nil; __managedObjectContext = nil; [__persistentStoreCoordinator removePersistentStore:store error:nil]; [__persistentStoreCoordinator release]; _

I have a main NSManagedObjectContext that's created in the appDelegate . Now, I'm using another NSManagedObjectContext for editing/adding new objects without affecting the main NSManagedObjectContext , until I save them. When I save the second NSManagedObjectContext , the changes are not reflected in the main NSManagedObjectContext , yet if I open the .sqlite database from simulator, the changes have been saved correctly into the .sqlite database. It doesn't matter if I fetch the data again, or even if I create a third NSManagedObjectContext , I cannot see those changes from the second

This topic has been discussed at many forum, but I am still not able to fully understand how performBlockAndWait actually works. As per my understanding, context.performBlockAndWait(block: () -> Void) will perform the block in its own queue while blocking the caller thread. Documentation says that: You group “standard” messages to send to the context within a block to pass to one of these methods. What are the "standard" messages? It also says that: Setter methods on queue-based managed object contexts are thread-safe. You can invoke these methods directly on any thread. Does that mean that I