CocoaDev

Hello, I’m just getting starting with Core Data, so this may be a silly question…

I’m trying to create a second managed object context, using the same persistent store coordinator, e.g.:

[ ManagedObjectContext provided by NSPersistentDocument] [ My own ManagedObjectContext ] | | | | [ Persistent Store Coordinator provided by NSPersistentDocument ]

I seem to be able to accomplish this using the following code:

//Get the persistent store coordinator of the current document
newContext = [[NSManagedObjectContext alloc] init];
NSPersistentStoreCoordinator *coordinator = self managedObjectContext] persistentStoreCoordinator];
[newContext setPersistentStoreCoordinator:coordinator];

// Add an object to the new context
[[NSManagedObject *newEntity = [NSEntityDescription insertNewObjectForEntityForName:@"Entity" newContext]; 
[newEntity setValue:@"Value" forKey:@"value"]; 

The problem is that this second context does not seem to be saved (everything in the first context is saved properly). So I tried to save the second context explicitly, using the save: method. However, I got an error message saying that “This NSPersistentStoreCoordinator has no persistent stores. It cannot perform a save operation” But I was able to save everything in the first context…

How can I save the objects that are in the second context?

Thanks for any help.

Take a look at MultipleStoresInCoreDataDocumentApp

Thanks for the suggestion. It gave me some ideas. I’ve now managed to get the NSPersistentStoreCoordinator to save the two contexts using [newContext save:nil]. I don’t know why this did not work before…