Strange behavior when using child/parent NSManagedObjectContext

Question

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.

Bec

Answer 1

My solution was to:

1) Use the background MOC as the parent MOC and the main MOC as a child. As a bonus I don't need to save the main MOC to get the permanent IDs.

[DC.backgroundMOC performBlock:^{
    // Add, save and update managed objects
    [DC saveContext]; // The changes is being pushed to the main context
}];

2) Use NSManagedObjectContextDidSaveNotification to keep the main MOC up to date (the main MOC is updating the UI)

- (void) backgroundMOCSaved:(NSNotification*)notification {
    [mainMOC performBlock:^{
        [mainMOC mergeChangesFromContextDidSaveNotification:notification];
    }];
}