Question

My app is downloading JSON objects in when the app enters background mode. The app converts them to core data entities. The issue that I’m running in is that I need to merge the managed object contexts for these core data entities with the main managed object context.

The way to merge these changes is through notifications:

 [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(contextHasChanged:) name:NSManagedObjectContextDidSaveNotification object:nil];


- (void)contextHasChanged:(NSNotification*)notification
{

    NSLog(@"received notification with object: %@",[[notification object] description]);
    if ([notification object] == [AppUser managedObjectContext]) return;

    if (![NSThread isMainThread]) {
        [self performSelectorOnMainThread:@selector(contextHasChanged:) withObject:notification waitUntilDone:YES];
        return;
    }

    [[AppUser managedObjectContext] mergeChangesFromContextDidSaveNotification:notification];
}

For some reason my code does not receive these notifications while running in background. Does the app continue to generate notifications while it is running in background mode? Or is it something with the location of where/when I register for such notifications that’s wrong?

Thank you for the clarification!

Answer 1

app continues to send notifications either in main or background. you need to take care of
the observer should not be released during add observer and posting notification. i thnk there may some mistak in implementaion read this

https://developer.apple.com/library/mac/#documentation/Cocoa/Reference/CoreDataFramework/Classes/NSManagedObjectContext_Class/NSManagedObjectContext.html