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    <p>Haven't tried this myself, but take a look at <code>NSManagedObjectContextWillSaveNotification</code>. I would try registering for those notifications coming from background context. Then in the handler you could do a synchronous dispatch to main thread and pass contexts' deleted object IDs:</p> <pre><code>- (void)handleBackgroundSave:(NSNotification *)note { NSManagedObjectContext *context = [note object]; NSSet *deletedObjectIDs = [[context deletedObjects] valueForKey:@"objectID"]; dispatch_sync(dispatch_get_main_queue(), ^{ // deletedObjectIDs can be passed across threads // if NSFetchedResultsController's fetchedObjects contains deleted objects // you have to disable it and refetch after DidSaveNotification }); } </code></pre> <p>Since the dispatch is synchronous, it should block actual deletion until you deal with it in main thread's context. Keep in mind this wasn't tested and may result in some nasty deadlocks.</p> <p>Another thing worth pointing out is that interactive updates (as in <code>NSFetchedResultsControllerDelegate</code> implementation) will hog UI thread when there's a lot of objects changing (like hundreds/thousands), so if you replace all of your Core Data objects during refresh you may as well disable frc on every WillSave and refetch on every DidSave. </p> <p>If you can afford targeting iOS 5+ then I would suggest exploring nested contexts - <a href="http://www.cocoanetics.com/2012/07/multi-context-coredata/" rel="nofollow">here is a nice overview of approaches</a>.</p>
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    1. POCrashing issue in using UITableViewController and Core Data
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    1. USJustin Boo
    1. USpwgr
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    1. COThanks. I will try your suggestion and see if works.
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      1. USBilly Kan
    2. COHi pwgr, I have experimented your ideas. The NSManagedObjectContextWillSaveNotification doesn't help because the notification itself was posted asynchronously so while my handler is synchronous, the MOC save will proceed without waiting my handler's completion.
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    3. CONow what I did is borrow your NSManagedObjectContextWillSaveNotification idea by defining a delegate on my refresh module such that it'd call my delegate methods before and after the refresh. I then set my table view controller to be the delegate and therefore be able to do something before the refresh. Taking your advice, I'd want to disable frc before the refresh and then enable it again after the refresh. My question is: how can I "disable" a frc?
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Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

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