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    <p>Your design is all needlessly complex and redundant. I think the relationship shows as nil because you've got the wrong class assigned to your <code>self.existingItem</code> property.</p> <p>Firstly, there is no reason to create another context just for another view on the same foreground thread. Just pass the existing context to the next view and save yourself the headache of merging to context for no functional reason.</p> <p>Secondly, this block:</p> <pre><code>}else{ self.existingItem = (Item *)[self.addEditContext objectWithID:[self.existingItem objectID]]; } </code></pre> <p>... is completely pointless because you are setting <code>self.existingItem</code> to itself. You might as well have written:</p> <pre><code>self.existingItem = self.existingItem; </code></pre> <p>... because object ids are fixed in the persistent store once an object as been saved. If the object hasn't been saved then the ID is temporary and the other context won't be able to find it anyway. </p> <p>The most likely cause of the problem is with the definition of the <code>existingItem</code> property. If you defined it as <code>id</code> or <code>NSManagedObject</code> then it won't respond to the the <code>title</code> selector and will return nil. It would error out but you've cast it as a <code>Item</code> so the compiler thinks it will respond to all the messages that an <code>Item</code> object would. </p> <p>Don't use cast unless you know you will be forcing an object to mimic another. Otherwise, you are just creating opportunities to hide errors from the compiler. </p>
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    1. POCore Data - relationship goes nil unexpectedly
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    1. USTechZen
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      1. VTUpMod
    1. COThanks for your comments. existingItem is definitely set as @property(retain,nonatomic) Item *existingItem so that's not it. The reason I created another context is that I want to let the user make a bunch of changes to the existingItem (or when adding a new one), but there's a cancel button on the page to rollback everything in case the user decides. I felt the simplest way to do this would be to create a separate context, so that the changes don't affect the main thread's context. Is there a better way to do this?
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    2. COI also tried using a NSUndoManager to track and rollback changes, instead of multiple contexts. But it also has the same problem. The 'title' relationship is fine in RootView's didSelectRowAtIndexPath, till the point when it calls [self presentModalViewController:navController animated:YES] and then it just disappears from both the RootView and the DetailView. Now with UndoManager, when the edits are cancelled, the title is restored on the view, but it's still not showing up in the DetailView (even though everything's on the same context). Does this suggest anything I might be doing wrong?
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    3. COAlso, I added another relationship (1-to-1) which works fine and shows up in the DetailView. The title relationship is many-to-one (from Items to title ... so a title can be associated with multiple items, but each Item has one title).
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