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POCore Data: updating a managed object doesn't call the NSFetchedResultsControllerDelegate
 

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  1. POCore Data: updating a managed object doesn't call the NSFetchedResultsControllerDelegate
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    <p>I have an issue with my table view not updating when I programmatically change some existing managed object property. I would expect my <code>NSFetchedResultsControllerDelegate</code> to be called in such case, but it isn't.</p> <p>Apple doc says:</p> <blockquote> <p>An instance of <code>NSFetchedResultsController</code> uses methods in this protocol to notify its delegate that the controller’s fetch results have been changed due to an add, remove, move, or <strong>update</strong> operations.</p> </blockquote> <p>In more details, my managed object as an int property called <code>status</code> that takes values from an <code>enum</code>. My table view only display those objects which have their <code>status</code> equal to <code>upToDate</code> (one of the enum's values). To do so, my FetchedResultController has a predicate that tests for that status:</p> <pre><code>predicate = [NSPredicate predicateWithFormat:@"doc.status == %d", upToDate]; </code></pre> <p>It works fine, but updates are not reflected when I change an out-of-date object back to status <code>upToDate</code>. My code is modified from Apple's template.</p> <p>Here is what I tried:</p> <pre><code>myObject.status = [NSNumber numberWithInt:upToDate]; [managedObjectContext save:nil]; [managedObjectContext processPendingChanges]; [myTableView reloadData]; </code></pre> <p>And finally, I managed to have my table view update with a call to:</p> <pre><code>[fetchedResultsController performFetch:&amp;error]; [myTableView reloadData]; </code></pre> <p>But even then, none of my <code>NSFetchedResultsControllerDelegate</code> methods get called, in contradiction with Apple's doc. Additionally, no smooth animation happen.</p> <p>I expected <code>controllerWillChangeContent:</code>, <code>controller:didChangeObject:atIndexPath:forChangeType:newIndexPath:</code>, and <code>controllerDidChangeContent:</code> to be called.</p> <p>I suppose I missed something, possibly something obvious, but I can't see what. Does <code>performFetch:</code> need to be called every time some managed object potentially changes? When does the <code>NSFetchedResultsControllerD</code> <em>really</em> call its delegate?</p> <p>Thanks.</p>
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    1. USJean-Denis Muys
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      1. POCore Data: updating a managed object doesn't call the NSFetchedResultsControllerDelegate
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    1. COAny solutions you found for this behavior? Am facing similar situations where my delegate callbacks are never triggered for an update operation. Addition of new objects or deletion of existing objects anyhow does call the delegate method though. What might be the reason?
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      1. POCore Data: updating a managed object doesn't call the NSFetchedResultsControllerDelegate
      1. USRaj Pawan Gumdal
 

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