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PORefresh NSFetchedResultsController data?
 

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    <p>I can create new managed objects inside my app, in a separate view I have a table view which shows all the objects I have.</p> <p>When I create a new managed object (in a totally separate view), I am sending out a notification which is trying to get my table view to reload with the new data which includes the new object i just made. </p> <p>I'm not editing the table view. </p> <p>There is only one managed context. </p> <p>I can't grasp what I am doing wrong. If I close the app and relaunch my new object is in the table view. I am trying to call reloadData when I get the notification a new object has been made, and I've also tried performing the fetch again, but all I end up with is an empty table view.</p> <p>In terms of code, my ListViewController:</p> <pre><code>@interface MyNotesViewController : UIViewController { NSManagedObjectContext * __managedObjectContext; UITableView * _notesTableView; MyNotesTableViewDelegate_DataSource * _tableDelegate_DataSource; } </code></pre> <p>My viewDidLoad looks like this:</p> <pre><code>- (void)viewDidLoad { [super viewDidLoad]; _tableDelegate_DataSource = [[MyNotesTableViewDelegate_DataSource alloc] init]; _tableDelegate_DataSource.managedObjectContext = __managedObjectContext; [_notesTableView setDataSource:_tableDelegate_DataSource]; NSError * _coreDataError; BOOL success = [[_tableDelegate_DataSource fetchedResultsController] performFetch:&amp;_coreDataError]; if(success){ [_notesTableView reloadData]; } } </code></pre> <p>In my delegate/datasource object I have:</p> <pre><code>@interface MyCommutesTableViewDelegate_DataSource : NSObject &lt;UITableViewDataSource, NSFetchedResultsControllerDelegate&gt; { NSManagedObjectContext * __managedObjectContext; NSFetchedResultsController * __fetchedResultsController; } @property (nonatomic, retain) NSManagedObjectContext *managedObjectContext; @end </code></pre> <p>Implementation excerpt:</p> <pre><code>-(NSFetchedResultsController*)fetchedResultsController{ if(!__fetchedResultsController){ NSFetchRequest * request = [[NSFetchRequest alloc] init]; [request setEntity:[NSEntityDescription entityForName:@"Note" inManagedObjectContext:__managedObjectContext]]; [request setFetchBatchSize:10]; NSSortDescriptor * sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"noteDate" ascending:NO]; [request setSortDescriptors:[NSArray arrayWithObject:sortDescriptor]]; [sortDescriptor release]; __fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:request managedObjectContext:__managedObjectContext sectionNameKeyPath:nil cacheName:nil]; __fetchedResultsController.delegate = self; [request release]; } return __fetchedResultsController; } </code></pre> <p>I have the stander UITableView data source methods here:</p> <pre><code>- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return 1; } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{ id &lt;NSFetchedResultsSectionInfo&gt; sectionInfo = [[__fetchedResultsController sections] objectAtIndex:section]; return [sectionInfo numberOfObjects]; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"NotesTableViewCell"; NotesTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { NSArray * topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"NotesTableViewCell" owner:nil options:nil]; for(id currentObject in topLevelObjects){ if([currentObject isKindOfClass:[UITableViewCell class]]){ cell = (NotesTableViewCell*) currentObject; break; } } } // Configure the cell. Note * _note = [__fetchedResultsController objectAtIndexPath:indexPath]; [...] return cell; } </code></pre> <p><strong>UPDATE</strong></p> <p>I reverted to simply requesting all objects because I had to quick fix my problem, and then I realised, after I save my context, my fetch request I had previously used on the app launch, now returns no data, there's no error but it just returns nothing.</p> <p>So I guess there's no issue with how I'm implementing NSFetchResultsController. But how could the request start not returning results after I save a new object ? </p> <p>Note I still get all of my objects if I relaunch, including the newly added one.</p> <p>standard request:</p> <pre><code>-(NSArray*)getNotes{ NSFetchRequest * request = [[NSFetchRequest alloc] init]; NSEntityDescription * entity = [NSEntityDescription entityForName:@"Note" inManagedObjectContext:[self managedObjectContext]]; [request setEntity:entity]; NSSortDescriptor * sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"noteDate" ascending:NO]; [request setSortDescriptors:[NSArray arrayWithObject:sortDescriptor]]; [sortDescriptor release]; NSError * coreDataError; NSArray * fetchedObjects = [[self managedObjectContext] executeFetchRequest:request error:&amp;coreDataError]; [request release]; if(fetchedObjects != nil){ return fetchedObjects; } else { NSLog(@"ERR: %@", coreDataError); return nil; } } </code></pre> <p>I am waiting for a notification telling me a new object has been added to Core Data, and then I am calling the above method and then calling reloadData on my tableview... </p>
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