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POCannot get Core Data to Delete Table View Row
 

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  1. POCannot get Core Data to Delete Table View Row
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    <p>I am getting the following error:</p> <pre><code>Unresolved error (null), (null) </code></pre> <p>Any ideas what this could be related to - I am trying to allow the users a swipe option to delete an item from Core Data... Adding &amp; Displaying the data works - however deleting shows the error...</p> <pre><code>@implementation List @synthesize eventsArray; @synthesize managedObjectContext, fetchedResultsController, List; ... - (void)viewDidLoad { [super viewDidLoad]; if (managedObjectContext == nil) { managedObjectContext = [(ApplicationAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; } UIBarButtonItem *editButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemEdit target:self action:@selector(editAction)]; self.navigationItem.leftBarButtonItem = editButton; [editButton release]; UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target: self action:@selector(addAction)]; self.navigationItem.rightBarButtonItem = addButton; [addButton release]; } - (void)viewDidUnload { [super viewDidUnload]; self.fetchedResultsController.delegate = nil; } - (void)viewWillAppear:(BOOL)animated { [super viewWillAppear:animated]; List = [[NSMutableArray alloc] init]; NSError *error; NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Items" inManagedObjectContext:managedObjectContext]; [fetchRequest setEntity:entity]; NSArray *fetchedObjects = [managedObjectContext executeFetchRequest:fetchRequest error:&amp;error]; for (NSManagedObject *info in fetchedObjects) { [List insertObject:[info valueForKey:@"Name"] atIndex:0]; } [fetchRequest release]; [self.tableView reloadData]; } ... #pragma mark - Table view data source - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { // Return the number of sections. return 1; } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { // Return the number of rows in the section. return [List count]; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease]; } // Get and display the values for the keys; the key is the attribute name from the entity cell.textLabel.text = [List objectAtIndex:indexPath.row]; // Add a standard disclosure for drill-down navigation cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator; return cell; } -(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath { if (editingStyle == UITableViewCellEditingStyleDelete) { NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext]; [context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]]; // Save the context. NSError *error = nil; if (![context save:&amp;error]) { /* Replace this implementation with code to handle the error appropriately. abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button. */ NSLog(@"Unresolved error %@, %@", error, [error userInfo]); abort(); } } } - (void)dealloc { [fetchedResultsController release]; [List release]; [super dealloc]; } @end </code></pre>
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USMatt Clements
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
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      1. PTAnswer
    1. This table or related slice is empty.
    1. COare you using multiple threads in your application ? Like using the same context in different threads or something ?
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      1. POCannot get Core Data to Delete Table View Row
      1. USHeikoG
    2. CO@HeikoG - I don't believe so....
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      1. POCannot get Core Data to Delete Table View Row
      1. USMatt Clements
 

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Guidance
A row detail

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.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

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