newrequestviewcontroller.m

- (void)viewDidLoad {
  [super viewDidLoad];
  UIBarButtonItem *saveButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemSave target:self action:@selector(createRequest)];
  self.navigationItem.rightBarButtonItem = saveButton;
  [saveButton release];
  self.request = [NSEntityDescription insertNewObjectForEntityForName:@"Request" inManagedObjectContext:self.context];
}

- (void)createRequest
{
  self.request.timestamp = [NSDate date];

  NSError *error = nil;
  if (![self.context save:&error]) {
    NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
    abort();
  }
  [self.navigationController popViewControllerAnimated:YES];
}

rootviewcontroller.m

- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath {

  Request *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
  cell.textLabel.text = [[managedObject valueForKey:@"title"] description];
}


#pragma mark -
#pragma mark Add a new object

- (void)showNewRequestView
{
  NewRequestViewController* nr = [[NewRequestViewController alloc] init];
  nr.context = self.fetchedResultsController.managedObjectContext;
  [self.navigationController pushViewController:nr animated:YES];
  [nr release];
}



#pragma mark -
#pragma mark Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
  return [[self.fetchedResultsController sections] count];
}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
    return [sectionInfo numberOfObjects];
}


// Customize the appearance of table view cells.
- (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];
  }

  // Configure the cell.
  [self configureCell:cell atIndexPath:indexPath];

  return cell;
}



/*
// Override to support conditional editing of the table view.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath {
// Return NO if you do not want the specified item to be editable.
return YES;
}
*/


// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {

  if (editingStyle == UITableViewCellEditingStyleDelete) {
    // Delete the managed object for the given index path
    NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
    [context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]];

    // Save the context.
    NSError *error = nil;
    if (![context save:&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();
    }
  }   
}


- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath {
  // The table view should not be re-orderable.
  return NO;
}


#pragma mark -
#pragma mark Table view delegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
  // Navigation logic may go here -- for example, create and push another view controller.
  Request *selectedObject = [[self fetchedResultsController] objectAtIndexPath:indexPath];
  // ...
  DetailViewController* detailViewController = [[DetailViewController alloc] init];
  detailViewController.item = selectedObject;
  [self.navigationController pushViewController:detailViewController animated:YES];
  [detailViewController release];
}


#pragma mark -
#pragma mark Fetched results controller

- (NSFetchedResultsController *)fetchedResultsController {

  if (fetchedResultsController_ != nil) {
    return fetchedResultsController_;
  }

  /*
     Set up the fetched results controller.
     */
  // Create the fetch request for the entity.
  NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
  // Edit the entity name as appropriate.
  NSEntityDescription *entity = [NSEntityDescription entityForName:@"Request" inManagedObjectContext:self.managedObjectContext];
  [fetchRequest setEntity:entity];

  // Set the batch size to a suitable number.
  [fetchRequest setFetchBatchSize:20];

  // Edit the sort key as appropriate.
  NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"timestamp" ascending:NO];
  NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];

  [fetchRequest setSortDescriptors:sortDescriptors];

  // Edit the section name key path and cache name if appropriate.
  // nil for section name key path means "no sections".
  NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:@"Root"];
  aFetchedResultsController.delegate = self;
  self.fetchedResultsController = aFetchedResultsController;

  [aFetchedResultsController release];
  [fetchRequest release];
  [sortDescriptor release];
  [sortDescriptors release];

  NSError *error = nil;
  if (![fetchedResultsController_ performFetch:&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();
  }

  return fetchedResultsController_;
}    


#pragma mark -
#pragma mark Fetched results controller delegate


- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
  [self.tableView beginUpdates];
}


- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
           atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type {

             switch(type) {
               case NSFetchedResultsChangeInsert:
                  [self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
                  break;

               case NSFetchedResultsChangeDelete:
                  [self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
                  break;
             }
           }


- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
       atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
      newIndexPath:(NSIndexPath *)newIndexPath {

        UITableView *tableView = self.tableView;

        switch(type) {

          case NSFetchedResultsChangeInsert:
          [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
          break;

          case NSFetchedResultsChangeDelete:
          [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
          break;

          case NSFetchedResultsChangeUpdate:
                        [self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
                        break;

          case NSFetchedResultsChangeMove:
        [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
        [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
        break;
        }
      }


- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
  [self.tableView endUpdates];
}


/*
// Implementing the above methods to update the table view in response to individual changes may have performance implications if a large number of changes are made simultaneously. If this proves to be an issue, you can instead just implement controllerDidChangeContent: which notifies the delegate that all section and object changes have been processed. 

- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
// In the simplest, most efficient, case, reload the table view.
[self.tableView reloadData];
}
*/


#pragma mark -
#pragma mark Memory management

- (void)didReceiveMemoryWarning {
  // Releases the view if it doesn't have a superview.
  [super didReceiveMemoryWarning];

  // Relinquish ownership any cached data, images, etc that aren't in use.
}


- (void)viewDidUnload {
  // Relinquish ownership of anything that can be recreated in viewDidLoad or on demand.
  // For example: self.myOutlet = nil;
}


- (void)dealloc {
  [fetchedResultsController_ release];
  [managedObjectContext_ release];
  [super dealloc];
}