fetchedResultsController.fetchedObjects.count = 0 but it is full of objects - ios

Question

I am using pretty standard implementation of fetchedResultsController for output in tableView. In the end of -viewDidLoad I am making first call:
NSError *error = nil;
if (![[self fetchedResultsController] performFetch:&error])
{
NSLog(#"Error! %#",error);
abort();
}
this is my fetchedResultsController:
- (NSFetchedResultsController *) fetchedResultsController
{
if (_fetchedResultsController != nil)
{
return _fetchedResultsController;
}
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Preparation"
inManagedObjectContext:_context];
[fetchRequest setEntity:entity];
int i = 1;
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"ismer == %d", i];
fetchRequest.predicate = predicate;
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"name" ascending:YES];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects: sortDescriptor, nil];
fetchRequest.sortDescriptors = sortDescriptors;
_fetchedResultsController = [[NSFetchedResultsController alloc]initWithFetchRequest:fetchRequest managedObjectContext:_context sectionNameKeyPath:nil cacheName:nil];
_fetchedResultsController.delegate = self;
NSLog(#"_fetchedResultsController.fetchedObjects.count - %d", _fetchedResultsController.fetchedObjects.count);
return _fetchedResultsController;
}
my tableView methods:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [[self.fetchedResultsController sections]count];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
id <NSFetchedResultsSectionInfo> secInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
return [secInfo numberOfObjects];
}
- (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];
}
CDPreparation *drug = (CDPreparation *)[self.fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = [NSString stringWithFormat:#"%#", drug.name];
return cell;
}
So, question is:
in log of _fetchedResultsController.fetchedObjects.count is equal to 0, but visually tableView is filled with objects. Why I have two different results for count?

Answer 1

An NSFetchedResultsController doesn't actually perform the fetch request until you call performFetch:, so the result count is 0.
If you log fetchedObjects.count after calling performFetch:, you'll see a number which matches the tableView row count.