CODEWITHSUNDEEP
iosobjective-cuitableviewcore-datansfetchedresultscontroller
CodeLover
CodeLover

Reputation: 155

Can't fetch number of cells in tableView

I have a main tableViewController, touch a button self.navigation will push addItem viewController, click save self.navigation with pop the add VC, then we're back on the main one, I successfully add and save, also fetch, but when it comes to fetching number of cells, number returns 0, heres the method

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{

id <NSFetchedResultsSectionInfo> secInfo = [[self.fetchedResultsController sections]     objectAtIndex:section];
NSLog(@"No. of cells determined: %lu", (unsigned long)[secInfo numberOfObjects]);
return[secInfo numberOfObjects];

}

NSLog gives me 0, whats the problem, this gave me headache.

Here's the fetch request:

- (NSFetchedResultsController*) fetchedResultsController {

// Fetch Request
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Goal"
                                          inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];

NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"title"
                                                               ascending:NO];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setSortDescriptors:sortDescriptors];




// setting _fethcedResultsController
_fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
                                                                managedObjectContext:self.managedObjectContext
                                                                  sectionNameKeyPath:nil
                                                                           cacheName:nil];




// setting _fetchedResultsController to self
_fetchedResultsController.delegate = self; // for the tableview updating thing



// Thats it
return _fetchedResultsController;

}

Please note that when I run a check for items, it's not nil:

// fetching all items to check how many of them exists
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
[fetchRequest setEntity: [NSEntityDescription entityForName:@"Goal"
                                     inManagedObjectContext:self.managedObjectContext]];
NSManagedObjectContext *moc = self.managedObjectContext;

NSError *fetchError = nil;
NSArray *goals = [moc executeFetchRequest:fetchRequest error:&fetchError];

NSLog(@"No. of goals: %lu", (unsigned long)[goals count]);
// end of check for items

Upvotes: 1

Views: 151

Answers (1)

CodeLover
CodeLover

Reputation: 155

I forgot to put this code of line: 

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

in method

- (NSFetchedResultsController*) fetchedResultsController;

so before I did, the app always creates new fetchedResultsController and over-write the old one.

Upvotes: 1

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