how to sort a view-based tableview - ios

Question

I can't manage to sort a view-based tableview. I use an arrayController that control an entity of core data.
I tried to select a column and in the attribute inspector I used as a sort key the attributes name relative to that column and compare: as a selector... when I build and run I click on the header and now display the arrow that change every click, but the nothing happens with the rows. no sorting.
How can I fix it?
I think I'm missing something easy, but I can't get over it.

Answer 1

You may want to consider using an NSFetchedResultsController. From the Apple documentation for NSFetchedResultsController,
You use a fetched results controller to efficiently manage the results returned from a Core Data fetch request to provide data for a UITableView object.
The code looks like this where the line that provides the sort descriptor starts with NSSortDescriptor.
- (NSFetchedResultsController *)fetchedResultsController
{
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"YourEntityName"
inManagedObjectContext:yourManagedObjectContext];
[fetchRequest setEntity:entity];
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"YourSortKey"
ascending:YES];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setSortDescriptors:sortDescriptors];
NSError *error = nil;
NSArray *fetchedObjects = [yourManagedObjectContext executeFetchRequest:fetchRequest
error:&error];
if (fetchedObjects == nil) {
// Handle the error
}
yourFetchedResultsController = [[NSFetchedResultsController alloc]
initWithFetchRequest:fetchRequest
managedObjectContext:self.managedObjectContext
sectionNameKeyPath:nil
cacheName:nil];
return yourFetchedResultsController;
}