Creating table sections with NSFetchedResultsController

Question

I'm using NSFetchedResultsController to drive the data for my UITableViewController. A simplified version of the managed object I am fetching looks like this (well for example):

Person:
-(BOOL)hasPet;
-(BOOL)hasDog;

Basically, I want my table to only show those Person objects who have a pet. So that's simple, I can use a predicate. Now, for those who hasPet == YES, I want to put them in the table in 2 sections, first section hasDog == YES, and the second is hasDog == NO. This is where I'm a little fuzzy. Here is where I configure my results controller, hopefully someone can help steer me in the right direction.

- (NSFetchedResultsController *)fetchedResultsController {
if (nil != fetchedResultsController) {
    return fetchedResultsController;
}

NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Homework" inManagedObjectContext:managedObjectContext];
[fetchRequest setEntity:entity];

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"hasPet == %@", [NSNumber numberWithBool:YES]];
[fetchRequest setPredicate:predicate];

NSSortDescriptor *dogDescriptor = [[NSSortDescriptor alloc] initWithKey:@"hasDog" ascending:YES];
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:dogDescriptor, sortDescriptor, nil];

[fetchRequest setSortDescriptors:sortDescriptors];

NSFetchedResultsController *aController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:nil cacheName:nil];
aController.delegate = self;
self.fetchedResultsController = aController;

    // Release things

return fetchedResultsController;
}

Is a sort descriptor where I need to be focusing my attention?

Answer 1

It's simple! Just provide the NSFetchedResultsController with a sectionNameKeyPath (which in this case would be hasDog) in its initializer.

The one caveat to this, however, is the section names will be 0 & 1 respectively, but it's easily curable.