NSFetchedResultsController init

- (NSFetchedResultsController *)fetchedResultsController {
    // Set up the fetched results controller if needed.
    if (fetchedResultsController == nil) {
        // Create the fetch request for the entity.
        NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
        // Edit the entity name as appropriate.
        NSEntityDescription *entity = [NSEntityDescription entityForName:@"Earthquake"
                                                  inManagedObjectContext:managedObjectContext];
        [fetchRequest setEntity:entity];
        
        // Edit the sort key as appropriate.
        NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"date" 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:managedObjectContext
                                              sectionNameKeyPath:nil
                                                       cacheName:nil];
        self.fetchedResultsController = aFetchedResultsController;
        
        [aFetchedResultsController release];
        [fetchRequest release];
        [sortDescriptor release];
        [sortDescriptors release];
    }
    
    return fetchedResultsController;
}