UITable won't refresh even with reload called on main thread - ios

Question

I have a main view controller(SecondViewController) with a UITable and a navigation controller. When a navigation bar button is pressed, a menu drops down from the navigation bar on top of the table. This menu is created by adding a view controller as a subview like so:
//SecondViewController.m
self = sortMenu.secondVC;
[self addChildViewController:sortMenu];
[self.view addSubview:sortMenu.view];
[sortMenu didMoveToParentViewController:self];
sortMenu contains a button that changes the order the cells are displayed in by calling a class method of the main view controller.
//SortMenuViewController.m
- (IBAction)sortButtonPressed:(id)sender {
[_secondVC sortButtonPressed:[sender tag]];
}
In sortButtonPressed, it calls a method to make a fetch request with updated sort filter value.
//SecondViewController.m
-(void)sortButtonPressed:(NSInteger)sortDescriptor{
_sortDescriptor = sortDescriptor;
currentPredicate = [NSPredicate predicateWithFormat:#"dataset & %d > 0", 4];
[self fetchResultsUsingSegmentedControlIndex];
}
The fetch request is performed and returns the data in a new order.
//SecondViewController.m
- (IBAction)fetchResultsUsingSegmentedControlIndex
{
NSString* sectionNameKeyPath = nil;
NSArray* sortDescriptors = nil;
NSSortDescriptor *scientificNameDescriptor = [[NSSortDescriptor alloc] initWithKey:#"scientificName" ascending:YES];
NSSortDescriptor *commonNameFirstDescriptor = [[NSSortDescriptor alloc] initWithKey:#"commonNameFirst" ascending:YES];
NSSortDescriptor *commonNameLastDescriptor = [[NSSortDescriptor alloc]
initWithKey:#"commonNameLast"
ascending:YES
selector:#selector(localizedCaseInsensitiveCompare:)];
if (_sortDescriptor == kSortByCommonNameFirst )
{
sortDescriptors = [[NSArray alloc] initWithObjects:commonNameFirstDescriptor, commonNameLastDescriptor, scientificNameDescriptor, nil];
sectionNameKeyPath = #"commonNameFirst";
}
else if (_sortDescriptor == kSortByCommonNameLast )
{
sortDescriptors = [[NSArray alloc] initWithObjects:commonNameLastDescriptor, commonNameFirstDescriptor, scientificNameDescriptor, nil];
sectionNameKeyPath = #"commonNameLast";
}
else if (_sortDescriptor == kSortByScientificName )
{
sortDescriptors = [[NSArray alloc] initWithObjects:scientificNameDescriptor, commonNameFirstDescriptor, commonNameLastDescriptor, nil];
sectionNameKeyPath = #"scientificName";
}
NSError *error;
NSLog(#"current predicate: %#", currentPredicate);
[[self fetchedResultsControllerWithsectionNameKeyPath:sectionNameKeyPath sortDescriptors:sortDescriptors predicate:currentPredicate] performFetch:&error];
[scientificNameDescriptor release];
[commonNameLastDescriptor release];
[commonNameFirstDescriptor release];
[sortDescriptors release];
NSUInteger sectionsCt = [[speciesFetchedResultsController sections] count];
int sum = 0;
for (int i=1; i < sectionsCt; i++){
id <NSFetchedResultsSectionInfo> sectionInfo = [[speciesFetchedResultsController sections] objectAtIndex:i];
NSUInteger numOfObj = [sectionInfo numberOfObjects];
NSLog(#" in section %d number of objects is %lu ", i, (unsigned long)numOfObj);
sum = sum + numOfObj;
}
[_table performSelectorOnMainThread:#selector(reloadData)
withObject:nil
waitUntilDone:NO];
}
When I call fetchResultsUsingSegmentedControlIndex from the main view controller (before dropping down the sort menu), it works correctly. However, when called from sortMenu, numberOfRowsInSection, numberOfSectionsInTableView, and cellForRowAtIndexPath are not called. I have tried to call reloadData on the main thread with performSelectorOnMainThread and also dispatching it to the main queue, but neither works.
I originally created a sort menu by adding a pickerview to the main view controller on pressing the navigation bar button, and my table reloaded correctly. Since creating a separate view controller for the menu (to have greater design control), it doesn't work.

Answer 1

Ended up using delegation.
// SortMenuViewController.h
#import <UIKit/UIKit.h>
#protocol SortMenuViewControllerDelegate <NSObject>
-(void)sortButtonPressed:(NSInteger)sortDescriptor;
-(void)viewButtonPressed:(NSInteger)viewDescriptor;
#end
#interface SortMenuViewController : UIViewController{
}
//SortMenuViewController.m
- (IBAction)changeSort:(id)sender {
[_delegate sortButtonPressed:[sender tag]];
}
//SecondViewController.h
#interface SecondViewController : UIViewController <NSFetchedResultsControllerDelegate, SortMenuViewControllerDelegate>{
}
-(void)sortButtonPressed:(NSInteger)sortDescriptor{
_sortDescriptor = sortDescriptor;
currentPredicate = [NSPredicate predicateWithFormat:#"dataset & %d > 0", dataset];
[self fetchResultsUsingSegmentedControlIndex];
}