RestKit and Collapsible Menu, synchronize with Core Data - core-data

Question

I'm using RestKit and RRNCollapsableTable. The problem is, when I load view for the first time, RestKit is downloading data from JSON. That delay causes menu to not load. What I'm trying to do is to make CollapsableTable wait for data.
[self requestData:^(BOOL success) {
if (success) {
_menu = [self buildMenu];
[self model];
}
}];
- (void)requestData:(void (^)(BOOL success))completionBlock {
NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:#"Messages"];
NSSortDescriptor *byId = [NSSortDescriptor sortDescriptorWithKey:#"customNewsId" ascending:YES];
fetchRequest.sortDescriptors = #[byId];
NSError *error = nil;
// Setup fetched results
self.fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
managedObjectContext:[RKManagedObjectStore defaultStore].mainQueueManagedObjectContext
sectionNameKeyPath:#"customNewsId"
cacheName:nil];
//[self.fetchedResultsController setDelegate:self];
BOOL fetchSuccessful = [self.fetchedResultsController performFetch:&error];
if (!fetchSuccessful) {
abort();
}
[[RKObjectManager sharedManager] getObjectsAtPath:#"api/json/get/bZmroLaBCG" parameters:nil success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
RKLogInfo(#"Load complete: Table should refresh...");
//[[NSUserDefaults standardUserDefaults] setObject:[NSDate date] forKey:#"LastUpdatedAt"];
//[[NSUserDefaults standardUserDefaults] synchronize];
NSError *error = nil;
if ([[RKManagedObjectStore defaultStore].mainQueueManagedObjectContext hasChanges] && ![[RKManagedObjectStore defaultStore].mainQueueManagedObjectContext saveToPersistentStore:&error]) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
completionBlock(YES);
} failure:^(RKObjectRequestOperation *operation, NSError *error) {
RKLogError(#"Load failed with error: %#", error);
completionBlock(NO);
}];
completionBlock(YES);
}
Then BuildMenu is just iterating over fetched objects and put them in section.
-(NSArray *)buildMenu {
__block NSMutableArray *collector = [NSMutableArray new];
NSInteger sections = [self.fetchedResultsController.sections count];
for (NSInteger i = 0; i < sections; i++) {
Messages *message = [_fetchedResultsController objectAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:i]];
MenuSection *section = [MenuSection new];
section.items = #[message.message,message.pushNotificationMessage];
section.title = message.title;
NSLog(#"section.title - %#",section.title);
[collector addObject:section];
}
return [collector copy];
}
Method model is responsible for DataSource for CollapsableTable.
-(NSArray *)model {
return _menu;
}
Thanks in advance for any help.
Greetings.