Objective C - NSManagedObjectContext and NSFetchedResultsController release handling - objective-c

Question

i need some information about memory management with NSManagedObjectContext objects.
I`m programming on an ipad-App and i work with core data objects.
My UIApplicationDelegate controls the NSManagedObjectContext:
- (NSManagedObjectContext *)managedObjectContext {
if (__managedObjectContext != nil)
{
return __managedObjectContext;
}
NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if (coordinator != nil)
{
__managedObjectContext = [[NSManagedObjectContext alloc] init];
[__managedObjectContext setPersistentStoreCoordinator:coordinator];
}
return __managedObjectContext;
}
I`m using instances of the ManagedObjectContext to display my Core Data Objects.
like this.
example table view controller:
CRMAppDelegate *appDelegate = (CRMAppDelegate*) [[UIApplication sharedApplication] delegate];
self.managedObjectContext = appDelegate.managedObjectContext;
// Initialize NSFetchedResultsController to retrieve data from the database.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
[fetchRequest setEntity:[NSEntityDescription entityForName:#"Contact" inManagedObjectContext:self.managedObjectContext]];
// Sort results ascending by last name, first name.
NSSortDescriptor *sortDescriptorFirstLetterLastName = [[NSSortDescriptor alloc] initWithKey:#"firstLetterOfLastName" ascending:YES];
NSSortDescriptor *sortDescriptorLastName = [[NSSortDescriptor alloc] initWithKey:#"name_last" ascending:YES];
NSSortDescriptor *sortDescriptorFirstName = [[NSSortDescriptor alloc] initWithKey:#"name_first" ascending:YES];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptorFirstLetterLastName, sortDescriptorLastName, sortDescriptorFirstName, nil];
[fetchRequest setSortDescriptors:sortDescriptors];
[sortDescriptors release];
[sortDescriptorFirstLetterLastName release];
[sortDescriptorFirstName release];
[sortDescriptorLastName release];
/*
if ([self.managedObjectContext countForFetchRequest:fetchRequest error:NULL] == 0) {
[self reloadContactData];
}
*/
// Create NSFetched Results controller instance.
fetchedResultsController = [[NSFetchedResultsController alloc]
initWithFetchRequest:fetchRequest
managedObjectContext:self.managedObjectContext
sectionNameKeyPath:#"firstLetterOfLastName"
cacheName:#"ContactsViewCache"];
[fetchRequest release];
self.fetchedResultsController.delegate = self;
// Load data.
NSError *error;
if (![fetchedResultsController performFetch:&error]) {
// Update to handle the error appropriately.
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
}
Is it ok to instance the NSManagedObjectContext like this? Because, the retainCount of the context is increasing til 10 while i`m testing my APP, even though i'm releasing the the context in "viewDidUnload" and "dealloc".
I`ve tried retain the context in a handler class like this:
- (NSManagedObjectContext *)getManagedObjectContext
{
NSManagedObjectContext *context = [self.managedObjectContext autorelease];
return context;
}
Whats the best way to interact with NSManagedObjectContext - objects and instances?
Thx and sry for my stuoid question :)

Answer 1

The value returned by retainCount is meaningless. Don't bother looking at it.
Use the Leaks instrument or heapshot analysis to determine if your app is leaking.