Core Data: Fetched Results Controller causing over release/crash - objective-c

Question

I am using core data, and have a UITableViewController which loads the data from core data. This is a modal view and if I load the modal view for the third time, it crashes with EXC_BAD_ACCESS.
- (NSFetchedResultsController *)fetchedResultsController {
if (fetchedResultsController != nil) {
return fetchedResultsController;
}
// Create and configure a fetch request
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Ride" inManagedObjectContext:managedObjectContext];
[fetchRequest setEntity:entity];
// Create the sort descriptors array
NSSortDescriptor *sectionTitle = [[NSSortDescriptor alloc] initWithKey:#"dateStart" ascending:NO];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sectionTitle, nil];
[fetchRequest setSortDescriptors:sortDescriptors];
// Create and initialize the fetch results controller
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:nil cacheName:#"Root"];
self.fetchedResultsController = aFetchedResultsController;
fetchedResultsController.delegate = self;
// Memory management
[aFetchedResultsController release];
[fetchRequest release];
[sectionTitle release];
[sortDescriptors release];
return fetchedResultsController;
}//end
The crash says that it is coming from this line:
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Ride" inManagedObjectContext:managedObjectContext];
This is in viewDidLoad:
if (managedObjectContext == nil) {
managedObjectContext = [MyAppDelegate instance].managedObjectContext;
}
Presenting the modal view:
History *history = [[[History alloc] init] autorelease];
UINavigationController *nav = [[[UINavigationController alloc] initWithRootViewController:history] autorelease];
[self presentModalViewController:nav animated:YES];
Dismissing Modal:
- (void)done {
[self dismissModalViewControllerAnimated:YES];
}
Stack Trace that gives EXC_BAD_ACCESS:
Now, in order to setup this view with core data, I followed the Core Data Books example project and my code looks almost identical. Why would it be crashing after a few times of loading the modal view?

Answer 1

Ok, I figured it out, my managedObjectContext was not being retained because I was not using self. So, I fixed it by doing:
// Core Data
if (managedObjectContext == nil) {
self.managedObjectContext = [MyAppDelegate instance].managedObjectContext;
}