NSManagedObjectContext nil when calling second time

NSManagedObjectContext nil when calling second time

I have an an error everytime I want to access Core Data more than once. I
have a table view, where I'm trying to receive data and display it.
In my AppDelegate I have get a singleton object which is set to my
ViewController:
- (void)applicationDidFinishLaunching:(UIApplication *)application {
SecondViewController *tableController = [[SecondViewController alloc]
init];
tableController.managedObjectContext = [self managedObjectContext];
self.navigationController = [[UINavigationController alloc]
initWithRootViewController:tableController];
[window addSubview: [self.navigationController view]];
[window makeKeyAndVisible];
}
- (NSManagedObjectContext *) managedObjectContext {
if (managedObjectContext != nil) {
NSLog(@"managedObjectContext already in use. Returning instance.");
return managedObjectContext;
}
NSPersistentStoreCoordinator *coordinator = [self
persistentStoreCoordinator];
if (coordinator != nil) {
managedObjectContext = [[NSManagedObjectContext alloc] init];
[managedObjectContext setPersistentStoreCoordinator: coordinator];
}
NSLog(@"managedObjectContext nil. Returning new instance.");
return managedObjectContext;
}
Then I'm fetching the data in the tableView:
- (void)fetchRecords {
NSLog(@"Fetching records.");
// Define our table/entity to use
NSEntityDescription *entity = [NSEntityDescription
entityForName:@"Event" inManagedObjectContext:managedObjectContext];
// Setup the fetch request
NSFetchRequest *request = [[NSFetchRequest alloc] init];
[request setEntity:entity];
// Define how we will sort the records
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc]
initWithKey:@"timeStamp" ascending:NO];
NSArray *sortDescriptors = [NSArray arrayWithObject:sortDescriptor];
[request setSortDescriptors:sortDescriptors];
// Fetch the records and handle an error
NSError *error;
NSMutableArray *mutableFetchResults = [[managedObjectContext
executeFetchRequest:request error:&error] mutableCopy];
if (!mutableFetchResults) {
NSLog(@"Error fetching data.");
}
// Save our fetched data to an array
[self setEventArray: mutableFetchResults];
NSLog(@"Records found: %i", [eventArray count]);
}
This works fine for the first attempt but then, I'm getting this error:
2013-09-07 19:55:03.715 CooperTest[2697:11603] managedObjectContext nil.
Returning new instance.
2013-09-07 19:55:03.729 CooperTest[2697:11603] Fetching records.
2013-09-07 19:55:03.732 CooperTest[2697:11603] Records found: 3
2013-09-07 19:55:03.734 CooperTest[2697:11603] Rows in table: 3
2013-09-07 19:55:04.874 CooperTest[2697:11603] Fetching records.
2013-09-07 19:55:04.878 CooperTest[2697:11603] *** Terminating app due to
uncaught exception 'NSInvalidArgumentException', reason: '+entityForName:
nil is not a legal NSManagedObjectContext parameter searching for entity
name 'Event''
libc++abi.dylib: terminate called throwing an exception
Any ideas on this? I did not setup a new project and ticked the "use core
data" option, because it wasn't there. So I added the CoreData.framework
and some Code in the AppDelegate. Also the Model and classes are there
correct (I was able to store 3 records justa t the end of fetchData()).