If I create an array of strings (via key-value coding) containing the names of a Managed Object entity's attributes which are stored in the App Delegate the first time, I get an array of NSStrings without any problems. If I subsequently make the same call later from the same entry point in code, that same collection becomes an array of NULL objects- even though nothing in the Core Data Context has changed.
One unappealing work-around involves re-creating the string array every time, but I'm wondering if anyone has a guess as to what's happening behind the scenes.
// Return an array of strings with the names of attributes the Activity entity
- (NSArray *)activityAttributeNames {
#pragma mark ALWAYS REFRESH THE ENTITY NAMES?
//if (activityAttributeNames == nil) {
// Create an entity pointer for Activity
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Activity" inManagedObjectContext:managedObjectContext];
NSArray *entityAttributeArray = [[NSArray alloc] initWithArray:[[entity attributesByName] allValues]];
// Extract the names of the attributes with Key-Value Coding
activityAttributeNames = [entityAttributeArray valueForKeyPath:@"name"];
[entityAttributeArray release];
//}
return activityAttributeNames;
}