Question

I am new to core data so please excuse me if I get some of the terms wrong.

I have several objects in my xcdatamodel file. They are all inter connected with relationships and inverse relationships. If I connect two of these objects with the following code the inverse relationship is not set.

[managedObj1 setValue: managedObj2 forKey:@"relatiohipName"]; 

I seem to have to manually set the inverse relationship myself with the following code

[managedObj1 setValue: managedObj2 forKey:@"relatiohipName"];
[managedObj2 setValue: managedObj1 forKey:@"inverseRelatiohipName"];

This seems wrong to me but its the only way I can seem to get the mechanism to work. I have looked at the sqlite DB after running the first block of code and the inverse relationship is not filled in but if I run the second code the relationship is there.

Also, it seems like once I create an object in Core Data I can’t alter it after that. The dp remains the same. Once I exit the app and restart it I seem to lose all the relationships and attributes of the object. the resulting objects in my code have nothing but nil member variables.

EDIT:

The commented out stuff is the way it was done before and the uncommented stuff is how I’m doing it now with no luck.

Here is where I am creating the objects:

NSEntityDescription* mobileEntity = [NSEntityDescription entityForName:@"WebServiceAuthService_mobileAdvertisementVO" inManagedObjectContext:managedObjectContext];
WebServiceAuthService_mobileAdvertisementVO *newObject = [NSEntityDescription insertNewObjectForEntityForName:[mobileEntity name] inManagedObjectContext:managedObjectContext];
//WebServiceAuthService_mobileAdvertisementVO *newObject = [NSEntityDescription insertNewObjectForEntityForName:@"WebServiceAuthService_mobileAdvertisementVO" inManagedObjectContext:managedObjectContext];    

Here is where I am assigning one of the objects member variables:

[self setValue:newChild forKey:@"advertisement"];
            //self.advertisement = newChild;

Here is where I am saving the context:

NSError *error = nil;
if (managedObjectContext != nil) 
{
    if ([managedObjectContext hasChanges] && ![managedObjectContext save:&error]) 
    {
        DLog(@"Unresolved error %@, %@", error, [error userInfo]);
        abort();
    }

}

Answer 1

Important safety tip. If you subclass NSManagedObject DO NOT use @synthesize for your member variables. Use @dynamic instead.