Use a notification. First, you must start listening to the notification like this
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(fetchDidComplete)
name:@"fetchDidComplete"
object:nil];
Where ever you set fetchComplete to true, post a notification like this
[[NSNotificationCenter defaultCenter] postNotificationName:@"fetchDidComplete"
object:self
userInfo:nil];
Then you should have a method called fetchDidComplete that will do the post completion work. Don't forget to stop listening to the notification once done.
[[NSNotificationCenter defaultCenter] removeObserver:self
name:@"fetchDidComplete"
object:nil];