Subscription With NSNotifications

DataController.m

- (void) getSubscriptionFromServer {

  // call out to server
  
  if(success == ture){  
    [[NSNotificationCenter defaultCenter] postNotificationName:@"getSubscriptionFromServerPassed" object:nil];  
  } else{
    [[NSNotificationCenter defaultCenter] postNotificationName:@"getSubscriptionFromServerFailed" object:nil];  
  }
}

Subscription.m

- (void) findSubscription{

  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(subscriptionPassed) name:@"getSubscriptionFromServerPassed" object:nil];
  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(subscriptionFailed) name:@"getSubscriptionFromServerFailed" object:nil];

  [myObject getSubscriptionFromServer];

}

- (void) subscriptionPassed{
  [[NSNotificationCenter defaultCenter] removeObserver:self name:@"getSubscriptionFromServerPassed" object:nil];
  //Handle subscription call passed
}

- (void) subscriptionFailed{
  [[NSNotificationCenter defaultCenter] removeObserver:self name:@"getSubscriptionFromServerFailed" object:nil];
  //Handle subscription call failed
}