Where is the best place to remove Observer from Notification Center

Question

I think that should be here:

-(void) viewWillDisappear:(BOOL)animated
{
    [super viewDidDisappear:animated];

    NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];
    [nc removeObserver:self];

}

or maybe in -dealloc.

Both sound strange to me so I´m not totally sure of it.

First, in my AppDelegate I´m listening to a Remote Notification Via Parse

- (void)application:(UIApplication *)application
didReceiveRemoteNotification:(NSDictionary *)userInfo {
    [PFPush handlePush:userInfo];

    NSString * urlToGo = [userInfo objectForKey:@"url"];
    NSLog (@"Recibo notificación con paremetro url: %@", urlToGo);


    NSNotification *note = [NSNotification
                            notificationWithName:PUSH_NOTIFICATION
                            object:self
                            userInfo:userInfo];

    [[NSNotificationCenter defaultCenter] postNotification:note];

}

and in myViewController - (void) viewDidLoad { [super viewDidLoad];

    _lastMenuSelected=menu1;

    NSNotificationCenter *center = [NSNotificationCenter defaultCenter];
    NSOperationQueue *mainQueue = [NSOperationQueue mainQueue];
    [center addObserverForName:PUSH_NOTIFICATION
                        object:nil
                         queue:mainQueue
                    usingBlock:^(NSNotification *note) {

                     // Save in property to load parameter in prepareForSegure
                        _urlToLoadFromPush = urlToGoReceivedFromPush;
                    [self showPush:self];

                    }];


}



- (void)showPush:(id)sender {

    PushViewController * pushViewController=(PushViewController*)[self.storyboard instantiateViewControllerWithIdentifier:@"PushId"];

    pushViewController.url  = _urlToLoadFromPush;
    UINavigationController* nVC=[[UINavigationController alloc] initWithRootViewController:pushViewController];
    [self presentViewController:nVC animated:YES completion:^{
        //[_delegate logout];
    }];


}

Answer 1

Since you seem to be adding the observer in the viewDidLoad method (which is only called once as of iOS 6), you should remove the observer in the dealloc method.

Answer 2

Don't remove the observer in viewWillDisappear beacause generally we require to post the notification when the view is in the stack but not appearing. So always try to remove the observers in -(void)dealloc with the name of observer.