Question

I have made a custom UINavigationController class so that I can have a UIAlertView popup and say, are you sure you want to leave this view when tapping the back button.

I have a customer the method like so below:

- (UIViewController *)popViewControllerAnimated:(BOOL)animated
{
    if([[self.viewControllers lastObject] class] == [weddingSetupController class]){

        UIAlertView *exitAlert = [[UIAlertView alloc] 
                                  initWithTitle:@"Are you sure?" 
                                  message:@"By leaving the setup, all current changes will be lost. The setup can be retsrated later if you decide to leave now. However, it is recomened for your best experience that you complete the setup." 
                                  delegate:self cancelButtonTitle:@"No" 
                                  otherButtonTitles:@"Yes", nil
                                  ];

        [exitAlert show];

        return nil;
    } 
    else {
        return [super popViewControllerAnimated:animated];
    }
}

It works well, although an issue is, that while if I say ‘No’, it stays on the same view, not popping the parent view, the navigation bar does pop. So I get the view not to pop but the bar always returns to the state of its parent view.

Answer 1

When you press the back button on the navigation bar, it’s calling:

- (UINavigationItem *)popNavigationItemAnimated:(BOOL)animated;

in UINavigationBar, which in turn calls popViewControllerAnimated on the navigation controller. Override this method (I use a category, to avoid subclassing) and take your same approach. Your overriding point was just a step late.