Completion block for popViewController

Question

When dismissing a modal view controller using dismissViewController, there is the option to provide a completion block. Is there a similar equivalent for

Answer 1

I had the same issue. And because I had to use it in multiple occasions, and within chains of completion blocks, I created this generic solution in an UINavigationController subclass:

- (void) navigationController:(UINavigationController *) navigationController didShowViewController:(UIViewController *) viewController animated:(BOOL) animated {
    if (_completion) {
        dispatch_async(dispatch_get_main_queue(),
        ^{
            _completion();
            _completion = nil;
         });
    }
}

- (UIViewController *) popViewControllerAnimated:(BOOL) animated completion:(void (^)()) completion {
    _completion = completion;
    return [super popViewControllerAnimated:animated];
}

Assuming

@interface NavigationController : UINavigationController 

and

@implementation NavigationController {
    void (^_completion)();
}

and

- (id) initWithRootViewController:(UIViewController *) rootViewController {
    self = [super initWithRootViewController:rootViewController];
    if (self) {
        self.delegate = self;
    }
    return self;
}