Question

I have a view controller which contains a table view, and which is wrapped within a navigation controller, i.e. in the app delegate these two are created and set as:

UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:self.myViewController];
self.window.rootViewController = navController;

If the user clicks on a row within a table then another view controller is created and pushed to the navigation controller’s stack:

   [self.navigationController pushViewController:webPageController animated:YES];

The webPageController loads and reads local files. If a file is missing I want to abort the loading of the webPageController and the displaying of its view and have the table view displayed.
How should I achieve this?

If the webPageController detects a problem I’ve tried experimenting with it calling various things such as:

[self.navigationController popViewControllerAnimated:YES];

or

 [self.navigationController.navigationBar popNavigationItemAnimated:YES];

To pop itself off the navigation stack, however these aren’t working, is it wrong for a navigation controller to attempt to pop itself like this? What is the canonical way of implementing this?

Thanks

Answer 1

That should be fine. Where are you calling popViewControllerAnimated:? If you’re calling before viewDidAppear, you’ll likely run into problems. ViewControllers need to finish the appearing and disappearing before they can make any kind of pop or push to their stack. If you do it before, you get really weird results. The most common symptom of this is it doesn’t work. Often buttons inside it will get messed up as well.