How to navigate through 3 crossing view controllers - ios

Question

I have a UITableViewController (A) listing some cities.
When the user taps on a row, he goes to the UIPageViewController (B) which dispatches several pages in a UIViewControllers (X), the form, displaying the detail of that city, e.g. population, history....
So when the user is consulting a city he can swipe horizontally to consult the previous and the next cities.
On this view (X) there is a "Show Map" button. If the user taps on this button he gets taken to the UIViewController (C) displaying the MKMapView containing the pins of ALL the cities in the list "A".
So if the user is consulting the city Boston, then he clicks on the "Show Map" button, he sees the map with all the cities, then he taps on the New York pin, I bring him back to the view B (containing X) with the API
// viewControllers: A,B,C; we go from C to B
[previousControllerB SetCity:NewYorkCityID];
[self.navigationController popViewControllerAnimated:YES];
Simple. And it works well.
On the UITableViewController A (the list) I have put a "Show Map" button too, so the user can consult the Map displaying all the city-pins without passing through the controller B. It works.
While on the map, the user clicks on the pin "New York" and I have to display the View X within the UIPageViewController B. So the user can still swipe and go forth and back with the cities.
Here comes the trouble.
If I go back to the view controller A (list) then I push the view B (form), I get a bad animation. I don't want to see the controllerA.
// viewControllers: A,C; we go from C to A then to B thanks to the segue GoToControllerB
[self.navigationController popToViewController:controllerA animated:YES]; // even animated:NO gives bad results
[controllerA performSegueWithIdentifier:#"GoToControllerB" sender:NewYorkCityID];
If I instantiate a brand new viewController B and push it, it doesn't work. The transition blocks at 50%, I see a black half-a-screen (right side) then more nothing happens.
// viewControllers: A,C; we instantiate B then we go from C to B
ViewControllerB *controllerB = [self.storyboard instantiateViewControllerWithIdentifier:#"ControllerB"];
controllerB.view = controllerB.view;
[controllerB SetCity:NewYorkCityID];
[self.navigationController pushViewController:controllerB animated:YES];
I noticed that this problem happens only if I instantiate and push a UIPageViewController, and it never happens if I instantiate and push a UIViewControllers.
So the first question is how to instantiate and push the UIPageViewController.
Then, in this latest case, since I instantiate the view B from the controller C, I get a wrong sequence of controllers (A,C,B). The right sequence should be always
A,B,C (so: list, form, map)
or
A,C (so: list, map)
in this case, if the user from C (map), clicks on a city-pin and goes to B (form), the back button here must always bring him from B to A (the list) and not to the Map (C).
So I thought the following: if the user clicks on a city-pin on the map, firstly I instantiate the viewController B (so the sequence now is A,C,B) then I remove the controller C from the self.navigationController.viewControllers.
so when the user is on B and tap on the back button he always goes to the A controller.
Could this work? How to do that? Any sample code? Thank you.

Answer 1

Try this for maintain your navigation sequence ...A -> B -> C
1. go to ViewController C
ViewControllerc *objvcC = [self.storyboard instantiateViewControllerWithIdentifier:#"ViewControllerC"];
[self.navigationController pushViewController:objvcC animated:YES];
2. then add ViewController to existing navigation stack
ViewControllerB *objViewControllerB = [self.storyboard instantiateViewControllerWithIdentifier:#"ViewControllerB"];
NSMutableArray *existNavigationArray = [self.navigationController.viewControllers mutableCopy];
[existNavigationArray insertObject:objViewControllerB atIndex:existNavigationArray.count -1];
self.navigationController.viewControllers = existNavigationArray;