How to set the delegate with a storyboard - objective-c

Question

I've been debating with this for a while now, hope you can help me.
I've been creating an app using storyboards mostly, I have a point where I popup a modal box to add a new record, popup works fine, the problem is dismissing it.
I've followed Apple's instructions on how to properly close modal boxes using delegates, and that works fine, except I need to add a navigation controller to my modal box, because the add process requires two steps (here fullscreen):
The problem lies in setting the delegate, so here are my two questions:
1- In my root view class (My Tab) is a delegate of the Add class (the modal), everything is set up right except this:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"showAdd"]) {
[[segue destinationViewController] setDelegate:self];
}
}
The problem lies in that [segue destinationViewController] is returning the navigationcontroller and not the AddDrinkViewController class (see the storyboard). How do I get around this? If I remove the navigation controller altogether, the code works fine setting the appropriate delegate.
2- Is there any way to set the delegate by dragging the outlets in the storyboard?
Thanks!

Answer 1

You're right, the destinationViewController will be a UINavigationController in this case. I wrote a category to handle this common situation:
// category .h file
#interface UIStoryboardSegue (NavControllerExtensions)
// Gets destinationViewCotroller. But if that controller
// is a NavigationController, returns the nav controller's
// top level view controller instead.
#property (readonly) id topLevelDestinationViewController;
#end
// category .m file
#implementation UIStoryboardSegue (NavControllerExtensions)
- (id)topLevelDestinationViewController
{
id dest = self.destinationViewController;
if ([dest isKindOfClass:[UINavigationController class]]) {
UINavigationController* nav = dest;
dest = nav.topViewController;
}
return dest;
}
#end
So now you can just do this in any of your prepareForSegue methods, and not need to worry about whether there even exists a NavigationController:
[[segue topLevelDestinationViewController] setDelegate:self]
// another example:
MyViewController *vc = segue.topLevelDestinationViewController;
vc.delegate = self; // etc.
To answer your second question, I couldn't find a way to set the delegate within IB.

Answer 2

I found a shorter way in my case (same as yours):
AddDrinkViewController *controller=[[[segue destinationViewController]viewControllers]objectAtIndex:0];

Answer 3

Basically you need to create an
Instance of UINavigationController and assign destinationViewController to it
and grab its topView controller
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"showAdd"]) {
UINavigationController *navigationController = segue.destinationViewController;
AddDrinkViewController *addDrinkcontroller = (AddDrinkViewController *)navigationController.topViewController;
addDrinkcontroller.delegate = self;
}
}