Adding UIBarButtonItem to all Navigation View Controllers inside a UITabBarController programmatically - ios

Question

The structure is as follows:
View
Tab Bar Controller
Navigation Controller
View Controller
Navigation Controller
View Controller
Navigation Controller
View Controller
Navigation Controller
View Controller
Navigation Controller
View Controller
Navigation Controller
View Controller
The above controllers have been initialised in interface builder.
What I'm trying to do is add a right UIBarButtonItem to each navigation controller but not having any success.
Here's what I've tried:
- (void)viewDidLoad
{
[super viewDidLoad];
self.view.backgroundColor = [UIColor clearColor];
self.view.opaque = NO;
self.tabBarController.view.frame = self.view.bounds;
NSArray *currentViewControllers = self.tabBarController.viewControllers;
NSMutableArray *updatedViewControllers = [NSMutableArray array];
for (int i=0; i<currentViewControllers.count; i++) {
UINavigationController *tempNav = [[UINavigationController alloc]init];
tempNav = [currentViewControllers objectAtIndex:i];
UIBarButtonItem *dismissButton = [[UIBarButtonItem alloc]
initWithTitle:#"Done"
style:UIBarButtonItemStyleBordered
target:self
action:#selector(dismissLibraryBrowser)];
tempNav.navigationItem.rightBarButtonItem = dismissButton;
[updatedViewControllers addObject:tempNav];
[dismissButton release];
[tempNav release];
NSLog(#"Added controller number %d",i);
}
self.tabBarController.viewControllers = [NSArray arrayWithArray:updatedViewControllers];
[self.view addSubview:tabBarController.view];
}
The code executes without any errors, but the button doesn't appear. I'm sure I've misunderstood something here. Would appreciate some guidance.

Answer 1

You are over complicating things slightly with recreating viewControllers and temporary arrays. You just need to manipulate the objects loaded from the nib
[self.tabBarController.viewControllers enumerateObjectsUsingBlock:^(UINavigationController *navigationController, NSUInteger idx, BOOL *stop) {
UIViewController *rootViewController = [navigationController.viewControllers objectAtIndex:0];
UIBarButtonItem *rightBarButtonItem =
[[UIBarButtonItem alloc] initWithTitle:#"Done"
style:UIBarButtonItemStyleBordered
target:self
action:#selector(dismissLibraryBrowser)];
rootViewController.navigationItem.rightBarButtonItem = rightBarButtonItem;
}];
As for the structure of your app - the docs for UITabBarController say
When deploying a tab bar interface, you must install this view as the root of your window. Unlike other view controllers, a tab bar interface should never be installed as a child of another view controller.
So I would suggest having a look at restructuring some stuff, if you need it only occasionally why not consider presenting it modally?