Cannot add buttons to table view toolbar - iphone

Question

So I have a root view with table view. I display the toolbar like this:
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
self.navigationController.toolbarHidden = NO;
}
And I implement the setToolbarItems method:
- (void)setToolbarItems:(NSArray *)toolbarItems animated:(BOOL)animated
{
UIBarButtonItem *buttonItem;
buttonItem = [[UIBarButtonItem alloc] initWithTitle:#"Hello" style:UIBarButtonItemStyleDone target:self action:#selector(goBack:)];
self.navigationController.toolbarItems = [ NSArray arrayWithObject: buttonItem ];
}
The result is an empty tolbar. Why?

Answer 1

From the docs:
toolbarItems
The toolbar items associated with the view controller.
#property(nonatomic, retain) NSArray *toolbarItems
Discussion
This property contains an array of UIBarButtonItem objects and works in >conjunction with a UINavigationController object. If this view controller is >embedded inside a navigation controller interface, and the navigation >controller displays a toolbar, this property identifies the items to display in >that toolbar.
You can set the value of this property explicitly or use the >setToolbarItems:animated: method to animate changes to the visible set of >toolbar items.
In other words, try accessing it through the actual view controller, not it's navigation controller like so:
self.toolbarItems = [ NSArray arrayWithObject: buttonItem ];

Answer 2

But who calls your implementation of setToolbarItems?
You're supposed to call setToolbarItems on your own view, not re-implement it. Then, the NavigationController will find them in the instance variable and render them.
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
self.navigationController.toolbarHidden = NO;
UIBarButtonItem *buttonItem;
buttonItem = [[UIBarButtonItem alloc] initWithTitle:#"Hello" style:UIBarButtonItemStyleDone target:self action:#selector(goBack:)];
[self setToolbarItems: [ NSArray arrayWithObject: buttonItem ]];
}