How to switch between UITabBarController programmatically - ios4

Question

I have an application with UITabBarController, where the first tab contains a ViewController of an HomePage. What I have to do, is to switch between the tabs (this is pretty simple: [[self tabBarController] setSelectedIndex:index]), AND to navigate through outlets of the selectedTab from the "HomePage".
Just to explain myself: TabElement1--->TabElementX---->UISegmentedController:segmentY
The problem is that the UISegmentedController is nil because it is not initialized yet (at least the first time I do the operation). How should I fix this problem? The tab elements are loaded with nibs.
EDIT-- Here's some code:
#implementation HomeViewController // Tab Indexed 0
// ...
- (void)playVideoPreview {
NSArray *array;
array = [[self tabBarController] viewControllers];
// This is a test where I programmatically select the tab AND the switch.
[[[array objectAtIndex:2] switches] setSelectedSegmentIndex:1];
[[self tabBarController] setViewControllers:array];
}
#end
#implementation TGWebViewController // Tab Indexed 2
// ...
#synthesize switches; // In .h file: #property (nonatomic, retain) IBOutlet UISegmentedControl switches; Properly linked within the XIB.
- (IBAction)switchHasChangedValue {
// Foo operations.
}
Now the first time I fire playVideoPreview I manage to get Into the Tab Indexed 2, TGWebViewController, but switches doesn't exists yet, so I find myself with the segmentedControl named "switches" with the first segment selected. If I get back to HomeViewController, then I fire again playVideoPreview, I get the correct behaviour.

Answer 1

I've fixed the problem using the delegates and a boolean. Now, when the loading of the ViewController at index 2 of TabBar is finished, it sends a message to its delegate which tells what segment has to be selected.
EDIT Here's the code (hope it helps):
// Method in the first View that asks to tab the tab bar to launch the other
// view controller
- (void)playVideoPreview {
NSArray *array;
array = [[self tabBarController] viewControllers];
if ( ![[array objectAtIndex:2] catSwitch] ) {
[[array objectAtIndex:2] setDelegate:self];
[[array objectAtIndex:2] setHasBeenLaunchedByDelegate:YES];
} else {
[self selectTab];
}
[[self tabBarController] setViewControllers:array];
[[self tabBarController] setSelectedIndex:2];
}
// Now the operations performed by the second View Controller
- (void)somewhereInYourCode {
if ( hasBeenLaunchedByDelegate ) {
[[self delegate] selectTab];
}
}
// In the First View Controller this is the delegate method,
// launched from the Second View Controller
- (void)selectTab {
NSArray *array;
array = [[self tabBarController] viewControllers];
[[[array objectAtIndex:2] catSwitch] setSelectedSegmentIndex:[[bannerPreview pageControl] currentPage]];
}
// Some declaration
#protocol SecondViewControllerDelegate;
class SecondViewController : ViewController {
id<TGWebViewControllerDelegate> delegate;
}
#end
#protocol SecondViewControllerDelegate
- (void)selectTab;
#end
// Meanwhile in the first view
class FirstViewController : ViewController <SecondViewControllerDelegate> {
// ...
}