steps to add tabbarcontroller to AppDelegate using Interface Builder in XCode 4.2 Empty Application template

Question

while I'm stuck at this question I cannot find the right steps to add a UITabBarController to the AppDelegate (not programatically) but by using interface builder for the "Empty Application" template, I tried to add a new empty xib file, then dropped uitabbarcontroller into it, but there is no way to link it (from IB) to AppDelegate !! i.e. when I move the blue line from tabbarcontroller object (in document outline) to File's Owner, interface builder shows only the "Delegate" option in the shown list so there is no IBOutlet option in there.

so, what are the exact steps for adding a tabbarcontroller and connect it to appDelegate using the interface builder way (for the Empty Application template, using XCode 4.2 and IOS 5 SDK) ?

step1: create new Empty Application template project.

... waiting for the next steps...

thanks so much in advance.

Answer 1

Step 1: create new Empty Application template project.
Step 2: add

@property (nonatomic, strong) IBOutlet UITabBarController *tabBarController;
@property (nonatomic, strong) IBOutlet UIWindow *window;

in your app delegate. (dont forget to synthesize these) Step 3: change this line in your app delegate:

@interface AppDelegate : NSObject <UIApplicationDelegate, UITabBarControllerDelegate>

Step 4: modify this method

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
[self.window addSubview:[self.tabBarController view]];
[self.window makeKeyAndVisible];
return YES;
}  

Step 5: create a new empty xib. Drag a tab bar controller on to it as well as an empty object.
Set the empty object's class to AppDelegate. Set Files Owner to UIApplication.

Step 6: drag the 'delegate' property from your files owner on to your appdelegate class and drag the tab bar outlet from you appdelegate class to your tabbarcontroller

Step 7: Add a window and drag the 'window' connection from your appdelegate to the window.

Step 8: Dont forget to go into the project settings and set the main-base nib file to the new xib you created.

Thats it. Hope I didn't miss anything.

Answer 2

I don't understand what is the need to add a UITabBarController through the main window. With Xcode 4.2, Apple has made some changes in the default templates. It does not provide a MainWindow.xib in the Empty Application. That is why, if you open up the AppDelegate.h, you will see:

@property (strong, nonatomic) UIWindow *window;

It does not have an IBOutlet for the window as we used to see in previous Xcode versions. What you want to achieve is a UITabBarController with Core Data support. You could add the tabBarController programatically, and still add CoreData support.

Answer 3

Here's what I had to do.

From your storyboard's Objects list (Controllers & Objects) in the Utilities panel, drag over a generic "Object" (yellow cube) to your Tab Bar Controller Scene page (I place the object under the "Exit" object).

Set the class of the object to your appDelegate. Now you should be able to link your Tab Bar Controller's delegate to your appDelegate object. You can also link the appDelegate to the Tab Bar Controller if you've created a property such as

@property (weak, nonatomic, readwrite) IBOutlet UITabBarController *tabs