Pushing View Controller with Two Nav Controllers

Question

I've got an app where I am pushing a modal view controller. It is working fine, but I am concerned I haven't coded it in the most correct fashion. I have instanstiated two navigation controllers, which seems a bit dodgy to me.

Basically I've created a tab bar controller with 3 tabs, then made one of those tabs / view controllers the root. Later I am (using some home-grown markup on core text) popping a view controller when the user touches a particular word in a paragraph. The pushed view controller has a back button which works fine and the app seems to be OK.

Like I said it all works, but it seems I am coding in circles here. Is this correct?

AppDelegate.h

#import <Foundation/Foundation.h>

@interface AppDelegate : NSObject <UIApplicationDelegate, UITabBarControllerDelegate>
{
    UIWindow *window;
    UITabBarController *tabBarController;
}
@property (strong, nonatomic) UIWindow *window;
@property (strong, nonatomic) UITabBarController *tabBarController;
@end

From AppDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

    ViewController *viewController = [[ViewController alloc] initWithNibName:@"ViewController" bundle:nil];
    ViewController2 *viewController2 = [[ViewController2 alloc] initWithNibName:@"ViewController2" bundle:nil];
    ViewController3 *viewController3 = [[ViewController3 alloc] initWithNibName:@"ViewController3" bundle:nil];

    UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:viewController];
    self.tabBarController = [[UITabBarController alloc] init];
    self.tabBarController.viewControllers = [NSArray arrayWithObjects:nav, viewController2, viewController3, nil];
    self.tabBarController.delegate = self;
    self.window.rootViewController = self.tabBarController;
    [self.window makeKeyAndVisible];
    return YES;
}

ViewController3.h

#import <UIKit/UIKit.h>
#import "JSCoreTextView.h"
#import "PopupViewController.h"

@class JSTwitterCoreTextView;

@interface ReadingViewController : UIViewController <JSCoreTextViewDelegate>
{
    JSTwitterCoreTextView *_textView;
    UIScrollView *_scrollView;
}
@end

From ViewController3.m

Here I am instantiating another navigation controller. Is this a good idea?

- (void)textView:(JSCoreTextView *)textView linkTapped:(AHMarkedHyperlink *)link
{
    PopupViewController *popupVC = [[PopupViewController alloc] initWithNibName:@"PopupViewController" bundle:nil];
    UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:popupVC];
    [nav setModalPresentationStyle:UIModalPresentationFullScreen];
    [nav setModalTransitionStyle:UIModalTransitionStyleCoverVertical];
    [self presentModalViewController:nav animated:YES];
}

From PopupViewController.m

- (void)viewDidLoad
{
    [super viewDidLoad];
    [self.navigationItem setRightBarButtonItem:[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone 
                 target:self 
                 action:@selector(done:)]];
}

- (void)done:(id)sender
{
    [self.parentViewController dismissModalViewControllerAnimated:YES];
}

Answer 1

It appears the answer is "yes". I was under the impression there is a single Navigation Controller for the app, but it's more like one per tab, depending on if there are going to be further pushes from that tab.