Dismiss all Detail Views when switching Tabs on TabBarController - ios

Question

My iOS app has:
TabBarController
NavigationController1
TableView1
ViewController1 (Details View)
NavigationController2
TableView2
ViewController2 (Details View)
Behavior:
When the app loads, I see the TableView1.
I select an Item in the table, and it takes me via Show (Push) segue the details view 1.
I switch to the second tab on the bottom, and see TableView2.
I select an item and it takes me to details view 2
I navigate back to first tab, and see details view 1
Desired:
When performing last step, I'd like to dismiss the details view and see the first TableView1, and when switching back to second tab, I want that one to be dismissed and to see the table view.
I've tried different combinations of dismissViewControllerAnimated and popToRootViewControllerAnimated but I just don't seem to figure it out.
MainTabBarController.h
#interface MainTabBarController : UITabBarController <UITabBarControllerDelegate>
MainTabBarController.m
- (void)viewDidLoad {
[super viewDidLoad];
self.delegate = self;
}
...
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController{
// NSLog Works fine, and displays information in the output
NSLog (#"%# %lu", tabBarController.selectedViewController.title, tabBarController.selectedIndex);
// None of the lines below achieve the desired result
[viewController.navigationController popToRootViewControllerAnimated:YES];
[viewController dismissViewControllerAnimated:YES completion:nil];
[tabBarController.navigationController popToRootViewControllerAnimated:YES];
[tabBarController dismissViewControllerAnimated:YES completion:nil];
}

Answer 1

One option is to make use of the UITabBarControllerDelegate. Listen for changes to the tab selection. Based on the new tab, get the tab's navigation controller and call its popToRootViewControllerAnimated: method.
Update based on the code added to the question:
The problem is with how you try to pop the view controllers. You want this:
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController{
// NSLog Works fine, and displays information in the output
NSLog (#"%# %lu", tabBarController.selectedViewController.title, tabBarController.selectedIndex);
// If the selected tab's root controller is a navigation controller
// pop to the top view controller in the tab's navigation stack
if ([viewController isKindOfClass:[UINavigationController class]]) {
UINavigationController *nav = (UINavigationController *)viewController;
[nav popToRootViewControllerAnimated:NO];
}
}

Answer 2

Here is a simple solution for this.
Try to implement the following methods of UIViewContorller
- (void)viewWillDisappear:(BOOL)animated; // Called when the view is dismissed, covered or otherwise hidden. Default does nothing
- (void)viewDidDisappear:(BOOL)animated; // Called after the view was dismissed, covered or otherwise hidden. Default does nothing
Go to your detail-1 view controller and implement the method - (void)viewWillDisappear:(BOOL)animated.
Do a pop for that controller.
Same you should do for the detail-2
Here is the code snippet that will help you.
In Appdelegate.m
#interface AppDelegate ()<UITabBarControllerDelegate>
#property(nonatomic, strong) MainTabBarController *rootTabBarController;
#end
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.rootTabBarController = [[MainTabBarController alloc]init];
self.rootTabBarController.delegate = self;
self.window.rootViewController = self.rootTabBarController;
[self.window makeKeyAndVisible];
}
TabBarController delegate implementation
-(void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController {
NSUInteger index = [self.rootTabBarController.viewControllers indexOfObject:viewController];
NSLog(#"Index : %lu", (unsigned long)index);
switch (index) {
case 0:
// pop other tab barcontrollers pushed or modal windows
[self.rootTabBarController flushViewControllerStackForIndex:1];
break;
case 1:
[self.rootTabBarController flushViewControllerStackForIndex:0];
break;
default:
break;
}
}
MainTabBarController.m
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
[self setViewControllers:#[
[[UINavigationController alloc] initWithRootViewController:[[FirstViewController alloc]init]],
[[UINavigationController alloc] initWithRootViewController:[[SecondViewController alloc]init]]
] animated:YES];
}
-(void)flushViewControllerStackForIndex:(NSUInteger )index {
[[self.viewControllers objectAtIndex:index] popToRootViewControllerAnimated:NO];
}
Here is screenshot in sequence for the sample I ran.
Here is the Sample code.
That should solve your purpose & is the right approach.
Now you may need to fine tune your own logic in flushViewControllerStackForIndex to check if there is just only controller being pushed on stack or a combination of push & modal. So better try to navigate on the Stack & do-a-dismiss-if-a-modal or do-a-pop-if-a-push.
Hope that helps.

Answer 3

You can directly set the view controllers currently on the navigation stack. All you have to is directly set the viewControllers property of the navigation controllers when switch tabs in the tabbar controller.
Set NavigationController1.viewcontrollers = #[tableView1] when you switch to tab1