I develop project right now and I use MVVM-C Architecture pattern and Programmatically UIKit.

I use TabBarController and UINavigationController. I have a 4 tab in TabBarController:

->HomeTab

->SearchTab

->NotificationTab

->ProfileTab

Home Tab has 2 page:

->HomePage: page where the timeline appears like instagram.

->AccountPage: the page that shows another user's account when I click on a user in the timeline

SearchTab and NotificationTab is not important

ProfileTab has 2 page:

->ProfilePage:the profile page of the user of the app

->AccountPage:the page that shows another user's account when I click on my followers button.

This approach is the same on instagram. When I click on a profile in the timeline, I can see another user's page. I can also access the same user in the followers section of my own profile page.

The same pages appear in different tabbar.

My question is that when I create this accountViewController(AccountPage) on both home and profile, 2 accountViewController instances are created in memory. I am not sure if this is the right approach? Can I create a single instance of this accountViewController and access it as both homeTab and profileTab?

What is the correct way to do this? How does instagram do this?

I develop project right now and I use MVVM-C Architecture pattern and Programmatically UIKit.

I use TabBarController and UINavigationController. I have a 4 tab in TabBarController:

->HomeTab

->SearchTab

->NotificationTab

->ProfileTab

Home Tab has 2 page:

->HomePage: page where the timeline appears like instagram.

->AccountPage: the page that shows another user's account when I click on a user in the timeline

SearchTab and NotificationTab is not important

ProfileTab has 2 page:

->ProfilePage:the profile page of the user of the app

->AccountPage:the page that shows another user's account when I click on my followers button.

This approach is the same on instagram. When I click on a profile in the timeline, I can see another user's page. I can also access the same user in the followers section of my own profile page.

The same pages appear in different tabbar.

My question is that when I create this accountViewController(AccountPage) on both home and profile, 2 accountViewController instances are created in memory. I am not sure if this is the right approach? Can I create a single instance of this accountViewController and access it as both homeTab and profileTab?

What is the correct way to do this? How does instagram do this?

• ios
• swift
• uikit
• uinavigationcontroller
• uitabbarcontroller

• 1 No, you can't use only one instance of a view controller and show it in two places. Remember, a view can only have one superview and a view controller can only have one parent view controller. – HangarRash Commented 2 days ago

1 Answer 1

If you want to use the same controller instance for any Account Page on your app you can go with this:

Use a shared Coordinator class to manage both controllers. Just make sure that your ViewModel for the controller is handling the user's data to avoid any inconsistencies.

 class AccountCoordinator {
     var accountVC: AccountViewController?
 
     func loadAccount(user: User, navigationController: UINavigationController) {
         if let existingVC = accountVC {
             existingVC.viewModel.updateUser(user) // Update existing controller
         } else {
             let viewModel = AccountViewModel(user: user)
             let viewController = AccountViewController(viewModel: viewModel)
             accountViewController = viewController
             navigationController.pushViewController(viewController, animated: true)
         }
     }

 }

So basically whenever you want to show the account page you will run it through this coordinator.