UIBarButton missing in DetailViewController

Question

Workflow design:

Swift 4.0, Xcode 9.2

The "Item" UIBarButton is missing when I run the below application. It is visible in storyboard though. Here's what I did:

1. Created a Master-Detail app from scratch
2. Embedded a TabBarController in the detail view
3. Removed the Segue from MasterViewController into NavigationController of the DetailViewController
4. Added a UIBarButton by dragging a UIBarButton into the first Tab view formed from the DetailViewController

Answer 1

Cocoa doesn't handle embedding a tabbar controller inside a navigation controller well (explained e.g. here).

You'll have to reverse the containment: Try to embed the detail VC in a navigation controller, and the navigation controller inside the tabbar controller, like this:

TabVC -> NavC -> DetailVC

For every additional tab you'll have to add a navigation controller. This way every tab can have it's own bar button items.