iOS 16 beta | UINavigationController / UINavigationBar title does not appear after being updated

Overview

The UINavigationController / UINavigationBar title text no longer appears when updating a view controller's title property programatically.

Example

Given a view controller that is hosted within a UINavigationController:

final class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        // start out with no title
    }

    private func updateTitle() {
        // update the title later on ...
        title = "Hello"
    }
}

In this case the title label remains blank after calling updateTitle() instead of updating to "Hello!".

Details

• This only happens if the title starts out as nil or empty string
• Triggering a layout (e.g. rotating the screen) will restore the title
• Manually calling navigationController?.navigationBar.setNeedsLayout() restores the title
• Inspecting the view hierarchy, it appears the UILabel within the navigation bar has an alpha of 0.0 which is why it appears blank even after setting the title, it's not till after triggering a layout the alpha is reset to 1.0

(lldb) po navigationController?.navigationBar.perform(Selector("recursiveDescription"))
...
<_UINavigationBarTitleControl: 0x7f84f5f11560; frame = (172.333 10; 45.3333 23); layer = <CALayer: 0x6000039e89a0>>

  | <UILabel: 0x7f84f5f12000; frame = (0 0; 45.3333 23); text = 'Hello'; alpha = 0; userInteractionEnabled = NO; backgroundColor = UIExtendedGrayColorSpace 0 0; layer = <_UILabelLayer: 0x600001ab4410>>

   | <UIView: 0x7f84d5f0fbc0; frame = (0 0; 0 0); userInteractionEnabled = NO; layer = <CALayer: 0x6000039d7780>>

Environment

This only occurs when building with Xcode 14 beta 6 (14A5294g) and running on iOS 16 beta.

Notes

I was curious if anyone else encountered this?

We initially missed this as many of our view controller had some default titles set but there were a few where titles get set asynchronously after viewDidLoad which surfaced this issue.

I wonder if some of the changes related to SwiftUI listed in the release notes may have accidentally changed the behaviour:

By default, a navigation bar only renders if it has content to display. If a navigation bar has no title, toolbar items, or search content, it’s automatically hidden. Use the navigationBarHidden(_:) or the new .toolbar(.visible) modifier to explicitly show an empty navigation bar. (84996257)

I've filed a feedback FB11379313 with a sample project that reproduces this issue.

Thanks