[iOS] Shell Back Button Label

[jayambadkar]

Description

When using navigation pages with Shell-based navigation on an iOS .NET MAUI app, the back button label will set itself to the same as the page title if the title is short enough, otherwise it will do the expected behaviours (when page title is longer) and have a label of 'Back' (see images below).

I do not believe that this is intended behaviour as that would not make much sense. I should also add that this does not happen on Windows or on an Android emulator (12.0 - API 31), but I was unable to test the behaviour on MacCatalyst.

Steps to Reproduce

1. Create a new dotnet MAUI project.
2. Create the MainPage and another page, e.g. DemoPage, and register pages and routes on AppShell.xaml.cs
3. Insert a button with command Shell.Current.GoToAsync(nameof(DemoPage)); on the MainPage
4. Run the app on an iOS iPhone 15.5 simulator with Hot Reload enabled.
5. Navigate to DemoPage
6. Edit the title parameter in ContentPage there by making it longer and shorter to see the back button's unexpected behaviors on simulator live.

Alternatively clone this repo (https://github.com/ThatJammyDodger/iOSNav) and run it in iOS simulator, using the buttons to see what happens.

Results:

Dotnet version: 6.0.400-preview.22301.10

Version with bug

6.0.400 (current)

Last version that worked well

Unknown/Other

Affected platforms

iOS

Affected platform versions

iOS 15.5

Did you find any workaround?

https://github.com/PureWeen/ShanedlerSamples/blob/main/ShanedlerSamples/Library/Workarounds/ShellWorkarounds.iOS.cs
Edit: Yes, see comment below

Relevant log output

No response

[warpedgeoid]

I'm sorry, but how is setting the back button text to "Back" when the page title is too long a bug? This would seem to be the expected behavior. Are you asking for this behavior to be added to non-iOS platforms?

[jayambadkar]

I'm sorry, but how is setting the back button text to "Back" when the page title is too long a bug? This would seem to be the expected behavior. Are you asking for this behavior to be added to non-iOS platforms?

No, that is not the problem. So that it is more clear to you, I have made a screen recording.
The first page's title is 'The Main Page', not 'Short', therefore what I have shown in this recording and the screenshots above demonstrates the wrong behaviour.

Button.Demo.mov

[kristinx0211]

verified repro on IOS with above project.

[JamesRoche]

This is a real issue for me too. Is there a workaround?

[EthanHipps]

Also experiencing this issue in my own project

[jayambadkar]

Found workaround: in the code behind for the affected page(s), add this in the constructor:

Shell.SetBackButtonBehavior(this, new BackButtonBehavior() { TextOverride = "Back", });

You can also add any icons or stuff like that you want to override if you want to but this text override works for now as I have tested. Let me know if not.

For example:

namespace iOSNav.View;
public partial class DemoPage : ContentPage
{
	public DemoPage(DemoViewModel vm)
	{
		InitializeComponent();
		Shell.SetBackButtonBehavior(this, new BackButtonBehavior()
		{
			TextOverride = "Back",
		});
		BindingContext = vm;
	}
}