Using Tibet binding on a iOS UILabel AttributedText property gives weird results in comparison to Fluent binding

[Digifais]

🐛 Bug Report

As discussed in Discord with @Cheesebaron regarding re-triggering value converters in Fluent bindings, I've tried using a Tibet binding instead with AttributedText and got very strange results. Instead of getting my attributed string as returned in my value converter with the correct text, it gets returned with { postfixed.

Also spans are not working anymore as in my value converter, I possibly return an attributed string with the original text, or an attributed string with a * prefixed and a foreground color span on that character. The text that shows is then *{ in all black instead of * Behaald diploma with the * in red for example.

With Fluent binding, I just get * Behaald diploma with the * in red as expected.

Expected behavior

Tibet binding returns the correct attributed string.

Reproduction steps

public class RequiredAttributedStringValueConverter : MvxValueConverter<string, NSMutableAttributedString>
{
    protected override NSMutableAttributedString Convert(string value, Type targetType, object parameter,
        CultureInfo culture)
    {
        var required = (bool?)parameter;

        var mutableString = new NSMutableAttributedString(value);
        if (required.HasValue && !required.Value)
        {
            return mutableString;
        }

        value = $"* {value}";
        mutableString = new NSMutableAttributedString(value);
        mutableString.AddAttribute(UIStringAttributeKey.ForegroundColor, Colors.Red.ToPlatformColor(),
                new NSRange(0, 1));

        return mutableString;
    }
}

Fluent binding:
set.Bind(_lblEducationYear).For(v => v.AttributedText).To(model => model.LblEducationYear).WithConversion<RequiredAttributedStringValueConverter>(((OnboardingEducationInputListItem)DataContext).ShouldValidateFields)

Tibet binding:
set.Bind(_lblEducationName, "AttributedText RequiredAttributedString(LblEducationName, ShouldValidateFields)")

Configuration

Version: 8.0.2 (can't migrate yet since project is still not on .NET)

Platform:

• 📱 iOS
• 🤖 Android
• 🏁 WPF
• 🌎 UWP
• 🍎 MacOS
• 📺 tvOS
• 🐒 Xamarin.Forms

[entdark]

Try

this.AddBindings(_lblEducationName, "AttributedText RequiredAttributedString(LblEducationName, ShouldValidateFields)");