[BUG] this.IsValid() updated after ReactiveCommand is invoked

[reactiveui]

[BUG] this.IsValid() updated after ReactiveCommand is invoked

[worldbeater]

If you place a call to this.WhenAnyValue below a call to this.ValidationRule, you'll get the following behavior:

IsValid = False
Property value = 1
Property value = 12
Property value = 123
IsValid = True
Property value = 1234
Entered method
Property value = 12345
Entered method
Property value = 1234
Entered method
IsValid = False
Property value = 123
Property value = 12
Property value = 1

The modified code looks as such:

public class ViewModel : ReactiveValidationObject<ViewModel>
{
    private readonly ReactiveCommand<string, Unit> Command;

    private string _myProperty;
    public string MyProperty
    {
        get => _myProperty;
        set => this.RaiseAndSetIfChanged(ref _myProperty, value);
    }

    public ViewModel()
    {
        Command = ReactiveCommand.Create<string>(x => SetMyProperty(x), this.IsValid());

        this.ValidationRule(
            viewModel => viewModel.MyProperty,
            x => !string.IsNullOrEmpty(x) && x.Length > 3,
            "Enter a value");
        
        // The call to WhenAny is now placed below a call to ValidationRule.
        this.WhenAnyValue(x => x.MyProperty)
            .Do(x => Console.WriteLine("Property value = " + x))
            .InvokeCommand(Command);

        this.IsValid()
            .Subscribe(x => Console.WriteLine("IsValid = " + x));
    }

    private Unit SetMyProperty(string value)
    {
        Console.WriteLine("Entered method");
        return Unit.Default;
    }
}

Both WhenAny and ValidationRule are using CurrentThreadScheduler since #97, so the call order matters now. Hopefully we will deploy the new version of the package to NuGet soon.

[antoine-l]

If I understand, the solution you are proposing will only work once the new NuGet package is deployed?

[glennawatson]

Yep he indicated since #97 and the release won't be immediate and will be a few days at least.

[worldbeater]

ReactiveUI.Validation with the fix is now shipped to NuGet as ^1.6.4. (Thanks Glenn for the new CI!)

[antoine-l]

It works with 1.6.4. Thank you very much!

[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.