CanExecute responding to validation state

[leoshusar]

I am creating some form ViewModels and I want to dynamically disable SaveCommand when the form is invalid. However I don't see any simple way to do this.

There are 3 workarounds (?) I can think of:

• add NotifyCanExecuteChangedFor attribute to all properties that need to be validated
• subscribe to this.ErrorsChanged
• override OnPropertyChanged like this:

protected override void OnPropertyChanged(PropertyChangedEventArgs e)
{
    if (e.PropertyName is nameof(HasErrors))
    {
        SaveCommand.NotifyCanExecuteChanged();
    }

    base.OnPropertyChanged(e);
}

however neither of these feel clean to me.
Is there anything I've missed?

I would imagine some attribute similar to NotifyCanExecuteChangedFor, that would be applied to the form class and would react to the validation state. Or maybe at least partial OnHasErrorsChanged. Is this a feature request worthy thing?