Complex MultiBinding validation

Question

I have a form that has multiple fields. I have also a "Validate" button that will action a DB input. I would like that button to be activated only if the bare minimum fields are defined by the user.

So far it was quite simple as all the fields were text:

<Button x:Name="Manage" Content="Manage">
    <Button.IsEnabled>
        <MultiBinding Mode="OneWay" Converter="{StaticResource FieldsFilledinToVisible}">
            <Binding ElementName="name1" Path="Text"/>
            <Binding ElementName="name2" Path="Text"/>
        </MultiBinding>
    </Button.IsEnabled>
</Button>

Converter being:

public class AllValuesDefinedConverter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        bool isEnabled = false;
        for (int i = 0; i < values.Length; i++)
        {
            isEnabled = isEnabled || string.IsNullOrEmpty(values[i].ToString());
        }
        return !isEnabled;
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        return null;
    }
}

But would now have to consider extra check boxes, where the condition should be [Any of these checkboxes checked + previous text fields defined --> Activate the validation button]:

<WrapPanel Style="{StaticResource WrapStyle_Inputs}">
    <CheckBox Content="Check1" IsChecked="{Binding Checked1, Mode=TwoWay}"/>
    <CheckBox Content="Check2" IsChecked="{Binding Checked2, Mode=TwoWay}"/>
    <CheckBox Content="Check3" IsChecked="{Binding Checked3, Mode=TwoWay}"/>
</WrapPanel>

Would you know how I could do so?

thank you!

Answer 1

Converters are the wrong tool for the job. You should instead look at validation, commands, and view models. Your view model would implement validation logic and expose a command that your button is bound to. The command would only be executable if your validation logic passes.