Validation

[ManniAT]

Hi,

I bind a PropertyGrid to a pretty complex object generated by Linq2SQL.
I implemented IDataErrorInfo on the object.
Further let the PropertyGrid autogenerate the properties.

Now I have two Problems - this[string ColumnName] never gets called.
Next - the property Grid tries to bind "Error" (I know I can fix this in code behind - but this would break my so far "no code behind" MVVM design) - but this isn't very important.
Last not least I implemented "IsValid" like in the following snippet.

    public static bool IsValid(this DependencyObject obj) {
            // The dependency object is valid if it has no errors,
            //and all of its children (that are dependency objects) are error-free.
            return !Validation.GetHasError(obj) &&
                GetVisualTreeChildren(obj)
                .OfType<DependencyObject>()
                .All(child => IsValid(child));
        }
        //VisualTreeHelper don't have a method to get all the children of a visual object
        private static IEnumerable GetVisualTreeChildren(DependencyObject parent) {
            for (int i = 0; i < VisualTreeHelper.GetChildrenCount(parent); i++)
                yield return VisualTreeHelper.GetChild(parent, i);
        }


//OK handler in VM using the IsValid extension
    protected override bool HandleOKCanExecute(object arg) {
            if (this.TheView != null) {
                return(this.TheView.IsValid());
                }
            return (false);
        }

I further know that I could decorate my object with attributes - but the reason to use your PropertyGrid is that the object is large (a lot of properties) and I don't want to define all these things. And it would be hard without touching the Linq2Sql autogenerated code.

Main Problem - no validation (this[string ColumnName] occurs.

Manfred

[ManniAT]

I just tried the sample (last post) from this thread.
http://www.telerik.com/community/forums/wpf/property-grid/validation.aspx

Also no validation....

I use version 2013.1.408.45 (FW 4.5).

[ManniAT]

Hi,

I could manage it by creating my own class...

    public class XPropertyGrid : RadPropertyGrid {


        #region HandleIDataErrorInfo handling
        public bool HandleIDataErrorInfo {
            get { return (bool)GetValue(HandleIDataErrorInfoProperty); }
            set { SetValue(HandleIDataErrorInfoProperty, value); }
        }
        // Using a DependencyProperty as the backing store for HandleIDataErrorInfo.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty HandleIDataErrorInfoProperty =
            DependencyProperty.Register("HandleIDataErrorInfo", typeof(bool), typeof(XPropertyGrid),
                new FrameworkPropertyMetadata(true));
        #endregion

        public XPropertyGrid() {
            AutoGeneratingPropertyDefinition += XPropertyGrid_AutoGeneratingPropertyDefinition;
        }

        void XPropertyGrid_AutoGeneratingPropertyDefinition(object sender, global::Telerik.Windows.Controls.Data.PropertyGrid.AutoGeneratingPropertyDefinitionEventArgs e) {
            if (!HandleIDataErrorInfo) {
                return;
            }
            if (e.PropertyDefinition.DisplayName == "Error") {
                e.Cancel = true;
            }
            Binding bnD = e.PropertyDefinition.Binding as Binding;
            if (bnD != null) {
                bnD.ValidatesOnDataErrors = true;
                bnD.ValidatesOnExceptions = true;
            }
        }
    }
}

Manfred

[Ivan Ivanov]

Hi Manfred,

 Please excuse me for the delayed reply. Basically, RadPropertyGrid support IDataErrorInfo, but the default binding generated for auto-generated PropertyDefinition does not have the ValidatesOnDataErrors and NotifyOnValidationError properties set to true. I Guess that you should be able to handle this without creating a new class, just subscribe to the auto-generating event and set the properties to true there.

All the best,
Ivan Ivanov
the Telerik team