DatePicker Today Button in Calendar - Enhacement

[AndrzejKl]

I need this button in my App, so I found style adding this button to Calendar. But I think Helper will be more flexible, so maybe You consider to add my class (or similar) to Helper folder?
I'm not familiar wit GitHub requests, so more safe will be to put this here:

public class DatePickerHelper
    {
        public static readonly DependencyProperty ShowTodayButtonProperty = DependencyProperty.RegisterAttached("ShowTodayButton", typeof(bool), typeof(DatePickerHelper), new FrameworkPropertyMetadata(false, ShowTodayButtonChanged));
        public static readonly DependencyProperty ShowTodayButtonContentProperty = DependencyProperty.RegisterAttached("ShowTodayButtonContent", typeof(string), typeof(DatePickerHelper), new FrameworkPropertyMetadata("Today", ShowTodayButtonContentChanged));

        private static void ShowTodayButtonContentChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            //Call twice to update Button Content if was setted after ShowTodayButton
            SetShowTodayButton(d, !GetShowTodayButton(d));
            SetShowTodayButton(d, !GetShowTodayButton(d));
        }

        private static void ShowTodayButtonChanged(object sender, DependencyPropertyChangedEventArgs e)
        {
            if (sender is DatePicker)
            {
                var d = (DatePicker)sender;
                var showButton = (bool)(e.NewValue);

                if (showButton)
                {
                    //I want to reproduce this xaml in c#:
                    //<Style TargetType="{x:Type Calendar}">
                    //    <Setter Property="Template">
                    //        <Setter.Value>
                    //            <ControlTemplate TargetType="{x:Type Calendar}">
                    //                <StackPanel Name="PART_Root"
                    //                            HorizontalAlignment="Center">
                    //                    <CalendarItem Name="PART_CalendarItem"
                    //                                    Background="{TemplateBinding Control.Background}"
                    //                                    BorderBrush="{TemplateBinding Control.BorderBrush}"
                    //                                    BorderThickness="{TemplateBinding Control.BorderThickness}"
                    //                                    Style="{TemplateBinding Calendar.CalendarItemStyle}" />
                    //                    <Button Command="SelectToday"
                    //                            Content="Today" />
                    //                </StackPanel>
                    //            </ControlTemplate>
                    //        </Setter.Value>
                    //    </Setter>
                    //</Style>

                    Setter setter = new Setter();
                    setter.Property = Calendar.TemplateProperty;
                    ControlTemplate template = new ControlTemplate(typeof(Calendar));
                    var stackPanel = new FrameworkElementFactory(typeof(StackPanel));
                    stackPanel.Name = "PART_Root";
                    stackPanel.SetValue(StackPanel.HorizontalAlignmentProperty, HorizontalAlignment.Center);

                    var calendar = new FrameworkElementFactory(typeof(CalendarItem));
                    calendar.Name = "PART_CalendarItem";

                    calendar.SetBinding(CalendarItem.BackgroundProperty,
                        new Binding(CalendarItem.BackgroundProperty.Name)
                    {
                        Path = new PropertyPath(Control.BackgroundProperty),
                        RelativeSource = new RelativeSource(RelativeSourceMode.TemplatedParent)
                    });

                    calendar.SetBinding(CalendarItem.BorderBrushProperty, new Binding(CalendarItem.BorderBrushProperty.Name)
                     {
                         Path = new PropertyPath(Control.BorderBrushProperty),
                         RelativeSource = new RelativeSource(RelativeSourceMode.TemplatedParent)
                     });

                    calendar.SetBinding(CalendarItem.BorderThicknessProperty, new Binding(CalendarItem.BorderThicknessProperty.Name)
                   {
                       Path = new PropertyPath(Control.BorderThicknessProperty),
                       RelativeSource = new RelativeSource(RelativeSourceMode.TemplatedParent)
                   });

                    calendar.SetBinding(CalendarItem.StyleProperty, new Binding(CalendarItem.StyleProperty.Name)
                    {
                        Path = new PropertyPath(Calendar.CalendarItemStyleProperty),
                        RelativeSource = new RelativeSource(RelativeSourceMode.TemplatedParent)
                    });

                    stackPanel.AppendChild(calendar);

                    var btn = new FrameworkElementFactory(typeof(Button));
                    btn.SetValue(Button.ContentProperty, GetShowTodayButtonContent(d));

                    var SelectToday = new RoutedCommand("Today", typeof(DatePickerHelper));

                    d.CommandBindings.Add(new CommandBinding(SelectToday,
              (s, ea) =>
              {
                  (s as DatePicker).SelectedDate = DateTime.Now.Date;
                  (s as DatePicker).IsDropDownOpen = false;
              },
              (s, ea) => { ea.CanExecute = true; }));

                    btn.SetValue(Button.CommandProperty, SelectToday);

                    stackPanel.AppendChild(btn);

                    template.VisualTree = stackPanel;
                    setter.Value = template;

                    Style Temp = new Style(typeof(Calendar));

                    Temp.Setters.Add(setter);

                    d.CalendarStyle = Temp;
                }
            }
        }

        [AttachedPropertyBrowsableForType(typeof(DatePicker))]
        public static bool GetShowTodayButton(DependencyObject obj)
        {
            return (bool)obj.GetValue(ShowTodayButtonProperty);
        }

        [AttachedPropertyBrowsableForType(typeof(DatePicker))]
        public static void SetShowTodayButton(DependencyObject obj, bool value)
        {
            obj.SetValue(ShowTodayButtonProperty, value);
        }

        [AttachedPropertyBrowsableForType(typeof(DatePicker))]
        public static string GetShowTodayButtonContent(Control obj)
        {
            return (string)obj.GetValue(ShowTodayButtonContentProperty);
        }

        [AttachedPropertyBrowsableForType(typeof(DatePicker))]
        public static void SetShowTodayButtonContent(Control obj, string value)
        {
            obj.SetValue(ShowTodayButtonContentProperty, value);
        }
    }

Then You can only write in xaml:

<DatePicker Controls:DatePickerHelper.ShowTodayButton="True"
                Controls:DatePickerHelper.ShowTodayButtonContent="Hoy">
</DatePicker>

It will produce:

I'm sure that it can be done better, but it's working, so it's a good start ;)
What do You think?