WPF niceties. Collection grouping in ViewModel

Having to group a collection shown in UI by a command fired from the View, I’ve came to a nice solution by writing an extension method to the ObservableCollection<T> class.

The extension method:

public static class ObservableCollectionExtensions
{
    public static void VisualGroupingBy<T>(this ObservableCollection<T> collection,
                                           Expression<Func<T, object>> groupByExpresson)
    {
        var view = CollectionViewSource.GetDefaultView(collection);
        collection.VisualGroupingClear();

        var propertyName = ReflectionHelper.GetPropertyName(groupByExpresson);

        view.GroupDescriptions.Add(new PropertyGroupDescription(propertyName));
    }

    public static void VisualGroupingClear<T>(this ObservableCollection<T> collection)
    {
        var view = CollectionViewSource.GetDefaultView(collection);
        view.GroupDescriptions.Clear();
    }
}

How to use it:

public ObservableCollection<Address> Addresses { get; set; }
public void GroupAddressesByCity()
{
    Addresses.VisualGroupingBy(address => address.City);
}

Clean, no magic strings, readable…