How to use the ValueTemplateSelector in propertygrid

I have a property grid that binds to a dynamic collection through the SelectedObjects property (I do not know what type of data I will get, every item can be of a different type, string boolean etc). I also have my own DataFactory which processes correctly all the items in the collection. Everything works fine and displays correctly with a texbox.
But now, according to the type of data I get, I want to use different datatemplates/editors.
I though of using a ValueTemplateSelector for that but I am not sure how to go about it.
Mimicking what I would do with a DatatemplateSelector, here is what I have so far:

<UserControl>
<UserControl.Resources>
<local:PropertyEditorSelector x:Key="propertyEditorSelector" />
</UserControl.Resources>

<PropertyGrid SelectedObjects="{Binding Path=MyCollection}"
IsItemDefaultContextMenuEnabled="False"
ItemTemplateSelector="{StaticResource propertyEditorSelector}">
<PropertyGrid.DataFactory><local:MyDataFactory/></PropertyGrid.DataFactory>
<PropertyGrid>
</UserControl>

//code behind
public class PropertyEditorSelector : ValueTemplateSelector
{
public override DataTemplate SelectTemplate(object item, DependencyObject container)
{
var temp = string.Empty; //check for type here and act accordingly
return null;
}

public PropertyEditorSelector(PropertyGrid grid) : base(grid)
{
}
}


The problem is that the ValueTemplateSelector does not have an empty constructor like the DataTemplateSelector so my xaml code does not even compile.

Can someone help out?