How to create two HierarchicalDataTemplates which are mutually-referential in Silverlight?

Answer 1

The only reasonable solution I've found is to create a third ViewModel type which would wrap either of the first two types (Resource or Property) and provide common properties to bind to: (e.g. children). This still is not very optimal, though, if the two types need very different templates because at that point, I am using the VisualStateManager to switch between templates for the data.

<HierarchicalDataTemplate x:Key="TreeItemTemplate"
                          ItemSource="{Binding Children}">
  <ContentPresenter Content="{Binding}">
    <VisualStateManager.Groups>
      <VisualStateGroup>
        <VisualState Name="IsResource">
          <!-- set resource template -->
        </VisualState>
        <VisualState Name="IsProperty">
          <!-- set property template -->
        </VisualState>
      </VisualStateGroup>
    </VisualStateManager.Groups>
  </ContentPresenter>
</HierarchicalDataTemplate>