NodeTemplateSelector - Reevaluate

I have created a class that inherits from TypeTemplate that enables me to have two different NodeTemplates applied depending on the value of the "Enabled" property of a custom FlowDiagramNode.

Is there a way that I can force the diagram to re-evaluate the templates as I am changing the Enabled property in code and need to apply the other template?

Having spent some time looking into this I have concluded the following (in case it is of use to others):

Background research included http://www.pluralsight-training.net/community/blogs/dbox/archive/2007/10/01/48635.aspx 

which led me to the post by Neil Mosafi in http://social.msdn.microsoft.com/forums/en-US/wpf/thread/faf81960-ca5d-4256-b08b-cbabc7d5516e/

The solution means that I have implemented my required functionality using data triggers only and don't have to create a template matcher class inheriting from TypeTemplate any more.

Now I can take the default style for the EndNode which looks something like:

    <DataTemplate x:Key="EndNodeTemplate">

        <Grid>

            <Border Name="Border" Background="DarkRed" CornerRadius="15" Style="{StaticResource BrightStyleBaseStyle}" BorderThickness="0" Padding="1" >

                <Border CornerRadius="14" Background="{StaticResource EndNodeBackground}" />

            </Border>

            <ContentPresenter Name="ContentPresenter" Content="{Binding}"

                        ContentTemplateSelector="{Binding NodeContentTemplateSelector, RelativeSource={RelativeSource AncestorType={x:Type ms:DiagramNodeElement}}}"

                        />

        </Grid>

        <DataTemplate.Triggers>

            <Trigger SourceName="ContentPresenter" Property="ContentTemplateSelector" Value="{x:Null}">

                <Setter TargetName="ContentPresenter" Property="ContentTemplate" Value="{StaticResource NodeContentTemplate}" />

            </Trigger>

        </DataTemplate.Triggers>

    </DataTemplate>

Then create the "Disabled" template:

    <DataTemplate x:Key="EndNodeDisabledTemplate">

        <Grid>

            <Border Name="Border" Background="Gray" CornerRadius="15" Style="{StaticResource BrightStyleBaseStyle}" BorderThickness="0" Padding="1" >

                ...

		...

Now I create the selector template:

    <DataTemplate x:Key="EndNodeTemplateSelectorKey">
        <ContentPresenter Content="{Binding}" Name="cp" />
        <DataTemplate.Triggers>
            <DataTrigger Binding="{Binding Enabled}" Value="True">
                <Setter TargetName="cp" Property="ContentTemplate" Value="{StaticResource EndNodeTemplate}" />
            </DataTrigger>
            <DataTrigger Binding="{Binding Enabled}" Value="False">
                <Setter TargetName="cp" Property="ContentTemplate" Value="{StaticResource EndNodeDisabledTemplate}" />
            </DataTrigger>
        </DataTemplate.Triggers>
    </DataTemplate>

Then my FlowDiagramFormatter looks like:

            <ms:FlowDiagramFormatter x:Key="Formatter"
                                         NodeTemplateSelector="{StaticResource NodeTemplateSelector}"

Now I have a node who template will change if the Enabled property of the node changes.