How do I insert ToolBar separators when binding ItemSource - wpf

Question

I am binding a ToolBar to a collection of command view model objects. The objects in the collection have a property IsSeparator that when true I would like represented with a <Separator/> in the ToolBar.
My basic markup looks like this:
<ToolBar Grid.Row="1" ItemsSource="{Binding Path=ToolBarCommands}">
<ToolBar.ItemTemplate>
<DataTemplate>
<Button ToolTip="{Binding Path=ToolTip}" Command="{Binding Path=Command}">
<Button.Content>
<Image Width="16" Height="16" Source="{Binding Path=IconStream}"/>
</Button.Content>
</Button>
</DataTemplate>
</ToolBar.ItemTemplate>
</ToolBar>
I've played around with ItemContainerStyle much like this example for MenuItems but to no avail.
Any help is appreciated.

Answer 1

I followed Josh's suggestion about using a DataTemplateSelector and I'm just going to post code to help others.
public class ToolBarItemTemplateSelector : DataTemplateSelector
{
public DataTemplate ButtonTemplate { get; set; }
public DataTemplate SeparatorTemplate { get; set; }
public override DataTemplate SelectTemplate(object item, DependencyObject container)
{
var toolBarItem = (ToolBarItemViewModel) item;
Debug.Assert(toolBarItem != null);
if (!toolBarItem.IsSeparator)
{
return ButtonTemplate;
}
return SeparatorTemplate;
}
}
<DataTemplate x:Key="buttonTemplate" DataType="{x:Type infrastructure:ToolBarItemViewModel}">
<Button Command="{Binding Command}" ToolTip="{Binding ToolTip}" Style="{DynamicResource ResourceKey={x:Static ToolBar.ButtonStyleKey}}">
<Image Source="{Binding ImageSource}" Width="16" Height="16" />
</Button>
</DataTemplate>
<DataTemplate x:Key="separatorTemplate">
<Separator Style="{StaticResource {x:Static ToolBar.SeparatorStyleKey}}" />
</DataTemplate>
<local:ToolBarItemTemplateSelector ButtonTemplate="{StaticResource buttonTemplate}" SeparatorTemplate="{StaticResource separatorTemplate}" x:Key="toolBarItemTemplateSelector" />
<ToolBar AutomationProperties.AutomationId="toolBar" ItemsSource="{Binding ToolBarItems}" x:Name="toolBar" Band="1" BandIndex="1" ItemTemplateSelector="{StaticResource toolBarItemTemplateSelector}"/>

Answer 2

Rather than inserting Separator objects, you could just grab Separator's ControlTemplate (in Blend, right click a separator -> Edit Template -> Edit a Copy) and incorporate it directly into your button template. You can use a DataTrigger to control its visibility, perhaps binding to a "BeginGroup" property on your object.
If you want to have a dedicated Separator object in your collection you could use a DataTemplateSelector.