Using Path=. and Converter inside Binding - wpf

Question

I have trouble defining a trigger for TreeViewItems. I believe it is just some syntax problem, but I don't know what else to write...
This is the Trigger:
<DataTrigger Binding="{Binding Path=., Converter=IsNodeConverter}" Value="True">
<Setter Property="Focusable" Value="False"/>
</DataTrigger>
Since it is defined inside TreeView.ItemContainerStyle, the DataContext should be the contained item itself. The Item can either be of type Node or Entry and I want to trigger for all Items that are of type Node. So I wrote a converter:
public class IsNodeConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
if (value is Node)
return true;
return false;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
Which returns true if it gets a Node as input and false otherwise.
But in the part Binding="{Binding Path=., Converter=IsNodeConverter}" the compiler complains: "IValueConverter cannot convert from string." (original: "Vom TypeConverter-Objekt für IValueConverter wird das Konvertieren aus einer Zeichenfolge nicht unterstützt.") I don't understand this at all: DataContext is an object of type Entry or Node, and Binding Path=. should keep it that way. So what is the problem? What string is the compiler talking about? How do I correct this so that the compiler does not complain?
Here is the full code of the TreeView for reference. The collection ´AllNodesAndEntries´ is an ObservableCollection<object> that contains both Nodes and Entrys.
<TreeView ItemsSource="{Binding AllNodesAndEntries}">
<TreeView.Resources>
<HierarchicalDataTemplate ItemsSource="{Binding Children}" DataType="{x:Type usrLibVM:Node}">
<TextBlock Text="{Binding Name}" Background="LightBlue"/>
</HierarchicalDataTemplate>
<DataTemplate DataType="{x:Type usrLibVM:Entry}">
<TextBlock Text="{Binding Name}" Background="LightSalmon"/>
</DataTemplate>
</TreeView.Resources>
<TreeView.ItemContainerStyle>
<Style TargetType="{x:Type TreeViewItem}">
<Style.Triggers>
<DataTrigger Binding="{Binding Path=., Converter=IsNodeConverter}" Value="True">
<Setter Property="Focusable" Value="False"/>
</DataTrigger>
</Style.Triggers>
</Style>
</TreeView.ItemContainerStyle>
</TreeView>

Answer 1

Your converter is certainly declared in a ResourceDictionary, so it should be referenced as StaticResource:
Binding="{Binding Path=., Converter={StaticResource IsNodeConverter}}"
or shorter:
Binding="{Binding Converter={StaticResource IsNodeConverter}}"

Answer 2

Based on answer in thread Using Value Converters in WPF without having to define them as resources first :
<DataTrigger Value="False">
<DataTrigger.Binding>
<Binding> <!-- <Binding Path="."> is possible but not necessary -->
<Binding.Converter>
<converterNamespace:IsNodeConverter/>
</Binding.Converter>
</Binding>
</DataTrigger.Binding>
<Setter Property="Focusable" Value="False"/>
</DataTrigger>