Fill button into a datagrid cell - wpf

Question

I have a data grid and for the column HCode I have/need buttons, but the property Code can be null/empty in which case the Button will not be visible.
I'd like to know if there are options or defining a mouse-click handler for the cell is the way to go.
Below is the DataGridTemplate defining the column
<DataGridTemplateColumn Header="HCode" MinWidth="120">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<Button Content="{Binding Code}"
Style="{StaticResource BStyle}"
Background="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=TextBlock}, Path=Background}"
Click="ButtonBase_OnClick"
HorizontalContentAlignment="Stretch"
VerticalContentAlignment="Center"
/>
<!--Visibility="{qc:Binding '$P != null && $P.Length > 0 ? Visibility.Visible : Visibility.Collapsed', P={Binding Code}}"-->
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
Below is the style that is used
<Style x:Key="BStyle"
TargetType="{x:Type Button}">
<Setter Property="SnapsToDevicePixels"
Value="true" />
<Setter Property="BorderThickness"
Value="0" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="120*"></ColumnDefinition>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="30*"></RowDefinition>
</Grid.RowDefinitions>
<ContentPresenter Margin="0"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
RecognizesAccessKey="True" />
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
<Setter Property="Foreground"
Value="Blue" />
<Style.Triggers>
<Trigger Property="IsMouseOver"
Value="true">
<Setter Property="Foreground"
Value="Red" />
</Trigger>
</Style.Triggers>
</Style>

Answer 1

You could define two DataTriggers. Try this:
<Button Content="{Binding Code}"
Background="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=TextBlock}, Path=Background}"
Click="ButtonBase_OnClick"
HorizontalContentAlignment="Stretch"
VerticalContentAlignment="Center">
<Button.Style>
<Style TargetType="Button" BasedOn="{StaticResource BStyle}">
<Style.Triggers>
<DataTrigger Binding="{Binding Code}" Value="{x:Null}">
<Setter Property="Visibility" Value="Collapsed" />
</DataTrigger>
<DataTrigger Binding="{Binding Code.Length}" Value="0">
<Setter Property="Visibility" Value="Collapsed" />
</DataTrigger>
</Style.Triggers>
</Style>
</Button.Style>
</Button>
Or:
<DataTrigger Binding="{Binding Code.Length, FallbackValue=0}" Value="0">
<Setter Property="Visibility" Value="Collapsed" />
</DataTrigger>