Conditionally installing a certain ComponentGroup

[hypetsch]

We want to modify our installer to optionally exclude a specific module, for example by using a parameter like "NO_TOOL=1".

Currently the simplified structure looks like this:

<ComponentGroup Id="Tool" Directory="TOOL_DIRECTORY">
   <!-- Executable -->
   <Component>
      <File Source="$(Tool.TargetPath)" KeyPath="yes">
         ...
      </File>
   </Component>

   <!-- Dependencies -->
   <Files Include="$(Tool.TargetDir)/**">
      ...
   </Files>
</ComponentGroup>

<Feature Id="Feature1" Level="1000">
   <ComponentGroupRef Id="Tool" />
   <ComponentGroupRef Id="Module1" />
</Feature>

<Feature Id="Feature2" Level="1000">
   <ComponentGroupRef Id="Tool" />
   <ComponentGroupRef Id="Module2" />
</Feature>

<Feature Id="Feature3" Level="1000">
   <ComponentGroupRef Id="Module3" />
</Feature>

...where Tool is a utility that is, by default, installed alongside some features (Feature1 and Feature2), but not with Feature3. Deploying Tool should remain the default and require no user interaction, but there should be an option to disable its deployment.

What would be the best way to achieve this?

[OlegSirenko]

I think the best solution for your case is usage of File's condition attribute:
Condition (String) : [WiX v5] Only valid when the File element is not a child of the Component element. The condition expression to be evaluated at install time. When false the File will not be installed.