How do I use a Property defined in a wixproj file inside a component

Question

I have declared a property inside a PropertyGroup in a wixproj file.

<PropertyGroup>
    <Permit>false</Permit>
</PropertyGroup>

I use this property as a Condition to run several commands BeforeBuild and AfterBuild

<Exec Condition=" '$(Permit)' == 'true' " Command="--command here--" />

In my Product.wxs file, I have defined some components that I want to include or exclude based on the defined Permit property.

<ComponentGroup Id="ProductComponents">

    <ComponentRef Id="SomeComponent"/>

    <!--Component to add based on the property-->
    <?if $(Permit)=true ?>
        <ComponentRef Id="PermissionComponent"/>
    <?endif?>
</ComponentGroup>

Anytime I build the project, I get this error.

Ill-formed preprocessor variable '$(Permit)'. Variables must have a prefix (like 'var.', 'env.', or 'sys.') and a name at least 1 character long. If the literal string '$(Cache)' is desired, use '$$(Cache)'.

I have already tried all the specified prefix but it still doesn't work. Is there something I am not doing right?

Answer 1

You can add your variable to <DefineConstants> wix setting in the wixproj file. Like this (there may be already other constants defined, you probably want to keep those. Also watch out for configurations, you may need to add it for release/debug/etc):

<PropertyGroup>
    <Permit>false</Permit>
</PropertyGroup>
...
<DefineConstants>Debug;Permit=$(Permit)</DefineConstants>

And then just use:

<?if $(var.Permit)=true ?>