xmlxpathwixprocessing-instruction

Is it possible to extract the value from processing-instruction ('define') with XPath?

I would like to extract the version number from this code:

<?xml version="1.0" encoding="UTF-8"?>
<Include>
  <?define ProductVersion = "1.0.0.0" ?>
</Include>

I want the output to be: 1.0.0.0, is it possible to do this?

Solution

  • If you are using Visual Studio to create the WIX based installer then you can define your ProductVersion variable in the .wixproj file.

      <Target Name="BeforeBuild">
    <PropertyGroup>
      <DefineConstants>ProductVersion=1.0</DefineConstants>
      ...
    </PropertyGroup>
  </Target>

    This would be accessible from .wxs file by $(var.ProductVersion). Now you can use XPath to read the value of DefineConstants from your .wixproj file. This will get you ProductVersion = "1.0.0.0"