Cannot reference dependency assemblies in T4 template when using TransformOnBuild

Question

We\'re trying to use T4 with Visual Studio 2010 (SP1) to build scripts for another language that are based upon some of our existing C# classes. I\'m hoping for the followin

Answer 1

I created a seperate solution that contained my needed referenced assemblies. The I had my buildscript build the reference solution first, then transform the templates, then build the solution containing the generated code.

Answer 2

Unfortunately, the msbuild T4 host doesn't yet support embedded macro or msbuild variables in assembly names.

However, it does support Windows environment variables "%foo%", so although it means some machine-level setup, you can get something that works across in-IDE and build time transforms.

Answer 3

My understanding is that Visual Studio 2013 will finally solve this problem, but that doesn't do me much good as I'm still on Visual Studio 2012. After a lot of effort I finally ran across a solution.

In the project that has the template you wish to run, add the following as a pre-build step on the Build Events tab of the project properties page.

set textTransformPath="%CommonProgramFiles(x86)%\Microsoft Shared\TextTemplating\$(VisualStudioVersion)\TextTransform.exe"
if %textTransformPath%=="\Microsoft Shared\TextTemplating\$(VisualStudioVersion)\TextTransform.exe" set textTransformPath="%CommonProgramFiles%\Microsoft Shared\TextTemplating\$(VisualStudioVersion)\TextTransform.exe"
set ProjectDir=$(ProjectDir)
%textTransformPath% "%ProjectDir%StringGenerator.tt"

The first two lines take care of the differences between locating TextTransform.exe on 32-bit and 64-bit systems. The third line is the key. I need the path to the project location inside my template, so I set a local environment variable equal to the value of the build's $(ProjectDir) property. Inside my template, just use the following:

var projectDir = Environment.GetEnvironmentVariable("ProjectDir");

This has solved my issue.

Answer 4

If you want to reference dependency assemblies within a T4 script using macros and have text templating succeed during build-time, then you have to use project properties.

Within your project:

  <Import Project="$(ProgramFiles)\Microsoft Visual Studio\2017\Enterprise\MSBuild\Microsoft\VisualStudio\v15.0\TextTemplating\Microsoft.TextTemplating.targets" />
  <PropertyGroup>
    <T4ProjectDir>$(ProjectDir)</T4ProjectDir>
  </PropertyGroup>
  <ItemGroup>
   <T4ParameterValues Include="T4ProjectDir">
    <Value>$(T4ProjectDir)</Value>
    <Visible>false</Visible>
   </T4ParameterValues>
  </ItemGroup>

Where the path to your text templating environment may be different.

Then use $(T4ProjectDir) as you would use any other macro in your text template.

Or you could also simply refer to existing properties:

  <ItemGroup>
   <T4ParameterValues Include="ProjectDir">
    <Value>$(ProjectDir)</Value>
    <Visible>false</Visible>
   </T4ParameterValues>
  </ItemGroup>