Product of build-time T4 transformation is used only in the next build

Question

I have a VS project that contains:

a pre-build action running TextTransform on a template.tt to generate generated.cs
generated.cs listed as one of the files to compile (i.e. in the list of project files)

When I build the project, the pre-build action is executed, generated.cs is re-created, but VS compiles the previous version of generated.cs (which I guess it loaded in memory when the build process started).

How to make the build use the new version of generated.cs (i.e. the one generated in the pre-build action)? How to force the build order?

^{Note that the text transformation input is dynamic and hence cannot be done in design time.}

score 4 · Answer 1 · answered Jan 05 '10 at 17:34

4

I don't think you need a custom pre-build action. Just add the ".tt" file to your project and set its "Custom Tool" property to "TextTemplatingFileGenerator". You might want to make sure that the *.generated.cs files are also added to the project, but I think that VS takes care of that.

answered Jan 05 '10 at 17:34

Spongman

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This doesn't seem to work for me. I think Zvika was saying they wanted the T4 template to work its magic whenever his project is built. This is what I want also. Though, I'm using T4MVC with ASP.NET MVC 3. For example, if I take a project that builds, add a new file that should get picked up by T4MVC, then build the project again, I don't see the change that should have been done by T4MVC. I have to explicitly trigger an update by right-clicking on the .tt file and choosing Run Custom Tool. – Derek Morrison Dec 06 '10 at 12:11
this will only generate the output when you Save the `.tt` file. – Tomer W Dec 27 '17 at 09:19

score 4 · Answer 2 · edited Sep 25 '17 at 14:29

There's now a solution to this problem! Oleg Sych has a post on his blog detailing how to make transform-at-build-time work.

Here's the source: https://web.archive.org/web/20140116193428/http://www.olegsych.com/2010/04/understanding-t4-msbuild-integration/

Basically, you just include the T4 build targets in your project file and set the TransformOnBuild property to true.

Here's the relevant excerpt:

<Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
  <PropertyGroup>
    <TransformOnBuild>true</TransformOnBuild>
  </PropertyGroup>
<Import Project="$(MSBuildExtensionsPath)\Microsoft\VisualStudio\TextTemplating\v10.0\Microsoft.TextTemplating.targets" />

Note that the Microsoft.TextTemplating.targets file has to be included AFTER the Microsoft.CSharp.targets.

This generates the files but omit their relative namespace. how can i overcome this ? — Tomer W, Dec 27 '17 at 21:47

Product of build-time T4 transformation is used only in the next build

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