Using Tailwind the right way for .NET

Tailwind.targets

<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <!-- This file exposes the following parameters -->
  <!-- TailwindVersion: The version of the Tailwind Standalone CLI to download. -->
  <!-- TailwindDownloadPath: The path to where to download the Tailwind Standalone CLI. This property is optional, and defaults to %LOCALAPPDATA% on Windows, and $XDG_CACHE_HOME on Linux and MacOS. -->
  <!-- TailwindInputStyleSheetPath: The path to the input stylesheet. -->
  <!-- TailwindOutputStyleSheetPath: The path to the output stylesheet. -->
  <!-- TailwindOptimizeOutputStyleSheet: Whether to optimize the output stylesheet. This property is optional, and defaults to false. -->
  <!-- TailwindMinifyOutputStyleSheet: Whether to minify the output stylesheet. This property is optional, and defaults to false when Configuration is Debug, and true when Configuration is Release. -->
  <!-- TailwindGenerateSourceMap: Whether to generate a source map for the output stylesheet. This property is optional. -->
  <!-- TailwindOutputSourceMapPath: The path to where to write the generated source map file. This property is optional, and when not specified, inline source maps are generated. Requires TailwindGenerateSourceMap to be true. -->
  <!-- TailwindDownloadUrl: The URL to the Tailwind Standalone CLI. This property is optional, and defaults to downloading the specified version from GitHub. -->

  <!-- To override these properties, create a PropertyGroup in the csproj file -->
  <!-- For example: -->
  <!-- <PropertyGroup> -->
  <!--    <TailwindVersion>v4.0.14</TailwindVersion> -->
  <!--    <TailwindInputStyleSheetPath>Styles/main.css</TailwindVersion> -->
  <!--    <TailwindOutputStyleSheetPath>wwwroot/main.css</TailwindVersion> -->
  <!-- </PropertyGroup -->

  <PropertyGroup>
    <TailwindOptimizeOutputStyleSheet Condition="'$(TailwindOptimizeOutputStyleSheet)' == ''">false</TailwindOptimizeOutputStyleSheet>

    <TailwindMinifyOutputStyleSheet Condition="$(TailwindMinifyOutputStyleSheet) == '' And '$(Configuration)' == 'Debug'">false</TailwindMinifyOutputStyleSheet>
    <TailwindMinifyOutputStyleSheet Condition="$(TailwindMinifyOutputStyleSheet) == '' And '$(Configuration)' == 'Release'">true</TailwindMinifyOutputStyleSheet>

    <!-- The path to where Tailwind should be downloaded to -->
    <!-- This should be a path that is writable by the current user, as well as one that is accessible in CI/CD pipelines -->
    <!-- By default, this is set to the local app data folder on Windows, and $XDG_CACHE_HOME on Linux and MacOS -->

    <!-- On Linux and MacOS, use $XDG_CACHE_HOME or $HOME/.cache -->
    <TailwindDownloadPath Condition="'$(TailwindDownloadPath)' == '' And ($([System.OperatingSystem]::IsLinux()) Or $([System.OperatingSystem]::IsMacOS()))">$([MSBuild]::ValueOrDefault($([System.Environment]::GetEnvironmentVariable('XDG_CONFIG_HOME')), $([System.IO.Path]::Combine($([System.Environment]::GetEnvironmentVariable('HOME')), '.cache'))))</TailwindDownloadPath>

    <!-- On Windows, use local app data (%LOCALAPPDATA%) -->
    <TailwindDownloadPath Condition="'$(TailwindDownloadPath)' == '' And $([System.OperatingSystem]::IsWindows())">$(LOCALAPPDATA)</TailwindDownloadPath>
  </PropertyGroup>

  <!-- Validate the parameters before download or building -->
  <Target Name="ValidateParameters" BeforeTargets="DownloadTailwind; Tailwind">
    <!-- Ensure the version is specified -->
    <Error Condition="'$(TailwindVersion)' == ''" Text="Tailwind version not specified. Please specify the version. For example: &lt;PropertyGroup&gt;&lt;TailwindVersion&gt;v4.0.14&lt;/TailwindVersion&gt;&lt;/PropertyGroup&gt;"/>

    <!-- Ensure the input stylesheet path is specified & the file exists -->
    <Error Condition="'$(TailwindInputStyleSheetPath)' == ''" Text="Tailwind input stylesheet not specified. Please specify the path to the input stylesheet in the csproj file. For example: &lt;PropertyGroup&gt;&lt;TailwindInputStyleSheetPath&gt;Styles/main.css&lt;/TailwindInputStyleSheetPath&gt;&lt;/PropertyGroup&gt;"/>
    <Error Condition="!Exists('$(TailwindInputStyleSheetPath)')" Text="Tailwind input stylesheet '$(TailwindInputStyleSheetPath)' does not exist. Please specify a path to a stylesheet. For example: &lt;PropertyGroup&gt;&lt;TailwindInputStyleSheetPath&gt;Styles/main.css&lt;/TailwindInputStyleSheetPath&gt;&lt;/PropertyGroup&gt;"/>

    <!-- Ensure the output stylesheet path is specified -->
    <Error Condition="'$(TailwindOutputStyleSheetPath)' == ''" Text="Tailwind output stylesheet not specified. Please specify the path to the output stylesheet in the csproj file. For example: &lt;PropertyGroup&gt;&lt;TailwindOutputStyleSheetPath&gt;Styles/main.css&lt;/TailwindOutputStyleSheetPath>&lt;/PropertyGroup&gt;"/>

    <!-- Ensure the download path is specified -->
    <Error Condition="'$(TailwindDownloadPath)' == ''" Text="Tailwind download path not specified. Please specify the download path in the csproj file. For example: &lt;PropertyGroup&gt;&lt;TailwindDownloadPath&gt;/tmp&lt;/TailwindDownloadPath&gt;&lt;/PropertyGroup&gt;"/>
  </Target>

  <!-- This line supports hot reload by instructing dotnet watch to be aware of modifications to the input stylesheet -->
  <ItemGroup Condition="Exists('$(TailwindInputStyleSheetPath)')">
    <Watch Include="$(TailwindInputStyleSheetPath)"/>
  </ItemGroup>

  <!-- Detect whether the system is using glibc or musl -->
  <Target Name="DetectLddVersion" BeforeTargets="DownloadTailwind" Condition="$([System.OperatingSystem]::IsLinux())">
    <Exec Command="ldd --version"
          ConsoleToMsBuild="true"
          EchoOff="true"
          IgnoreExitCode="true"
          StandardOutputImportance="Low"
          StandardErrorImportance="Low">
      <Output TaskParameter="ConsoleOutput" PropertyName="LddVersion" />
    </Exec>

    <PropertyGroup>
      <IsMusl Condition="'$(LddVersion)' != '' And $(LddVersion.Contains('musl'))">true</IsMusl>
    </PropertyGroup>
  </Target>

  <Target Name="DownloadTailwind">
    <PropertyGroup>
      <!-- Determine which version of Tailwind to use based on the current OS & architecture -->
      <TailwindReleaseName Condition="$([System.OperatingSystem]::IsLinux()) And '$(IsMusl)' == '' And $([System.Runtime.InteropServices.RuntimeInformation]::OSArchitecture) == X64">tailwindcss-linux-x64</TailwindReleaseName>
      <TailwindReleaseName Condition="$([System.OperatingSystem]::IsLinux()) And '$(IsMusl)' == '' And $([System.Runtime.InteropServices.RuntimeInformation]::OSArchitecture) == Arm64">tailwindcss-linux-arm64</TailwindReleaseName>

      <TailwindReleaseName Condition="$([System.OperatingSystem]::IsLinux()) And '$(IsMusl)' == 'true' And $([System.Runtime.InteropServices.RuntimeInformation]::OSArchitecture) == X64">tailwindcss-linux-x64-musl</TailwindReleaseName>
      <TailwindReleaseName Condition="$([System.OperatingSystem]::IsLinux()) And '$(IsMusl)' == 'true' And $([System.Runtime.InteropServices.RuntimeInformation]::OSArchitecture) == Arm64">tailwindcss-linux-arm64-musl</TailwindReleaseName>

      <TailwindReleaseName Condition="$([System.OperatingSystem]::IsMacOS()) And $([System.Runtime.InteropServices.RuntimeInformation]::OSArchitecture) == X64">tailwindcss-macos-x64</TailwindReleaseName>
      <TailwindReleaseName Condition="$([System.OperatingSystem]::IsMacOS()) And $([System.Runtime.InteropServices.RuntimeInformation]::OSArchitecture) == Arm64">tailwindcss-macos-arm64</TailwindReleaseName>

      <TailwindReleaseName Condition="$([System.OperatingSystem]::IsWindows()) And $([System.Runtime.InteropServices.RuntimeInformation]::OSArchitecture) == X64">tailwindcss-windows-x64.exe</TailwindReleaseName>
      <TailwindReleaseName Condition="$([System.OperatingSystem]::IsWindows()) And $([System.Runtime.InteropServices.RuntimeInformation]::OSArchitecture) == Arm64">tailwindcss-windows-arm64.exe</TailwindReleaseName>

      <TailwindDownloadUrl Condition="'$(TailwindDownloadUrl)' == '' And $(TailwindVersion) != 'latest'">https://github.com/tailwindlabs/tailwindcss/releases/download/$(TailwindVersion)/$(TailwindReleaseName)</TailwindDownloadUrl>
      <TailwindDownloadUrl Condition="'$(TailwindDownloadUrl)' == '' And $(TailwindVersion) == 'latest'">https://github.com/tailwindlabs/tailwindcss/releases/latest/download/$(TailwindReleaseName)</TailwindDownloadUrl>

      <TailwindDestinationFolder>$([System.IO.Path]::Combine('$(TailwindDownloadPath)', 'Tailwind', '$(TailwindVersion)'))</TailwindDestinationFolder>

      <TailwindCliPath>$([System.IO.Path]::Combine('$(TailwindDestinationFolder)', '$(TailwindReleaseName)'))</TailwindCliPath>
    </PropertyGroup>

    <!-- Download the file if it hasn't been already -->
    <!-- Note: Using latest will always reach out to GitHub to see if a new version is available -->
    <DownloadFile DestinationFolder="$(TailwindDestinationFolder)"
                  DestinationFileName="$(TailwindReleaseName)"
                  SourceUrl="$(TailwindDownloadUrl)"
                  SkipUnchangedFiles="true"
                  Retries="3"
                  Condition="'$(TailwindVersion)' == 'latest' Or !Exists('$(TailwindCliPath)')">
      <Output TaskParameter="DownloadedFile" PropertyName="TailwindCliPath"/>
    </DownloadFile>

    <!-- On unix systems, make the file executable -->
    <Exec Condition="Exists('$(TailwindCliPath)') And ($([System.OperatingSystem]::IsLinux()) Or $([System.OperatingSystem]::IsMacOS()))"
          Command="chmod +x '$(TailwindCliPath)'"
          EchoOff="true"/>
  </Target>

  <!-- When building the project, run the Tailwind CLI -->
  <!-- This target can also be executed manually. For example, with dotnet watch: `dotnet watch msbuild /t:Tailwind` -->
  <!-- In order to use hot reload, run both `dotnet watch run` and `dotnet watch msbuild /t:Tailwind` -->
  <Target Name="Tailwind" DependsOnTargets="DownloadTailwind" BeforeTargets="Build">
    <PropertyGroup>
      <!-- Normalize the paths provided -->
      <TailwindCliPath>$([MSBuild]::NormalizePath('$(TailwindCliPath)'))</TailwindCliPath>
      <TailwindInputStyleSheetPath>$([MSBuild]::NormalizePath('$(TailwindInputStyleSheetPath)'))</TailwindInputStyleSheetPath>
      <TailwindOutputStyleSheetPath>$([MSBuild]::NormalizePath('$(TailwindOutputStyleSheetPath)'))</TailwindOutputStyleSheetPath>
      <TailwindOutputSourceMapPath Condition="'$(TailwindOutputSourceMapPath)' != ''">$([MSBuild]::NormalizePath('$(TailwindOutputSourceMapPath)'))</TailwindOutputSourceMapPath>

      <TailwindBuildCommand>"$(TailwindCliPath)" -i "$(TailwindInputStyleSheetPath)" -o "$(TailwindOutputStyleSheetPath)"</TailwindBuildCommand>

      <!-- Add optimize flag if specified -->
      <TailwindBuildCommand Condition="'$(TailwindOptimizeOutputStyleSheet)' == 'true'">$(TailwindBuildCommand) --optimize</TailwindBuildCommand>

      <!-- Add minify flag if specified -->
      <TailwindBuildCommand Condition="'$(TailwindMinifyOutputStyleSheet)' == 'true'">$(TailwindBuildCommand) --minify</TailwindBuildCommand>

      <!-- Add map flag if specified -->
      <TailwindBuildCommand Condition="'$(TailwindGenerateSourceMap)' == 'true' And '$(TailwindOutputSourceMapPath)' == ''">$(TailwindBuildCommand) --map</TailwindBuildCommand>

      <!-- Add map flag with output path if specified -->
      <TailwindBuildCommand Condition="'$(TailwindGenerateSourceMap)' == 'true' And '$(TailwindOutputSourceMapPath)' != ''">$(TailwindBuildCommand) --map "$(TailwindOutputSourceMapPath)"</TailwindBuildCommand>
    </PropertyGroup>

    <Exec Command="$(TailwindBuildCommand)" EchoOff="true"/>
  </Target>

  <!-- Delete the generated files when cleaning the project -->
  <Target Name="CleanTailwindOutput" AfterTargets="Clean">
    <!-- Delete the output stylesheet -->
    <Delete Files="$(TailwindOutputStyleSheetPath)"/>

    <!-- Delete external source map file if specified -->
    <Delete Files="$(TailwindOutputSourceMapPath)" Condition="'$(TailwindOutputSourceMapPath)' != ''"/>
  </Target>
</Project>

If you found this useful, leave a 👍 below!

👍 thanks!

Im the guy with the SpecialFolder problem on msbuild. This is how it currently looks in my code:
$([System.Environment]::GetFolderPath([System.Environment+SpecialFolder]::LocalApplicationData))

Maybe you can try building it on your system using windows and not WSL? I'm not really sure what the problem is.

Absolutely!

This should work for you on Windows:

<!-- Change the download path to this  -->
<TailwindDownloadPath Condition="'$(TailwindDownloadPath)' == '' And $([System.OperatingSystem]::IsWindows())">$(LOCALAPPDATA)</TailwindDownloadPath>

<!-- Remove the quotes from the build command -->
<TailwindBuildCommand>$(TailwindCliPath) -i $(TailwindInputStyleSheetPath) -o $(TailwindOutputStyleSheetPath) --cwd $(ProjectDir)</TailwindBuildCommand>

Thank you for catching this!

Removing the quotes on the build command is slightly worrying. I'll need to look for a more permanent solution there. Until I find a permanent solution, you won't be able to use a path that includes a space anywhere.

I'm still getting the same error unfortunately, I also tried building your mudblazor-tailwind template and I get the same error.

Just to make sure I understand, you changed the TailwindDownloadPath here to the below?

<TailwindDownloadPath Condition="'$(TailwindDownloadPath)' == '' And $([System.OperatingSystem]::IsWindows())">$(LOCALAPPDATA)</TailwindDownloadPath>

And similarly, the TailwindBuildCommand here:

<TailwindBuildCommand>$(TailwindCliPath) -i $(TailwindInputStyleSheetPath) -o $(TailwindOutputStyleSheetPath) --cwd $(ProjectDir)</TailwindBuildCommand>

Yes I copy pasted your code and changed both, making sure that I changed the TailwindDownloadPath for windows and not linux/mac. I made sure to check that msbuild works on my mvc projects and it does.

I've provided a revised version here. I tried it myself on Windows & it works.

Let me know it if works for you as well!