如何从.csproj文件中知道计算机上是否安装了nodejs？

Question

I am building *.less files using a custom target in *.csproj and the original compiler that requires nodejs. Node isn't available on all development machines, so I need to be able to switch off the target if node isn't present on a computer. How can I do that?

<Target Name="CompileLessCss" BeforeTargets="Compile"
        Inputs="@(LessCssRoot);@(LessCssInput)" Outputs="@(LessCssOutput)">
    <Exec Command="node &quot;$(SolutionDir)/Tools/less.js/bin/lessc&quot; --verbose @(LessCssRoot) @(LessCssOutput)" ConsoleToMSBuild="true">
      <Output TaskParameter="ConsoleOutput" PropertyName="OutputOfExec" />
    </Exec>
</Target>

Answer 1

You can either check if a nodejs path is available in the $(PATH) variable. Or you can execute node once with continue on error to determine if it is installed with the exec task, not pretty but it works.

<Exec ContinueOnError="True"  Command="node --help">
  <Output TaskParameter="ExitCode" PropertyName="ErrorCode"/>
</Exec>

<PropertyGroup>  
  <NodeInstalled>False</NodeInstalled>      
  <NodeInstalled Condition=" '$(ErrorCode)' == '0' ">True</NodeInstalled>
</PropertyGroup>

<Exec Command="node [args]"  Condition=" '$(NodeInstalled)' == 'True' " />