How to invoke the same msbuild target twice with different parameters from within msbuild project file itself.

Question

Dear ladies and sirs.

I have the following piece of msbuild code:

  <PropertyGroup>
    <DirA>C:\DirA\</DirA>
    <DirB>C:\DirB\</DirB>
  </PropertyGroup>

  <Target Name="CopyToDirA"
          Condition="Exists('$(DirA)') AND '@(FilesToCopy)' != ''"
          Inputs="@(FilesToCopy)"
          Outputs="@(FilesToCopy -> '$(DirA)%(Filename)%(Extension)')">
    <Copy SourceFiles="@(FilesToCopy)" DestinationFolder="$(DirA)" />
  </Target>

  <Target Name="CopyToDirB"
          Condition="Exists('$(DirB)') AND '@(FilesToCopy)' != ''"
          Inputs="@(FilesToCopy)"
          Outputs="@(FilesToCopy -> '$(DirB)%(Filename)%(Extension)')">
    <Copy SourceFiles="@(FilesToCopy)" DestinationFolder="$(DirB)" />
  </Target>

  <Target Name="CopyFiles" DependsOnTargets="CopyToDirA;CopyToDirB"/>

So invoking the target CopyFiles copies the relevant files to $(DirA) and $(DirB), provided they are not already there and up-to-date.

But the targets CopyToDirA and CopyToDirB look identical except one copies to $(DirA) and the other - to $(DirB). Is it possible to unify them into one target first invoked with $(DirA) and then with $(DirB)?

Thanks.

Answer 1

You should be able to generate an ItemGroup containing the Dirs and then % on that.

<ItemGroup>
    <Dirs Include="C:\DirA\;C:\DirB\">
</ItemGroup>
<Target Name="CopyFiles"
    Condition="Exists('%(Dirs)') AND '@(FilesToCopy)' != ''"
    Inputs="@(FilesToCopy)"
    Outputs="@(FilesToCopy -> '%(Dirs)%(Filename)%(Extension)')">
    <Copy SourceFiles="@(FilesToCopy)" DestinationFolder="%(Dirs)" />
</Target>

Or you can do 2 explicit calls:

<Target Name="CopyFiles">
    <MsBuild Projects="$(MSBuildProjectFile)" Targets="CopyASetOfFiles" Properties="FilesToCopy=@(FilesToCopy);DestDir=$(DirA)" />
    <MsBuild Projects="$(MSBuildProjectFile)" Targets="CopyASetOfFiles" Properties="FilesToCopy=@(FilesToCopy);DestDir=$(DirB)" />
</Target>

<Target Name="CopyASetOfFiles"
    Condition="Exists('$(DestDir)') AND '@(FilesToCopy)' != ''"
    Inputs="@(FilesToCopy)"
    Outputs="@(FilesToCopy -> '$(DestDir)%(Filename)%(Extension)')">
    <Copy SourceFiles="@(FilesToCopy)" DestinationFolder="$(DestDir)" />
</Target>

I haven't tested either syntax, but am relatively more confident of the second.

(The answer, if there is one, is in my Sayed Hashimi book on my desk - you'll have to wait until the first of:

1. Get the book
2. I get bored
3. Sayed finds this post and comes up with a brilliant tested answer)

Answer 2

Yes, what you want is called batching in MSBuild. The

;%(Dirs.Identity)

Defined in the Outputs will cause this task to be executed for each item in the Dirs ItemGroup.

<?xml version="1.0" encoding="utf-8"?>
<Project DefaultTargets="CopyFiles"
   xmlns="http://schemas.microsoft.com/developer/msbuild/2003" 
   ToolsVersion="3.5">

<ItemGroup>
    <Dirs Include="C:\DirA" />
    <Dirs Include="C:\DirB" />
</ItemGroup>

<Target Name="CopyFiles"
    Inputs="@(FilesToCopy);@(Dirs)"
    Outputs="@(FilesToCopy -> '%(Dirs.Identity)%(Filename)%(Extension)');%(Dirs.Identity)" >
    <Message Text="%(Dirs.Identity)" />
</Target>

</Project>

Outputs:

Build started 8/19/2009 10:11:57 PM.
Project "D:\temp\test.proj" on node 0 (default targets).
  C:\DirA
CopyFiles:
  C:\DirB
Done Building Project "D:\temp\test.proj" (default targets).

Change the Message task to Copy task with the following condition and you are done:

Condition="Exists('%(Dirs.Identity)') AND '@(FilesToCopy)' != ''"

Answer 3

As someone already mentiond the answer is batching.

Here are some links:

• MSBuild Batching Part 1
• MSBuild Batching Part 2
• MSBuild Batching Part 3
• MSBuild RE: Enforcing the Build Agent in a Team Build