Publish.targets

<Project>

  <PropertyGroup>
    <MSBuildAllProjects>$(MSBuildAllProjects);$(MSBuildThisFileFullPath)</MSBuildAllProjects>
  </PropertyGroup>

  <!-- This target filters the @(ReferenceCopyLocalPaths) item list based on the provided publish file exclusion list. -->
  <Target Name="_FilterReferenceCopyLocalPaths" AfterTargets="ResolveAssemblyReferences" Condition=" '@(NuGetPackageIdExclusionList)' != '' ">
    <ItemGroup>
      <!-- This duplicates each item in @(ReferenceCopyLocalPaths), once per item in @(NuGetPackageIdExclusionList). -->
      <_AllReferenceCopyLocalPathsWithExclusionListMetadata Include="@(ReferenceCopyLocalPaths)">
        <NuGetPackageIdExclusionList>%(NuGetPackageIdExclusionList.Identity)</NuGetPackageIdExclusionList>
      </_AllReferenceCopyLocalPathsWithExclusionListMetadata>

      <!-- This filters the list back down to just the items where the NuGetPackageId matches one of the items in NuGetPackageIdExclusionList (e.g. the excluded items of @(ReferenceCopyLocalPaths)). -->
      <ExcludedAllReferenceCopyLocalPaths Include="@(_AllReferenceCopyLocalPathsWithExclusionListMetadata)" Condition=" '%(_AllReferenceCopyLocalPathsWithExclusionListMetadata.NuGetPackageId)' == '%(_AllReferenceCopyLocalPathsWithExclusionListMetadata.NuGetPackageIdExclusionList)' " />

      <!-- Finally, actually remove the items that have been identified as excluded. -->
      <ReferenceCopyLocalPaths Remove="@(ExcludedAllReferenceCopyLocalPaths)" />
    </ItemGroup>
  </Target>

</Project>