How to copy linked content files using .NET Core csproj?

Question

I'm referencing this article in an attempt to copy linked files before each build:

<Target Name="CopyLinkedContentFiles" BeforeTargets="Build">
    <Copy SourceFiles="%(Content.Identity)" 
          DestinationFiles="%(Content.Link)" 
          SkipUnchangedFiles='true' 
          OverwriteReadOnlyFiles='true' 
          Condition="'%(Content.Link)' != ''" />
 </Target>

This doesn't appear to work for the new .NET Core csproj tooling. What would be an equivalent target that does?

EDIT: Example csproj content

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>netstandard2.0</TargetFramework>
    <Features>IOperation</Features>
    <Configurations>Debug;Release;Template</Configurations>
  </PropertyGroup>

  <ItemGroup>
    <Compile Include="..\MyRefProject\ChangeTypes.cs" Link="ChangeTypes.cs" />
    <Compile Include="..\MyRefProject\Parser.cs" Link="Parser.cs" />
    <Compile Include="..\MyRefProject\Calculator.cs" Link="Calculator.cs" />
    <Compile Include="..\MyRefProject\Converter.cs" Link="Converter.cs" />
  </ItemGroup>
</Project>

Answer 1

A Condition should be specified at the Target level but this won't help in this scenario because you can't use an elements metadata as a condition.

You also need to provide an output path. Your example will only copy linked content into the project's directory, not it's output directory.

<Target Name="CopyLinkedContentFiles" BeforeTargets="Build">
<Copy SourceFiles="%(Content.Identity)" 
        DestinationFiles="$(OutputPath)\%(Content.Link)" 
        SkipUnchangedFiles="true" 
        OverwriteReadOnlyFiles="true" />
</Target>

The documentation for the Copy task can be found here.

I tested this using Visual Studio 2017 with two simple console projects. The second project included a couple of text files. The first project also references these files via content links. This is the .csproj file from the first project:

<Project Sdk="Microsoft.NET.Sdk">
    <PropertyGroup>
        <OutputType>Exe</OutputType>
        <TargetFramework>netcoreapp2.0</TargetFramework>
    </PropertyGroup>
    <ItemGroup>
        <Content Include="..\Project2\ReadMeFirst.txt" Link="ReadMeFirst.txt" />
        <Content Include="..\Project2\ReadMeSecond.txt" Link="ReadMeSecond.txt" />
    </ItemGroup>
    <Target Name="CopyLinkedContentFiles" BeforeTargets="Build">
        <Copy SourceFiles="%(Content.Identity)" 
            DestinationFiles="$(OutputPath)\%(Content.Link)" 
            SkipUnchangedFiles="true" 
            OverwriteReadOnlyFiles="true" />
    </Target>
</Project>