Add an example for 'Consume MSBuild properties and metadata' for IncrementalSourceGenerators

[rgbav]

I want to use metadata/properties as they are described in the Source Generator cookbook. My Problem is that i cannot make it work with IncrementalSourceGenerator. Is anyone able to extend the cookbook with an example?

[333fred]

The incremental generator cookbook already has this example: https://github.com/dotnet/roslyn/blob/main/docs/features/incremental-generators.cookbook.md#consume-msbuild-properties-and-metadata. Are you not able to get that to work?

[rgbav]

I am trying to use input of different yaml files for source generation. A file can have a certain "FileRole".
My Generator .csproj (i don't want to pack my generator so i don't use props)

<Project Sdk="Microsoft.NET.Sdk">
    <PropertyGroup>
        <TargetFramework>netstandard2.0</TargetFramework>
        <IsPackable>false</IsPackable>
        <Nullable>enable</Nullable>
        <LangVersion>latest</LangVersion>
        <EnforceExtendedAnalyzerRules>true</EnforceExtendedAnalyzerRules>
        <IsRoslynComponent>true</IsRoslynComponent>
    </PropertyGroup>
    
    <ItemGroup>
        <CompilerVisibleProperty Include="FileGenerator_FileRole" />
        <CompilerVisibleItemMetadata Include="AdditionalFiles" MetadataName="FileGenerator_FileRole"/>
    </ItemGroup>
    
    <ItemGroup>
        <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.11.0">
            <PrivateAssets>all</PrivateAssets>
            <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
        </PackageReference>
        <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0"/>
    </ItemGroup>

    <ItemGroup>
        <PackageReference Include="YamlDotNet" GeneratePathProperty="true" PrivateAssets="all" Version="16.3.0"/>
        <None Include="$(OutputPath)\$(AssemblyName).dll" Pack="true" PackagePath="analyzers/dotnet/cs" Visible="false"/>
        <None Include="$(PKGYamlDotNet)\lib\netstandard2.0\*.dll" Pack="true" PackagePath="analyzers/dotnet/cs" Visible="false"/>
    </ItemGroup>

    <PropertyGroup>
        <GetTargetPathDependsOn>$(GetTargetPathDependsOn);GetDependencyTargetPaths</GetTargetPathDependsOn>
    </PropertyGroup>

    <Target Name="GetDependencyTargetPaths">
        <ItemGroup>
            <TargetPathWithTargetPlatformMoniker Include="$(PKGYamlDotNet)\lib\netstandard2.0\YamlDotNet.dll" IncludeRuntimeDependency="false"/>
        </ItemGroup>
    </Target>
</Project>

The project that consumes the source generator defines this:

<Project Sdk="Microsoft.NET.Sdk">
    <PropertyGroup>
        <TargetFramework>net8.0</TargetFramework>
        <Nullable>enable</Nullable>
        <RootNamespace>FileGenerator.Sample</RootNamespace>
    </PropertyGroup>

    <ItemGroup>
        <ProjectReference Include="..\FileGenerator\FileGenerator.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false"/>
    </ItemGroup>

    <ItemGroup>
        <AdditionalFiles Include="SomeFile.yaml" FileGenerator_FileRole="ExampleValue"/>
    </ItemGroup>
</Project>

When debugging i get this options:

The property does not appear.

I have to add
<CompilerVisibleItemMetadata Include="AdditionalFiles" MetadataName="FileGenerator_FileRole"/>
to the project that uses the source generator project - then this metadata setting is visible. But is this the right way?
Do i have to use the props even if i don't want to pack the generator?

[333fred]

I have to add
<CompilerVisibleItemMetadata Include="AdditionalFiles" MetadataName="FileGenerator_FileRole"/>
to the project that uses the source generator project - then this metadata setting is visible. But is this the right way?

Yes, that is the only way. The metadata comes from the consuming project.