How do I specify conditional dependencies based on target framework in NuGet?

Question

I am building a NuGet package that references the Microsoft CommonServiceLocator assembly.

There are two versions of the Microsoft CommonServiceLocator out there:

• CommonServiceLocator - targets the full .NET framework and is referenced by the Microsoft EnterpriseLibrary components.
• Portable.CommonServiceLocator - contains both the full version of CommonServiceLocator and the recently released Portable Class Library version.

My project is a Portable Class Library but, because it's sometimes used with Enterprise Library, I need to sort of "conditionally" reference the portable version so there's no conflict.

• If the target framework is full .NET 4.0/4.5, use the original CommonServiceLocator package so people can also use the Enterprise Library bits (which also reference the CommonServiceLocator package).
• If the target framework is portable (or anything else) use the Portable.CommonServiceLocator package.

I see the new "group" feature in the NuGet docs showing how to specify dependencies in your .nuspec file and I think that will do what I want, but I'm not sure how to test it.

Here's what I think I need to do and I'm hoping someone can validate my approach or point me in the right direction:

<dependencies>
  <group>
    <!-- Always include regardless of target framework -->
    <dependency id="Autofac" />
  </group>
  <group targetFramework="net40">
    <!-- Also include the full CSL if it's full framework -->
    <dependency id="CommonServiceLocator" />
  </group>
  <group targetFramework="portable-win+sl50+wp8">
    <!-- Otherwise include the Portable CSL -->
    <dependency id="Portable.CommonServiceLocator" />
  </group>
</dependencies>

Specifically...

• Is my targetFramework syntax right? I can't find any examples, so I don't know if the + delimited mechanism is right or if it should be comma-delimited.
• Will the default group work? That group with the unspecified target framework - will that always be included or do I need to copy/paste it in every group?

Answer 1

Yeah, that's pretty much correct. Details on portable framework names can be found here http://docs.nuget.org/docs/creating-packages/creating-and-publishing-a-package#Framework_Names

One more thing I found, since win+sl50+wp8 by default includes net45 you might want to include it so that this dependency group gets installed.