How to use [StringSyntax("Route")] without referencing AspNetCore.App?

[ghord]

I've created a library that supports the same set of routes as AspNetCore. I would like for my library to take advantage of [StringSyntax('Route")] syntax highlighting in Visual Studio, without referencing whole AspNetCore framewrok.

If I reference AspNetCore.App framework in my project (via FrameworkReference), everything works fine and routes are highlighted correctly.

If I do not reference AspNetCore.App framework, [StringSyntax("Route")] attribute does not work (strings are not syntax-higlighted).

I've read some mentions that this code is placed in Microsoft.CodeAnalysis.ExternalAccess.AspNetCore, but I cannot find nuget with this dll that I could reference as an Analyzer. Is there something I can do to make it work?

[martincostello]

My understanding is that if you can't reference the attribute through a reference from another assembly, you can create your own copy of the attribute and it should work as the attributes are found/resolved by name, not the identity of where the type is defined.

Example copy so syntax highlighting works for TFMs that don't have the types defined in the framework itself.

[ghord]

The attribute is present and compiles fine, the issue is that its "Route" value is ignored:

[martincostello]

What about if you rename the parameter from t to test so the names match?

[ghord]

The name of the parameter does not change anything here. Here is how it looks once you add following line to the project:

<FrameworkReference Include="Microsoft.AspNetCore.App" />

[Skleni]

@ghord did you find a solution? I'm facing the same problem.

[ghord]

No, from my research it is provided by analyzer that comes with ASP.Net SDK and relies on internal Roslyn APIs, so no easy way to achieve this.

I think it should be possible to somehow use those apis using some trickery with IgnoreAccessChecksTo attribute and Reflection, but I didn't try.