Visual Studio extension: Json with schema item template - visual-studio

Question

I'd like to create a Visual Studio extension to allow the user to create a json file and automatically apply a custom JSON schema to it. I followed this article and so far, I succeeded in allowing the user to create the JSON file, but I have no idea how to automatically bind the custom schema to it.
I'd like this schema to be in the extension solution, this way, when I update the extension, the schema gets updated. As I'm using SideWaffle, I noticed that there is this "JSON Schema Selector Extension" item template but it does not work. It requires "Microsoft.Json.Core.Schema" that is nowhere to be found (not even in the Microsoft.JSON Nuget package...).

Answer 1

Late to this question, but the solution involves referencing a non-SDK VS assembly as of VS2019 (and everything prior). To prove it is non-SDK, it even changed identity in VS2019, it is now Microsoft.WebTools.Languages.Json as of VS2019 (whereas it was indeed Microsoft.Json.Core for older versions), and of course, it may change again in the future.
Knowing this, if you search online opensource repos, you will find some ideas for how to achieve the reference. Some people bundle a copy of the DLL in their repo (which is probably against some licensing terms). Personally, I did not go that route and I instead went for an overcomplicated path relative to $(MSBuildToolsPath):
<Reference Include="Microsoft.WebTools.Languages.Json">
<HintPath>$(MSBuildToolsPath)\..\..\..\Common7\IDE\Extensions\Microsoft\Web Tools\Languages\Microsoft.WebTools.Languages.Json.dll</HintPath>
<SpecificVersion>False</SpecificVersion>
<Private>false</Private>
</Reference>
Just looking at this, it is obvious that this approach is brittle, and the path may move in the future, but it avoids bootstrapping the dll.
Anyway, whichever way you choose to reference the assembly, as for everything else that is meant to come from VS itself, make sure it is Private=false, as you do not want your final VSIX bundle to include it.
Then it is a simple matter of implementing IJsonSchemaSelector:
[Export(typeof(IJsonSchemaSelector))]
public class LaunchConfigJsonSchemaProvider : IJsonSchemaSelector
{
private static readonly string Schema = #"<somehow resolve your extension install path and find your schema json>";
public event EventHandler AvailableSchemasChanged { add { } remove { } }
public Task<IEnumerable<string>> GetAvailableSchemasAsync()
{
return Task.FromResult((IEnumerable<string>)new[] { Schema });
}
public string GetSchemaFor(string fileLocation)
{
string ext = Path.GetExtension(fileLocation);
if (!".greatjson".Equals(ext, StringComparison.OrdinalIgnoreCase))
return null;
return Schema;
}
}