Display properties name for custom properties in Swagger

Question

I have a property named UserLanguage whose type is Language ( a record that I created ) which has three properties Name,Alpha2Code and Alpha3Code.

So in my request models, I give property as Language but on swagger, it only appears like this

{
  "name" : "",
  "userlanguage" : {}
}

I want to appear like this :

 {
      "name" : "",
      "userLanguage" : {
          "name" : "",
          "alpha2Code" : "",
          "alpha3Code" : ""
       }
 }

This is the language record:

public record Language
{
    public static readonly Language None = new(string.Empty, string.Empty, string.Empty);
    
    private Language(
        string alpha2Code, 
        string alpha3Code,
        string name)
    {
        Name = name;
        Alpha2Code = alpha2Code;
        Alpha3Code = alpha3Code;
    }
    public string Alpha2Code { get; private set; } = string.Empty;
    public string Alpha3Code { get; private set; } = string.Empty;
    public string? Name { get; private set; }
}

This is the request:

public sealed record UserDetailsRequest(
    string Name,
    Language UserLanguage
);

How can I achieve it in .NET 6 Web API?

Answer 1

For the properties with a private setter,you would need a filter:

 public class AddPrivateSetPropertyFilter : ISchemaFilter
 {
     public void Apply(OpenApiSchema schema, SchemaFilterContext context)
     {
         if (schema?.Properties?.Count > 0)
             schema.Properties.Values.SingleOrDefault(v => v.ReadOnly = false);
     }
 }

Apply it in program.cs:

builder.Services.AddSwaggerGen(c=> c.SchemaFilter<AddPrivateSetPropertyFilter>());

It's ok onmyside: