Swagger (Swashbuckle for C#) shows Mongo ObjectId as several fields instead of single string

Question

I have controller method with ObjectId params:

[ProducesResponseType(200, Type = typeof(Test))]
[HttpGet]
[Route("{id}")]
public IActionResult Get(ObjectId id)
{...

For this API method swagger generates a form with both of complex ObjectId model and string Id instead of single string param: How I can remove extra fields and keep only string Id?

Answer 1

It is possible to filter output fields for swagger form generator:

public class SwaggerOperationFilter : IOperationFilter
{
    private readonly IEnumerable<string> objectIdIgnoreParameters = new[]
    {
        nameof(ObjectId.Timestamp),
        nameof(ObjectId.Machine),
        nameof(ObjectId.Pid),
        nameof(ObjectId.Increment),
        nameof(ObjectId.CreationTime)
    };

    public void Apply(Operation operation, OperationFilterContext context)
    {
        operation.Parameters = operation.Parameters.Where(x =>
            x.In != "query" || objectIdIgnoreParameters.Contains(x.Name) == false
        ).ToList();
    }
}

and use this filter in Startup.cs:

public void ConfigureServices(IServiceCollection services)
    {
        ...
        services.AddSwaggerGen(options =>
        {
            ...
            options.OperationFilter<SwaggerOperationFilter>();
        });
...

As the result, we have only Id field: