Remove default "string" from swagger UI using .NET

Question

Im using Swagger in .NET 5

After click on Try it out Swagger displays a "string" in the body. (Please see the below screenshot)

I want it to display "{}" instead.

That's what I tried:

public class EmptyStringRequestBodyFilter : IOperationFilter
    {
        public void Apply(OpenApiOperation operation, OperationFilterContext context)
        {
            var schema = operation.RequestBody?.Content?.FirstOrDefault().Value?.Schema;

            if (schema != null)
            {
                foreach (var property in schema.Properties)
                {
                    if (property.Value.Type == "string")
                    {
                        property.Value.Example = new OpenApiString("{}");
                        property.Value.Default = new OpenApiString("{}");
                    }
                }
            }
        }
    }

and on Startup.cs :

 services.AddTransient<IOperationFilter, EmptyStringRequestBodyFilter>();

but it didn't help, I still get "string".

As I check how swagger generates by going to link http://localhost:<port>/swagger/v1/swagger.json

I see this

"requestBody": {
  "content": {
    "application/json-patch+json": {
      "schema": { }
    },

Seems like it use some default value..

How can I replace to "{}" or just have empty?

Thx.

Answer 1

The following has been working for me:

 public class MyClassSchemaFilter : ISchemaFilter
    {
        public void Apply(OpenApiSchema schema, SchemaFilterContext context)
        {
            if (context.Type == typeof(MyClass))
            {
                schema.Properties.Clear();
                schema.Type = "object";
            }
        }
    }

and on Startup.cs:

services.AddSwaggerGen(c =>
            {
                c.SwaggerDoc("v1", new OpenApiInfo { Title = "AAA", Version = "v1" });
                c.SchemaFilter<StartSessionSchemaFilter>();
});