oneof response bodies

[SebastianEngelmann]

Hi, I have a question regarding the response body. My API endpoint, which I created with actix-web, returns either struct a or struct b. Is there a way to model this with utoipa? I would need something like OneOf. Unfortunately I have not found an example in the docs. The code block is about lines 5 and 6.

#[utoipa::path(
    get,
    path = "/api/v1/app/{id}",
    responses(
        (status = 200, description = "struct a", body = StructA),
        (status = 200, description = "struct b", body = StructB),
        (status = 400, description = "No valid ID", body = String, example = json!(["no valid id"])),
        (status = 500, description = "Internal Server Error"),
        (status = NOT_FOUND, description= "ID was not found", example = json!(["no id found"]))
    ),
    params(
        ("id" = String, description = "id")
    )
)]

Is there a way I can tell swagger to return either struct a or struct b?

[juhaku]

@SebastianEngelmann There are 2 ways around this question.

1. One either have different content type per response content as seen on the example in the docs: https://docs.rs/utoipa/latest/utoipa/attr.path.html#response-attributes (Define multiple response return types).
2. Create an enum out of your response struct.

   #[derive(ToSchema)]
   enum Response {
       A(StructA),
       B(StructB)
   }
   
   #[utoipa::path(
       get,
       path = "/api/v1/app/{id}",
       responses(
           (status = 200, description = "struct a or b", body = Response),
       ),
       params(
           ("id" = String, description = "id")
       )
   )]

[SebastianEngelmann]

Thank you so much!

[juhaku]

Welcome 🙂