I'm trying to make an API library for our web services, and I'm wondering if it's possible to do something like this:

abstract class UserRequest(val userId: Int) {
  def success(message: String)
  def error(error: ApiError)
}

api.invokeRequest(new UserRequest(121) {
  override def success(message: String) = {
    // handle success
  }

  override def error(error: ApiError) = {
    // handle the error
  }
}

I'm talking about passing parameters to the anonymous inner class, and also overriding the two methods.

I'm extremely new to Scala, and I realize my syntax might be completely wrong. I'm just trying to come up with a good design for this library before I start coding it.

I'm willing to take suggestions for this, if I'm doing it the completely wrong way, or if there's a better way.

The idea is that the API will take some sort of request object, use it to make a request in a thread via http, and when the response has been made, somehow signal back to the caller if the request was a success or an error. The request/error functions have to be executed on the main thread.