Spray routing: How to respond with different content-types?

Question

In spray I would like to respond with different content-types, depending on the given Accept header. I've seen a couple of suggestions in the question by rompetroll, but I would like to hear if there are any canonical way of doing it (i. e. simple or already implemented).

In essence what I imagine should happen is something like:

path("somepath") {
  get {
    // Find whatever we would like to return (lazily)
    ...
    // Marshall resource and complete depending on the `Accept` header
    ...
  }
}

Thanks in advance.

Answer 1

Spray is actually looking into the Accept header value and validates against it. So if route is returning application/json or text/plain and client accepts image/jpeg than spray will return 406 Not Acceptable. If client will request application/json ortext/plain from this route than he will receive repsonse with matching Content-Type.

The main trick here is to use correct marshallers for return objects. You can read more about marshalling here.

Also you can override MediaType with respondWithMediaType directive, but I think it is better to use correct marshallers.