How to match specific accept headers in a route? - scala

Question

I want to create a route that matches only if the client sends a specific Accept header. I use Spray 1.2-20130822.
I'd like to get the route working:
def receive = runRoute {
get {
path("") {
accept("application/json") {
complete(...)
}
}
}
}
Here I found a spec using an accept() function, but I can't figure out what to import in my Spray-Handler to make it work as directive. Also, I did not find other doc on header directives but these stubs.

Answer 1

I would do this way:
def acceptOnly(mr: MediaRange*): Directive0 =
extract(_.request.headers).flatMap[HNil] {
case headers if headers.contains(Accept(mr)) ⇒ pass
case _ ⇒ reject(MalformedHeaderRejection("Accept", s"Only the following media types are supported: ${mr.mkString(", ")}"))
} & cancelAllRejections(ofType[MalformedHeaderRejection])
Then just wrap your root:
path("") {
get {
acceptOnly(`application/json`) {
session { creds ⇒
complete(html.page(creds))
}
}
}
}
And by the way the latest spray 1.2 nightly is 1.2-20130928 if you can, update it

Answer 2

There is no pre-defined directive called accept directive. You can see the full list of available directives here.
However, you can use the headerValueByName directive to make a custom directive that does what you desire:
def accept(required: String) = headerValueByName("Accept").flatMap {
case actual if actual.split(",").contains(required) => pass
case _ => reject(MalformedHeaderRejection("Accept", "Accept must be equal to " + required))
}
Put this code in scope of your spray Route, then just use as you have shown in your question.