def mapRequest(f: HttpRequest ⇒ HttpRequest): Directive0


Transforms the request before it is handled by the inner route.

The mapRequest directive is used as a building block for Custom Directives to transform a request before it is handled by the inner route. Changing the request.uri parameter has no effect on path matching in the inner route because the unmatched path is a separate field of the RequestContextRequestContext value which is passed into routes. To change the unmatched path or other fields of the RequestContextRequestContext use the mapRequestContext directive.

See Request Transforming Directives for an overview of similar directives.


def transformToPostRequest(req: HttpRequest): HttpRequest = req.copy(method = HttpMethods.POST)
val route =
  mapRequest(transformToPostRequest) {
    extractRequest { req =>
      complete(s"The request method was ${}")

Get("/") ~> route ~> check {
  responseAs[String] shouldEqual "The request method was POST"
final Route route = mapRequest(req ->
  req.withMethod(HttpMethods.POST), () ->
  extractRequest(req -> complete("The request method was " + req.method().name()))

// tests:
  .assertEntity("The request method was POST");
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