optionalHeaderValueByType

def optionalHeaderValueByType[T <: HttpHeader: ClassTag](): Directive1[Option[T]]

Description

Optionally extracts the value of the HTTP request header of the given type.

The optionalHeaderValueByType directive is similar to the headerValueByType directive but always extracts an OptionOptional value instead of rejecting the request if no matching header could be found.

Example

Scala

copysourceval route =
  optionalHeaderValueByType(Origin) {
    case Some(origin) => complete(s"The first origin was ${origin.origins.head}")
    case None         => complete("No Origin header found.")
  }

val originHeader = Origin(HttpOrigin("http://localhost:8080"))

// tests:
// extract Some(header) if the type is matching
Get("abc") ~> originHeader ~> route ~> check {
  responseAs[String] shouldEqual "The first origin was http://localhost:8080"
}

// extract None if no header of the given type is present
Get("abc") ~> route ~> check {
  responseAs[String] shouldEqual "No Origin header found."
}

Java

copysourceimport static org.apache.pekko.http.javadsl.server.Directives.complete;
import static org.apache.pekko.http.javadsl.server.Directives.optionalHeaderValueByType;

final Route route =
    optionalHeaderValueByType(
        Origin.class,
        origin -> {
          if (origin.isPresent()) {
            return complete(
                "The first origin was " + origin.get().getOrigins().iterator().next());
          } else {
            return complete("No Origin header found.");
          }
        });

// tests:

// extract Some(header) if the type is matching
Host host = Host.create("localhost", 8080);
Origin originHeader = Origin.create(HttpOrigin.create("http", host));
testRoute(route)
    .run(HttpRequest.GET("abc").addHeader(originHeader))
    .assertEntity("The first origin was http://localhost:8080");

// extract None if no header of the given type is present
testRoute(route).run(HttpRequest.GET("abc")).assertEntity("No Origin header found.");