headerValueByType
Signature
def headerValueByType[T <: HttpHeader: ClassTag](): Directive1[T]
The signature shown is simplified, the real signature uses magnets. [1]
| [1] | See The Magnet Pattern for an explanation of magnet-based overloading. |
Description
Traverses the list of request headers and extracts the first header of the given type.
The headerValueByType directive finds a header of the given type in the list of request header. If no header of
the given type is found the request is rejected with a MissingHeaderRejection.
If the header is expected to be missing in some cases or to customize handling when the header is missing use the optionalHeaderValueByType directive instead.
注釈
Custom headers will only be matched by this directive if they extend ModeledCustomHeader
and provide a companion extending ModeledCustomHeaderCompanion, otherwise the routing
infrastructure does now know where to search for the needed companion and header name.
To learn more about defining custom headers, read: Custom Headers.
Example
val route =
headerValueByType[Origin]() { origin =>
complete(s"The first origin was ${origin.origins.head}")
}
val originHeader = Origin(HttpOrigin("http://localhost:8080"))
// tests:
// extract a header if the type is matching
Get("abc") ~> originHeader ~> route ~> check {
responseAs[String] shouldEqual "The first origin was http://localhost:8080"
}
// reject a request if no header of the given type is present
Get("abc") ~> route ~> check {
inside(rejection) { case MissingHeaderRejection("Origin") => }
}
Contents
