pathPrefixTest

Signature

def pathPrefixTest[L](pm: PathMatcher[L]): Directive[L]

Description

Checks whether the unmatched path of the RequestContext has a prefix matched by the given PathMatcher. Potentially extracts one or more values (depending on the type of the argument) but doesn’t consume its match from the unmatched path.

This directive is very similar to the pathPrefix directive with the one difference that the path prefix it matched (if it matched) is not consumed. The unmatched path of the RequestContext is therefore left as is even in the case that the directive successfully matched and the request is passed on to its inner route.

For more info on how to create a PathMatcher see The PathMatcher DSL.

As opposed to its rawPathPrefixTest counterpart pathPrefixTest automatically adds a leading slash to its PathMatcher argument, you therefore don’t have to start your matching expression with an explicit slash.

Depending on the type of its PathMatcher argument the pathPrefixTest directive extracts zero or more values from the URI. If the match fails the request is rejected with an empty rejection set.

Example

Scala
sourceval completeWithUnmatchedPath =
  extractUnmatchedPath { p =>
    complete(p.toString)
  }

val route =
  pathPrefixTest("foo" | "bar") {
    concat(
      pathPrefix("foo") { completeWithUnmatchedPath },
      pathPrefix("bar") { completeWithUnmatchedPath }
    )
  }

// tests:
Get("/foo/doo") ~> route ~> check {
  responseAs[String] shouldEqual "/doo"
}

Get("/bar/yes") ~> route ~> check {
  responseAs[String] shouldEqual "/yes"
}
Java
sourceimport static akka.http.javadsl.server.Directives.path;
import static akka.http.javadsl.server.Directives.pathEnd;
import static akka.http.javadsl.server.Directives.pathPrefix;
import static akka.http.javadsl.server.Directives.pathPrefixTest;
final Route route =
    concat(
        pathPrefixTest(segment("foo").orElse("bar"), () ->
            concat(
                  pathPrefix("foo", () -> completeWithUnmatchedPath.get()),
                  pathPrefix("bar", () -> completeWithUnmatchedPath.get())
            )
        )
    );
// tests:
testRoute(route).run(HttpRequest.GET("/foo/doo")).assertEntity("/doo");
testRoute(route).run(HttpRequest.GET("/bar/yes")).assertEntity("/yes");
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