Akka-Http

structible-akka-http is available for Scala 2.12 and 2.13.

It provides derivations for:

• PathMatcher
• Unmarshaller

Make sure to familiarize yourself with creating structible instances before looking at the examples below.

Dependency

sbt

libraryDependencies += "com.github.cerst" % "structible-akka-http" % "0.6.4"

Maven

<dependency>
  <groupId>com.github.cerst</groupId>
  <artifactId>structible-akka-http</artifactId>
  <version>0.6.4</version>
</dependency>

Gradle

dependencies {
  compile group: 'com.github.cerst', name: 'structible-akka-http', version: '0.6.4'
}

PathMatcher Example

import akka.http.scaladsl.server.Directives._
import akka.http.scaladsl.server.{PathMatcher1, Route}
import com.github.cerst.structible.akkahttp.ops._
import com.github.cerst.structible.core.DefaultConstraints._
import com.github.cerst.structible.core._

object PathMatcherExample {

  final class ItemId private (val value: Long) extends AnyVal

  object ItemId {

    private val structible: Structible[Long, ItemId] = Structible.structible(new ItemId(_), _.value, c >= 0)

    // not declared as implicit because you usually call patch matchers explicitly within the Akka routing Dsl
    val pathMatcher: PathMatcher1[ItemId] = structible.toPathMatcher

    def apply(value: Long): ItemId = structible.construct(value)

  }

  val route: Route = {
    path("items" / ItemId.pathMatcher) { itemId =>
      complete(itemId.toString)
    }
  }

}

Unmarshaller Example

This derivation was originally added to address a quirk in an Http Api which returned the id of a generated resource as plain text. Hence, the response entity needed to be unmarshalled directly as in Unmarshal(response.entity).to[A].
As long as you receive a properly formatted message, use a derivation for the employed messaging protocol and library (e.g. your favorite JSON library).

import akka.http.scaladsl.unmarshalling.{Unmarshal, Unmarshaller}
import akka.stream.Materializer
import com.github.cerst.structible.akkahttp.ops._
import com.github.cerst.structible.core.DefaultConstraints._
import com.github.cerst.structible.core._

import scala.concurrent.{ExecutionContext, Future}

object UnmarshallerExample {

  final class ItemId private (val value: Long) extends AnyVal

  object ItemId {

    private val structible: Structible[Long, ItemId] = Structible.structible(new ItemId(_), _.value, c >= 0)

    implicit val unmarshallerForItemId: Unmarshaller[String, ItemId] = structible.toUnmarshaller

    def apply(value: Long): ItemId = structible.construct(value)
  }

  // this works seamlessly for e.g. HttpResponse.entity instead of String
  def toItemId(input: String)(implicit ec: ExecutionContext, mat: Materializer): Future[ItemId] = {
    Unmarshal(input).to[ItemId]
  }

}