ActorFlow.askWithContext

Use the “Ask Pattern” to send each stream element (without the context) as an ask to the target actor (of the new actors API), and expect a reply of Type StatusReply[T]StatusReply<T> where the T will be unwrapped and emitted downstream.

Actor interop operators

Dependency

The Akka dependencies are available from Akka’s library repository. To access them there, you need to configure the URL for this repository.

sbt

resolvers += "Akka library repository".at("https://repo.akka.io/maven")

Maven

<project>
  ...
  <repositories>
    <repository>
      <id>akka-repository</id>
      <name>Akka library repository</name>
      <url>https://repo.akka.io/maven</url>
    </repository>
  </repositories>
</project>

Gradle

repositories {
    mavenCentral()
    maven {
        url "https://repo.akka.io/maven"
    }
}

This operator is included in:

sbt

val AkkaVersion = "2.9.1"
libraryDependencies += "com.typesafe.akka" %% "akka-stream-typed" % AkkaVersion

Maven

<properties>
  <scala.binary.version>2.13</scala.binary.version>
</properties>
<dependencyManagement>
  <dependencies>
    <dependency>
      <groupId>com.typesafe.akka</groupId>
      <artifactId>akka-bom_${scala.binary.version}</artifactId>
      <version>2.9.1</version>
      <type>pom</type>
      <scope>import</scope>
    </dependency>
  </dependencies>
</dependencyManagement>
<dependencies>
  <dependency>
    <groupId>com.typesafe.akka</groupId>
    <artifactId>akka-stream-typed_${scala.binary.version}</artifactId>
  </dependency>
</dependencies>

Gradle

def versions = [
  ScalaBinary: "2.13"
]
dependencies {
  implementation platform("com.typesafe.akka:akka-bom_${versions.ScalaBinary}:2.9.1")

  implementation "com.typesafe.akka:akka-stream-typed_${versions.ScalaBinary}"
}

Signature

ActorFlow.askWithStatusAndContextActorFlow.askWithStatusAndContext { scala=“#askWithStatusAndContextI,Q,A,Ctx(ref:akka.actor.typed.ActorRef[Q])(makeMessage:(I,akka.actor.typed.ActorRef[akka.pattern.StatusReply[A]])=>Q)(implicittimeout:akka.util.Timeout):akka.stream.scaladsl.Flow[(I,Ctx),(A,Ctx),akka.NotUsed]” java =“#askWithStatusAndContextI,Q,A,Ctx” }

Description

Use the Ask pattern to send a request-reply message to the target ref actor when you expect the reply to be akka.pattern.StatusReply. The stream context is not sent, instead it is locally recombined to the actor’s reply.

If any of the asks times out it will fail the stream with an AskTimeoutExceptionAskTimeoutException.

The ask operator requires

• the actor ref,
• a makeMessage function to create the message sent to the actor from the incoming element, and the actor ref accepting the actor’s reply message
• a timeout.

Reactive Streams semantics