kalix.scalasdk.DeferredCall.scala Maven / Gradle / Ivy
/*
* Copyright 2021 Lightbend Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package kalix.scalasdk
import scala.concurrent.Future
/**
* Represents a call to a component service that has not yet happened, but will be handed to Kalix for execution. Used
* with forwards and side effects.
*
* @tparam I
* the message type of the parameter for the call
* @tparam O
* the message type that the call returns
*
* Not for user extension.
*/
trait DeferredCall[I, O] {
/**
* The message to pass to the call when the call is invoked.
*/
def message: I
/**
* The metadata to pass with the message when the call is invoked.
*/
def metadata: Metadata
/**
* Execute this call right away and get the async result back for composition. Can be used to create an async reply in
* an [[kalix.scalasdk.action.Action]] using {{{effects.asyncReply}}} and {{{effects.asyncEffect}}}.
*/
def execute(): Future[O]
/**
* Update with given metadata
*/
def withMetadata(metadata: Metadata): DeferredCall[I, O]
}