+doc #19429 initial merge of docs-dev and docs

akka-docs/rst/scala/code/docs/stream/cookbook/RecipeManualTrigger.scala

@@ -0,0 +1,93 @@
+package docs.stream.cookbook
+
+import akka.stream.ClosedShape
+import akka.stream.scaladsl._
+import akka.stream.testkit._
+import scala.concurrent.duration._
+
+class RecipeManualTrigger extends RecipeSpec {
+
+  "Recipe for triggering a stream manually" must {
+
+    "work" in {
+
+      val elements = Source(List("1", "2", "3", "4"))
+      val pub = TestPublisher.probe[Trigger]()
+      val sub = TestSubscriber.manualProbe[Message]()
+      val triggerSource = Source.fromPublisher(pub)
+      val sink = Sink.fromSubscriber(sub)
+
+      //#manually-triggered-stream
+      val graph = RunnableGraph.fromGraph(GraphDSL.create() { implicit builder =>
+        import GraphDSL.Implicits._
+        val zip = builder.add(Zip[Message, Trigger]())
+        elements ~> zip.in0
+        triggerSource ~> zip.in1
+        zip.out ~> Flow[(Message, Trigger)].map { case (msg, trigger) => msg } ~> sink
+        ClosedShape
+      })
+      //#manually-triggered-stream
+
+      graph.run()
+
+      sub.expectSubscription().request(1000)
+      sub.expectNoMsg(100.millis)
+
+      pub.sendNext(())
+      sub.expectNext("1")
+      sub.expectNoMsg(100.millis)
+
+      pub.sendNext(())
+      pub.sendNext(())
+      sub.expectNext("2")
+      sub.expectNext("3")
+      sub.expectNoMsg(100.millis)
+
+      pub.sendNext(())
+      sub.expectNext("4")
+      sub.expectComplete()
+    }
+
+    "work with ZipWith" in {
+
+      val elements = Source(List("1", "2", "3", "4"))
+      val pub = TestPublisher.probe[Trigger]()
+      val sub = TestSubscriber.manualProbe[Message]()
+      val triggerSource = Source.fromPublisher(pub)
+      val sink = Sink.fromSubscriber(sub)
+
+      //#manually-triggered-stream-zipwith
+      val graph = RunnableGraph.fromGraph(GraphDSL.create() { implicit builder =>
+        import GraphDSL.Implicits._
+        val zip = builder.add(ZipWith((msg: Message, trigger: Trigger) => msg))
+
+        elements ~> zip.in0
+        triggerSource ~> zip.in1
+        zip.out ~> sink
+        ClosedShape
+      })
+      //#manually-triggered-stream-zipwith
+
+      graph.run()
+
+      sub.expectSubscription().request(1000)
+      sub.expectNoMsg(100.millis)
+
+      pub.sendNext(())
+      sub.expectNext("1")
+      sub.expectNoMsg(100.millis)
+
+      pub.sendNext(())
+      pub.sendNext(())
+      sub.expectNext("2")
+      sub.expectNext("3")
+      sub.expectNoMsg(100.millis)
+
+      pub.sendNext(())
+      sub.expectNext("4")
+      sub.expectComplete()
+    }
+
+  }
+
+}