PubSubInAkka.fs

module Program

open System
open Akka
open Akka.Actor
open Akka.FSharp
open Akka.Configuration


type Message =
    | Subscribe
    | Unsubscribe
    | Msg of IActorRef * string


[<EntryPoint>]
let main argv = 
    let subscriber  (mailbox:Actor<_>) msg =
        let eventStream = mailbox.Context.System.EventStream
        match msg with
        | Msg (sender, content) -> printfn "%A says %s - %A" (sender.Path) content (mailbox.Self.Path)
        | Subscribe -> subscribe typeof<Message> mailbox.Self eventStream |> ignore
        | Unsubscribe -> unsubscribe typeof<Message> mailbox.Self eventStream |> ignore


    let actorSystem = System.create "myActorSystem" (Configuration.load ())
    let subscriber1 = spawn actorSystem "subscriber1" (actorOf2 subscriber)
    let subscriber2 = spawn actorSystem "subscriber2" (actorOf2 subscriber)
    let subscriber3 = spawn actorSystem "subscriber3" (actorOf2 subscriber)

    let publisher = spawn actorSystem "publisher" (actorOf2 
            (fun mailbox msg ->
                publish msg mailbox.Context.System.EventStream))

    subscriber1 <! Subscribe
    publisher  <! Msg (publisher, "hello")
    subscriber1 <! Unsubscribe

    subscriber1 <! Subscribe
    subscriber2 <! Subscribe
    subscriber3 <! Subscribe
    publisher  <! Msg (publisher, "hello again")

    actorSystem.AwaitTermination  ()

    0 // return an integer exit code