[Feature] Adding support for SSE events to autosource controllers

[bjartek]

I am currently playing with a small project where I do some CRUD operations and send events via SSE to clients when operations occur.

 val (enumerator, channel) = Concurrent.broadcast[JsValue]

  def streamUpdates = Action {
    Ok.stream(enumerator &> EventSource()).as("text/event-stream")
  }

And exposing streamUpdates at say /GET //events is all that is needed. (Not sure what to do it the auto source controller is typed.

Then in the methods that do actions that you want to push you can do:

 def update(id: BSONObjectID): EssentialAction = Action(parse.json){ request =>

    Json.fromJson[JsObject](request.body)(reader).map{ t =>
      Async{
        res.update(id, t).map{ _ =>
          val event = JsObject(List("type" -> JsString("update"), "data" -> t))
          channel.push(event)
          Ok(Json.toJson(id)(idWriter))
        }
      }
    }.recoverTotal{ e => BadRequest(JsError.toFlatJson(e)) }
  }

In JS you can then do: http://www.html5rocks.com/en/tutorials/eventsource/basics/ to react on updates.