Streaming to Play 2.6 websocket - connection getting closed

[Yaser Arshad]

Hi,

I am trying to setup a simple process where I want to stream data from mongo to my play app using websocket. I am able to get the data through streaming API, but once the data is loaded on the web, the stream gets closed, and it wont take any new inserts/updates in Mongo. My goal is to keep the connection open so any inserts/updates to mongo get reflected in the UI in realtime. Here is how I am doing it: 

My websocket:

def ws = WebSocket.accept[Any, String] { _ =>

  val src : Future[Source[BSONDocument, Future[State]]]  = MongoService.personSource()
  val converter : Flow[BSONDocument,String, NotUsed] = Flow[BSONDocument].map(b => b.get("firstName").get.toString)
  val sink = Sink.ignore

  val result = src.map(s => {
    Flow.fromSinkAndSource(sink, s.via(converter))
  })

  Await.result(result, Duration.Inf)

} 

My Mongo Query: 

def personSource(): Future[Source[BSONDocument, Future[State]]]  ={
  val query = BSONDocument.empty
  val source = dbFromConnection(connection3).map{ collection =>{
    collection.find(query).cursor[BSONDocument].documentSource()
  }}
  source
}

[Cédric Chantepie]

Hi, a MongoDB cursor without awaitData/tailable options won't wait for new documents (anyway that's could only make sense with a capped collection).