Mastering Play Framework for Scala

WebSocket using Iteratee

Let's define a WebSocket connection, which accepts strings and sends back the reverse of a string using Iteratee:

 def websocketBroadcast = WebSocket.using[String] {
    request =>
      val (out, channel) = Concurrent.broadcast[String]
      val in = Iteratee.foreach[String] {
        word => channel.push(word.reverse)
      }
      (in, out)
  }

The WebSocket.using method creates a WebSocket of a specific type using an Iteratee (inbound channel) and its corresponding enumerator (outbound channel). In the preceding code snippet, we return a tuple of the Iteratee in and the Enumerator out.

The Concurrent object is also a helper, which provides utilities to use Iteratees, Enumerators, and Enumeratees concurrently. The broadcast[E] method creates an Enumerator ...