Play2.2 basic websockets example

play2.2.0_websockets

//This shows an updated websocket example for play2.2.0 utilizing Concurrent.broadcast vs Enumerator.imperative, which 
// is now deprecated.

object Application extends Controller {

 def index =  WebSocket.using[String] { request =>

   //Concurernt.broadcast returns (Enumerator, Concurrent.Channel)
    val (out,channel) = Concurrent.broadcast[String]

    //log the message to stdout and send response back to client
    val in = Iteratee.foreach[String] {
      msg => println(msg)
             //the channel will push to the Enumerator   
             channel push("RESPONSE: " + msg)
    }

    (in,out)
  }

  
}

This can be tested using Chrome's console:

var ws = new WebSocket("ws://localhost:9000/ws");
ws.onmessage = function( message ) { console.log( message ); };
ws.send("This is a test");

MessageEvent {ports: Array[0], data: "RESPONSE: This is a test", source: null, lastEventId: "", origin: "ws://localhost:9000"…}

Interestingly I got an error trying to use the console test code you posted above. I had to change the last line to be inside a function:

ws.onopen = function() {
    ws.send("This is a test");
}

How do I push a message to the client without waiting for a request from it ? This code only allows sending message in response to a message received from the client.

@amitabh123 you can just use the channel's push method. If your class has access to the channel, then all you would need to do is issue pushes.