text: ###############################################################################
  #
  # The MIT License (MIT)
  #
  # Copyright (c) Tavendo GmbH
  #
  # Permission is hereby granted, free of charge, to any person obtaining a copy
  # of this software and associated documentation files (the "Software"), to deal
  # in the Software without restriction, including without limitation the rights
  # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  # copies of the Software, and to permit persons to whom the Software is
  # furnished to do so, subject to the following conditions:
  #
  # The above copyright notice and this permission notice shall be included in
  # all copies or substantial portions of the Software.
  #
  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  # THE SOFTWARE.
  #
  ###############################################################################
  
  from autobahn.twisted.websocket import WebSocketServerProtocol, \
      WebSocketServerFactory
  
  
  class MyServerProtocol(WebSocketServerProtocol):
  
      def onConnect(self, request):
          print("Client connecting: {0}".format(request.peer))
  
      def onOpen(self):
          print("WebSocket connection open.")
  
      def onMessage(self, payload, isBinary):
          if isBinary:
              print("Binary message received: {0} bytes".format(len(payload)))
          else:
              print("Text message received: {0}".format(payload.decode('utf8')))
  
          # echo back message verbatim
          self.sendMessage(payload, isBinary)
  
      def onClose(self, wasClean, code, reason):
          print("WebSocket connection closed: {0}".format(reason))
  
  
  if __name__ == '__main__':
  
      import sys
  
      from twisted.python import log
      from twisted.internet import reactor
  
      log.startLogging(sys.stdout)
  
      factory = WebSocketServerFactory(u"ws://127.0.0.1:9000")
      factory.protocol = MyServerProtocol
  
      reactor.listenTCP(9000, factory)
      reactor.run()
  