Python example to handle on_close in ERP websocket

unknown

hi there,

we are trying to use the websocket API example you are providing to the community, but we face often some disconnects, and the method on_close is getting called. Iwould like to get some help here on what to do when this happens, is there somehow an easy way to reconnect ?

Could you provide me with a python example that handles such a situation when on_close() is called, as i would like to immediately reconnect?

In my code, i try to send a new authentification request with get_sts_token() but this is crashing, we get a 'WebSocketConnectiononClosedException: Connection is already closed.'

Any help and code python is welcome

Thank you

Gurpreet

Yes, the Python example code is only to get users started quickly with API, and cannot handle every exception scenario that an application might encounter in production.

Here is a quick change that I tried and it works for if the websocket gets disconnected. You will have to make similar change in your application and check it for errors and robustness. There are a lot of assumptions built in - like your network has recovered and target machine is available for connections:

def on_close(_):
  """ Called when websocket is closed """
  global web_socket_open
  web_socket_open = False
  print("WebSocket Closed")
  time.sleep(10)
  print("Restarting...")
  start()

def start():
  global sts_token, refresh_token, expire_time
  sts_token, refresh_token, expire_time = get_sts_token(None)
  if not sts_token:
    sys.exit(1)

  # Start websocket handshake
  ws_address = "wss://{}:{}/WebSocket".format(hostname, port)
  print("Connecting to WebSocket " + ws_address + " ...")
  web_socket_app = websocket.WebSocketApp(ws_address, on_message=on_message,
                      on_error=on_error,
                      on_close=on_close,
                      subprotocols=['tr_json2'])
  web_socket_app.on_open = on_open

  # Event loop
  wst = threading.Thread(target=web_socket_app.run_forever, kwargs={'sslopt': {'check_hostname': False}})
  wst.start()

  try:
    while True:
      # Give 30 seconds to obtain the new security token and send reissue
      if int(expire_time) > 30:
        time.sleep(int(expire_time) - 30)
      else:
        # Fail the refresh since value too small
        sys.exit(1)
      sts_token, refresh_token, expire_time = get_sts_token(refresh_token)
      if not sts_token:
        sys.exit(1)

      # Update token.
      if logged_in:
        send_login_request(web_socket_app, sts_token, True)
  except KeyboardInterrupt:
    web_socket_app.close()