Clearing cookie in web socket handler.

Question

Within Tornado's tornado.websocket.WebSocketHandler get_secure_cookie() works however the clear_cookie() function raises the following exception:

    raise RuntimeError("Method not supported for Web Sockets")
RuntimeError: Method not supported for Web Sockets

Pretty obvious by the description there that it's not supported. Why is this the case?

Answer 1

It's not supported because once the connection is established, websockets are no longer HTTP and cannot send HTTP headers like Set-Cookie. You'll have to send a message which your javascript can handle by changing the cookie (either setting it directly if it is script-accessible, or making a separate HTTP requests if it is HTTP-only).