This documentation regards version 10.1, however the current version is 10.7.0.
handleWebSocketMessagesForOptionalProtocol
Signature
def handleWebSocketMessagesForOptionalProtocol(handler: Flow[Message, Message, Any], subprotocol: Option[String]): RouteDescription
Handles WebSocket requests with the given handler and rejects other requests with an ExpectedWebSocketRequestRejection.
If the subprotocol parameter is None any WebSocket request is accepted. If the subprotocol parameter is Some(protocol) a WebSocket request is only accepted if the list of subprotocols supported by the client (as announced in the WebSocket request) contains protocol. If the client did not offer the protocol in question the request is rejected with an UnsupportedWebSocketSubprotocolRejection.
To support several subprotocols you may chain several handleWebSocketMessagesForOptionalProtocol routes.
The handleWebSocketMessagesForOptionalProtocol directive is used as a building block for WebSocket Directives to handle websocket messages.
For more information about the WebSocket support, see Server-Side WebSocket Support.