WS: Make web socket DI friendly

[kliushnichenko]

It would be nice to have a websocket handler DI-friendly in the same way controllers are, for avaje-inject in particular.

The following example won't work due to avaje module lateinit nature:

{
    install(AvajeInjectModule.of(
                BeanScope.builder()
                        .bean(WebsocketHandler.class, new WebsocketHandler()))
    );
    ws("/ws", require(WebsocketHandler.class));
}

The only way I managed to make it is by moving ws() into a separate lateinit extension that should be initialized after Avaje

[jknack]

do you want to do it? Should we look for annotated web socket handler and add a new code generator for WS?

[kliushnichenko]

Something like:

@Websocket("/ws/{id}")
public class WsHandler {

  @OnConnect
  public String onConnect(Context ctx) {
    return "welcome";
  }

  @OnMessage
  public String onMessage(Websocket ws, WebSocketMessage message) {
    return message.value();
  }

  @OnClose
  public void onClose(Websocket ws, WebSocketCloseStatus status) {}

  @OnError
  public void onError(Websocket ws, Throwable cause) {}
}

[jknack]

done #3917