Interceptors

There is no difference between regular interceptors and WebSocket interceptors. The following example uses a manually instantiated method-scoped interceptor. As with HTTP-based applications, you can also use gateway-scoped interceptors (i.e., decorate the gateway class with @UseInterceptors()). Global interceptors registered with app.useGlobalInterceptors() or the APP_INTERCEPTOR token apply to gateways as well.

@UseInterceptors(new TransformInterceptor())
@SubscribeMessage('events')
handleEvent(client: Client, data: unknown): WsResponse<unknown> {
  const event = 'events';
  return { event, data };
}

@UseInterceptors(new TransformInterceptor())
@SubscribeMessage('events')
handleEvent(client, data) {
  const event = 'events';
  return { event, data };
}