ng2-stompjs | Angular 6 and 7 - Stomp service over Websockets | Websocket library

ERROR in src/app/components/dashboard/dashboard.component.html:1:1 - error NG8001: 'StackLayout' is ot a known element:

1. If 'StackLayout' is an Angular component, then verify that it is part of this module.
2. To allow any element add 'NO_ERRORS_SCHEMA' to the '@NgModule.schemas' of this component.

1

dashboard.component.tns.html

I have been researching for a way to limit the number of clients who can subscribe to a specific stomp topic but have not yet understood, which could be the right approach according to my needs.

My use case is a game, which I am developing in Angular (ng2-stompjs stomp client) and Spring Boot Websockets (for the moment, the Spring in-memory message broker is in use).

The idea is that a user can be connected and subscribed to a "/lobby" stomp topic, and there he sees the opened game rooms, that could be in different statuses. for example, in-play or not started yet due to the low number of players joined. I'd like to intercept and programmatically restrict a possible subscription of a client, to a specific "/room/{roomId}" topic, IF the MAX number of players has been reached, for example, 4. There could also be some simple client-side validation to restrict that, but I believe only client-side is not sufficient

So my main questions are: How can a specific stomp topic subscription be intercepted in Spring? Is it possible to return to the client-requestor some kind of error message that subscription could not be done?

I'd really appreciate your help, thank you in advance!

I am trying to build a angular client that uses websockets, and I am using @stomp/ng2-stompjs I am following this guide https://stomp-js.github.io/guide/ng2-stompjs/ng2-stomp-with-angular7.html

Everything works perfectly except that I need to set in the connectHeaders the token that I use to authenticate server side, to do this I read that I need to use the function beforeConnect

I tried in various way but I don't understand how to use it, it gets stuck or it sends a empty token

My rxStompConfig:

export class RxStompConfig extends InjectableRxStompConfig {