ngrx/signalr - connectionState$

connectionState.ts

const offline$ = fromEvent(window, 'offline').pipe(map(_ => false));
const online$ = fromEvent(window, 'online').pipe(map(_ => true));
const hasInternetConnection$ = merge(
    of(navigator.onLine),
    offline$,
    online$
);

const hubsStatuses$ = this.store.pipe(
  select(selectHubsStatuses)
);

const connectionState$ = combineLatest(hubsStatuses$, hasInternetConnection$).pipe(
  map(([hubsStatuses, hasInternetConnection]) => {
    if (!hasInternetConnection) {
      return 'RED';
    }

    const allHubsConnected = hubsStatuses.every(hs => hs.state === SignalRStates.connected);
    const anyHubDisconnected = hubsStatuses.some(hs => hs.state === SignalRStates.disconnected);

    if (allHubsConnected) {
      return 'GREEN';
    }
    if (anyHubDisconnected) {
      return 'RED';
    }
    return undefined;
  })
);