Events, Subject, BehaviourSubject nothing working in app.component.ts ionic v4

Ionic Framework
1

i want to change menu according to login logout. using all 3 options for subscribing data. but nothing working. not firing after logout/login.

firing only once on app load. and working after reload page but i dont want to reload page.

2

Use ionic events to check login/logout

3

not working in app.component.ts in v4 after app load

4

Can you share your code ?

5

app.component.ts

import { Events } from '@ionic/angular';
-------------------
constructor( private events: Events ) { this.initializeApp(); }
-------------------
public val:string;
-------------------
initializeApp() {
  this.events.subscribe('hant', user => {
          this.val = user;
   });
}

login.ts

import { Events } from '@ionic/angular';
-------------------
constructor( private events: Events ) {}
-------------------
this.events.publish('hant', 'allow');