MVC

 You can set authentication guard to restrict users which are not loggedin. 1) Service of auth guard    import { Injectable } from '@angular/core' ; import { Router , CanActivate , ActivatedRouteSnapshot , RouterStateSnapshot , UrlTree } from '@angular/router' ; import { CookieService } from 'ngx-cookie-service' ; @ Injectable ({ providedIn: 'root' }) export class AuthGuardService implements CanActivate { constructor ( private _router : Router , private _cookieService : CookieService ) { } userid = "" ; canActivate ( route : ActivatedRouteSnapshot , state : RouterStateSnapshot ): boolean | UrlTree { this . userid = this . _cookieService . get ( 'userid' ) if ( this . userid == "" ) { alert ( 'You are not allowed to view this page. You are redirected to login Page' ); this . _router . navigate ([ "login" ],{ queryParams: { retUrl: route . url } }); return false ; /

   we can update about data changes to any component using bellow simple method 1) Service to publish and receive data import {Injectable} from '@angular/core'; import {Subject} from 'rxjs'; @Injectable({ providedIn: 'root' }) export class GlobalFooService { private fooSubject = new Subject<any>(); publishSomeData(data: any) { this.fooSubject.next(data); } getObservable(): Subject<any> { return this.fooSubject; } } 2) Data sending component @Component({ selector: 'app-home', templateUrl: 'home.page.html', styleUrls: ['home.page.scss'] }) export class HomePage { constructor(private globalFooService: GlobalFooService) { } onSomeButtonClick() { this.globalFooService.publishSomeData({ foo: 'bar' }); } } 3) Data receiving component @Component({ selector: 'app-root', templateUrl: 'app.component.htm