argos/dmp-frontend/src/app/guards/auth.guard.ts

import { Injectable } from '@angular/core';
import { Router, CanActivate, ActivatedRouteSnapshot, RouterStateSnapshot } from '@angular/router';
import { TokenService, TokenProvider } from '../services/login/token.service';

@Injectable()
export class AuthGuard implements CanActivate {

    constructor(private router: Router, private tokenService: TokenService) { }

    canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot) {

        if(this.tokenService.isLoggedIn() == true){
            return true;
        }
        // not logged in so redirect to login page with the return url
        this.router.navigate(['/login'], { queryParams: { returnUrl: state.url }});
        return false;
        
    }
}