Conditional routing change default route in Angular 2

I'm creating an app that when the user enters to the page they go to the default route which is "Login" page. What I want is based on a condition (if the user has a local storage variable id, a method called isAuthenticaded() returns true if not false) the user must see the "Polls" page instead of "Login" page.

I can think two different ways to approach this:

1. 
   Change default page: if the method returns true the default page should be "Polls" if not "Login".
   
   
2. 
   Redirect the user: if the method returns true the user is redirected to "Polls".
   

What's the best approach to achieve this? How can I do one or both of the point to get conditional routing?

This is my routing config with the isAuthenticated() method:

import {Component} from 'angular2/core'
import {HTTP_PROVIDERS, Http} from 'angular2/http';
import 'rxjs/Rx'; // load the full rxjs
import {RouteConfig, ROUTER_DIRECTIVES, Router} from 'angular2/router';


import { PollsComponent } from './pollslist/pollslist.component'
import { Login } from './login/login'

@Component({
selector: 'my-app',
templateUrl: 'app/app.component.html',
directives: [ROUTER_DIRECTIVES, Login, PollsComponent],
providers: [HTTP_PROVIDERS]
})

@RouteConfig([
{ path: '/login', name: 'Login', component: Login, useAsDefault: true },
{ path: '/polls', name: 'Polls', component: PollsComponent }

])

export class AppComponent {
isAuthenticated() {
if (localStorage.getItem('id')) {
return true;
} else {
return false;
}

}

}

Continue reading...