title: Have angular-oauth2-oidc retrieve access token from other tabs
body: <p>I'm using the <a href="https://github.com/manfredsteyer/angular-oauth2-oidc" rel="noreferrer">angular-oauth2-oidc</a> library in combination with the Implicit Flow (with an IdentityServer4 server). I've successfully set up <a href="https://manfredsteyer.github.io/angular-oauth2-oidc/docs/additional-documentation/refreshing-a-token-(silent-refresh).html" rel="noreferrer">the Silent Refresh suggestion from the docs</a>.</p>
  
  <p>Here's how I bootstrap things in a wrapper service:</p>
  
  <pre class="lang-js prettyprint-override"><code>private userSubject = new Subject&lt;User&gt;();
  
  constructor(private config: ConfigService, private oAuthService: OAuthService)
  { }
  
  // Called on app load:
  configure(): void {
      const config: AuthConfig = {
        issuer: this.config.getIdentityUrl(),
        logoutUrl: this.config.getIdentityUrl() + '/connect/endsession',
        redirectUri: window.location.origin + '/',
        silentRefreshRedirectUri: window.location.origin + '/silent-refresh.html',
        clientId: 'my_client_id',
        scope: 'openid profile my_api',
        sessionChecksEnabled: true,
      };
  
      this.oAuthService.configure(config);
      this.oAuthService.tokenValidationHandler = new JwksValidationHandler();
  
      this.oAuthService
        .loadDiscoveryDocumentAndLogin()
        .then((_) =&gt; this.loadUserProfile());
  
      this.oAuthService.setupAutomaticSilentRefresh();
  }
  
  private loadUserProfile() {
    this.oAuthService.loadUserProfile()
      .then((userProfile) =&gt; {
        const user = new User(userProfile['name']);
        this.userSubject.next(user);
      });
  }
  </code></pre>
  
  <p>However, if I open the application in a new tab, the user also gets redirected to the IdentityServer (and immediately back to my app).</p>
  
  <p>My question: <strong>can I get the library to retrieve existing access token (and optionally user info) from other tabs of the same origin, to prevent the redirects?</strong> (Preferred because it doesn't require Ajax calls.)</p>
  
  <p>Alternatively, is there an easy way to try and use the Silent Refresh mechanism before we'd send someone to the IdentityServer?</p>