title: Angular2 - Use Dependency Injection outside Components
body: <p>In my app I use DI to pass information about the UserLogged around the different Components that need such info.
  This means that I have a <code>main.ts</code> class like this</p>
  
  <pre class="lang-ts prettyprint-override"><code>import {AppComponent} from './app.component';
  import {UserLogged} from './userLogged'
  
  bootstrap(AppComponent, [UserLogged]);
  </code></pre>
  
  <p>and the components that need to use the instance of <code>UserLogged</code> have a constructor like this</p>
  
  <pre class="lang-ts prettyprint-override"><code>constructor(private _user: UserLogged)
  </code></pre>
  
  <p>Now I would like to use the same instance of <code>UserLogged</code> also in simple TypeScript classes (which are not <code>@Component</code>). Is this possible? In other words, can I get hold of the same instance of <code>UserLogged</code> injected by DI also if I am outside a <code>@Component</code>?</p>