(Meteorjs/React) check if user is logged in
<p>right now I'm trying to create a login System in Meteor and React.
I want to display different Content, depending on wether or not the user is logged in.</p>

<pre><code>export default class LoginForm extends Component {

 render() {
    if (Meteor.userId() === null) return( // if user is not logged in
       display HTML stuff);
    }

    return( // user is logged in
         display other stuff
    );
 }
}
</code></pre>

<p>this does not work as Meteor.userId() is always undefined after logging in.</p>

<p>Are there other possibilities? I've this in blaze:</p>

<pre><code>  {{#if currentUser}} doStuff{{/if}}
</code></pre>

<p>Is is possible to use it in React as well?</p>