title: firebase.initializeApp callback/promise?
body: <p>This is my web page</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
      &lt;head&gt;
          &lt;meta charset="utf-8"&gt;
          &lt;meta http-equiv="X-UA-Compatible" content="IE=edge"&gt;
          &lt;meta name="viewport" content="width=device-width, initial-scale=1"&gt;
          &lt;title&gt;Calcolo Diliuzioni&lt;/title&gt;
  
      &lt;/head&gt;
      &lt;body&gt;
  
          &lt;h1&gt;My app&lt;/h1&gt;
  
          &lt;!-- Libreria per gestire l'autenticazione con google --&gt;
          &lt;script src="https://apis.google.com/js/platform.js" async defer&gt;&lt;/script&gt;
  
          &lt;!-- Firebae config --&gt;
          &lt;script src="https://www.gstatic.com/firebasejs/live/3.0/firebase.js"&gt;&lt;/script&gt;
          &lt;script&gt;
          // Initialize Firebase
          var config = {
          apiKey: "",
          authDomain: "",
          databaseURL: "",
          storageBucket: "",
          };
          firebase.initializeApp(config);
          &lt;/script&gt;
  
          &lt;script type="text/javascript"&gt;
              var user = firebase.auth().currentUser;
              if (user) {
                  console.log(user);
              } else {
                  console.log(user);
              }
          &lt;/script&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>Let's assume I have an already logged user. When I load the page in the console I got <code>null</code>. While I'm expecting to have the current user's object.</p>
  
  <p>If I run the same code in the browser console</p>
  
  <pre><code>var user = firebase.auth().currentUser;
  if (user) {
      console.log(user);
  } else {
      console.log(user);
  }
  </code></pre>
  
  <p>I'm able to get the current user's object. </p>
  
  <p>I think that the <code>firebase.initializeApp(config);</code> has some async behavior. What's the right way to work around it? Should I use a promise or something on the <code>firebase.initializeApp(config);</code> function? A sort of callback..</p>