title: Firebase signInSuccessWithAuthResult not called
body: <p>I'm using Firebase Auth for my website and I ran into a problem. I want to avoid the automatic redirect after signing in and as far as I know, if you return false in the callback it won't redirect. My problem is that the <a href="https://github.com/firebase/firebaseui-web#signinsuccesswithauthresultauthresult-redirecturl" rel="noreferrer">signInSuccessWithAuthResult</a> callback is not called. Why is it not called and is there a better way to achieve this?</p>
  
  <pre><code>window.addEventListener('load', function () {
   var uiConfig = {
      callbacks: {
          signInSuccessWithAuthResult: function(authResult, redirectUrl) {
            // User successfully signed in.
            console.log("sign in success");
            // don't redirect automatically
            return false;
          }
      },
      signInSuccessUrl: &lt;I dont want to go here&gt;,
      signInOptions: [
        // Leave the lines as is for the providers you want to offer your users.
        firebase.auth.GoogleAuthProvider.PROVIDER_ID,
        firebase.auth.EmailAuthProvider.PROVIDER_ID
      ],
      // Terms of service url.
      tosUrl: '&lt;your-tos-url&gt;',
      // Privacy policy url.
      privacyPolicyUrl: '&lt;your-privacy-policy-url&gt;'
  };
  
  firebase.auth().onAuthStateChanged(function (user) {
          if (user) {
            user.getIdToken().then(function (accessToken) {
                console.log("token retrieved: "+accessToken);
                // Send token to your backend via HTTPS
                var xhr = new XMLHttpRequest();
                xhr.open('POST', '/');
                xhr.setRequestHeader('Content-Type', "application/x-www-form-urlencoded");
                xhr.onload = function() {
                  console.log('Signed in as: ' + xhr.responseText);
                  document.getElementById('firebaseui-auth-container').hidden=true;
                };
                xhr.send('token=' + accessToken);
             });
           }
       });
  });
  </code></pre>