title: Expired authorization code in PHP facebook SDK
body: <p>I am using the new 4.* facebook php SDK and I am having an issue! ;)</p>
  
  <p>Basically I am trying to find a way to make requests to the graph api after the first redirect when the user is <strong>sent back to my site after logging in into facebook</strong>. In that case I do (in my <code>index.php</code>):</p>
  
  <pre><code>$h = FacebookRedirectLoginHelper("blablabla");
  $request = new FacebookRequest($h-&gt;getSessionFromRedirect(), 'GET', '/me');
  $me = $request-&gt;execute()-&gt;getGraphObject();
  </code></pre>
  
  <p>and it works perfectly and I can print the date about the logged user. </p>
  
  <p>My problem is that if I reload (f5) the page <code>index.php</code> then I get an exception:</p>
  
  <pre><code>Fatal error: Uncaught exception 'Facebook\FacebookAuthorizationException' with message 'This authorization code has expired.' in /home/nourdine/development/faisbuk/vendor/facebook/php-sdk-v4/src/Facebook/FacebookRequestException.php:87 
  </code></pre>
  
  <p>So my question is: where am I supposed to get a new authorization code in order to make new graph api calls with the authenticated user even in pages that are not executed as a result o the facebook login process?</p>
  
  <p>Thanks</p>