title: $this->session->set_flashdata() and then $this->session->flashdata() doesn't work in codeigniter
body: <p>Please take a look at the following code:</p>
  
  <pre><code>$this-&gt;session-&gt;set_flashdata('message', 'This is a message.');
  var_dump($this-&gt;session-&gt;flashdata('message'));
  </code></pre>
  
  <p>It returns <code>bool(false)</code>.</p>
  
  <p>I hope it doesn't <strong><em>NEED</em></strong> a <code>redirect()</code> to be recallable after that, because some times I need to call it right after setting the flashdata in a view.</p>
  
  <hr>
  
  <p><strong>Edit</strong> after <a href="https://stackoverflow.com/users/1679342/venkat">venkat</a>'s comment</p>
  
  <pre><code>$this-&gt;session-&gt;set_flashdata('message', 'This is a message.');
  $this-&gt;session-&gt;keep_flashdata('message');
  var_dump($this-&gt;session-&gt;flashdata('message'));
  </code></pre>
  
  <p>No difference unfortunately.</p>