title: $this->input->post() is empty while $_POST is set in Codeigniter
body: <p>I am having an issue in codeigniter where I try to get form data sent via post in this form:</p>
  
  <pre><code>    &lt;form action="http://localhost/Bookstore/index.php/cart/add/1" method="post"&gt;
          &lt;input id="url" name="url" type="text" value="http://localhost/Bookstore/index.php/book/id/1" class="hidden"&gt;
          &lt;button class="btn btn-primary" type="submit"&gt;
              &lt;i class="fa fa-shopping-cart"&gt;&lt;/i&gt; In den Warenkorb
          &lt;/button&gt;
      &lt;/form&gt;
  </code></pre>
  
  <p>However, when I try to access <code>$this-&gt;input-&gt;post('url')</code>, <code>$this-&gt;input-&gt;post()</code> does not contain anything while <code>$_POST</code> contains the data i need (<code>url</code>).</p>
  
  <p>Any ideas how to fix this? I would like to avoid using $_POST, because a have read it is not suggested in codeigniter.</p>