title: USe dynamic destination folder for uploaded file in Django
body: <p>I would like to create dynamically the destination of my uploaded files.
  But, it seems that the 'upload_to' option is only available for a models, not for forms. So the following code is wrong. </p>
  
  <blockquote>
    <p>class MyForm(forms.Form):</p>
  
  <pre><code>     fichier = forms.FileField(**upload_to='files/%m-%Y/'**)
  </code></pre>
  </blockquote>
  
  <p>In the view handling the uploaded file, the destination is static. How can I make it dynamic ?</p>
  
  <p>Thank you.</p>