title: Symfony 2 file upload set default file
body: <p>I have a form in my Symfony2 app where I ask a user to upload a file. This field is not required. Currently I process the user`s file with the following command:</p>
  
  <pre><code>$file = $form['attachement']-&gt;getData();
  </code></pre>
  
  <p>My question is how can I set a default file in case $file returns NULL, i.e. the user does not want to upload any file?
  Thank you.</p>