title: Django multiselect checkboxes
body: <p>I have a list of objects, each with it's own checkbox, where the user can select multiple of these. The list is a result of a query.</p>
  
  <p>How can I mark in the view which checkboxes are already selected? There doesn't seem to be an in operator in the template language.</p>
  
  <p>I want something along the lines of:</p>
  
  <pre><code>&lt;input {% if id in selectedIds %}checked {% endif %}&gt;
  </code></pre>