title: Django template user request
body: <p>I have a model Book which can be added to user's Favorites. So I defined 2 classes:</p>
  
  <pre><code>
  class Book(models.Model):
      name = models.CharField(max_length = 40)
  
  class UserFavorite(models.Model):
      book = models.ForeignKey(Book)
      user = models.ForeignKey(User)
  </code></pre>
  
  <p>Now I'd like to show on the main page popular books with an icon either "add to favorites" or "remove from favorites". Basically I pass array of popular books to a template and from the template I loop thru this array and should say "if book.is_in_favorites(request.user): ...", but this is not possible from template.</p>