Django Admin: how to display properties defined on model in an inline?

Question

This is a follow-up to this question. How do I display properties defined on a child model in an inline on the parent? To illustrate, I have this model:

class UserProfile(models.Model):     user = models.ForeignKey(User, unique=True, primary_key=True, related_name='profile')     ...     @property     def age(self):         if self.birthday is None:             return None          td = datetime.date.today() - self.birthday         return td.days / 365 

Question is: how do I show 'age' in an inline on User? This is what I have:

class UserProfileInline(admin.StackedInline):     model = UserProfile     fk_name = 'user'     max_num = 1     fieldsets = [         ('Demographics', {'fields': ['birthday', 'age']}),     ] 

I've tried a few things like this, including 'age()', defining a 'get_age' getter for the Inline, etc. They result in some version of this error:

ImproperlyConfigured: 'UserProfileInline.fieldsets[1][1]['fields']' refers to field 'age' that is missing from the form. 

Answer 1

Add the field to both the readonly_fields tuple and fieldsets field as well.

Note this only works in Django 1.2+.