Question

I have the following models:

class Category(models.Model):
    name = models.CharField(max_length=200)
    slug = models.SlugField()
    parent = models.ForeignKey('self', blank = True, null = True, related_name="children")

class Business(models.Model):
    user = models.OneToOneField(User)
    name = models.CharField(max_length=200)
    slug = models.SlugField()
    category = models.ForeignKey(Category)
    city = models.ForeignKey(City)

When adding a business using a modelForm, non-leaf categories show up in the select box.

For example, assuming that we have the following category hierarchy:

- Cars
     -- Car Rental
     -- Car Dealership
     -- Mechanics
- Restaurants
    -- Burgers
    -- Chinese
    -- Sushi
    -- Pizza
    -- Latin american
         -- Mexican
         -- Venezuelan
         -- Argentinian

With this hierarchy, all the choices but Cars, Restaurants and Latin American should show up in the Category select box, since these have children categories.

Answer 1

Category.objects.filter(children__isnull=True)


class MyModelForm(forms.ModelForm):
    def __init__(self, *args, **kwargs):
        super(MyModelForm, self).__init__(*args, **kwargs)
        self.fields['myfield'].queryset = Category.objects.filter(children__isnull=True)