How to bind models in Django given conditions?

Question

Django

There are 2 models:

class Code(models.Model):
    name = models.CharField(max_length=40, unique=True, verbose_name='Наименование')
    used = models.BooleanField(default=False, verbose_name='Используется ')

class Ordering(models.Model):
    num = models.PositiveIntegerField(auto_created=True, verbose_name='Номер заявки')
    system = models.ForeignKey(Code, on_delete=models.DO_NOTHING)

it is necessary that in the admin panel, about adding an entry to Ordering, not all fields from the Code model are displayed in the system field, but only those fields used where the value is True. How to implement it?

Answer 1

Hey!
Something like this should work
link to the source
in admin.py

@admin.register(Ordering)
class OrderingAdmin(admin.ModelAdmin):

  def formfield_for_foreignkey(self, db_field, request, **kwargs):
          if db_field.name == "system":
              kwargs["queryset"] = Code.objects.filter(used=True)
          return super().formfield_for_foreignkey(db_field, request, **kwargs)