После некоторой борьбы вот что я получил.
Сначала заставим ModelAdmin вызвать ModelForm:
class OptionAdmin(admin.ModelAdmin):
form = forms.OptionForm
Затем в форме используйте пользовательский виджет для рендеринга:
category = forms.ModelMultipleChoiceField(queryset=models.Category.objects.all(),widget=AdminCategoryBySupercategory)
Наконец, виджет:
class AdminCategoryBySupercategory(forms.CheckboxSelectMultiple):
def render(self, name, value, attrs=None, choices=()):
if value is None: value = []
has_id = attrs and 'id' in attrs
final_attrs = self.build_attrs(attrs, name=name)
output = [u'<ul>']
# Normalize to strings
str_values = set([force_unicode(v) for v in value])
supercategories = models.SuperCategory.objects.all()
for supercategory in supercategories:
output.append(u'<li>%s</li>'%(supercategory.name))
output.append(u'<ul>')
del self.choices
self.choices = []
categories = models.Category.objects.filter(super_category=supercategory)
for category in categories:
self.choices.append((category.id,category.name))
for i, (option_value, option_label) in enumerate(chain(self.choices, choices)):
if has_id:
final_attrs = dict(final_attrs, id='%s_%s' % (attrs['id'], i))
label_for = u' for="%s"' % final_attrs['id']
else:
label_for = ''
cb = forms.CheckboxInput(final_attrs, check_test=lambda value: value in str_values)
option_value = force_unicode(option_value)
rendered_cb = cb.render(name, option_value)
option_label = conditional_escape(force_unicode(option_label))
output.append(u'<li><label%s>%s %s</label></li>' % (label_for, rendered_cb, option_label))
output.append(u'</ul>')
output.append(u'</li>')
output.append(u'</ul>')
return mark_safe(u'\n'.join(output))
Не самое элегантное решение, но эй, оно сработало.