How to add optgroups to a django ModelMultipleChoiceField ?

Question

Hello Guys,

I have a form with a ModelMultipleChoiceField to list of categories. I would like to group categories using the Category.group field.

I thought that by changing the field.choices in the init function it will make the trick

class CategoriesField(forms.ModelMultipleChoiceField):
    def __init__(self, queryset, **kwargs):
        super(forms.ModelMultipleChoiceField, self).__init__(queryset, **kwargs)
        self.queryset = queryset.select_related()
        self.to_field_name=None

        group = None
        list = []
        self.choices = []

        for category in queryset:
            if not group:
                group = category.group

            if group != category.group:
                self.choices.append((group.title, list))
                group = category.group
                list = [(category.id, category.name)]
            else:
                list.append((category.id, category.name))
        try:
            self.choices.append((group.title, list))
        except:
            pass

But the ModelChoiceIterator still erase the self.choices info that are set in the __init__ function.

How can I do that the right way ?

Answer 1

Actually it is working like I just explain but dont forget that part :

class ProfilForm(ModelForm):
    categories  = CategoriesField(queryset=Category.objects.all().order_by('group'), label=_(u'Catégories'))