from django.contrib.contenttypes.models import ContentType from django.newforms.models import BaseModelFormSet, _modelformset_factory, save_instance from django.contrib.admin.options import InlineModelAdmin, flatten_fieldsets from django.db.models import ForeignKey class GenericInlineFormset(BaseModelFormSet): """A formset for child objects related to a parent.""" def __init__(self, instance=None, data=None, files=None): self.instance = instance self.rel_name = '-'.join( ( self.model._meta.app_label, self.model._meta.object_name.lower(), self.ct.name, self.obj_id.name ) ) super(GenericInlineFormset, self).__init__(queryset=self.get_queryset(), data=data, files=files, prefix=self.rel_name) def get_queryset(self): if self.instance is None: return [] return self.model._default_manager.filter( **{ self.ct.name : ContentType.objects.get_for_model(self.instance), self.obj_id.name : self.instance.pk }) def save_new(self, form, commit=True): kwargs = { self.ct.get_attname(): ContentType.objects.get_for_model(self.instance).pk, self.obj_id.get_attname(): self.instance.pk, } new_obj = self.model(**kwargs) return save_instance(form, new_obj, commit=commit) class GenericInlineModelAdmin(InlineModelAdmin): ct_field_name = None id_field_name = None formset = GenericInlineFormset def get_formset( self, request, obj=None ): if self.declared_fieldsets: fields = flatten_fieldsets(self.declared_fieldsets) else: fields = None opts = model._meta # if there is no field called `ct_field_name` let the exception propagate ct = opts.get_field(ct_field_name) if not isinstance(ct, ForeignKey) or ct.rel.to != ContentType: raise Exception("fk_name '%s' is not a ForeignKey to ContentType" % (ct_field_name)) obj_id = opts.get_field(id_field_name) # let the exception propagate FormSet = _modelformset_factory(self.model, form=self.form, formfield_callback=self.formfield_for_dbfield, formset=self.formset, extra=self.extra, fields=fields, exclude=[ct.name, obj_id.name] ) FormSet.ct = ct FormSet.obj_id = obj_id return FormSet class GenericStackedInline(GenericInlineModelAdmin): template = 'admin/edit_inline/stacked.html' class GenericTabularInline(GenericInlineModelAdmin): template = 'admin/edit_inline/tabular.html'