# Backport from Django 3.1.
class EmptyFieldListFilter(FieldListFilter):
+ with_empty_str = False
+
def __init__(self, field, request, params, model, model_admin, field_path):
self.lookup_kwarg = '%s__isempty' % field_path
self.lookup_val = params.get(self.lookup_kwarg)
raise IncorrectLookupParameters
lookup_condition = Q(**{'%s__isnull' % self.field_path: True})
+ if self.with_empty_str:
+ lookup_condition |= Q(**{self.field_path: ''})
if self.lookup_val == '1':
return queryset.filter(lookup_condition)
return queryset.exclude(lookup_condition)