Corrected the behavior of the SimpleFilter.lookups method to also be able to…

Corrected the behavior of the SimpleFilter.lookups method to also be able to return None. Also modified example in documentation to be a bite more realistic. Refs #5833. Thanks for the hint, Martin Mahner.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16150 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/admin/filters.py

@@ -63,7 +63,10 @@ class SimpleListFilter(ListFilter):
             raise ImproperlyConfigured(
                 "The list filter '%s' does not specify "
                 "a 'parameter_name'." % self.__class__.__name__)
-        self.lookup_choices = self.lookups(request)
+        lookup_choices = self.lookups(request)
+        if lookup_choices is None:
+            lookup_choices = ()
+        self.lookup_choices = lookup_choices
 
     def has_output(self):
         return len(self.lookup_choices) > 0

docs/ref/contrib/admin/index.txt

@@ -607,15 +607,12 @@ subclass::
                   class AuthDecadeBornListFilter(DecadeBornListFilter):
 
                       def lookups(self, request):
-                          if request.user.is_authenticated():
-                              return (
-                                  ('80s', 'in the eighties'),
-                                  ('other', 'other'),
-                              )
-                          else:
-                              return (
-                                  ('90s', 'in the nineties'),
-                              )
+                          if request.user.is_superuser:
+                              return super(AuthDecadeBornListFilter, self).lookups(request)
+
+                      def queryset(self, request, queryset):
+                          if request.user.is_superuser:
+                              return super(AuthDecadeBornListFilter, self).queryset(request, queryset)
 
         * a tuple, where the first element is a field name and the second
           element is a class inheriting from

tests/regressiontests/admin_filters/tests.py

@@ -43,6 +43,11 @@ class DecadeListFilterWithoutTitle(DecadeListFilter):
 class DecadeListFilterWithoutParameter(DecadeListFilter):
     title = 'publication decade'
 
+class DecadeListFilterWithNoneReturningLookups(DecadeListFilterWithTitleAndParameter):
+
+    def lookups(self, request):
+        pass
+
 class CustomUserAdmin(UserAdmin):
     list_filter = ('books_authored', 'books_contributed')
 
@@ -60,6 +65,9 @@ class DecadeFilterBookAdminWithoutTitle(ModelAdmin):
 class DecadeFilterBookAdminWithoutParameter(ModelAdmin):
     list_filter = (DecadeListFilterWithoutParameter,)
 
+class DecadeFilterBookAdminWithNoneReturningLookups(ModelAdmin):
+    list_filter = (DecadeListFilterWithNoneReturningLookups,)
+
 class ListFiltersTests(TestCase):
 
     def setUp(self):
@@ -453,3 +461,14 @@ class ListFiltersTests(TestCase):
         self.assertRaisesRegexp(ImproperlyConfigured,
             "The list filter 'DecadeListFilterWithoutParameter' does not specify a 'parameter_name'.",
             self.get_changelist, request, Book, modeladmin)
+
+    def test_simplelistfilter_with_none_returning_lookups(self):
+        """
+        A SimpleListFilter lookups method can return None but disables the
+        filter completely.
+        """
+        modeladmin = DecadeFilterBookAdminWithNoneReturningLookups(Book, site)
+        request = self.request_factory.get('/', {})
+        changelist = self.get_changelist(request, Book, modeladmin)
+        filterspec = changelist.get_filters(request)[0]
+        self.assertEqual(len(filterspec), 0)