Ticket #17895: 17895-more-docs-improved-api.diff

docs/ref/signals.txt

@@ -477 +477 @@
 .. data:: django.test.signals.setting_changed
    :module:
 
-Sent when some :ref:`settings are overridden <overriding-settings>` with the
+This signal is sent when the value of a setting is changed through the
 :meth:`django.test.TestCase.setting` context manager or the
 :func:`django.test.utils.override_settings` decorator/context manager.
 
+It's actually sent twice: when the new value is applied (``"setup"``) and when
+the original value is restored (``"teardown"``).
+
 Arguments sent with this signal:
 
 ``sender``
     The settings handler.
 
 ``setting``
-    Same as sender
+    The name of the setting.
 
 ``value``
-    The new setting value.
+    The value of the setting after the change. For settings that initially
+    don't exist, in the teardown phase, ``value`` is ``None``.
 
+``phase``
+    ``"setup"`` when the setting is set to its new value, ``"teardown"`` when
+    it's reset to its original value.
+
 template_rendered
 -----------------
 

tests/regressiontests/settings_tests/tests.py

@@ -76 +76 @@
 
 testvalue = None
 
-def signal_callback(sender, setting, value, **kwargs):
+def signal_callback(sender, setting, value, state, **kwargs):
     if setting == 'TEST':
         global testvalue
-        testvalue = value
+        testvalue = (value, state)
 
 signals.setting_changed.connect(signal_callback)
 
@@ -131 +131 @@
     def test_signal_callback_context_manager(self):
         self.assertRaises(AttributeError, getattr, settings, 'TEST')
         with self.settings(TEST='override'):
-            self.assertEqual(testvalue, 'override')
+            self.assertEqual(testvalue, ('override', 'setup'))
+        self.assertEqual(testvalue, (None, 'teardown'))
 
     @override_settings(TEST='override')
     def test_signal_callback_decorator(self):
-        self.assertEqual(testvalue, 'override')
+        self.assertEqual(testvalue, ('override', 'setup'))
 
     #
     # Regression tests for #10130: deleting settings.

django/test/utils.py

@@ -167 +167 @@
     delattr(loader, RESTORE_LOADERS_ATTR)
 
 
-class OverrideSettingsHolder(UserSettingsHolder):
-    """
-    A custom setting holder that sends a signal upon change.
-    """
-    def __setattr__(self, name, value):
-        UserSettingsHolder.__setattr__(self, name, value)
-        setting_changed.send(sender=self.__class__, setting=name, value=value)
-
-
 class override_settings(object):
     """
     Acts as either a decorator, or a context manager. If it's a decorator it
@@ -215 +206 @@
         return inner
 
     def enable(self):
-        override = OverrideSettingsHolder(settings._wrapped)
+        override = UserSettingsHolder(settings._wrapped)
         for key, new_value in self.options.items():
             setattr(override, key, new_value)
         settings._wrapped = override
+        for key, new_value in self.options.items():
+            setting_changed.send(sender=settings._wrapped.__class__,
+                                 setting=key, value=new_value, state='setup')
 
     def disable(self):
         settings._wrapped = self.wrapped
+        for key in self.options:
+            new_value = getattr(settings, key, None)
+            setting_changed.send(sender=settings._wrapped.__class__,
+                                 setting=key, value=new_value, state='teardown')
+