Ticket #12103: 12103_method_on_form.diff

django/contrib/auth/forms.py

@@ -79 +79 @@
             self.user_cache = authenticate(username=username, password=password)
             if self.user_cache is None:
                 raise forms.ValidationError(_("Please enter a correct username and password. Note that both fields are case-sensitive."))
-            elif not self.user_cache.is_active:
-                raise forms.ValidationError(_("This account is inactive."))
-
+            else:
+                self.confirm_login_allowed(user_cache)
+        
         # TODO: determine whether this should move to its own method.
         if self.request:
             if not self.request.session.test_cookie_worked():
@@ -89 +89 @@
 
         return self.cleaned_data
 
+    def confirm_login_allowed(self, user):
+        """
+        Controls whether the given ``auth.User`` object may log in. This is a policy setting,
+        independent of end-user authentication. This default behavior is to allow login by
+        active users, and reject login by inactive users.
+
+        If the given user cannot log in, this method should raise a ``forms.ValidationError``.
+
+        If the given user may log in, this method should return None.
+        """
+        if not user.is_active:
+            raise forms.ValidationError(_("This account is inactive."))
+
     def get_user_id(self):
         if self.user_cache:
             return self.user_cache.id

docs/topics/auth.txt

@@ -1000 +1000 @@
 
     A form for logging a user in.
 
+    The ``AuthenticationForm`` rejects users whose ``is_active`` flag is set to ``False``.
+    You may override this behavior with a custom policy to determine which users can log in.
+    Do this with a custom form that subclasses ``AuthenticationForm`` and overrides the
+    ``confirm_login_allowed(self, user)`` method.  This method will raise a ``forms.ValidationError``
+    if the given user may not log in.
+
+    For example, to allow all users to log in, regardless of activation status::
+
+    .. code-block:: python
+
+        class AuthenticationFormWithInactiveUsersOkay(AuthenticationForm):
+            def confirm_login_allowed(self, user):
+                return None
+
+    Or to allow only some active users to log in:
+
+    .. code-block:: python
+
+        class PickyAuthenticationForm(AuthenticationForm):
+            def confirm_login_allowed(self, user):
+                if not user.is_active:
+                    raise forms.ValidationError(_("This account is inactive."))
+                if user.username.startswith('b'):
+                    raise forms.ValidationError(_("Sorry, accounts starting with 'b' aren't welcome here."))
+
 .. class:: PasswordChangeForm
 
     A form for allowing a user to change their password.