feat: added message for PermissionRequiredMixin

AUTHORS

@@ -62,3 +62,4 @@ Authors ordered by first contribution
 - Davis Raymond Muro <davisraymondmuro@gmail.com>
 - Richard de Wit <henk.exe@gmail.com>
 - Pedro Rojas Gavidia <pedrorojas.gavidia@gmail.com> @pedrorojasg
+- Rainshaw Gao <rxg@live.com>

guardian/mixins.py

@@ -115,6 +115,10 @@ class SecureView(PermissionRequiredMixin, View):
         `permission_required` - the permission to check of form "<app_label>.<permission codename>"
                                 i.e. 'polls.can_vote' for a permission on a model in the polls application.
 
+    ``PermissionRequiredMixin.permission_denied_message``
+        *Default*: ``''``. A string to pass to the ``PermisssionDenied`` exception.
+            Will be available in the 403 template context as ``exception``.
+
     ``PermissionRequiredMixin.accept_global_perms``
 
         *Default*: ``False``,  If accept_global_perms would be set to True, then
@@ -138,9 +142,16 @@ class SecureView(PermissionRequiredMixin, View):
     return_403 = False
     return_404 = False
     raise_exception = False
+    object_permission_denied_message = ''
     accept_global_perms = False
     any_perm = False
 
+    def get_object_permission_denied_message(self):
+        """
+        Override this method to override the object_permission_denied_message attribute.
+        """
+        return self.object_permission_denied_message
+
     def get_required_permissions(self, request=None):
         """
         Returns list of permissions in format *<app_label>.<codename>* that
@@ -183,13 +194,14 @@ def check_permissions(self, request):
                                     redirect_field_name=self.redirect_field_name,
                                     return_403=self.return_403,
                                     return_404=self.return_404,
+                                    permission_denied_message=self.get_object_permission_denied_message(),
                                     accept_global_perms=self.accept_global_perms,
                                     any_perm=self.any_perm,
                                     )
         if forbidden:
             self.on_permission_check_fail(request, forbidden, obj=obj)
         if forbidden and self.raise_exception:
-            raise PermissionDenied()
+            raise PermissionDenied(self.get_object_permission_denied_message())
         return forbidden
 
     def on_permission_check_fail(self, request, response, obj=None):

guardian/utils.py

@@ -93,8 +93,8 @@ def get_identity(identity):
 
 def get_40x_or_None(request, perms, obj=None, login_url=None,
                     redirect_field_name=None, return_403=False,
-                    return_404=False, accept_global_perms=False,
-                    any_perm=False):
+                    return_404=False, permission_denied_message='',
+                    accept_global_perms=False, any_perm=False):
     login_url = login_url or settings.LOGIN_URL
     redirect_field_name = redirect_field_name or REDIRECT_FIELD_NAME
 
@@ -117,11 +117,12 @@ def get_40x_or_None(request, perms, obj=None, login_url=None,
     if not has_permissions:
         if return_403:
             if guardian_settings.RENDER_403:
-                response = render(request, guardian_settings.TEMPLATE_403)
+                response = render(request, guardian_settings.TEMPLATE_403,
+                                  context={'exception': permission_denied_message})
                 response.status_code = 403
                 return response
             elif guardian_settings.RAISE_403:
-                raise PermissionDenied
+                raise PermissionDenied(permission_denied_message)
             return HttpResponseForbidden()
         if return_404:
             if guardian_settings.RENDER_404: