From 7b13edb6c28f10d0fdf271fe26534ac16d262563 Mon Sep 17 00:00:00 2001
From: Radomir Dopieralski <openstack@sheep.art.pl>
Date: Fri, 25 Oct 2013 15:23:08 +0200
Subject: [PATCH] Use a @cached_property decorator

Instead of using an ugly code that uses __dict__ or hasattr,
use a @cached_property decorator that encapsulates the
property caching logic in a single place and makes it easier
to later replace with better caching techniques.

Re-use the cached_property from django.

Change-Id: I9e3e26cd4a8c7055854e851bc5f062a29981971e
---
 openstack_dashboard/api/nova.py               | 13 +++--
 .../dashboards/project/containers/views.py    | 49 +++++++++----------
 2 files changed, 30 insertions(+), 32 deletions(-)

diff --git a/openstack_dashboard/api/nova.py b/openstack_dashboard/api/nova.py
index 2686cc5616..2e39d7b22d 100644
--- a/openstack_dashboard/api/nova.py
+++ b/openstack_dashboard/api/nova.py
@@ -25,6 +25,7 @@ from __future__ import absolute_import
 import logging
 
 from django.conf import settings  # noqa
+from django.utils.functional import cached_property  # noqa
 from django.utils.translation import ugettext_lazy as _  # noqa
 
 from novaclient.v1_1 import client as nova_client
@@ -151,15 +152,13 @@ class SecurityGroup(base.APIResourceWrapper):
     """
     _attrs = ['id', 'name', 'description', 'tenant_id']
 
-    @property
+    @cached_property
     def rules(self):
         """Wraps transmitted rule info in the novaclient rule class."""
-        if "_rules" not in self.__dict__:
-            manager = nova_rules.SecurityGroupRuleManager(None)
-            rule_objs = [nova_rules.SecurityGroupRule(manager, rule)
-                         for rule in self._apiresource.rules]
-            self._rules = [SecurityGroupRule(rule) for rule in rule_objs]
-        return self.__dict__['_rules']
+        manager = nova_rules.SecurityGroupRuleManager(None)
+        rule_objs = [nova_rules.SecurityGroupRule(manager, rule)
+                     for rule in self._apiresource.rules]
+        return [SecurityGroupRule(rule) for rule in rule_objs]
 
 
 class SecurityGroupRule(base.APIResourceWrapper):
diff --git a/openstack_dashboard/dashboards/project/containers/views.py b/openstack_dashboard/dashboards/project/containers/views.py
index c063db28ab..d1ac13d082 100644
--- a/openstack_dashboard/dashboards/project/containers/views.py
+++ b/openstack_dashboard/dashboards/project/containers/views.py
@@ -24,6 +24,7 @@ Views for managing Swift containers.
 
 from django.core.urlresolvers import reverse  # noqa
 from django import http
+from django.utils.functional import cached_property  # noqa
 from django.utils.translation import ugettext_lazy as _  # noqa
 from django.views import generic
 
@@ -58,36 +59,34 @@ class ContainerView(browsers.ResourceBrowserView):
             exceptions.handle(self.request, msg)
         return containers
 
-    @property
+    @cached_property
     def objects(self):
         """ Returns a list of objects given the subfolder's path.
 
         The path is from the kwargs of the request.
         """
-        if not hasattr(self, "_objects"):
-            objects = []
-            self._more = None
-            marker = self.request.GET.get('marker', None)
-            container_name = self.kwargs['container_name']
-            subfolder = self.kwargs['subfolder_path']
-            prefix = None
-            if container_name:
-                self.navigation_selection = True
-                if subfolder:
-                    prefix = subfolder
-                try:
-                    objects, self._more = api.swift.swift_get_objects(
-                        self.request,
-                        container_name,
-                        marker=marker,
-                        prefix=prefix)
-                except Exception:
-                    self._more = None
-                    objects = []
-                    msg = _('Unable to retrieve object list.')
-                    exceptions.handle(self.request, msg)
-            self._objects = objects
-        return self._objects
+        objects = []
+        self._more = None
+        marker = self.request.GET.get('marker', None)
+        container_name = self.kwargs['container_name']
+        subfolder = self.kwargs['subfolder_path']
+        prefix = None
+        if container_name:
+            self.navigation_selection = True
+            if subfolder:
+                prefix = subfolder
+            try:
+                objects, self._more = api.swift.swift_get_objects(
+                    self.request,
+                    container_name,
+                    marker=marker,
+                    prefix=prefix)
+            except Exception:
+                self._more = None
+                objects = []
+                msg = _('Unable to retrieve object list.')
+                exceptions.handle(self.request, msg)
+        return objects
 
     def is_subdir(self, item):
         content_type = "application/pseudo-folder"