From 5dfd74c3602363d55bad38e71c86b4c8d103d861 Mon Sep 17 00:00:00 2001
From: Luke Hatcher <lukeman@gmail.com>
Date: Tue, 31 Jul 2012 15:24:26 -0400
Subject: [PATCH] permissions backend based on team membership

---
 symposion/teams/backends.py   | 33 +++++++++++++++++++++++++++++++++
 symposion_project/settings.py |  4 ++++
 2 files changed, 37 insertions(+)
 create mode 100644 symposion/teams/backends.py

diff --git a/symposion/teams/backends.py b/symposion/teams/backends.py
new file mode 100644
index 00000000..9b4ddf7e
--- /dev/null
+++ b/symposion/teams/backends.py
@@ -0,0 +1,33 @@
+from django.db.models import Q
+
+from .models import Team
+
+
+class TeamPermissionsBackend(object):
+    
+    def authenticate(self, username=None, password=None):
+        return None
+    
+    def get_team_permissions(self, user_obj, obj=None):
+        """
+        Returns a set of permission strings that this user has through his/her
+        team memberships.
+        """
+        if user_obj.is_anonymous() or obj is not None:
+            return set()
+        if not hasattr(user_obj, "_team_perm_cache"):
+            memberships = Team.objects.filter(
+                Q(memberships__user=user_obj),
+                Q(memberships__state="manager") | Q(memberships__state="member"),
+            )
+            perms = memberships.values_list(
+                "permissions__content_type__app_label",
+                "permissions__codename"
+            ).order_by()
+            user_obj._team_perm_cache = set(["%s.%s" % (ct, name) for ct, name in perms])
+        return user_obj._team_perm_cache
+
+    def has_perm(self, user_obj, perm, obj=None):
+        if not user_obj.is_active:
+            return False
+        return perm in self.get_team_permissions(user_obj, obj)
diff --git a/symposion_project/settings.py b/symposion_project/settings.py
index 8b81f04a..e8279f3c 100644
--- a/symposion_project/settings.py
+++ b/symposion_project/settings.py
@@ -194,6 +194,10 @@ ACCOUNT_LOGOUT_REDIRECT_URL = "home"
 ACCOUNT_USER_DISPLAY = lambda user: user.email
 
 AUTHENTICATION_BACKENDS = [
+    # Permissions Backends
+    "symposion.teams.backends.TeamPermissionsBackend",
+    
+    # Auth backends
     "account.auth_backends.EmailAuthenticationBackend",
 ]