--- a/src/ztfy/utils/property.py	Thu Oct 25 11:39:05 2012 +0200
+++ b/src/ztfy/utils/property.py	Thu Oct 25 18:57:12 2012 +0200
@@ -23,6 +23,8 @@
 # import Zope3 packages
 
 # import local packages
+from ztfy.utils.request import queryRequest, getRequestData, setRequestData
+from ztfy.utils.session import getSessionData, setSessionData
 
 
 class cached(object):
@@ -63,3 +65,46 @@
             return self
         obj.__dict__[self.__name__] = result = self.fget(obj)
         return result
+
+
+_marker = object()
+
+class request_property(object):
+    """Define a request cached property"""
+
+    def __init__(self, fget, key=None):
+        self.fget = fget
+        if key is None:
+            key = "%s.%s" % (fget.__module__, fget.__name__)
+        self.key = key
+
+    def __get__(self, obj, cls):
+        if obj is None:
+            return self
+        request = queryRequest()
+        data = getRequestData(self.key, request, _marker)
+        if data is _marker:
+            data = self.fget(obj)
+            setRequestData(self.key, data, request)
+        return data
+
+
+class session_property(object):
+    """Define a property for which computed value is stored into session"""
+
+    def __init__(self, fget, app, key=None):
+        self.fget = fget
+        self.app = app
+        if key is None:
+            key = "%s.%s" % (fget.__module__, fget.__name__)
+        self.key = key
+
+    def __get__(self, obj, cls):
+        if obj is None:
+            return self
+        request = queryRequest()
+        data = getSessionData(request, self.app, self.key, _marker)
+        if data is _marker:
+            data = self.fget(obj)
+            setSessionData(request, self.app, self.key, data)
+        return data