add utility for caching values in the request

git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@3794 fd906abe-77d9-0310-91a1-e0d9ade77398

zutil/rcache.py

@@ -31,7 +31,7 @@ def caching(self, method, id):
     item = annot.setdefault('cybertools.zutil.rcache', {})
     value = item.get(id, INVALID)
     if value is INVALID:
-        value = method()
+        value = method(self)
         item[id] = value
     return value
 

zutil/rcache.txt

@@ -12,12 +12,12 @@ $Id$
   ...         self.request = request
   ...
   ...     @rcache
-  ...     def calculate():
+  ...     def calculate(self):
   ...         print 'calculating'
   ...         return 42
   ...
   ...     @rcacheproperty
-  ...     def value():
+  ...     def value(self):
   ...         print 'calculating'
   ...         return 43