[Zope-dev] multiple monkeypatches

[Florent Guillaume]

Jim Penny  <jpenny@universal-fasteners.com> wrote:
> Is there a safe way to handle multiple monkeypatches?

Without an existing framework (I haven't looked at Adrian's PatchKit),
it's the same old problem as "intercepting interrupts" on good old 8-bit
computers. You just have to save and call the previous one.

What I do is this:

# 1. define my method
def manage_main(...):
    # ...
    ...
    res = self._myproduct_old_manage_main(...)
    ...
    return res
# 2. put the old version in a private variable
ObjectManager._myproduct_old_manage_main = ObjectManager.manage_main
# 3. patch
ObjectManager.manage_main = manage_main

If you want to play nice with refresh, you have to be a bit more
careful, because then you don't want to do step 2. A simple test for
absence of the _myproduct_old_manage_main attribute before doing it is
enough.

Florent

-- 
Florent Guillaume, Nuxeo (Paris, France)
+33 1 40 33 79 87  http://nuxeo.com  mailto:fg@nuxeo.com