[ZODB-Dev] Ordering before commit hooks

[Sidnei da Silva]

On Wed, Aug 31, 2005 at 06:02:21PM -0400, Jim Fulton wrote:
| You might be right, but the only credible use case I've seen
| is to go last.  The example Julien has something going first
| and something going last.  Looking at the code, I don't see
| why the thing he wanted to go first needed to do so.
| The example you gave above had subscribers that wanted to go last.
| What evidence to I have of other orderings?  Julien did give
| a "future need" to order two specific systems.  IMO, having
| one system implement that requirement explicitly by invoking
| the other would be much clearer than having the
| requirement implemented implicitly through integers orders.

I would instead fire 'before' and 'after' events for each of those
systems, and a system that wants to explicitly run after/before
another system would do so as a subscriber to the explicit event
fired.

Otherwise, if system 'A' is hardcoded to call system 'B' and you want
to add a system 'AB' that runs between 'A' and 'B' them you have to
resort to code modification or monkey patching, which brings us back
to memories of Zope 2.

-- 
Sidnei da Silva
Enfold Systems, LLC.
http://enfoldsystems.com