[Zope-dev] Bulletproof ZCatalog proposal

[Shane Hathaway]

"Phillip J. Eby" wrote:
> That is, in ZPatterns one can specify triggers such as:
> 
> WHEN OBJECT DELETED, CHANGED CALL
> someCatalog.manage_uncatalog(self.absolute_url(1))
> WHEN OBJECT ADDED, CHANGED CALL
> someCatalog.manage_catalog(self,self.absolute_url(1))

After I read this again I realized what you were saying.  This
capability of ZPatterns is very brittle, don't you think?  If the
catalog is updated manually before the special ZPatterns object is added
to the queue, the behavior is undefined AFAIK--either the later changes
to the catalog will be ignored, will cause a conflict, or some objects
will be written twice in the same transaction.

However, if we could specify transaction commit priorities, and the
ZPatterns update came first, auto-indexing came second, and everything
else followed, I think it would work.  Or perhaps ZPatterns should be
able to register things that occur *before* the two-phase commit
protocol.

Shane