[Zope-dev] Observer / Notification Interface Proposal

[Phillip J. Eby]

At 07:19 PM 5/24/00 -0400, Tres Seaver wrote:
>I have started a page for an implementation of the GangOfFour Observer
>pattern within Zope:
>
>  <URL
>http://www.zope.org/Members/michel/Projects/Interfaces/ObserverAndNotificat
ion>
>
>Please comment, either here or in the wiki.
>

Is this only for events occurring within a transaction, or across
transactions?  If across transactions, how do you intend to handle
persistent references, acquisition, and cross-database references?  (My
suggestion would be to use a path to the callable.)

Second, I think there should be an opportunity for the observer to specify
more detail about what it wants to be called *for*.  I.e., either a
specific event or an event mask, to avoid unnecessary calls for irrelevant
events.

I realize this is all very implementation oriented, but that's me.  :)

(Oh, btw on "ObserverInterface", I'm guessing you mean the contract
requires that *observable* not worry about delays, not the other way around.)