[Zope-PTK] Topics support in PTK

[Tres Seaver]

On Tue, 13 Feb 2001, Michael Bernstein wrote:

> Tres Seaver wrote:
> > 
> > Sigve Tjora wrote:
> > >
> > > Is there any work done on the subject?
> > 
> > We have two possible implementations.  One starts from ZTopic,
> > and works to make it "portalish".  The other is simpler (no caching
> > of result sets), but easier to configure, and is already "portalish".
> 
> Which approach involves the least amount of work for you?

I'm not sure;  it depends more on which approach gives us the
correct semantics and maintainability.

> Starting from ZTopics, after you've made them 'portalish'
> how much extra work to make them as easy to configure as the
> other?

I have ZTopics working (with a one-line patch) in portals right
now;  they aren't configurable except via the ZMI, but they
behave as you would expect.  They need a fair bit of cleanup
before I'd really want to incorporate them into the core of the
CMF, however:

 * ZTopics are intimate with the guts of the existing catalog
   implementation;  disentangling the product (so that it will
   continue to work in the face of future catalog changes) is
   non-trivial.

 * The current ZTopics configuration allows/expects the user to
   type Python expressions in order to establish criteria.  I
   don't want to allow this at *all*, for member-generated
   topics, so we will have to do a lot of thinking to use them.

> Starting from the 'other' implementation, how much extra
> work to add caching?

I'm not confident that we can do a reasonable job of caching
the result sets without re-introducing dependencies on catalog
internals (which is the real Achilles heel of ZTopics).

Tres.
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Tres Seaver                                tseaver@digicool.com
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