[Zope] RE: Two newbie questions

Paul Everitt Paul@digicool.com
Wed, 8 Sep 1999 15:02:50 -0400


Michael wrote:
> Wow. I had no idea anyone was reading my old posts. I feel so special!

Hey, nobody reads my _new_ posts. :^)

> But seriously, this has been my personal hobby horse for 
> quite a while now, but
> I've refrained from bugging DC about it (they've been busy).

I have no idea what you're referring to...:^)

> In any case, ZTables does indeed have the 'hierarchy' 
> functionality that we
> want, but it has yet to be released. A related proposal 
> called 'Topics' popped
> up on the Zope site yesterday:
> http://www.zope.org:18200/Members/Amos/TopicProposal , which 
> seems to apply
> ZTables Hierarchies to ZCatalog albeit with a somewhat 
> different interface.

As mentioned in a private note to Michael just now:

"""
I don't think it's the same machinery.  In fact, the machinery has not
been created yet.  It's just a statement of what we'll build this week
and next.

Hierarchies are keyed very tightly to the machinery of ZTables, where
the data itself are contained inside the ZTable object.  Hierarchies
leverage this fact to provide folderish, pseudo-objects based on the
tabular representation of data.

There are probably many cases where people don't want to be constrained
into a flat, rigid schema for all their data, as is the case with
ZTables.
"""

> This is EXACTLY what I've been waiting for! I knew you guys 
> would get around to
> it eventually. With the minor quibble that it would be nice 
> to have logical
> operators besides 'OR' to chain queries within a Topic, this 
> proposal seems
> perfect.

Propose away!  Be prepared to be quite specific about the behavior and
the interface.

> The one thing that is unclear is whether you can set 
> properties on a Topic, or
> if you would have to place a Document with properties on it 
> into the Topic.

Don't worry, Topics will be (I think) folderish objects that can have
properties.  More importantly, they can contain things like DTML
methods, allowing you to spew multiple representions of data in that
topic, such as RDF, RSS, or CDF.

> BTW, as this is so useful in contexts other than 
> news/informational, I propose
> changing the name from Topics to 'Category' or 'ZCategory'.

I think the idea of Topic better represents the idea that it has its own
identity away from the objects that might have some particulary piece of
metadata.

--Paul

Paul Everitt       Digital Creations
paul@digicool.com  540.371.6909
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