[Zope-PTK] Impressions of the PTK from my Christmas project

Shane Hathaway shane@digicool.com
Tue, 02 Jan 2001 18:06:04 -0500


alan runyan wrote:
> I have also witnessed people run into the same brick walls with the
> ptk.  I've used it successfully on a prototype of a system, but never
> in a production environment (yet).  But I would like to comment on
> ZClasses.  They are just too damn cool, and Paul E. continually talks
> 'through the web', 'self revealing interface', and all other sorts of
> 'ease of use for The People'  visions.  I have showed people ZClasses
> and it blows their minds (great for prototyping and getting something
> out).. but I always have to say 'well.. we would have to rewrite
> it for it to be more stable' and people just dont understand -- whats
> wrong with these ZClasses?  granted coding python is easy, but being
> of the remote control generation, it doesnt get easier than TTW
> ZClasses.  I mean... its f#$@ing EASY.  so, when *will* they be fully
> baked?  and if not, tell us where not to go with ZClasses.  for simple
> content objects, why not ZClasses?

You're right, ZClasses are a very cool concept.  But here are some
details that need work:

1) You can't change ZClass base classes after they're created, except
through a crude hack.
2) ZClasses get broken when a base class disappears (because of product
upgrades or whatnot.)
3) Broken ZClasses can cause other ZClasses to break.
4) Distribution of ZClasses is difficult and error-prone.
5) Permission mappings are difficult to understand.
6) Only site managers can create ZClasses.

The concept itself is great.  It's just that the current implementation
of ZClasses has a few issues that prevent them from being as useful as
they could be.

However, unless you intend to be a software distributor (like us), all
of the issues listed above are easy to work around.  It's just hard to
distribute ZClasses to lots of people.

> According to the Zope Book (I just looked) there doesnt seem to be ANY
> mention of the fact that ZClassses arent fully baked and why/why not
> use them over Python based objects and when is the best use of the two
> together.

I'd say you can use ZClasses unless you intend to distribute your
software on a wide scale.  Perhaps saying ZClasses aren't baked is
inaccurate; what isn't there is the infrastructure that would permit
wide scale ZClass distribution.  Zope's import/export functionality is
good enough for small-scale distribution.

> the PTK has come a long way in the past 6 months and doesnt have too
> much further to go (membership, some type of workflow/review
> structure, ?ZClass vs Python? & !Documentation! )... most of the stuff
> 'underneath' seems to be working just fine - minus having to change
> someone's password when you change their group.  I've showed people
> what I could do with the PTK in fractions of the time it would take to
> develop on top of plumtree or other 'portal' frameworks -- usually
> witgh very positive results.
>
> the install of PTK I've never found to be a problem, usually have to
> restart ZOPE once or twice to get all the goodies to init, but then
> its usually smooth sailing.  I too will try it at the end of Jan.

Glad to hear it!  Unfortunately, however, not everyone has the same
success rate.  In fact, even Tres and I sometimes have trouble
installing it.

But that's one thing we're hoping to change.

Shane