[ZPatterns] ZPatterns Extensions

[Steve Spicklemire]

Hi Roche,

I am also use ZPatterns heavily on projects. Unfortunately (or=20
fortunately, depending how you see it) I've been too busy with a couple=20=

of projects to work much with PEAK.

On Monday, August 12, 2002, at 01:28  PM, Roch=E9 Compaan wrote:

> Hi people
>
> I am still amazed about the amount of resistance there is on the =
general
> Zope list to use ZPatterns but at the same time it catches a lot of =
Zope
> newbies' attention.  To be honest I am sick of people that just write
> off ZPatterns without motivating why, or just saying it's too =
difficult
> or it's not maintained.  This compels me to write a howto to =
illustrate
> how to do the simple things in ZPatterns, *but* I would like to test
> how all of you feel about what I have to say below.
>
> We have for the past 2 years invested a lot of time in ZPatterns and
> have a huge code-base that are using the ZPatterns framework.  To us =
it
> is still the best framework available for data abstraction and object
> collaboration in Zope and we continue to use it for new applications.
> Although Zope3 and Peak are things to look forward too we cannot wait
> until their release and definitely do not plan to use it in a =
production
> environment any time soon.  In short we made the most of ZPatterns and
> wrote a number of extensions that really extended its lifetime by a
> mile.  I'll elaborate on these extensions in a while but my questions
> to you are:
>
> 1.Are you still actively using ZPatterns?

Yes.. I can't imagine using Zope without it, or something like it =
(PEAK?)

> 2.Do you think we are wasting our time writing some howtos and =
releasing
> extensions that can benefit especially newcomers, even though Zope3 =
and
> Peak are on the horison?

That's harder to answer. I personally think that it would not be a waste=20=

of time, since I'm guessing that many of the concepts of ZPatterns are=20=

important enough that they will find their way into PEAK/Zope3, so that=20=

any work done in this area will be a step ahead in documenting the newer=20=

systems. Also, if like you, folks needs something today, they will be=20
immediately useful.

>
> Now our add-ons.
>
> The first was basically taking Steve Spicklemire's idea of "levers" =
that
> generate SQL and SkinScript further and making a file system product =
of
> it.  A SQLRack (as we call it) can generate SQL and SkinScript from
> ZClass propertysheets or a filesystem Dataskin's "_properties".

Cool! I've also been pushing levers into a filesystem based product, but=20=

nothing usable by anyone but me at this point. They do make building=20
complex systems a lot more manageable. I was thinking of having=20
specialized levers that can be configured to produce either catalog=20
queries, or database queries, or ???, based on configuration. I was also=20=

toying with expanding _properties to include things like indexes and=20
more specific type information that RDBs tend to prefer. The way I'm=20
working now, I have filesystem dataskins that work with my levers to do=20=

query/skin script generation. I also have a sub-class of Specialist that=20=

creates a sort of default, crude, "Object ZMI" so you can dig into the=20=

application without writing a full UI.

>
> The second one I find quite exciting since it solves the difficult =
time
> one generally has to make a ZPatterns app customisable by 3rd party
> developers.  We basically made Specialists and Racks skinnable by
> subclassing them from the CMF's SkinnableObjectManager.  To that we
> added FSSkinScript, short for filesystem skinscript.
>

This sounds like a great addition! I'm sure that both of these would be=20=

welcome additions.

I was also thinking that perhaps either Phil/Ty might permit some folks=20=

to commit to the CVS tree (at least the ZPatterns part) or maybe one of=20=

us should make a ZPatterns patch/CVS to keep up with issues that crop=20
up. I've been fairly happily developing with Steve A's Transaction=20
Agents, but with time, little things accumulate. ;-)

thanks for the note!
-steve

> Writing these extensions gave ZPatterns a new life for us and extended
> its usability. Naturally I got excited and just wondered if I am not
> just flogging a dead horse or if its worth pursuing this.
>
> Your comments are greatly appreciated.
>
>
> --
> Roch=E9 Compaan
> Upfront Systems                 http://www.upfrontsystems.co.za
>
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