[ZPatterns] ZPatterns Extensions

[Roché Compaan]

Christian Scholz wrote:
>>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.
> 
> 
> Well, I agree, it might look difficult at the beginning but actually isn't
> once you did your first app with it. I think it's not really getting
> clear from the original docs how you do things.
> 
> And I've actually have written a howto which was published in Stephan
> Richter's Zope book (but I actually don't know if it actually was published
> in english yet. Need to ask Stephan). It basically illustrated how you use
> ZPatterns to store simple ZClass object and then who to change this to
> store these objects in a database via SQL.

This can be a good starting point (I didn't even know Stephan wrote a 
Zope book).  Can I maybe have a look at it and incorporate some ideas
I have into it.

>>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 am.

Cool!

>>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?
> 
> 
> I don't think so. It still makes sense as Zope3 might still take some
> time to arrive.
> 
> 
>>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".
> 
> 
> Well, I developed once some product call SQLAttributeProvider which basically
> was thought as an replacement for the basic skinscript for getting, updating
> and deleting objects by simply giving the tablename and field definitions
> and so on. 

I remember the thread on the list when you were busy with this and I'd
love to see how it ended up - even if it's not working that well.

>>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.
> 
> 
> That sounds quite cool :-) Are these products released?

No, but I plan to real soon.

> For most of my apps I use some scripts on top of ZPattern which use
> Formulator to edit the content of that specialist. Actually I am now
> planning to move all this into some sort of python product to make it
> more usable but I am still in the planning phase and don't have that much
> time.

Regrettably I haven't really used Formulator in our apps.  I'm not 
completely unfamiliar with it though - I started creating Formulator XUL 
Fields for Zope3 but I didn't have time to complete it.  I think, in the
same why that one uses class introspection to generate SQL and 
SkinScript one can generate basic Formulator forms that one can 
customise further.  Then one really has a RAD environment.

> Well, for me ZPatterns is definitely not dead ;-)
> (though I must say that I don't use it because of it's data storage
> independance but more or less because of it's triggers and the possibility
> to alter objects with skinscript in certain situations (like linking
> other specialists to it). 

Thanks for your response and please send me any code snippets or docs 
that you think could be useful.

-- 
Roché Compaan
Upfront Systems                 http://www.upfrontsystems.co.za