[Zope] - OO paradigm

[LD Landis]

Michael,

  I still feel like a dummy, so there are probably much better answers
  coming your way... but here's my take on things...

  I would expect that the organization of a ZOPESite conforms to what you
  are suggesting (strictness, etc), where acquisition plays a role in
  supplying parameters that control how the object services respond to the
  requests.

  Sure, some inheritance "across the tree" seems useful, and I think (if I
  understand what I've heard on this list), there are people thinking about
  how to do this.  As I understand it, you're right... you need to
  implement things branch by branch, where maybe only a few things are
  different (parameterized templates would solve this maybe? smarter ones
  than I are working it).

  ANYWAY...

  Don't forget that one of the goals (IMO anyway) of ZOPE is to provide a
  clean separation between the presentation and the application layers of
  an application.  You can have an application that is completely unaware
  of how its services are being exposed... This is a real cool concept and
  requires rethinking of how you build systems.  (I haven't succeeded yet,
  but have been preaching this approach for several years).

  I am really looking forward to getting into the documents that Amos and
  crew have been working so hard on (I see that there is an ANNOUNCEMENT of
  another new Guide just ahead in my e-mail!)

  Anyway, if you read the DTML reference, etc, you'll see that two things
  need to be strived for:
    - Keep HTML out of the application classes
    - Keep application logic out of the DTML... let iterators, and other
      object accessors ask the exposed application object services for
      stuff.
  
  This is going to be (IMO) revolutionary in that it is going to facilitate
  demonstrating the difference between CORBA objects (durable services) and
  the transient objects provided by "object languages" such as Java,
  Python, Smalltalk, or even C++.

Michael Bernstein wrote:
> 
> I've been examining Zope with quite a bit of interest for a while now,
> and I have a question about the basic architecture:
> 
> The object hierarchy seems to be 'exact', that is, strictly exclusive.
> No object can appear in more than one branch of the tree. However, In
> many cases, user oriented design requires several alternative navigation
> hierarchies, which would require objects to inherit from more than one
> branch.
> 
> An example would be an event calendar, where events can be organized
> chronologicaly ( Years>Months>Days) but also according to an event
> category heirarchy (All events>entertainment>music>concerts). These
> heirarchies only intersect at the leaf node of an individual event.
> 
> Most product catalogs can be profitably organized using multiple
> heirarchies as well.
> 
> So how would you do this in Zope? you could of course represent the
> alternative heirarchies by branching off the bottom of the primary, or
> as folder properties, but that doesn't seem as elegant or maintainable.
> perhaps the answer is some sort of 'pseudo heirarchy' object that could
> be placed at or near the top of the object tree.
> 
> What do you all think?
> 
> Michael Bernstein.
> 
> 
> 


-- 
--
Cheers,
	--ldl
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LD Landis ldl@HealthPartners.Com N0YRQ    Voice 612/883-5511 Fax 612/883-6363
HealthPartners, 8100 34th Avenue So, PO Box 1309, Minneapolis, MN  55440-1309
Shape your life not from your memories, but from your hopes.       (Borrowed)
Still programming for the day-job... haven't yet gotten that Microsoft PR job
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