[Zope] enthusiastic newbie needs guidance

[Yanick Duchesne]

Hi everyone, 

I was a Java addict until I discovered Python and Zope. I am just getting
into Zope, trying to put together a contact manager app as an exercise.
I have a few questions:

a) The contact manager will hold information for contacts(people) within
organizations(companies); organizations will be categorized by predefined
industries, etc. I am not sure how to model this; I am still a bit confused
about how to approach a problem in Zope; it's so different... My first
idea was this:

- Create an 'Organization' ZClass, in which there is a 'Contact' ZClass
- Create an 'Industry' ZClass

Then:

- Create an 'Organizations' folder (contains Organization instances)
- Create an 'Industry' folder (contains Industry instances)

Now, my question is this: how do I relate an organization instance to
an industry instance? How do I materialize that possibility through the
UI - I mean, how do I show the different industries in a listbox in the
Organization's create/update screens? I am still quite confused about
how objects in given folders have access to objects in other folders.
Could someone help me on this - an example may be?

b) Objects, references and ZODB

Suppose I successfuly assign an industry object to an organization object,
how is that persisted in ZODB? I mean, does the organization object only
keep a persistent reference to the industry object, or does it copy the
industry object entirely? What is the proper way to handle such cases
in Zope?

c) "mutable sub-objects should be treated immutably" - from a ZODB point
of view.

I am not sure I completely understand this (I understand mutable and
immutable allright, but I do not see what makes a mutable object being
treated immutably, and how/why it affects ZODB).

Yanick 
yduchesne@zdnetonebox.com :)



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