[Zope3-Users] Re: Newbie relationship question

[Carlo Cardelli]

[Sorry to start a new thread, but I had 'Reply-To' disabled...]

Albertas Agejevas wrote:
>  > Now, I have to render the 'invCust' object as a selection-list showing
>  > the custNames of all possible Customers, where the user can select the
>  > appropriate Customer for the Invoice. Editing the Invoice, the
>  > selection-list should position itself showing the Customer set 
> previously.
>  > In other words, I need a widget that somewhat behave like
>  > "Plone.Archetypes.ReferenceWidget".
>  > I know that this is a very basic problem. Anyone already implemented it?
> 
> What you need to do is define the customer field as a choice in the 
> interface:
> 
>     class IInvoice(Interface):
>     ...
>     invCust = Choice(title=u"Customer",
>              vocabulary="Customers")
> 
> and define the "Customers" vocabulary, that will list all customers in
> your app.  Look at zope.schema.vocabulary.SimpleVocabulary.
> 

Thank for your answer, that gave me a starting point.
Sorry to be annoying, but after such starting point I am stuck again:

- how do I get all my Customers instances? The Customer class is marked 
as 'Persistent' and 'IContentType'.
- how do I connect them to the vocabulary in a way to store a 
'reference' to the object and not, say, only its custName?

I have to fill 2 slots in the following:

def CustomerVocabulary():
     allterms = []
     for customer in [ ...What goes here...? ]:
         oneTerm = zope.schema.vocabulary.SimpleTerm
                  ([...What goes here...?], title=customer.custName)
         allterms.append(oneTerm)

     return zope.schema.vocabulary.SimpleVocabulary(allterms)

A somewhat derived question:
- Given a certain Invoice, how do I use the 'reference' to the Customer 
Object to access the Customer of the Invoice?

Again, these are basic questions, but I am not able to find 
documentation about this.