[Zope] Referencing Objects from id's stored in a lines property. -- Yet Another Update

[Tom Jenkins]

Hey Ron,

complaw@hal-pc.org wrote:
> I'm considering using a DTML document having a lines property that stores 
> id's of related objects (i.e., objects where there is to be a user-defined
> relation).  Essentially, the lines property would be a container of id's of
> objects available to the object having the lines container.  
> 
> I can load the id's into the lines property (that is easy).  However, does
> anyone know of the DTML code needed to sequentially list each of the elements 
> in the lines property (which is a Python list) and then call that object to 
> obtain and then display the title corresponding to the object id?
> 
> The following code works...
> 
> <P>Here they are, one by one.<BR>
> <dtml-in cases>
>   <A HREF="<dtml-var sequence-item>"><dtml-var sequence-item></A><BR>
> </dtml-in>
> 
> But the above code only lists the id's, not the titles to the id's (which 
> would be easier for the user to understand).
>  

Ok you're close.
<dtml-in cases>
   <A HREF="<dtml-var sequence-item>"><dtml-var 
expr="_.getitem(_['sequence-item']).title"></A><BR>
</dtml-in>

The key is that the sequence-item has the id as a string, so you need to 
get the item that the id refers to out of the _ namespace.

Actually this code is a little nastier than it needs to be because of a 
(soon-to-be-fixed?) problem with name "sequence-item".  The following 
code also works
<dtml-in cases>
  <dtml-let sequence_item="_['sequence-item']">
   <A HREF="<dtml-var sequence_item>"><dtml-var 
expr="_.getitem(sequence_item).title"></A><BR>
  </dtml-let>
</dtml-in>

the embedded '-' in sequence-item means we have to use the 
_['sequence-item'] whenever we drop down into expression.

hope that helps
-- 
Tom Jenkins
devIS - Development Infostructure
http://www.devis.com