[Zope] RE: CST and disappearing variables (still)

[Chris McDonough]

 >
 > Is there anything special I need to be concerned about regarding 
persistence
 > when using CST?

Just what's in the documentation.. which by the rest of your message it
appears you've already read (or you intuited the right way of doing things).

 > For example, in a Python Script, I do the following:
 >
 >   item = {}
 >   ... populate item with some stuff ...
 >
 >   cart = session.get('cart', [])
 >   cart.append(item)
 >   session.set('cart', cart)
 >
 > Is this something that CST should be able to handle properly?

Yes... the last session.set is necessary due to the mutability of
"cart", but you knew that.

 > The only other thing I do that might be strange is getting the 
session data
 > more than once in a transaction as follows:
 >
 > When the final Python Script 'sendOrder' is called from the Web, it goes
 > something like this:
 >
 >   session = context.SDM.getSessionData()
 >   message = container.message(container, custinfo=session['custinfo'])
 >   ... send message ...
 >
 > The DTML Method 'message' called above has this:
 >
 >   <dtml-with custinfo mapping>
 >   ... name, address, etc. variables from 'custinfo' ...
 >   </dtml-with>
 >
 >   <dtml-var textview>
 >
 > The DTML Method 'textview' inserted at the end of the 'message' has this:
 >
 >   <dtml-let items="Items()">
 >   <dtml-unless items>
 >   Your cart is empty.
 >   </dtml-unless>
 >   <dtml-if items>
 >   <dtml-in items mapping>
 >   ... display items ...
 >   </dtml-in>
 >   </dtml-if>
 >
 > The Python Script 'Items' is as follows:
 >
 >   session = context.SDM.getSessionData()
 >   return session.get('cart', [])
 >
 > So, 'textview' calls the Python Script 'Items' which gets the session 
data
 > again.  Is there anything wrong with doing this, or can you see anything
 > dangerous in my logic?  It seems so clear and simple to me, but I'm
 > questioning pretty much everything now.

No, it seems normal. :-(  Darn.

You're not working with multiple frames or windows, are you?

-- 
Chris McDonough                    Zope Corporation
http://www.zope.org             http://www.zope.com
"Killing hundreds of birds with thousands of stones"