Re: [Zope] Save references in a list as object attribut

29 Jan 2010

      Thierry Florac wrote:
...
Le vendredi 29 janvier 2010,
  Vladislav Vorobiev <vavvav@mykniga.de> a écrit :
======================================================================
...
I try to save references to objects as attribute in a list.
object.refList=getattr([self.
context.pfad, 'object'],
[self.context.pfad, 'object1'])
After adding and transaction commit I can get my linked objects with
all attributes and methods
myObject.refList
[<myType at object>]
myObject.refList[0].objectValues()[0].getPhysicalPath()
('', 'path', 'object')
myObject.refList[0].objectValues()[0].absolute_url()
http://localhost/pfad/object
I restart the instance and get some other results
myObject.refList
[<myType at object>]
myObject.refList[0].objectValues()[0].getPhysicalPath()
('object',)
myObject.refList[0].objectValues()[0].absolute_url()
'object'
It seems that the in list referenced object ist no more in context
after restart.
the constructor for this looks like:
object  = myObject()
id=myObject
myObject.id   = id
myObject.title= id
myObject.refList=getattr([self.context.pfad, 'object'],
[self.context.pfad, 'object1'])
self.context._setObject(id, ob)
======================================================================
Modifying an object's list attribute "in place" doesn't mark the
persistent object as modified ; so as soon as the object is removed from
the cache, it's modifications are lost.
You should probably :
 - use persistent lists (persistent.list.PersistentList) instead of
   "basic" lists
 - mark object as modified manually (myObject._p_changed = True)
 - or change value of object list attribute :
       myList = myObject.refList
       myList[0] = ...
       myObject.refList = myList
Hope this helps,
Thierry
Thierry thank you  for answer but it doesn't help.

I implement all what you sad. I tried with normal “list” and than 
swiched to “PersistentList”

code looks like that <http://www.dict.cc/englisch-deutsch/following.html>:

from persistent.list import PersistentList
import transaction

<snip>

myList=PersistentList([self.context.pfad, 'object])           
myList[0] = PersistentList([self.context.pfad, 'object])[0] #hope I 
anderstud you right

ob.refList= myList 
ob._p_changed = True
ob.refList._p_changed = True 
self.context._setObject(id, ob)

After add I call again:

ob._p_changed = True
ob.refList._p_changed = True 
transaction.commit()

I see the commitet trunsactions in ZMI

The same problem. After restart ist the Attribut not in context.

For example return's

Before restart: ***1
ob.refList[0].objectValues()[0].absolute_url()
/pfad/object/FirstObjectOfReferencedObject

After restart only the id of the object:
ob.refList[0].objectValues()[0].absolute_url()
FirstObjectOfReferencedObject

Here is a place for an other question:

Normaly self.absolute_url() returns url with hostname, 
(http://localhost/bla/bla)
but already <http://www.dict.cc/englisch-deutsch/already.html> befor 
restart I get without http://localhost/... <http://localhost/> see ***1

It seem's that I forgot something.  *I* 
<http://www.dict.cc/englisch-deutsch/I.html> would 
<http://www.dict.cc/englisch-deutsch/would.html> be 
<http://www.dict.cc/englisch-deutsch/be.html> *glad* 
<http://www.dict.cc/englisch-deutsch/glad.html> to if somebody explain 
me this problem.

Best regards

Vladislav