[Zope] Multiple select boxes saves selected id's even though the Objects are deleted. are deleted.

[Max Møller Rasmussen]

I have a zClass with a multiple selection. The selected items are selected
from a list of id's from a folder. 

They are then saved in the zClass as a list of strings.

But when one of the selected items on the folder is deleted the id is still
in the zClass.

Naturally it should be deleted from the "selected" list automatically, but I
don't think that is feasible. I would have to traverse a lot of different
subfolders to see if an object was selected there.

Is there a standard idiom for doing this?

(Don's say zPatterns please as this won't help here.)

Regards Max M

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Another way of explaining the same problem is here:

Folder1
   item1
   item2
   item3
   item4

selectBox = ['item1', 'item2', 'item3', 'item4']

selected = ['item1','item2']

After delete of item1 from Folder1

Folder1
   item2
   item3
   item4

selectBox = ['item2', 'item3', 'item4']

selected = ['item1','item2']

The problem is that 'item1' still is in selected.