Manipulating objects depends on whether they are based on the Archetypes subsystem or on the Dexterity subsystem.
For more information, consult the manual of the relevant subsystem:
After modifying the object, you need to reindex it in the
to update the search and listing information.
Cataloging has a quirk regarding the
modified metadata: when calling
reindexObject on an object, the value for
portal_catalog will be set to the time of the reindex, regardless of the
value of the modified property of the object.
In order to store the correct value you can do an extra reindex of the
object with the
modified index as parameter.
First do a normal
reindexObject, then call it with the modified index
For more information, see ** How to update this document.