code: def action_update(self):
          
  
          order = []
          form = self.request.form
          attachments = form.get("attachments", [])
  
          for attachment in attachments:
              # attachment is a form mapping, not a dictionary -> convert
              values = dict(attachment)
  
              uid = values.pop("UID")
              obj = api.get_object_by_uid(uid)
  
              # delete the attachment if the delete flag is true
              if values.pop("delete", False):
                  self.delete_attachment(obj)
                  continue
  
              # remember the order
              order.append(uid)
  
              # update the attachment with the given data
              obj.update(**values)
              obj.reindexObject()
  
          # set the attachments order to the annotation storage
          self.set_attachments_order(order)
  
          # redirect back to the default view
          return self.request.response.redirect(self.context.absolute_url())
docs: Form action enpoint to update the attachments