My problem :

I got an event, i process it with processEvent and i would like to set an attribute to the end of this process.

How can i do it?

public void processEvent(EventRequest request, EventResponse response)
     {
          Event event = request.getEvent();
          if(event.getName().equals("selection"))
          {
               Selection _selection = (Selection) event.getValue();
                        //doesn't work
                        request.getPortletSession().setAttribute("new_selection", _selection);
                        //doesn't work
                        this.getPortletContext().setAttribute("new_selection", _selection);
                        //doesn't work
                        request.setAttribute("new_selection", _selection);
          }
     }