T5: Edit page best practice?

[Geoff Callender]

Hi,

I'm looking for suggestions on how to improve this EditPerson page to  
T5 best practice.

        private Long _personId;

        @Persist
        private Person _person;

        public void onActivate(Long id) { _personId = id; }

        public Long onPassivate() { return _personId; }
        
        void onPrepareFromForm() {
                if (_person == null || _person.getId().equals(_personId)) {
                        _person = 
getSecurityFinderService().findPerson(_personId);
                }
        }

        Object onSuccess() {
                if (...a bit of validation logic detects an error...) {
                        _form.recordError(...);
                        return null;
                }
                etc...
                _person = null;
                return _nextPage;
        }

        Object onActionFromCancel() {
                _person = null;
                return _previousPage;
        }

        void cleanupRender() {
                _form.clearErrors();
        }

Some notes and questions:

1. Persist - Is there an alternative?  It's used here to keep _person  
populated in case onSuccess() detects an error and redisplays the page.

2. Housekeeping - I'm nullifying _person in each method that returns a  
different page.  This seems clumsy.  Suggestions?

3. Thread-safety - is there a thread-safety issue if the user has  
opened a new window in same browser - can T5 tell them apart or do  
they share the same HttpSession?

4. onPrepareFromForm() - this looks a bit clumsy to me.  If the user  
hits Reload, or if the user hits the Back button then "pagelinks" back  
in, onPrepareFromForm() wlll not call findPerson(...).  The _person  
isn't refreshed at all!  Thoughts?

Thanks,

Geoff