Fighting Reactors

I'm trying to get familiar with reactors. How you can make
VLR-SYSVAR-REACTOR used with
:VLR-SYSVARCHANGED event to react only to specific variable change (in my
case CVPORT)?
Thanks.
John

 

John,
IMO, sysvar reactor is too active to be useful. On some commands it
fires 10-20 times. But to answer your question, here is one way:


;;D. C. Broad, Jr - Demo
;;Initiate reactor
(if (null db:svr)
(setq db:svr (vlr-sysvar-reactor '("CVPORT") '(vlr-sysvarchanged . sysvardemo)))))

;;vlr-sysvar callback that reports only sysvars that are in
;;the reactor's data list
;;NOTE: This reactor fires many more times than it reports.
(defun sysvardemo (r data)
(if (member (car data) (vlr-data r))
(princ (strcat (car data) "changed, sysvardemo callback reporting."))))

 

Thanks Doug, I think this answer my question.