Arguments

reactor  (any reactor object)  the reactor to make a persistent reactor (stored inside dwg database)

Return

returns the reactor object, or NIL

Example

(setq rx (vlr-object-reactor nil nil '((:vlr-modified . cb))))  #<VLR-Object-Reactor>
(setq obj (vlax-ename->vla-object (entlast)))  #<VLA-OBJECT IAcadLine 00000000427C86C0>
(vlr-owner-add rx obj)  #<VLA-OBJECT IAcadLine 00000000427C86C0>

(vlr-pers rx)  #<VLR-Object-Reactor>
"rx" object reactor is now persistent in the drawing database

Remarks

Note :
if a drawing with persistent reactors is opened on a CAD system, where the associated reactor event handler(s) is not available (i.e. the Lisp or ARX/BRX code is not available), the missing event handler will trigger error/warning messages;
such can be annoying, and also slow-down overall performance (depending on reactor type)

see also (vlr-pers-p) and (vlr-pers-list) functions