Opening a Drawing Containing Persistent Reactors

AutoLISP Developer's Guide > Using the Visual LISP Environment > Advanced Topics > Attaching Reactors to AutoCAD Drawings > Transient versus Persistent Reactors >

A reactor is only a link between an event and a callback function. While this link remains, the callback function itself is not part of the reactor, and is normally not part of the drawing. The reactors saved in the drawing are only usable if their associated callback functions are loaded in AutoCAD. You can cause this to occur automatically when a drawing is opened if you define the reactor and callback functions in a separate-namespace VLX.

If you open a drawing containing VLISP reactor information and the associated callback functions are not loaded, AutoCAD displays an error message. You can use the vlr-pers-list function to return a list of all Persistent reactors in a drawing document.