Reacting to More User-Invoked Commands

When writing a reactor-based application, you need to handle any command that affects your objects in a significant way. One of your program design activities should be to review all possible AutoCAD editing commands and determine how your application should respond to each one. The format of the reactor-trace sheet shown near the end of Lesson 6 is very good for this purpose. Invoke the commands you expect your user to use, and write down the kind of behavior with which your application should respond. Other actions to plan for include

To prevent a very complex subject from becoming very, very complex, the tutorial does not try to cover all the possibilities that should be covered, and the functionality within this lesson is kept to an absolute minimum.

Even though you won't be building in the complete functionality for these extra commands, examine what a few additional editing functions would require you to do:

To begin, though, just plan for the following:

NoteIn addition to user-invoked AutoCAD commands, entities may also be modified or deleted through AutoLISP or ObjectARX. applications. The example provided in the Garden Path tutorial does not cover programmatic manipulation of the garden path polyline boundary, such as through (entdel <polyline entity>). In this case, the editor reactor events:vlr-commandWillStart and :vlr-commandEnded will not be triggered.