How to find Primary Point Group using vlisp

[tcorey]

When I use the AutoCAD List command on a Civil 3d Point, one reported datum is Primary Point Group.

I want to get at that information with vlisp, but when I vlax-dump a point, there is no mention of Primary Point Group. If that's a limitation of using vlisp, let me know, and I won't chase it. 

Maybe I have to go in through the point groups collection?

[Jeff_M · Accepted solution]

Yes, you need to iterate the pointgroups:

(defun getprimarypointgroup (pt c3ddoc / IDX PTGRP)
  (setq idx -1)
  (vlax-for grp	(vlax-get-property c3ddoc 'pointgroups)
    (if	(and (= (vlax-invoke-method grp 'containspoint (vlax-get-property pt 'number)) :vlax-true)
	     (> (vlax-get-property grp 'DrawPriority) idx)
	     )
      (progn
	(setq idx (vlax-get-property grp 'DrawPriority))
	(setq ptgrp grp)
      )
    )
  )
  ptgrp
)

[tcorey]

Thanks, Jeff.

[tcorey]

Jeff, at the end, where you have "ptgrp" out there by itself, is that like using a Return statement in c++? 

[tcorey]

When in doubt, give it a try. Yes, that works like a Return.

That's slick, Jeff. I didn't know lisp allowed that.

[Jeff_M]

Yep, lisp always returns the last thing it does. That's why most programs will end with (princ) so it exits 'quietly' instead of spitting out nil or some other value from the last used variable/calculation.