How to stop a routine after its first iteration?

[meddy001]

Hi all,

I've beat my head against the wall trying to understand and alter this useful LSP routine that was provided to me.
Its purpose is to change the description of Cogo Points. It prompts for the desired New Description, then asks for a selection of points, and then changes the description of the selected points to the New Description.

The routine works well, but I wish it cleanly ended the command after the first iteration. Instead, it prompts for the New Description once more.

Can anyone suggest an alteration to the routine so that it stops after this first iteration? Thanks in advance!

(defun c:chdesc (/ doc ss obj newdesc olddesc)
  (vl-load-com)
  (setq doc 
(vla-get-activedocument (vlax-get-acad-object)))
  (while (and (setq newdesc (getstring "\nNew point description:"))
       (not (eq newdesc ""))
       (setq ss (ssget '((0 . "AECC_COGO_POINT"))))
       (setq ctr -1)
       )
    
(vla-startundomark doc)
    (while (setq obj (ssname ss (setq ctr (1+ ctr))))
      (setq obj (vlax-ename->vla-object obj))
      (vlax-put obj 'rawdescription newdesc))
    (vla-endundomark doc)
    )  
  (princ)
)

[Tom Beauford]

Try untested:

(defun c:chdesc (/ doc ss obj newdesc olddesc)
  (vl-load-com)
  (setq doc 
(vla-get-activedocument (vlax-get-acad-object)))
  (while (and (setq newdesc (getstring "\nNew point description:"))
       (not (eq newdesc ""))
       (setq ss (ssget '((0 . "AECC_COGO_POINT"))))
       (setq ctr -1)
       )
    
(vla-startundomark doc)
    (setq obj (ssname ss (setq ctr (1+ ctr))))
    (setq obj (vlax-ename->vla-object obj))
    (vlax-put obj 'rawdescription newdesc))
    (vla-endundomark doc)
  (princ)
)

I simply removed the while loop for selecting Cogo points.

[meddy001]

Thank you very much for your reply and your effort, Tom.

I tested your revised code, and unfortunately it still prompts for the New Description after the first iteration, and now it only changes the description of the highest-numbered point in a selection of points (all other points in the selection remain unchanged).

Does that mean the other 'while' loop needs to be removed?
I'll keep tinkering with it myself, but I'm always open to suggestions. Thank you again.

[meddy001]

You pointed me in the right direction, Tom.
I removed the other while loop and it seems to work just fine.

Thanks again.

(defun c:chdesc (/ doc ss obj newdesc olddesc)
  (vl-load-com)
  (setq doc 
(vla-get-activedocument (vlax-get-acad-object)))
       (setq newdesc (getstring "\nNew point description:"))
       (not (eq newdesc ""))
       (setq ss (ssget '((0 . "AECC_COGO_POINT"))))
       (setq ctr -1)
    
(vla-startundomark doc)
    (while (setq obj (ssname ss (setq ctr (1+ ctr))))
      (setq obj (vlax-ename->vla-object obj))
      (vlax-put obj 'rawdescription newdesc))
    (vla-endundomark doc)  
  (princ)
)