Create custom document property, if doesn't exist

[jlaidle1]

How can you have a custom document property created, if it doesn't exist with LISP?

Thanks.

[jlaidle1]

This appears to be working, and also is not clearing out the property value if it already exists:

(vla-addcustominfo(vla-get-summaryinfo(vla-get-activedocument(Vlax-get-acad-object)))"Division" "")

[CodeDing · Accepted solution]

@jlaidle1,

While your method does work, it draws an error if that property already exists. IMO it would be best to check for that property first. Here's my take:

(defun c:test (/ newProp)
(vl-load-com)
(setq newProp "Division2")
(if (not (PropertyExists newProp))
  (vla-addcustominfo (vla-get-summaryinfo (vla-get-activedocument (Vlax-get-acad-object))) newProp "")
);if
(princ "\nComplete.")
(princ)
);defun

(defun PropertyExists (pName / sumInfo tmp eProp eVal)
;IN: pName - property name to search as string (NOT case sensitive)
;OUT: returns t if property exists, else nil
(setq sumInfo (vla-get-summaryinfo (vla-get-activedocument (Vlax-get-acad-object)))
      tmp 0)
(vla-GetCustomByIndex sumInfo tmp 'eProp 'eVal)
(while (and (not (eq (setq eProp (strcase eProp)) (setq pName (strcase pName)))) (< (+ tmp 1) (vla-numcustominfo sumInfo)))
(setq tmp (1+ tmp))
(vla-GetCustomByIndex sumInfo tmp 'eProp 'eVal)
);while
(if (eq eProp pName) t nil)
);defun

...should be pretty easy to edit as you wish. 

Best,

~DD