Attachment of Extended Data to an Entity

AutoCAD AutoLISP & Visual LISP

 
Attachment of Extended Data to an Entity
 
 
 

You can use xdata to store any type of information you want. For example, draw an entity (such as a line or a circle), then enter the following code to attach xdata to the entity:

(setq lastent (entget (entlast))) ; Gets the association
                                  ; list of definition data
                                  ; for the last entity.
(regapp "NEWDATA")                ; Registers the
                                  ; application name.
(setq exdata                      ; Sets the variable
 '((-3 ("NEWDATA"                 ; exdata equal to the
  (1000 . "This is a new thing!") ; new extended data—
  )))                             ; in this case, a text
)                                 ; string.
(setq newent  
  (append lastent exdata))  ; Appends new data list to 
                            ; entity's list.
(entmod newent)             ; Modifies the entity with the new 
                            ; definition data.

To verify that your new xdata has been attached to the entity, enter the following code and select the object:

(entget (car (entsel)) '("NEWDATA"))

This example shows the basic method for attaching extended data to an entity.