Attachment of Extended Data to an Entity

AutoLISP Developer's Guide > Using the AutoLISP Language > Using AutoLISP to Manipulate AutoCAD Objects > Extended Data - xdata >

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.