CLASS EXISTS()
From Lianjapedia
Contents
Purpose
Function to check whether a class has been defined
Syntax
CLASS_EXISTS(<expC>)
See Also
DEFINE CLASS, FUNCTION_EXISTS(), ENDFUNC, FUNCTION, ISSET(), PEXIST(), PROCEDURE, RETURN, SET CLASSLIB, SET LIBRARY, SET PROCEDURE, TYPE(), UNSET(), VARTYPE()
Description
The CLASS_EXISTS() function can be used to check whether a class has been defined. CLASS_EXISTS() will return .T. (true) if the class named <expC> has been defined and .F. (false) if it has not been defined. Classes are defined using the DEFINE CLASS command. Class libraries are loaded using SET CLASSLIB.
Example
set classlib to myclasses1 ? set([classlib]) list classes ? class_exists("mybutton1")