Re: Disabling customization items

[Kevin Rodgers]

Bill Wohler wrote:

> How does one disable items in the customization interface?
>
> Let's say I have the option foo with three features "a", "b", or "c".
>
>     (defcustom foo "a" nil
>       :type '(choice (const "a")
>                      (const "b")
>                      (const "c")))
>
> Let's say feature "b" is not available on a system. I'd like to indicate that
> that item is supported by my code, but not by the system. Thus, choice "b"
> should be disabled.
>
> Thus customization interface in 21.2 doesn't appear to support this. Has
> anyone figured out how to do this?

It's not dynamic, but it should be good enough for the situation you've 
described:


(defcustom foo "a" nil
  :type `(choice (const "a")
                 ,@(if (featurep 'b) (list '(const "b")))
                 (const "c")))

--
Kevin Rodgers