About advices.

About advices.

[Constantin Kulikov]

What the right way to use advices? (I know that best way it to not use it
at all.;))

At my current level of understanding:

1) You declare advices with `defadvice'. (acces arguments of original
function by `ad-get-arg').
Example:
(defadvice switch-to-buffer (after my-switch-to-buffer-advice)
  (let ((buf (ad-get-arg 0)))
    do something))

2) Then you call `ad-activate'.
Example: (ad-activate 'switch-to-buffer)
The problem here is that it will activate all advices for that function
that were defined before this `ad-activate' call, not only
`my-switch-to-buffer-advice'

3) I'm not sure. You can enable/disable certain advices with
`ad-enable-advice'/`ad-disable-advice'. Example:
(ad-disable-advice 'switch-to-buffer 'after 'my-switch-to-buffer-advice)

4) `ad-deactivate' will disable all advices for function.
Example: (ad-deactivate 'switch-to-buffer)

Am I right?

Re: About advices.

[Stefan Monnier]

> What the right way to use advices? (I know that best way it to not use it
> at all.;))

Here's how in Emacs-24.4:

   (defun my-advice (&rest args)
     (message "After s-t-b: %S" args))
   
   (advice-add 'switch-to-buffer :after #'my-advice)

and when you're tired of those messages, you turn them off with

   (advice-remove 'switch-to-buffer #'my-advice)


-- Stefan

Re: About advices.

[Constantin Kulikov]

> Here's how in Emacs-24.4
nice. Thanks.