Re: Help setting nadvice for indent-region

[Michael Heerdegen]

Kaushal Modi <kaushal.modi@gmail.com> writes:

> Right, that's why my first approach was to use macro to generate an
> individual advice fn for each fn I was advising. But for my purpose,
> this-command works well.

FWIW, you can achieve this also without using a macro.

> With that, I now use the below as the solution which helps achieve these
> goals:
> (1) Apply indent-region/eval-region over the whole buffer if a region is
> not selected (and even if (mark) returns nil).
> (2) Print an assuring message that the function was applied over the whole
> buffer AFTER applying the orig-fun. This is because `indent-region` prints
> out an "Indenting region .." message, and if I want to display my "Executed
> .. on the whole buffer." message, I need to do it after ORIG-FUN is
> applied. So I cannot do that in the (interactive ..) form.
>
> ==== Current solution =====
>
> (defvar modi/region-or-whole-fns '(indent-region
>                                    eval-region)
>   "List of functions to act on the whole buffer if no region is selected.")
>
> (defun modi/advice-region-or-whole (orig-fun &rest args)
>   "Advice function that applies ORIG-FUN to the whole buffer if no region is
> selected.
> http://thread.gmane.org/gmane.emacs.help/109025/focus=109102 "
>   ;; Required to override the "r" argument of `interactive' in functions
> like
>   ;; `indent-region' so that they can be called without an active region.
>   (interactive (if (use-region-p)
>                    (list (region-beginning) (region-end))
>                  (list (point-min) (point-max))))
>   (prog1 ; Return value of the advising fn needs to be the same as ORIG-FUN
>       (apply orig-fun args)
>     (when (and (called-interactively-p 'interactive)
>                (not (use-region-p)))
>       (message "Executed %s on the whole buffer."
>                (propertize (symbol-name this-command)
>                            'face 'font-lock-function-name-face)))))
>
> (dolist (fn modi/region-or-whole-fns)
>   (advice-add fn :around #'modi/advice-region-or-whole))

That looks good.

> It's good to see my initial buggy overly complicated macro-based
> solution boil down to this more robust (, apparently bug-free),
> canonical and a relatively simpler one :)

The approach was ok, though I would have tried to avoid using a macro.
But well, it also changed the functions, not the interactive specs...


Michael.