Need to unhook a function in Makefile-mode

Need to unhook a function in Makefile-mode

[jgombos]

I have a C++ write file hook to automatically untabify the whole buffer
before saving.  It works great, but then when I open a Makefile in
Makefile-mode, the hook persists, which ruins Makefiles.  My .emacs file
contains:
<pre>
;; Define untabify-buffer.
(defun untabify-buffer()
  (interactive)
  "Untabify the current buffer.  Return nil.

  Must return nil, if added to write-file-hooks."
  (save-excursion
    (goto-char (point-min))
    (while (re-search-forward "[ \t]+$" nil t)
      (delete-region (match-beginning 0) (match-end 0)))
    (goto-char (point-min))
    (if (search-forward "\t" nil t)
        (untabify (1- (point)) (point-max))))
  nil)

;; LANGUAGE HOOKS ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(add-hook 'c++-mode-hook
	  '(lambda ()
		  (c-set-style "whitesmith")
		  (add-hook 'write-file-hooks 'untabify-buffer)
		  ))
</pre>
http://www.emacswiki.org/cgi-bin/emacs-en/UntabifyUponSave This article 
suggests a solution, but someone responded to that saying that the
alternative approach screws up formatting (eg. number of spaces equated with
a tab).  And I don't want to untabify manually (even though tabs are
highlighted in my view).  

I would like a Makefile write hook that will undo the C++ write file hook. 
Perhaps I've been spoiled with Mutt's "unhook" feature.  [Mutt is an MUA
that has hook (and unhook) features in the configuration scripts].
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Re: Need to unhook a function in Makefile-mode

[Colin S. Miller]

jgombos wrote:
> I have a C++ write file hook to automatically untabify the whole buffer
> before saving.  It works great, but then when I open a Makefile in
> Makefile-mode, the hook persists, which ruins Makefiles.  My .emacs file
> contains:
> <pre>
> ;; Define untabify-buffer.
> (defun untabify-buffer()
>   (interactive)
>   "Untabify the current buffer.  Return nil.
> 
>   Must return nil, if added to write-file-hooks."
>   (save-excursion
>     (goto-char (point-min))
>     (while (re-search-forward "[ \t]+$" nil t)
>       (delete-region (match-beginning 0) (match-end 0)))
>     (goto-char (point-min))
>     (if (search-forward "\t" nil t)
>         (untabify (1- (point)) (point-max))))
>   nil)
> 
> ;; LANGUAGE HOOKS ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> (add-hook 'c++-mode-hook
> 	  '(lambda ()
> 		  (c-set-style "whitesmith")
> 		  (add-hook 'write-file-hooks 'untabify-buffer)
> 		  ))

Jgombos,

try using local-write-file-hooks, which is the buffer-local version of write-file-hooks,
or at least it is in XEmacs.


Failing that, see add-local-hook,

Failing that
try

(add-hook 'ctypes-load-hook
  '(lambda ()
    (c-set-style "whitesmith")
    (add-hook 'write-file-hooks
       '(lambda ()
        (if (eq major-mode 'c++-mode) (untabify-buffer))))))


Ctypes is used by C, C++, and C# modes.

IIRC, -load-hooks are only called once, when the mode is first loaded,
whereas -mode-hooks are called each time a buffer enters that mode.


HTH,
Colin S. Miller

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Re: Need to unhook a function in Makefile-mode

[Stefan Kamphausen]

Hi,

jgombos <nabble.forum.jog@spamgourmet.com> writes:

> ;; LANGUAGE HOOKS ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> (add-hook 'c++-mode-hook
> 	  '(lambda ()
> 		  (c-set-style "whitesmith")
> 		  (add-hook 'write-file-hooks 'untabify-buffer)
> 		  ))
> </pre>
> http://www.emacswiki.org/cgi-bin/emacs-en/UntabifyUponSave This article 
> suggests a solution, but someone responded to that saying that the
> alternative approach screws up formatting (eg. number of spaces equated with
> a tab).  And I don't want to untabify manually (even though tabs are
> highlighted in my view).  

well the approach given over there in the wiki makes write-file-hooks
a /buffer local/ hook by calling

(make-local-hook 'write-contents-hooks)

I have been using that code for something like 5-8 years (can't really
remember) and it always did what I wanted.  Note however, it was used
in XEmacs and I never hade much code edititing in larger teams (at
least no teams not using that same code, too ;-)

Kind Regards
Stefan
-- 
Stefan Kamphausen --- http://www.skamphausen.de
a blessed +42 regexp of confusion (weapon in hand)
You hit. The format string crumbles and turns to dust.