Lisp recipe to set From header

Lisp recipe to set From header

[Matthew King]

I have the following:

;;; Set From header based on To header
(setq gnus-posting-styles
      '(("nn.+:"
	 (From (save-excursion
		 (set-buffer gnus-article-buffer)
		 (message-fetch-field "to"))))))

Which, as the comment says, sets the From header to be that of the
previous mail's To header. I have problems with my address being in the
Cc header instead or with there being more than one address in To, but
this is not important.

What I really want to do is only set the From address to be one from a
pre-set list and to fall back on user-mail-address if there is no match.

I don't know anywhere near enough lisp to write this though, so how
would I go about doing this?

Matthew

-- 
I must take issue with the term "a mere child," for it has been my
invariable experience that the company of a mere child is infinitely
preferable to that of a mere adult.
                                           --  Fran Lebowitz

Re: Lisp recipe to set From header

[Sébastien Kirche]

At 22:34 on Jan 27 2006, Matthew King said :

> I don't know anywhere near enough lisp to write this though, so how
> would I go about doing this?

If I understand correctly, you should take a look to
message-alternative-emails that provides exactly that : when replying to
a message where the To: is in the alternatives, that address is
automagicaly used for the From: of the reply. Otherwise it uses the
styles or the user-mail-address.

Its value should be a regexp, so regexp-opt could be useful to build it.
Here is an example :

(setq message-alternative-emails 
      (regexp-opt (cons user-mail-address
                        '("first@domain.net"
                          "second.value@other.fr"
                          "another@value.net"
                                 ))))
HTH.
-- 
Sébastien Kirche

Re: Lisp recipe to set From header

[David Z Maze]

Matthew King <matthew.king@monnsta.net> writes:

> I have the following:
>
> ;;; Set From header based on To header
> (setq gnus-posting-styles
>       '(("nn.+:"
> 	 (From (save-excursion
> 		 (set-buffer gnus-article-buffer)
> 		 (message-fetch-field "to"))))))
>
> What I really want to do is only set the From address to be one from a
> pre-set list and to fall back on user-mail-address if there is no
> match.

;; Totally untested:
(defvar mk-to-header-list
  '("matthew.king@monnsta.net")
  "Names it's valid to take from the To: header of messages.")

(defun mk-to-header-or-default ()
  "Returns the To: header of `gnus-article-buffer' if it's in
  `mk-to-header-list', or `user-mail-address' otherwise."
  (let ((to-header (save-excursion
                     (set-buffer gnus-article-buffer)
                     (message-fetch-field "to"))))
    (if (member to-header mk-to-header-list)
      to-header
      gnus-article-buffer)))

(setq gnus-posting-styles '(("nn.+:" (From (mk-to-header-or-default)))))

  --dzm