>> On Thu, 22 Mar 2012 20:58:17 +0100, Lars Magne Ingebrigtsen <larsi@gnus.org> wrote:

   > Uwe Brauer <oub@mat.ucm.es> writes:
   >> For example the function gnus-article-fill-cited-article runs on an
   >> article. How could I write a function based on
   >> TeX-to-char-paragraph-or-region which does what I want.

   > Start with a simpler function, like

   > (defun article-treat-ansi-sequences ()
   >   "Translate ANSI SGR control sequences into overlays or extents."
   >   (interactive)
   >   (save-excursion
   >     (when (article-goto-body)
   >       (let ((inhibit-read-only t))
   > 	(ansi-color-apply-on-region (point) (point-max))))))

   > And just replace the ansi stuff with the function you want to call.
Cool! 

That works nicely for the
TeX-to-char-paragraph-or-region function.

However for the org-preview function it does not!
Here is the code 

(defun article-treat-org-preview ()
  "Translate ANSI SGR control sequences into overlays or extents."
  (interactive)
  (save-excursion
    (when (article-goto-body)
      (let ((inhibit-read-only t))
		(org-preview-latex-fragment nil)))))

And the documentation of org-preview-latex-fragment 

,----
| `org-preview-latex-fragment' is an interactive Lisp function
|   -- loaded from "org"
| (org-preview-latex-fragment &optional SUBTREE)
| 
| Documentation:
| Preview the LaTeX fragment at point, or all locally or globally.
| If the cursor is in a LaTeX fragment, create the image and overlay
| it over the source code.  If there is no fragment at point, display
| all fragments in the current text, from one headline to the next.  With
| prefix SUBTREE, display all fragments in the current subtree.  With a
| double prefix arg C-u C-u, or when the cursor is before the first headline,
| display all fragments in the buffer.
`----


I obtain an error whose bug trace I attach.

I had the following trivial function 

(defun org-preview-article ()
  "Saves the article to temporary buffer and apply
`org-preview-latex-fragment'."
  (interactive)
  (let* ((tempfile "/tmp/texfile"))
	(shell-command (format "touch %s" tempfile))
				   (delete-file tempfile)
				   (with-current-buffer gnus-article-buffer
					 (write-region (point-min) (point-max) tempfile nil nil nil 'utf-8-unix)
					 (find-file tempfile)
					 (org-preview-latex-fragment nil))))

which sort of works but is not what I want.