[AUCTeX] Re: ESS, AUCTeX, S/Rweave (noweb) and mode switching

[Michael Hoffman]

Brett Presnell wrote:

> (Side question: shouldn't TeX-PDF-mode be picked up from the master
> file?)

It would be nice.

> The problem is that once I move into a code chunk in a .Rnw file
> (automatically switching from AUCTeX to ESS mode) and then back out of
> the code chunch (automatically switching back to AUCTeX mode),
> TeX-master and TeX-PDF-mode both get set to nil.  Worse, this also
> causes the invaluable reftex to lose all its reference information.
>
> Typing C-cC-n (i.e., running TeX-normal-mode) causes all the
> auctex/reftex information to be reset properly.  However, the Noweb
> menu disappears when I do this and when I move back into a code chunk
> the buffer remains in PDFLaTeX/M mode instead of ESS[S] mode.  Typing
> C-cC-n again seems to toggle this behavior, but then TeX-master and
> TeX-PDF-mode get set to nil again.  Obviously this whole process
> becomes especially annoying when editing a complicated document.
>
> FWIW, I can partially automate the call of TeX-normal-mode with
>
>   (add-hook 'noweb-select-doc-mode-hook 
> 	    (function (lambda ()
>                         (TeX-normal-mode t))))

I recommend this instead as it will not deactivate the mark when 
changing modes:

  (add-hook 'noweb-select-doc-mode-hook
            '(lambda ()
               ; avoid infinite loops
               (unless (boundp 'in-noweb-select-doc-mode-hook)
                 (let* ((in-noweb-select-doc-mode-hook t)
                        ; don't deactivate the mark when changing modes
                        (deactivate-mark))
                   (TeX-normal-mode t)))))

I do not have any problem with the Noweb menu disappearing.