Re: [O] Help with export filter?

[Rasmus]

Hi Tom,

address@hidden (Thomas S. Dye) writes:

> Aloha all,
>
> Inspired by discussions and code on the mailing list, I managed to
> cobble together the headline filter below.  It "works" in that the
> pdf output from LaTeX export is exactly what I want.  I'm thrilled!
>
> It has one unwanted side effect.  In the tex file, a headline tagged
> with either :newpage: or :clearpage: includes some extra baggage, like
> this:
>
>   \newpage
>   \section*{Introduction\hfill{}\textsc{}}
>   \label{sec-5}
>
> I tried setting the option tags:nil, but then my export tags had no
> effect.  Can someone suggest how I can avoid the \hfill etc.?  Or, am I
> picking nits here?
>
> ***** Filter headline tags
>
> #+name: filter-headline-tags
> #+BEGIN_SRC emacs-lisp :results silent
>
>   (defun tsd-filter-headline-tags (contents backend info)
>     "Ignore headlines with tag `ignoreheading' and/or start LaTeX
>   section with `newpage' or `clearpage' command."
>     (cond ((and (org-export-derived-backend-p backend 'latex)
>                 (string-match "\\`.*newpage.*\n" (downcase contents))
>                 (string-match "\\`.*ignoreheading.*\n" (downcase contents)))
>            (replace-match "\\\\newpage\n" nil nil contents))
>           ((and (org-export-derived-backend-p backend 'latex)
>                 (string-match "\\`.*clearpage.*\n" (downcase contents))
>                 (string-match "\\`.*ignoreheading.*\n" (downcase contents)))
>            (replace-match "\\\\clearpage\n" nil nil contents))
>           ((and (org-export-derived-backend-p backend 'latex 'html 'ascii)
>                 (string-match "\\`.*ignoreheading.*\n" (downcase contents)))
>            (replace-match "" nil nil contents))
>           ((and (org-export-derived-backend-p backend 'latex)
>                 (string-match "\\(\\`.*\\)newpage\\(.*\n\\)" (downcase 
> contents)))
>            (replace-match "\\\\newpage\n\\1\\2"  nil nil contents))
>           ((and (org-export-derived-backend-p backend 'latex)
>                 (string-match "\\(\\`.*\\)clearpage\\(.*\n\\)" (downcase 
> contents)))
>            (replace-match "\\\\clearpage\n\\1\\2"  nil nil contents))))
> #+END_SRC

Here's an edited filter that works with the enclosed test document.
Note that you could split this into different filters, but it may be
non-trivial with this identification-scheme since things would be
moving around.

(defun tsd-filter-headline-tags (contents backend info)
  "Ignore headlines with tag `ignoreheading' and/or start LaTeX
  section with `newpage' or `clearpage' command."
  (cond ((and (org-export-derived-backend-p backend 'latex)
              (string-match "\\`.*newpage.*\n" (downcase contents))
              ;; if you want to get rid of labels use the string
              ;; "\\`.*ignoreheading.*\n.*\n"
              (string-match "\\`.*ignoreheading.*\n" (downcase contents)))
         (replace-match "\\\\newpage\n" nil nil contents))
        ((and (org-export-derived-backend-p backend 'latex)
              (string-match "\\`.*clearpage.*\n" (downcase contents))
              (string-match "\\`.*ignoreheading.*\n" (downcase contents)))
         (replace-match "\\\\clearpage\n" nil nil contents))
        ((and (org-export-derived-backend-p backend 'latex 'html 'ascii)
              (string-match "\\`.*ignoreheading.*\n" (downcase contents)))
         (replace-match "" nil nil contents))
        ((and (org-export-derived-backend-p backend 'latex)
              (string-match 
"\\(\\`.*?\\)\\(?:\\\\hfill{}\\)?\\\\textsc{.*?newpage.*?}\\(.*\n\\)"
                            (downcase contents)))
         (replace-match "\\\\newpage\n\\1\\2"  nil nil contents))
        ((and (org-export-derived-backend-p backend 'latex)
              (string-match 
"\\(\\`.*?\\)\\(?:\\\\hfill{}\\)?\\\\textsc{.*?clearpage.*?}\\(.*\n\\)" 
(downcase contents)))
         (replace-match "\\\\clearpage\n\\1\\2"  nil nil contents))))

(add-to-list 'org-export-filter-headline-functions 'tsd-filter-headline-tags)

* my first headline
  cont0
* ignored headline                                            :ignoreheading:
  cont1 (ignored headline)
* heading with newpage                                              :newpage:
  newline before *here*
* heading with clearpage                                          :clearpage:
  clearpage before *here*
* ignored heading with newpage                                 :newpage:tag2:
  newline before *here*.  =tag2= is lost.
* ignore heading with clearpage                     :ignoreheading:clearpage:
  clearpage before *here*

—Rasmus

-- 
🐉