Re: [O] Collapse LaTeX source before start of main document?

[Eric Schulte]

Matt Lundin <address@hidden> writes:

> Chris Malone <address@hidden> writes:
>
> (Note: When using gmail, please adjust the settings to send your
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>
>> When I include the actual contents of my abstract, this preliminary material
>> section (the #+begin ... #+end block) is rather large.  I'd like to be able
>> to put this material into a headline so that I could collapse it - but I
>> don't want this headline exported as content of the main document.
>>
>> In other words, is there a property or tag that I can add to a headline that
>> causes LaTeX export to ignore the fact that it is a headline (i.e. \chapter,
>> \section, \subsection, etc.), but still export its contents?  Something
>> like:
>
> You could add a hook to remove headlines with a "prelim" tag:
>
> --8<---------------cut here---------------start------------->8---
> (defun my-org-export-remove-tagged-headlines (tag)
>   (save-excursion
>     (goto-char (point-min))
>     (while (re-search-forward (concat ":" tag ":") nil t)
>       (delete-region (point-at-bol) (point-at-eol)))))
>
> (add-hook 'org-export-preprocess-hook (lambda () 
> (my-org-export-remove-tagged-headlines "prelim")))
> --8<---------------cut here---------------end--------------->8---
>

I found the very useful but sadly outdated snippet from 2011.  If anyone
is interested, the following snippet implements the same functionality
within the new export framework.

--8<---------------cut here---------------start------------->8---
(defun org-export-remove-prelim-headlines (tree backend info)
  "Remove headlines tagged \"prelim\" while retaining their
contents before any export processing."
  (org-element-map tree org-element-all-elements
    (lambda (object)
      (when (and (equal 'headline (org-element-type object))
                 (member "prelim" (org-element-property :tags object)))
        (mapc (lambda (el)
                (let ((new-object
                       (if (equal 'headline (org-element-type el))
                           (org-element-put-property el
                             :level (1- (org-element-property :level el)))
                         el)))
                  (message "%s level %s"
                           (org-element-property :raw-value new-object)
                           (org-element-property :level new-object))
                  (org-element-insert-before new-object object)))
              (cddr object))
        (org-element-extract-element object)))
    info nil org-element-all-elements)
  tree)

(add-hook 'org-export-filter-parse-tree-functions
          'org-export-remove-prelim-headlines)
--8<---------------cut here---------------end--------------->8---

In addition it promotes all headlines under the removed "prelim"-tagged
headline.  This is useful to support structures like the following.

--8<---------------cut here---------------start------------->8---
* Appendix                                                           :prelim:
#+LaTeX: \begin{appendices}
** Definitions
** Data Sets
** Tooling
#+LaTeX: \end{appendices}
--8<---------------cut here---------------end--------------->8---

Best,

-- 
Eric Schulte
https://cs.unm.edu/~eschulte
PGP: 0x614CA05D (see https://u.fsf.org/yw)