Re: Filter for HTML footnotes?

[Juan Manuel Macías]

M. ‘quintus’ Gülker writes:

> I recently discovered export filters and found some useful applications
> for them. For instance, the scientific domain I work in (law) uses
> footnote citations, and in these footnotes we abbreviate some words
> which would otherwise be written out in ordinary text, like name
> particles. Since I use org-cite these footnotes are automatically
> generated. So what I did was to write a filter which abbreviates these
> words on export in footnotes. I added the filter function to both
> org-export-filter-footnote-definition-functions and
> org-export-filter-footnote-reference-functions and indeed, when I export
> to LaTeX or ODT it does its job just fine. However, when I export to
> HTML instead, it does not. When I looked at the text passed to the
> filter when exporting as HTML, it turned out what the function receives
> is not the content of the footnote, but only the markup for the footnote
> number. That came a bit by surprise.

> So, what is the correct way to target the content of a footnote in a
> filter across backends?

Hi,

I think a function for `org-export-filter-parse-tree-functions' would
work better here. For example, this function replaces "lorem ipsum" with
"foo" in all footnote definitions:

#+BIND: org-export-filter-parse-tree-functions (fnt-filter-replace)

#+begin_src emacs-lisp :exports results :results none
  (defun fnt-filter-replace (tree backend info)
    (org-element-map tree 'footnote-definition
      (lambda (fnt)
        (let* ((contents (org-element-interpret-data
                          (org-element-contents fnt)))
               (contents-new (with-temp-buffer
                               (insert contents)
                               (save-excursion
                                 (goto-char (point-min))
                                 (while (re-search-forward "lorem ipsum" nil t)
                                   (replace-match "foo" t nil)))
                               (org-element-parse-buffer))))
          (apply #'org-element-set-contents
                 fnt
                 (list contents-new))))
      info)
    tree)
#+end_src

Best regards,

Juan Manuel