On Orgmode Links and LaTeX Footnotes

When you're using hyperlinks in Orgmode and export them to LaTeX/PDF, there aren't any visual clues that those links actually exists. Unless you set colorlinks=true in your hypersetup. But even if you set colorlinks=true there is still a problem. When you print the PDF and keep it in black and white. Filters come to the rescue.

(defvar org-export-latex-add-link-footnotes nil
  "If non-nil links will be added as footnotes if exported to latex.")

(defun org-export-latex-link-footnote (text backend info)
  "Create a footnote in latex for each link. So when printed the information isn't lost."
  (when (and org-export-latex-add-link-footnotes
             (org-export-derived-backend-p backend 'latex)
             (string-match "\\\\href{\\(.*\\)}{\\(.*\\)}" text))
    (when (some (lambda (type)
                  (string-prefix-p type (match-string 1 text)))
                '("http" "https" "ftp" "mailto" "doi"))
      (format "%s \\footnote{\\url{%s}} " text (match-string 1 text)))))
(add-to-list 'org-export-filter-link-functions #'org-export-latex-link-footnote)

What org-export-latex-link-footnote does, is that it extracts the URL of a LaTeX \href and appends it as a \footnote. So the URL isn't lost after the PDF has been printed. The footnote export process is only active if org-export-latex-add-link-footnotes is non-nil. I set this on a per document basis with #+BIND.