contrib/lisp/ox-extra.el

   1 ;;; ox-extra.el --- Convenience functions for org export
   2
   3 ;; Copyright (C) 2014  Aaron Ecay
   4
   5 ;; Author: Aaron Ecay <aaronecay@gmail.com>
   6
   7 ;; This program is free software; you can redistribute it and/or modify
   8 ;; it under the terms of the GNU General Public License as published by
   9 ;; the Free Software Foundation, either version 3 of the License, or
  10 ;; (at your option) any later version.
  11
  12 ;; This program is distributed in the hope that it will be useful,
  13 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 ;; GNU General Public License for more details.
  16
  17 ;; You should have received a copy of the GNU General Public License
  18 ;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19
  20 ;;; Commentary:
  21
  22 ;; This file contains some convenience functions for org export, which
  23 ;; are not part of org's core.  Call `ox-extras-activate' passing a
  24 ;; list of symbols naming extras, which will be installed globally in
  25 ;; your org session.
  26 ;;
  27 ;; For example, you could include the following in your .emacs file:
  28 ;;
  29 ;;    (require 'ox-extra)
  30 ;;    (ox-extras-activate '(latex-header-blocks ignore-headlines))
  31 ;;
  32
  33 ;; Currently available extras:
  34
  35 ;; - `latex-header-blocks' -- allow the use of latex blocks, the
  36 ;; contents of which which will be interpreted as #+latex_header lines
  37 ;; for export.  These blocks should be tagged with #+header: :header
  38 ;; yes.  For example:
  39 ;; #+header: :header yes
  40 ;; #+begin_export latex
  41 ;;   ...
  42 ;; #+end_export
  43
  44 ;; - `ignore-headlines' -- allow a headline (but not its children) to
  45 ;; be ignored.  Any headline tagged with the 'ignore' tag will be
  46 ;; ignored (i.e. will not be included in the export), but any child
  47 ;; headlines will not be ignored (unless explicitly tagged to be
  48 ;; ignored), and will instead have their levels promoted by one.
  49
  50 ;; TODO:
  51 ;; - add a function to org-mode-hook that looks for a ox-extras local
  52 ;;   variable and activates the specified extras buffer-locally
  53 ;; - allow specification of desired extras to be activated via
  54 ;;   customize
  55
  56 ;;; Code:
  57
  58 (require 'ox)
  59 (require 'cl-lib)
  60
  61 (defun org-latex-header-blocks-filter (backend)
  62   (when (org-export-derived-backend-p backend 'latex)
  63     (let ((positions
  64            (org-element-map (org-element-parse-buffer 'greater-element nil) 'export-block
  65              (lambda (block)
  66                (when (and (string= (org-element-property :type block) "LATEX")
  67                           (string= (org-export-read-attribute
  68                                     :header block :header)
  69                                    "yes"))
  70                  (list (org-element-property :begin block)
  71                        (org-element-property :end block)
  72                        (org-element-property :post-affiliated block)))))))
  73       (mapc (lambda (pos)
  74               (goto-char (nth 2 pos))
  75               (cl-destructuring-bind
  76                   (beg end &rest ignore)
  77                   ;; FIXME: `org-edit-src-find-region-and-lang' was
  78                   ;; removed in 9c06f8cce (2014-11-11).
  79                   (org-edit-src-find-region-and-lang)
  80                 (let ((contents-lines (split-string
  81                                        (buffer-substring-no-properties beg end)
  82                                        "\n")))
  83                   (delete-region (nth 0 pos) (nth 1 pos))
  84                   (dolist (line contents-lines)
  85                     (insert (concat "#+latex_header: "
  86                                     (replace-regexp-in-string "\\` *" "" line)
  87                                     "\n"))))))
  88             ;; go in reverse, to avoid wrecking the numeric positions
  89             ;; earlier in the file
  90             (reverse positions)))))
  91
  92
  93 ;; During export headlines which have the "ignore" tag are removed
  94 ;; from the parse tree.  Their contents are retained (leading to a
  95 ;; possibly invalid parse tree, which nevertheless appears to function
  96 ;; correctly with most export backends) all children headlines are
  97 ;; retained and are promoted to the level of the ignored parent
  98 ;; headline.
  99 ;;
 100 ;; This makes it possible to add structure to the original Org-mode
 101 ;; document which does not effect the exported version, such as in the
 102 ;; following examples.
 103 ;;
 104 ;; Wrapping an abstract in a headline
 105 ;;
 106 ;;     * Abstract                        :ignore:
 107 ;;     #+LaTeX: \begin{abstract}
 108 ;;     #+HTML: <div id="abstract">
 109 ;;
 110 ;;     ...
 111 ;;
 112 ;;     #+HTML: </div>
 113 ;;     #+LaTeX: \end{abstract}
 114 ;;
 115 ;; Placing References under a headline (using ox-bibtex in contrib)
 116 ;;
 117 ;;     * References                     :ignore:
 118 ;;     #+BIBLIOGRAPHY: dissertation plain
 119 ;;
 120 ;; Inserting an appendix for LaTeX using the appendix package.
 121 ;;
 122 ;;     * Appendix                       :ignore:
 123 ;;     #+LaTeX: \begin{appendices}
 124 ;;     ** Reproduction
 125 ;;     ...
 126 ;;     ** Definitions
 127 ;;     #+LaTeX: \end{appendices}
 128 ;;
 129 (defun org-export-ignore-headlines (data backend info)
 130   "Remove headlines tagged \"ignore\" retaining contents and promoting children.
 131 Each headline tagged \"ignore\" will be removed retaining its
 132 contents and promoting any children headlines to the level of the
 133 parent."
 134   (org-element-map data 'headline
 135     (lambda (object)
 136       (when (member "ignore" (org-element-property :tags object))
 137         (let ((level-top (org-element-property :level object))
 138               level-diff)
 139           (mapc (lambda (el)
 140                   ;; recursively promote all nested headlines
 141                   (org-element-map el 'headline
 142                     (lambda (el)
 143                       (when (equal 'headline (org-element-type el))
 144                         (unless level-diff
 145                           (setq level-diff (- (org-element-property :level el)
 146                                               level-top)))
 147                         (org-element-put-property el
 148                           :level (- (org-element-property :level el)
 149                                     level-diff)))))
 150                   ;; insert back into parse tree
 151                   (org-element-insert-before el object))
 152                 (org-element-contents object)))
 153         (org-element-extract-element object)))
 154     info nil)
 155   (org-extra--merge-sections data backend info)
 156   data)
 157
 158 (defun org-extra--merge-sections (data _backend info)
 159   (org-element-map data 'headline
 160     (lambda (hl)
 161       (let ((sections
 162              (cl-loop
 163               for el in (org-element-map (org-element-contents hl)
 164                             '(headline section) #'identity info)
 165               until (eq (org-element-type el) 'headline)
 166               collect el)))
 167         (when (and sections
 168                    (> (length sections) 1))
 169           (apply #'org-element-adopt-elements
 170                  (car sections)
 171                  (cl-mapcan (lambda (s) (org-element-contents s))
 172                             (cdr sections)))
 173           (mapc #'org-element-extract-element (cdr sections)))))
 174     info))
 175
 176 (defconst ox-extras
 177   '((latex-header-blocks org-latex-header-blocks-filter org-export-before-parsing-hook)
 178     (ignore-headlines org-export-ignore-headlines org-export-filter-parse-tree-functions))
 179   "A list of org export extras that can be enabled.
 180
 181 Should be a list of items of the form (NAME FN HOOK).  NAME is a
 182 symbol, which can be passed to `ox-extras-activate'.  FN is a
 183 function which will be added to HOOK.")
 184
 185 (defun ox-extras-activate (extras)
 186   "Activate certain org export extras.
 187
 188 EXTRAS should be a list of extras (defined in `ox-extras') which
 189 should be activated."
 190   (dolist (extra extras)
 191     (let* ((lst (assq extra ox-extras))
 192            (fn (nth 1 lst))
 193            (hook (nth 2 lst)))
 194       (when (and fn hook)
 195         (add-hook hook fn)))))
 196
 197 (defun ox-extras-deactivate (extras)
 198   "Deactivate certain org export extras.
 199
 200 This function is the opposite of `ox-extras-activate'.  EXTRAS
 201 should be a list of extras (defined in `ox-extras') which should
 202 be activated."
 203   (dolist (extra extras)
 204     (let* ((lst (assq extra ox-extras))
 205            (fn (nth 1 lst))
 206            (hook (nth 2 lst)))
 207       (when (and fn hook)
 208         (remove-hook hook fn)))))
 209
 210 (provide 'ox-extra)
 211 ;;; ox-extra.el ends here