1 ;;; org-md.el --- Markdown Back-End for Org Export Engine
3 ;; Copyright (C) 2012 Free Software Foundation, Inc.
5 ;; Author: Nicolas Goaziou <n.goaziou@gmail.com>
6 ;; Keywords: org, wp, tex
8 ;; This program is free software; you can redistribute it and/or modify
9 ;; it under the terms of the GNU General Public License as published by
10 ;; the Free Software Foundation, either version 3 of the License, or
11 ;; (at your option) any later version.
13 ;; This program is distributed in the hope that it will be useful,
14 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
15 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 ;; GNU General Public License for more details.
18 ;; You should have received a copy of the GNU General Public License
19 ;; along with this program. If not, see <http://www.gnu.org/licenses/>.
23 ;; This library implements a Markdown back-end (vanilla flavour) for
24 ;; Org exporter, based on `e-html'.
26 ;; It provides two commands for export, depending on the desired
27 ;; output: `org-md-export-as-markdown' (temporary buffer) and
28 ;; `org-md-export-to-markdown' ("md" file).
36 ;;; User-Configurable Variables
38 (defgroup org-export-md nil
39 "Options specific to Markdown export back-end."
44 (defcustom org-md-headline-style
'atx
45 "Style used to format headlines.
46 This variable can be set to either `atx' or `setext'."
49 (const :tag
"Use \"atx\" style" atx
)
50 (const :tag
"Use \"Setext\" style" setext
)))
56 (org-export-define-derived-backend md e-html
57 :export-block
("MD" "MARKDOWN")
58 :filters-alist
((:filter-parse-tree . org-md-separate-elements
))
60 (?m
"Export to Markdown"
61 ((?M
"To temporary buffer"
62 (lambda (s v b
) (org-md-export-as-markdown s v
)))
63 (?m
"To file" (lambda (s v b
) (org-md-export-to-markdown s v
)))
64 (?o
"To file and open"
65 (lambda (s v b
) (org-open-file (org-md-export-to-markdown s v
))))))
66 :translate-alist
((bold . org-md-bold
)
67 (code . org-md-verbatim
)
68 (example-block . org-md-example-block
)
69 (footnote-definition . ignore
)
70 (footnote-reference . ignore
)
71 (headline . org-md-headline
)
72 (horizontal-rule . org-md-horizontal-rule
)
73 (inline-src-block . org-md-verbatim
)
74 (italic . org-md-italic
)
76 (line-break . org-md-line-break
)
78 (paragraph . org-md-paragraph
)
79 (plain-list . org-md-plain-list
)
80 (plain-text . org-md-plain-text
)
81 (quote-block . org-md-quote-block
)
82 (quote-section . org-md-example-block
)
83 (section . org-md-section
)
84 (src-block . org-md-example-block
)
85 (template . org-md-template
)
86 (verbatim . org-md-verbatim
)))
92 (defun org-md-separate-elements (tree backend info
)
93 "Make sure elements are separated by at least one blank line.
95 TREE is the parse tree being exported. BACKEND is the export
96 back-end used. INFO is a plist used as a communication channel.
98 Assume BACKEND is `md'."
100 tree org-element-all-elements
102 (unless (eq (org-element-type elem
) 'org-data
)
103 (org-element-put-property
105 (let ((post-blank (org-element-property :post-blank elem
)))
106 (if (not post-blank
) 1 (max 1 post-blank
)))))))
107 ;; Return updated tree.
112 ;;; Transcode Functions
116 (defun org-md-bold (bold contents info
)
117 "Transcode BOLD object into Markdown format.
118 CONTENTS is the text within bold markup. INFO is a plist used as
119 a communication channel."
120 (format "**%s**" contents
))
123 ;;;; Code and Verbatim
125 (defun org-md-verbatim (verbatim contents info
)
126 "Transcode VERBATIM object into Markdown format.
127 CONTENTS is nil. INFO is a plist used as a communication
129 (let ((value (org-element-property :value verbatim
)))
130 (format (cond ((not (string-match "`" value
)) "`%s`")
131 ((or (string-match "\\``" value
)
132 (string-match "`\\'" value
))
138 ;;;; Example Block and Src Block
140 (defun org-md-example-block (example-block contents info
)
141 "Transcode EXAMPLE-BLOCK element into Markdown format.
142 CONTENTS is nil. INFO is a plist used as a communication
144 (replace-regexp-in-string
146 (org-remove-indentation
147 (org-element-property :value example-block
))))
152 (defun org-md-headline (headline contents info
)
153 "Transcode HEADLINE element into Markdown format.
154 CONTENTS is the headline contents. INFO is a plist used as
155 a communication channel."
156 (unless (org-element-property :footnote-section-p headline
)
157 (let* ((level (org-export-get-relative-level headline info
))
158 (title (org-export-data (org-element-property :title headline
) info
))
159 (todo (and (plist-get info
:with-todo-keywords
)
160 (let ((todo (org-element-property :todo-keyword
162 (and todo
(concat (org-export-data todo info
) " ")))))
163 (tags (and (plist-get info
:with-tags
)
164 (let ((tag-list (org-export-get-tags headline info
)))
167 (mapconcat 'identity tag-list
":"))))))
169 (and (plist-get info
:with-priority
)
170 (let ((char (org-element-property :priority headline
)))
171 (and char
(format "[#%c] " char
)))))
172 ;; Headline text without tags.
173 (heading (concat todo priority title
)))
175 ;; Cannot create an headline. Fall-back to a list.
176 ((or (org-export-low-level-p headline info
)
177 (not (memq org-md-headline-style
'(atx setext
)))
178 (and (eq org-md-headline-style
'atx
) (> level
6))
179 (and (eq org-md-headline-style
'setext
) (> level
2)))
181 (if (not (org-export-numbered-headline-p headline info
)) "-"
182 (concat (number-to-string
183 (car (last (org-export-get-headline-number
186 (concat bullet
(make-string (- 4 (length bullet
)) ?
) heading tags
189 (replace-regexp-in-string "^" " " contents
)))))
190 ;; Use "Setext" style.
191 ((eq org-md-headline-style
'setext
)
192 (concat heading tags
"\n"
193 (make-string (length heading
) (if (= level
1) ?
= ?-
))
197 (t (concat (make-string level ?
#) " " heading tags
"\n\n" contents
))))))
202 (defun org-md-horizontal-rule (horizontal-rule contents info
)
203 "Transcode HORIZONTAL-RULE element into Markdown format.
204 CONTENTS is the horizontal rule contents. INFO is a plist used
205 as a communication channel."
211 (defun org-md-italic (italic contents info
)
212 "Transcode ITALIC object into Markdown format.
213 CONTENTS is the text within italic markup. INFO is a plist used
214 as a communication channel."
215 (format "*%s*" contents
))
220 (defun org-md-item (item contents info
)
221 "Transcode ITEM element into Markdown format.
222 CONTENTS is the item contents. INFO is a plist used as
223 a communication channel."
224 (let* ((type (org-element-property :type
(org-export-get-parent item
)))
225 (struct (org-element-property :structure item
))
226 (bullet (if (not (eq type
'ordered
)) "-"
227 (concat (number-to-string
228 (car (last (org-list-get-item-number
229 (org-element-property :begin item
)
231 (org-list-prevs-alist struct
)
232 (org-list-parents-alist struct
)))))
235 (make-string (- 4 (length bullet
)) ?
)
236 (case (org-element-property :checkbox item
)
240 (let ((tag (org-element-property :tag item
)))
241 (and tag
(format "**%s:** "(org-export-data tag info
))))
242 (org-trim (replace-regexp-in-string "^" " " contents
)))))
247 (defun org-md-line-break (line-break contents info
)
248 "Transcode LINE-BREAK object into Markdown format.
249 CONTENTS is nil. INFO is a plist used as a communication
256 (defun org-md-link (link contents info
)
257 "Transcode LINE-BREAK object into Markdown format.
258 CONTENTS is the link's description. INFO is a plist used as
259 a communication channel."
260 (let ((--link-org-files-as-html-maybe
262 (lambda (raw-path info
)
263 ;; Treat links to `file.org' as links to `file.html', if
264 ;; needed. See `org-e-html-link-org-files-as-html'.
266 ((and org-e-html-link-org-files-as-html
268 (downcase (file-name-extension raw-path
"."))))
269 (concat (file-name-sans-extension raw-path
) "."
270 (plist-get info
:html-extension
)))
272 (type (org-element-property :type link
)))
273 (cond ((member type
'("custom-id" "id"))
274 (let ((destination (org-export-resolve-id-link link info
)))
275 (if (stringp destination
) ; External file.
276 (let ((path (funcall --link-org-files-as-html-maybe
278 (if (not contents
) (format "<%s>" path
)
279 (format "[%s](%s)" contents path
)))
281 (and contents
(concat contents
" "))
283 (format (org-export-translate "See section %s" :html info
)
284 (mapconcat 'number-to-string
285 (org-export-get-headline-number
288 ((org-export-inline-image-p link org-e-html-inline-image-rules
)
290 (let ((caption (org-export-get-caption
291 (org-export-get-parent-element link
))))
292 (when caption
(org-export-data caption info
)))
294 ((string= type
"coderef")
295 (let ((ref (org-element-property :path link
)))
296 (format (org-export-get-coderef-format ref contents
)
297 (org-export-resolve-coderef ref info
))))
298 ((equal type
"radio")
299 (let ((destination (org-export-resolve-radio-link link info
)))
300 (org-export-data (org-element-contents destination
) info
)))
301 ((equal type
"fuzzy")
302 (let ((destination (org-export-resolve-fuzzy-link link info
)))
303 ;; Ignore invisible "#+TARGET: path".
304 (unless (eq (org-element-type destination
) 'keyword
)
305 (if (org-string-nw-p contents
) contents
307 (let ((number (org-export-get-ordinal destination info
)))
309 (if (atom number
) (number-to-string number
)
310 (mapconcat 'number-to-string number
".")))))))))
311 (t (let* ((raw-path (org-element-property :path link
))
313 ((member type
'("http" "https" "ftp"))
314 (concat type
":" raw-path
))
316 ;; Treat links to ".org" files as ".html",
319 (funcall --link-org-files-as-html-maybe
321 ;; If file path is absolute, prepend it
322 ;; with protocol component - "file://".
323 (if (not (file-name-absolute-p raw-path
)) raw-path
324 (concat "file://" (expand-file-name raw-path
))))
326 (if (not contents
) (format "<%s>" path
)
327 (format "[%s](%s)" contents path
)))))))
332 (defun org-md-paragraph (paragraph contents info
)
333 "Transcode PARAGRAPH element into Markdown format.
334 CONTENTS is the paragraph contents. INFO is a plist used as
335 a communication channel."
336 (let ((first-object (car (org-element-contents paragraph
))))
337 ;; If paragraph starts with a #, protect it.
338 (if (and (stringp first-object
) (string-match "\\`#" first-object
))
339 (replace-regexp-in-string "\\`#" "\\#" contents nil t
)
345 (defun org-md-plain-list (plain-list contents info
)
346 "Transcode PLAIN-LIST element into Markdown format.
347 CONTENTS is the plain-list contents. INFO is a plist used as
348 a communication channel."
354 (defun org-md-plain-text (text info
)
355 "Transcode a TEXT string into Markdown format.
356 TEXT is the string to transcode. INFO is a plist holding
357 contextual information."
358 (when (plist-get info
:with-smart-quotes
)
359 (setq text
(org-export-activate-smart-quotes text
:html info
)))
360 ;; Protect ambiguous #. This will protect # at the beginning of
361 ;; a line, but not at the beginning of a paragraph. See
362 ;; `org-md-paragraph'.
363 (setq text
(replace-regexp-in-string "\n#" "\n\\\\#" text
))
364 ;; Protect ambiguous !
365 (setq text
(replace-regexp-in-string "\\(!\\)\\[" "\\\\!" text nil nil
1))
366 ;; Protect `, *, _ and \
367 (setq text
(replace-regexp-in-string "[`*_\\]" "\\\\\\&" text
))
368 ;; Handle special strings, if required.
369 (when (plist-get info
:with-special-strings
)
370 (setq text
(org-e-html-convert-special-strings text
)))
371 ;; Handle break preservation, if required.
372 (when (plist-get info
:preserve-breaks
)
373 (setq text
(replace-regexp-in-string "[ \t]*\n" " \n" text
)))
380 (defun org-md-quote-block (quote-block contents info
)
381 "Transcode QUOTE-BLOCK element into Markdown format.
382 CONTENTS is the quote-block contents. INFO is a plist used as
383 a communication channel."
384 (replace-regexp-in-string
386 (replace-regexp-in-string "\n\\'" "" contents
)))
391 (defun org-md-section (section contents info
)
392 "Transcode SECTION element into Markdown format.
393 CONTENTS is the section contents. INFO is a plist used as
394 a communication channel."
400 (defun org-md-template (contents info
)
401 "Return complete document string after Markdown conversion.
402 CONTENTS is the transcoded contents string. INFO is a plist used
403 as a communication channel."
408 ;;; Interactive function
411 (defun org-md-export-as-markdown (&optional subtreep visible-only
)
412 "Export current buffer to a text buffer.
414 If narrowing is active in the current buffer, only export its
417 If a region is active, export that region.
419 When optional argument SUBTREEP is non-nil, export the sub-tree
420 at point, extracting information from the headline properties
423 When optional argument VISIBLE-ONLY is non-nil, don't export
424 contents of hidden elements.
426 Export is done in a buffer named \"*Org MD Export*\", which will
427 be displayed when `org-export-show-temporary-export-buffer' is
430 (let ((outbuf (org-export-to-buffer
431 'md
"*Org MD Export*" subtreep visible-only
)))
432 (with-current-buffer outbuf
(text-mode))
433 (when org-export-show-temporary-export-buffer
434 (switch-to-buffer-other-window outbuf
))))
438 (defun org-md-export-to-markdown (&optional subtreep visible-only pub-dir
)
439 "Export current buffer to a Markdown file.
441 If narrowing is active in the current buffer, only export its
444 If a region is active, export that region.
446 When optional argument SUBTREEP is non-nil, export the sub-tree
447 at point, extracting information from the headline properties
450 When optional argument VISIBLE-ONLY is non-nil, don't export
451 contents of hidden elements.
453 When optional argument PUB-DIR is set, use it as the publishing
456 Return output file's name."
458 (let ((outfile (org-export-output-file-name ".md" subtreep pub-dir
)))
459 (org-export-to-file 'md outfile subtreep visible-only
)))
463 ;;; org-md.el ends here