org-mode/lisp/ox-md.el

493 lines
16 KiB
EmacsLisp
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

;;; ox-md.el --- Markdown Back-End for Org Export Engine
;; Copyright (C) 2012-2014 Free Software Foundation, Inc.
;; Author: Nicolas Goaziou <n.goaziou@gmail.com>
;; Keywords: org, wp, markdown
;; This file is part of GNU Emacs.
;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;; This library implements a Markdown back-end (vanilla flavor) for
;; Org exporter, based on `html' back-end. See Org manual for more
;; information.
;;; Code:
(eval-when-compile (require 'cl))
(require 'ox-html)
;;; User-Configurable Variables
(defgroup org-export-md nil
"Options specific to Markdown export back-end."
:tag "Org Markdown"
:group 'org-export
:version "24.4"
:package-version '(Org . "8.0"))
(defcustom org-md-headline-style 'atx
"Style used to format headlines.
This variable can be set to either `atx' or `setext'."
:group 'org-export-md
:type '(choice
(const :tag "Use \"atx\" style" atx)
(const :tag "Use \"Setext\" style" setext)))
;;; Define Back-End
(org-export-define-derived-backend 'md 'html
:export-block '("MD" "MARKDOWN")
:filters-alist '((:filter-parse-tree . org-md-separate-elements))
:menu-entry
'(?m "Export to Markdown"
((?M "To temporary buffer"
(lambda (a s v b) (org-md-export-as-markdown a s v)))
(?m "To file" (lambda (a s v b) (org-md-export-to-markdown a s v)))
(?o "To file and open"
(lambda (a s v b)
(if a (org-md-export-to-markdown t s v)
(org-open-file (org-md-export-to-markdown nil s v)))))))
:translate-alist '((bold . org-md-bold)
(code . org-md-verbatim)
(comment . (lambda (&rest args) ""))
(comment-block . (lambda (&rest args) ""))
(example-block . org-md-example-block)
(fixed-width . org-md-example-block)
(footnote-definition . ignore)
(footnote-reference . ignore)
(headline . org-md-headline)
(horizontal-rule . org-md-horizontal-rule)
(inline-src-block . org-md-verbatim)
(inner-template . org-md-inner-template)
(italic . org-md-italic)
(item . org-md-item)
(line-break . org-md-line-break)
(link . org-md-link)
(paragraph . org-md-paragraph)
(plain-list . org-md-plain-list)
(plain-text . org-md-plain-text)
(quote-block . org-md-quote-block)
(quote-section . org-md-example-block)
(section . org-md-section)
(src-block . org-md-example-block)
(template . org-md-template)
(verbatim . org-md-verbatim)))
;;; Filters
(defun org-md-separate-elements (tree backend info)
"Fix blank lines between elements.
TREE is the parse tree being exported. BACKEND is the export
back-end used. INFO is a plist used as a communication channel.
Make sure there's no blank line before a plain list, unless it is
located right after a paragraph. Otherwise, add a blank line
between elements. Blank lines between items are preserved.
Assume BACKEND is `md'."
(org-element-map tree (remq 'item org-element-all-elements)
(lambda (elem)
(org-element-put-property
elem :post-blank
(if (and (eq (org-element-type (org-export-get-next-element elem info))
'plain-list)
(not (and (eq (org-element-type elem) 'paragraph)
(org-export-get-previous-element elem info))))
0
1))))
;; Return updated tree.
tree)
;;; Transcode Functions
;;;; Bold
(defun org-md-bold (bold contents info)
"Transcode BOLD object into Markdown format.
CONTENTS is the text within bold markup. INFO is a plist used as
a communication channel."
(format "**%s**" contents))
;;;; Code and Verbatim
(defun org-md-verbatim (verbatim contents info)
"Transcode VERBATIM object into Markdown format.
CONTENTS is nil. INFO is a plist used as a communication
channel."
(let ((value (org-element-property :value verbatim)))
(format (cond ((not (string-match "`" value)) "`%s`")
((or (string-match "\\``" value)
(string-match "`\\'" value))
"`` %s ``")
(t "``%s``"))
value)))
;;;; Example Block and Src Block
(defun org-md-example-block (example-block contents info)
"Transcode EXAMPLE-BLOCK element into Markdown format.
CONTENTS is nil. INFO is a plist used as a communication
channel."
(replace-regexp-in-string
"^" " "
(org-remove-indentation
(org-element-property :value example-block))))
;;;; Headline
(defun org-md-headline (headline contents info)
"Transcode HEADLINE element into Markdown format.
CONTENTS is the headline contents. INFO is a plist used as
a communication channel."
(unless (org-element-property :footnote-section-p headline)
(let* ((level (org-export-get-relative-level headline info))
(title (org-export-data (org-element-property :title headline) info))
(todo (and (plist-get info :with-todo-keywords)
(let ((todo (org-element-property :todo-keyword
headline)))
(and todo (concat (org-export-data todo info) " ")))))
(tags (and (plist-get info :with-tags)
(let ((tag-list (org-export-get-tags headline info)))
(and tag-list
(format " :%s:"
(mapconcat 'identity tag-list ":"))))))
(priority
(and (plist-get info :with-priority)
(let ((char (org-element-property :priority headline)))
(and char (format "[#%c] " char)))))
;; Headline text without tags.
(heading (concat todo priority title)))
(cond
;; Cannot create a headline. Fall-back to a list.
((or (org-export-low-level-p headline info)
(not (memq org-md-headline-style '(atx setext)))
(and (eq org-md-headline-style 'atx) (> level 6))
(and (eq org-md-headline-style 'setext) (> level 2)))
(let ((bullet
(if (not (org-export-numbered-headline-p headline info)) "-"
(concat (number-to-string
(car (last (org-export-get-headline-number
headline info))))
"."))))
(concat bullet (make-string (- 4 (length bullet)) ? ) heading tags
"\n\n"
(and contents
(replace-regexp-in-string "^" " " contents)))))
;; Use "Setext" style.
((eq org-md-headline-style 'setext)
(concat heading tags "\n"
(make-string (length heading) (if (= level 1) ?= ?-))
"\n\n"
contents))
;; Use "atx" style.
(t (concat (make-string level ?#) " " heading tags "\n\n" contents))))))
;;;; Horizontal Rule
(defun org-md-horizontal-rule (horizontal-rule contents info)
"Transcode HORIZONTAL-RULE element into Markdown format.
CONTENTS is the horizontal rule contents. INFO is a plist used
as a communication channel."
"---")
;;;; Italic
(defun org-md-italic (italic contents info)
"Transcode ITALIC object into Markdown format.
CONTENTS is the text within italic markup. INFO is a plist used
as a communication channel."
(format "*%s*" contents))
;;;; Item
(defun org-md-item (item contents info)
"Transcode ITEM element into Markdown format.
CONTENTS is the item contents. INFO is a plist used as
a communication channel."
(let* ((type (org-element-property :type (org-export-get-parent item)))
(struct (org-element-property :structure item))
(bullet (if (not (eq type 'ordered)) "-"
(concat (number-to-string
(car (last (org-list-get-item-number
(org-element-property :begin item)
struct
(org-list-prevs-alist struct)
(org-list-parents-alist struct)))))
"."))))
(concat bullet
(make-string (- 4 (length bullet)) ? )
(case (org-element-property :checkbox item)
(on "[X] ")
(trans "[-] ")
(off "[ ] "))
(let ((tag (org-element-property :tag item)))
(and tag (format "**%s:** "(org-export-data tag info))))
(and contents
(org-trim (replace-regexp-in-string "^" " " contents))))))
;;;; Line Break
(defun org-md-line-break (line-break contents info)
"Transcode LINE-BREAK object into Markdown format.
CONTENTS is nil. INFO is a plist used as a communication
channel."
" \n")
;;;; Link
(defun org-md-link (link contents info)
"Transcode LINE-BREAK object into Markdown format.
CONTENTS is the link's description. INFO is a plist used as
a communication channel."
(let ((link-org-files-as-md
(function
(lambda (raw-path)
;; Treat links to `file.org' as links to `file.md'.
(if (string= ".org" (downcase (file-name-extension raw-path ".")))
(concat (file-name-sans-extension raw-path) ".md")
raw-path))))
(type (org-element-property :type link)))
(cond ((member type '("custom-id" "id"))
(let ((destination (org-export-resolve-id-link link info)))
(if (stringp destination) ; External file.
(let ((path (funcall link-org-files-as-md destination)))
(if (not contents) (format "<%s>" path)
(format "[%s](%s)" contents path)))
(concat
(and contents (concat contents " "))
(format "(%s)"
(format (org-export-translate "See section %s" :html info)
(mapconcat 'number-to-string
(org-export-get-headline-number
destination info)
".")))))))
((org-export-inline-image-p link org-html-inline-image-rules)
(let ((path (let ((raw-path (org-element-property :path link)))
(if (not (file-name-absolute-p raw-path)) raw-path
(expand-file-name raw-path))))
(caption (org-export-data
(org-export-get-caption
(org-export-get-parent-element link)) info)))
(format "![img](%s)"
(if (not (org-string-nw-p caption)) path
(format "%s \"%s\"" path caption)))))
((string= type "coderef")
(let ((ref (org-element-property :path link)))
(format (org-export-get-coderef-format ref contents)
(org-export-resolve-coderef ref info))))
((equal type "radio") contents)
((equal type "fuzzy")
(let ((destination (org-export-resolve-fuzzy-link link info)))
(if (org-string-nw-p contents) contents
(when destination
(let ((number (org-export-get-ordinal destination info)))
(when number
(if (atom number) (number-to-string number)
(mapconcat 'number-to-string number "."))))))))
(t (let* ((raw-path (org-element-property :path link))
(path
(cond
((member type '("http" "https" "ftp"))
(concat type ":" raw-path))
((equal type "file")
(let ((path (funcall link-org-files-as-md raw-path)))
(if (not (file-name-absolute-p path)) path
;; If file path is absolute, prepend it
;; with "file://" component.
(concat "file://" (expand-file-name raw-path)))))
(t raw-path))))
(if (not contents) (format "<%s>" path)
(format "[%s](%s)" contents path)))))))
;;;; Paragraph
(defun org-md-paragraph (paragraph contents info)
"Transcode PARAGRAPH element into Markdown format.
CONTENTS is the paragraph contents. INFO is a plist used as
a communication channel."
(let ((first-object (car (org-element-contents paragraph))))
;; If paragraph starts with a #, protect it.
(if (and (stringp first-object) (string-match "\\`#" first-object))
(replace-regexp-in-string "\\`#" "\\#" contents nil t)
contents)))
;;;; Plain List
(defun org-md-plain-list (plain-list contents info)
"Transcode PLAIN-LIST element into Markdown format.
CONTENTS is the plain-list contents. INFO is a plist used as
a communication channel."
contents)
;;;; Plain Text
(defun org-md-plain-text (text info)
"Transcode a TEXT string into Markdown format.
TEXT is the string to transcode. INFO is a plist holding
contextual information."
(when (plist-get info :with-smart-quotes)
(setq text (org-export-activate-smart-quotes text :html info)))
;; Protect ambiguous #. This will protect # at the beginning of
;; a line, but not at the beginning of a paragraph. See
;; `org-md-paragraph'.
(setq text (replace-regexp-in-string "\n#" "\n\\\\#" text))
;; Protect ambiguous !
(setq text (replace-regexp-in-string "\\(!\\)\\[" "\\\\!" text nil nil 1))
;; Protect `, *, _ and \
(setq text (replace-regexp-in-string "[`*_\\]" "\\\\\\&" text))
;; Handle special strings, if required.
(when (plist-get info :with-special-strings)
(setq text (org-html-convert-special-strings text)))
;; Handle break preservation, if required.
(when (plist-get info :preserve-breaks)
(setq text (replace-regexp-in-string "[ \t]*\n" " \n" text)))
;; Return value.
text)
;;;; Quote Block
(defun org-md-quote-block (quote-block contents info)
"Transcode QUOTE-BLOCK element into Markdown format.
CONTENTS is the quote-block contents. INFO is a plist used as
a communication channel."
(replace-regexp-in-string
"^" "> "
(replace-regexp-in-string "\n\\'" "" contents)))
;;;; Section
(defun org-md-section (section contents info)
"Transcode SECTION element into Markdown format.
CONTENTS is the section contents. INFO is a plist used as
a communication channel."
contents)
;;;; Template
(defun org-md-inner-template (contents info)
"Return body of document after converting it to Markdown syntax.
CONTENTS is the transcoded contents string. INFO is a plist
holding export options."
;; Make sure CONTENTS is separated from table of contents and
;; footnotes with at least a blank line.
(org-trim (org-html-inner-template (concat "\n" contents "\n") info)))
(defun org-md-template (contents info)
"Return complete document string after Markdown conversion.
CONTENTS is the transcoded contents string. INFO is a plist used
as a communication channel."
contents)
;;; Interactive function
;;;###autoload
(defun org-md-export-as-markdown (&optional async subtreep visible-only)
"Export current buffer to a Markdown buffer.
If narrowing is active in the current buffer, only export its
narrowed part.
If a region is active, export that region.
A non-nil optional argument ASYNC means the process should happen
asynchronously. The resulting buffer should be accessible
through the `org-export-stack' interface.
When optional argument SUBTREEP is non-nil, export the sub-tree
at point, extracting information from the headline properties
first.
When optional argument VISIBLE-ONLY is non-nil, don't export
contents of hidden elements.
Export is done in a buffer named \"*Org MD Export*\", which will
be displayed when `org-export-show-temporary-export-buffer' is
non-nil."
(interactive)
(org-export-to-buffer 'md "*Org MD Export*"
async subtreep visible-only nil nil (lambda () (text-mode))))
;;;###autoload
(defun org-md-convert-region-to-md ()
"Assume the current region has org-mode syntax, and convert it to Markdown.
This can be used in any buffer. For example, you can write an
itemized list in org-mode syntax in a Markdown buffer and use
this command to convert it."
(interactive)
(org-export-replace-region-by 'md))
;;;###autoload
(defun org-md-export-to-markdown (&optional async subtreep visible-only)
"Export current buffer to a Markdown file.
If narrowing is active in the current buffer, only export its
narrowed part.
If a region is active, export that region.
A non-nil optional argument ASYNC means the process should happen
asynchronously. The resulting file should be accessible through
the `org-export-stack' interface.
When optional argument SUBTREEP is non-nil, export the sub-tree
at point, extracting information from the headline properties
first.
When optional argument VISIBLE-ONLY is non-nil, don't export
contents of hidden elements.
Return output file's name."
(interactive)
(let ((outfile (org-export-output-file-name ".md" subtreep)))
(org-export-to-file 'md outfile async subtreep visible-only)))
(provide 'ox-md)
;; Local variables:
;; generated-autoload-file: "org-loaddefs.el"
;; End:
;;; ox-md.el ends here