1 ;;; ox-rss.el --- RSS 2.0 Back-End for Org Export Engine
3 ;; Copyright (C) 2013, 2014 Bastien Guerry
5 ;; Author: Bastien Guerry <bzg@gnu.org>
6 ;; Keywords: org, wp, blog, feed, rss
8 ;; This file is not yet part of GNU Emacs.
10 ;; This program is free software: you can redistribute it and/or modify
11 ;; it under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation, either version 3 of the License, or
13 ;; (at your option) any later version.
15 ;; This program is distributed in the hope that it will be useful,
16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 ;; GNU General Public License for more details.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
25 ;; This library implements a RSS 2.0 back-end for Org exporter, based on
26 ;; the `html' back-end.
28 ;; It requires Emacs 24.1 at least.
30 ;; It provides two commands for export, depending on the desired output:
31 ;; `org-rss-export-as-rss' (temporary buffer) and `org-rss-export-to-rss'
32 ;; (as a ".xml" file).
34 ;; This backend understands two new option keywords:
36 ;; #+RSS_EXTENSION: xml
37 ;; #+RSS_IMAGE_URL: http://myblog.org/mypicture.jpg
39 ;; It uses #+HTML_LINK_HOME: to set the base url of the feed.
41 ;; Exporting an Org file to RSS modifies each top-level entry by adding a
42 ;; PUBDATE property. If `org-rss-use-entry-url-as-guid', it will also add
43 ;; an ID property, later used as the guid for the feed's item.
45 ;; You typically want to use it within a publishing project like this:
48 ;; 'org-publish-project-alist
50 ;; :base-directory "~/myhomepage/"
51 ;; :base-extension "org"
52 ;; :rss-image-url "http://lumiere.ens.fr/~guerry/images/faces/15.png"
53 ;; :html-link-home "http://lumiere.ens.fr/~guerry/"
54 ;; :html-link-use-abs-url t
55 ;; :rss-extension "xml"
56 ;; :publishing-directory "/home/guerry/public_html/"
57 ;; :publishing-function (org-rss-publish-to-rss)
58 ;; :section-numbers nil
59 ;; :exclude ".*" ;; To exclude all files...
60 ;; :include ("index.org") ;; ... except index.org.
61 ;; :table-of-contents nil))
63 ;; ... then rsync /home/guerry/public_html/ with your server.
65 ;; By default, the permalink for a blog entry points to the headline.
66 ;; You can specify a different one by using the :RSS_PERMALINK:
67 ;; property within an entry.
72 (declare-function url-encode-url
"url-util" (url))
74 ;;; Variables and options
76 (defgroup org-export-rss nil
77 "Options specific to RSS export back-end."
81 :package-version
'(Org .
"8.0"))
83 (defcustom org-rss-image-url
"http://orgmode.org/img/org-mode-unicorn-logo.png"
84 "The URL of the an image for the RSS feed."
85 :group
'org-export-rss
88 (defcustom org-rss-extension
"xml"
89 "File extension for the RSS 2.0 feed."
90 :group
'org-export-rss
93 (defcustom org-rss-categories
'from-tags
94 "Where to extract items category information from.
95 The default is to extract categories from the tags of the
96 headlines. When set to another value, extract the category
97 from the :CATEGORY: property of the entry."
98 :group
'org-export-rss
100 (const :tag
"From tags" from-tags
)
101 (const :tag
"From the category property" from-category
)))
103 (defcustom org-rss-use-entry-url-as-guid t
104 "Use the URL for the <guid> metatag?
105 When nil, Org will create ids using `org-icalendar-create-uid'."
106 :group
'org-export-rss
111 (org-export-define-derived-backend 'rss
'html
115 (lambda (a s v b
) (org-rss-export-as-rss a s v
)))
116 (?r
"As RSS file" (lambda (a s v b
) (org-rss-export-to-rss a s v
)))
117 (?o
"As RSS file and open"
119 (if a
(org-rss-export-to-rss t s v
)
120 (org-open-file (org-rss-export-to-rss nil s v
)))))))
122 '((:with-toc nil nil nil
) ;; Never include HTML's toc
123 (:rss-extension
"RSS_EXTENSION" nil org-rss-extension
)
124 (:rss-image-url
"RSS_IMAGE_URL" nil org-rss-image-url
)
125 (:rss-categories nil nil org-rss-categories
))
126 :filters-alist
'((:filter-final-output . org-rss-final-function
))
127 :translate-alist
'((headline . org-rss-headline
)
128 (comment .
(lambda (&rest args
) ""))
129 (comment-block .
(lambda (&rest args
) ""))
130 (timestamp .
(lambda (&rest args
) ""))
131 (plain-text . org-rss-plain-text
)
132 (section . org-rss-section
)
133 (template . org-rss-template
)))
138 (defun org-rss-export-as-rss (&optional async subtreep visible-only
)
139 "Export current buffer to a RSS buffer.
141 If narrowing is active in the current buffer, only export its
144 If a region is active, export that region.
146 A non-nil optional argument ASYNC means the process should happen
147 asynchronously. The resulting buffer should be accessible
148 through the `org-export-stack' interface.
150 When optional argument SUBTREEP is non-nil, export the sub-tree
151 at point, extracting information from the headline properties
154 When optional argument VISIBLE-ONLY is non-nil, don't export
155 contents of hidden elements.
157 Export is done in a buffer named \"*Org RSS Export*\", which will
158 be displayed when `org-export-show-temporary-export-buffer' is
161 (let ((file (buffer-file-name (buffer-base-buffer))))
162 (org-icalendar-create-uid file
'warn-user
)
163 (org-rss-add-pubdate-property))
164 (org-export-to-buffer 'rss
"*Org RSS Export*"
165 async subtreep visible-only nil nil
(lambda () (text-mode))))
168 (defun org-rss-export-to-rss (&optional async subtreep visible-only
)
169 "Export current buffer to a RSS file.
171 If narrowing is active in the current buffer, only export its
174 If a region is active, export that region.
176 A non-nil optional argument ASYNC means the process should happen
177 asynchronously. The resulting file should be accessible through
178 the `org-export-stack' interface.
180 When optional argument SUBTREEP is non-nil, export the sub-tree
181 at point, extracting information from the headline properties
184 When optional argument VISIBLE-ONLY is non-nil, don't export
185 contents of hidden elements.
187 Return output file's name."
189 (let ((file (buffer-file-name (buffer-base-buffer))))
190 (org-icalendar-create-uid file
'warn-user
)
191 (org-rss-add-pubdate-property))
192 (let ((outfile (org-export-output-file-name
193 (concat "." org-rss-extension
) subtreep
)))
194 (org-export-to-file 'rss outfile async subtreep visible-only
)))
197 (defun org-rss-publish-to-rss (plist filename pub-dir
)
198 "Publish an org file to RSS.
200 FILENAME is the filename of the Org file to be published. PLIST
201 is the property list for the given project. PUB-DIR is the
202 publishing directory.
204 Return output file name."
205 (let ((bf (get-file-buffer filename
)))
208 (org-icalendar-create-uid filename
'warn-user
)
209 (with-current-buffer bf
210 (org-rss-add-pubdate-property)
211 (write-file filename
)))
213 (org-icalendar-create-uid filename
'warn-user
)
214 (org-rss-add-pubdate-property)
215 (write-file filename
) (kill-buffer)))
217 'rss filename
(concat "." org-rss-extension
) plist pub-dir
))
219 ;;; Main transcoding functions
221 (defun org-rss-headline (headline contents info
)
222 "Transcode HEADLINE element into RSS format.
223 CONTENTS is the headline contents. INFO is a plist used as a
224 communication channel."
225 (unless (or (org-element-property :footnote-section-p headline
)
226 ;; Only consider first-level headlines
227 (> (org-export-get-relative-level headline info
) 1))
228 (let* ((author (and (plist-get info
:with-author
)
229 (let ((auth (plist-get info
:author
)))
230 (and auth
(org-export-data auth info
)))))
231 (htmlext (plist-get info
:html-extension
))
232 (hl-number (org-export-get-headline-number headline info
))
233 (hl-home (file-name-as-directory (plist-get info
:html-link-home
)))
234 (hl-pdir (plist-get info
:publishing-directory
))
235 (hl-perm (org-element-property :RSS_PERMALINK headline
))
237 (org-export-solidify-link-text
238 (or (org-element-property :CUSTOM_ID headline
)
239 (concat "sec-" (mapconcat 'number-to-string hl-number
"-")))))
240 (category (org-rss-plain-text
241 (or (org-element-property :CATEGORY headline
) "") info
))
243 (let ((system-time-locale "C"))
245 "%a, %d %b %Y %H:%M:%S %z"
246 (org-time-string-to-time
247 (or (org-element-property :PUBDATE headline
)
248 (error "Missing PUBDATE property"))))))
249 (title (replace-regexp-in-string
250 org-bracket-link-regexp
251 (lambda (m) (or (match-string 3 m
)
253 (org-element-property :raw-value headline
)))
255 (or (and hl-perm
(concat (or hl-home hl-pdir
) hl-perm
))
258 (file-name-nondirectory
259 (file-name-sans-extension
260 (plist-get info
:input-file
))) "." htmlext
"#" anchor
)))
261 (guid (if org-rss-use-entry-url-as-guid
264 (or (org-element-property :ID headline
)
265 (org-element-property :CUSTOM_ID headline
)
271 "<title>%s</title>\n"
273 "<author>%s</author>\n"
274 "<guid isPermaLink=\"false\">%s</guid>\n"
275 "<pubDate>%s</pubDate>\n"
276 (org-rss-build-categories headline info
) "\n"
277 "<description><![CDATA[%s]]></description>\n"
279 title publink author guid pubdate contents
))))
281 (defun org-rss-build-categories (headline info
)
282 "Build categories for the RSS item."
283 (if (eq (plist-get info
:rss-categories
) 'from-tags
)
285 (lambda (c) (format "<category><![CDATA[%s]]></category>" c
))
286 (org-element-property :tags headline
)
288 (let ((c (org-element-property :CATEGORY headline
)))
289 (format "<category><![CDATA[%s]]></category>" c
))))
291 (defun org-rss-template (contents info
)
292 "Return complete document string after RSS conversion.
293 CONTENTS is the transcoded contents string. INFO is a plist used
294 as a communication channel."
296 (format "<?xml version=\"1.0\" encoding=\"%s\"?>"
297 (symbol-name org-html-coding-system
))
298 "\n<rss version=\"2.0\"
299 xmlns:content=\"http://purl.org/rss/1.0/modules/content/\"
300 xmlns:wfw=\"http://wellformedweb.org/CommentAPI/\"
301 xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
302 xmlns:atom=\"http://www.w3.org/2005/Atom\"
303 xmlns:sy=\"http://purl.org/rss/1.0/modules/syndication/\"
304 xmlns:slash=\"http://purl.org/rss/1.0/modules/slash/\"
305 xmlns:georss=\"http://www.georss.org/georss\"
306 xmlns:geo=\"http://www.w3.org/2003/01/geo/wgs84_pos#\"
307 xmlns:media=\"http://search.yahoo.com/mrss/\">"
309 (org-rss-build-channel-info info
) "\n"
314 (defun org-rss-build-channel-info (info)
315 "Build the RSS channel information."
316 (let* ((system-time-locale "C")
317 (title (plist-get info
:title
))
318 (email (org-export-data (plist-get info
:email
) info
))
319 (author (and (plist-get info
:with-author
)
320 (let ((auth (plist-get info
:author
)))
321 (and auth
(org-export-data auth info
)))))
322 (date (format-time-string "%a, %d %b %Y %H:%M:%S %z")) ;; RFC 882
323 (description (org-export-data (plist-get info
:description
) info
))
324 (lang (plist-get info
:language
))
325 (keywords (plist-get info
:keywords
))
326 (rssext (plist-get info
:rss-extension
))
327 (blogurl (or (plist-get info
:html-link-home
)
328 (plist-get info
:publishing-directory
)))
329 (image (url-encode-url (plist-get info
:rss-image-url
)))
330 (ifile (plist-get info
:input-file
))
332 (concat (file-name-as-directory blogurl
)
333 (file-name-nondirectory
334 (file-name-sans-extension ifile
))
338 <atom:link href=\"%s\" rel=\"self\" type=\"application/rss+xml\" />
340 <description><![CDATA[%s]]></description>
341 <language>%s</language>
342 <pubDate>%s</pubDate>
343 <lastBuildDate>%s</lastBuildDate>
344 <generator>%s</generator>
345 <webMaster>%s (%s)</webMaster>
352 title publink blogurl description lang date date
353 (concat (format "Emacs %d.%d"
356 " Org-mode " (org-version))
357 email author image title blogurl
)))
359 (defun org-rss-section (section contents info
)
360 "Transcode SECTION element into RSS format.
361 CONTENTS is the section contents. INFO is a plist used as
362 a communication channel."
365 (defun org-rss-timestamp (timestamp contents info
)
366 "Transcode a TIMESTAMP object from Org to RSS.
367 CONTENTS is nil. INFO is a plist holding contextual
369 (org-html-encode-plain-text
370 (org-timestamp-translate timestamp
)))
372 (defun org-rss-plain-text (contents info
)
373 "Convert plain text into RSS encoded text."
375 (setq output
(org-html-encode-plain-text contents
)
376 output
(org-export-activate-smart-quotes
377 output
:html info
))))
381 (defun org-rss-final-function (contents backend info
)
382 "Prettify the RSS output."
386 (indent-region (point-min) (point-max))
387 (buffer-substring-no-properties (point-min) (point-max))))
391 (defun org-rss-add-pubdate-property ()
392 "Set the PUBDATE property for top-level headlines."
396 (let* ((entry (org-element-at-point))
397 (level (org-element-property :level entry
)))
399 (unless (org-entry-get (point) "PUBDATE")
402 "PUBDATE" (format-time-string
403 (cdr org-time-stamp-formats
)))))))
404 nil nil
'comment
'archive
)
406 (message "Property PUBDATE added to top-level entries in %s"
412 ;;; ox-rss.el ends here