ox: Add a defcustom to export properties drawers

* lisp/ox.el (org-export-with-drawers): Improve docstring.
(org-export-with-properties): New variable
(org-export--skip-p): Handle new variable.
(org-export-options-alist): Install new variable.
* lisp/ox-ascii.el (org-ascii-node-property,
  org-ascii-property-drawer): New functions.
* lisp/ox-html.el (org-html-node-property): New function.
(org-html-property-drawer): Export property drawers as "pre" blocks.
* lisp/ox-latex.el (org-latex-property-drawer,
  org-latex-node-property): New functions.
* lisp/ox-man.el (org-man-node-property, org-man-property-drawer): New
  functions.
* lisp/ox-md.el (org-md-node-property, org-md-property-drawer): New
  functions.
* lisp/ox-odt.el (org-odt-node-property): New function.
(org-odt-property-drawer): Export property drawers as fixed width
blocks.
* lisp/ox-texinfo.el (org-texinfo-node-property): New function.
(org-texinfo-property-drawer): Export property drawers as verbatim
blocks.
* doc/org.texi: Update manual.
* testing/lisp/test-ox.el: Add tests.

doc/org.texi

@@ -10461,6 +10461,7 @@ Other back-ends might be found in the @code{contrib/} directory
 @section Export settings
 @cindex Export, settings
 
+@cindex #+OPTIONS
 Export options can be set: globally with variables; for an individual file by
 making variables buffer-local with in-buffer settings (@pxref{In-buffer
 settings}), by setting individual keywords, or by specifying them in a
@@ -10482,34 +10483,41 @@ variables, include:
 
 @table @samp
 @item AUTHOR
+@cindex #+AUTHOR
 @vindex user-full-name
 The document author (@code{user-full-name}).
 
 @item CREATOR
+@cindex #+CREATOR
 @vindex org-export-creator-string
 Entity responsible for output generation (@code{org-export-creator-string}).
 
 @item DATE
+@cindex #+DATE
 @vindex org-export-date-timestamp-format
 A date or a time-stamp@footnote{The variable
 @code{org-export-date-timestamp-format} defines how this time-stamp will be
 exported.}.
 
 @item DESCRIPTION
+@cindex #+DESCRIPTION
 The document description.  Back-ends handle it as they see fit (e.g., for the
 XHTML meta tag), if at all.  You can use several such keywords for long
 descriptions.
 
 @item EMAIL
+@cindex #+EMAIL
 @vindex user-mail-address
 The email address (@code{user-mail-address}).
 
 @item KEYWORDS
+@cindex #+KEYWORDS
 The keywords defining the contents of the document.  Back-ends handle it as
 they see fit (e.g., for the XHTML meta tag), if at all.  You can use several
 such keywords if the list is long.
 
 @item LANGUAGE
+@cindex #+LANGUAGE
 @vindex org-export-default-language
 The language used for translating some strings
 (@code{org-export-default-language}).  E.g., @samp{#+LANGUAGE: fr} will tell
@@ -10517,6 +10525,7 @@ Org to translate @emph{File} (english) into @emph{Fichier} (french) in the
 clocktable.
 
 @item SELECT_TAGS
+@cindex #+SELECT_TAGS
 @vindex org-export-select-tags
 The tags that select a tree for export (@code{org-export-select-tags}).  The
 default value is @code{:export:}.  Within a subtree tagged with
@@ -10524,12 +10533,15 @@ default value is @code{:export:}.  Within a subtree tagged with
 below).
 
 @item EXCLUDE_TAGS
+@cindex #+EXCLUDE_TAGS
+@vindex org-export-exclude-tags
 The tags that exclude a tree from export (@code{org-export-exclude-tags}).
 The default value is @code{:noexport:}.  Entries with the @code{:noexport:}
 tag will be unconditionally excluded from the export, even if they have an
 @code{:export:} tag.
 
 @item TITLE
+@cindex #+TITLE
 The title to be shown (otherwise derived from buffer's name).  You can use
 several such keywords for long titles.
 @end table
@@ -10635,6 +10647,11 @@ Toggle export of planning information (@code{org-export-with-planning}).
 @vindex org-export-with-priority
 Toggle inclusion of priority cookies (@code{org-export-with-priority}).
 
+@item prop:
+@vindex org-export-with-properties
+Toggle inclusion of property drawers, or list properties to include
+(@code{org-export-with-properties}).
+
 @item stat:
 @vindex org-export-with-statistics-cookies
 Toggle inclusion of statistics cookies
@@ -13293,6 +13310,7 @@ string of these options for details.
 @vindex org-export-with-latex
 @vindex org-export-with-planning
 @vindex org-export-with-priority
+@vindex org-export-with-properties
 @vindex org-export-with-section-numbers
 @vindex org-export-with-special-strings
 @vindex org-export-with-sub-superscripts
@@ -13303,7 +13321,6 @@ string of these options for details.
 @vindex org-export-with-toc
 @vindex org-export-with-todo-keywords
 @vindex user-mail-address
-
 @multitable @columnfractions 0.32 0.68
 @item @code{:archived-trees}        @tab @code{org-export-with-archived-trees}
 @item @code{:exclude-tags}          @tab @code{org-export-exclude-tags}
@@ -13323,6 +13340,7 @@ string of these options for details.
 @item @code{:with-latex}            @tab @code{org-export-with-latex}
 @item @code{:with-planning}         @tab @code{org-export-with-planning}
 @item @code{:with-priority}         @tab @code{org-export-with-priority}
+@item @code{:with-properties}       @tab @code{org-export-with-properties}
 @item @code{:with-special-strings}  @tab @code{org-export-with-special-strings}
 @item @code{:with-sub-superscript}  @tab @code{org-export-with-sub-superscripts}
 @item @code{:with-tables}           @tab @code{org-export-with-tables}

lisp/ox-ascii.el

@@ -81,10 +81,12 @@
     (latex-fragment . org-ascii-latex-fragment)
     (line-break . org-ascii-line-break)
     (link . org-ascii-link)
+    (node-property . org-ascii-node-property)
     (paragraph . org-ascii-paragraph)
     (plain-list . org-ascii-plain-list)
     (plain-text . org-ascii-plain-text)
     (planning . org-ascii-planning)
+    (property-drawer . org-ascii-property-drawer)
     (quote-block . org-ascii-quote-block)
     (quote-section . org-ascii-quote-section)
     (radio-target . org-ascii-radio-target)
@@ -1440,6 +1442,18 @@ INFO is a plist holding contextual information."
 	 (unless org-ascii-links-to-notes (format " (%s)" raw-link))))))))
 
 
+;;;; Node Properties
+
+(defun org-ascii-node-property (node-property contents info)
+  "Transcode a NODE-PROPERTY element from Org to ASCII.
+CONTENTS is nil.  INFO is a plist holding contextual
+information."
+  (format "%s:%s"
+          (org-element-property :key node-property)
+          (let ((value (org-element-property :value node-property)))
+            (if value (concat " " value) ""))))
+
+
 ;;;; Paragraph
 
 (defun org-ascii-paragraph (paragraph contents info)
@@ -1509,6 +1523,15 @@ channel."
    " "))
 
 
+;;;; Property Drawer
+
+(defun org-ascii-property-drawer (property-drawer contents info)
+  "Transcode a PROPERTY-DRAWER element from Org to ASCII.
+CONTENTS holds the contents of the drawer.  INFO is a plist
+holding contextual information."
+  (org-string-nw-p contents))
+
+
 ;;;; Quote Block
 
 (defun org-ascii-quote-block (quote-block contents info)

lisp/ox-html.el

@@ -76,6 +76,7 @@
     (latex-fragment . org-html-latex-fragment)
     (line-break . org-html-line-break)
     (link . org-html-link)
+    (node-property . org-html-node-property)
     (paragraph . org-html-paragraph)
     (plain-list . org-html-plain-list)
     (plain-text . org-html-plain-text)
@@ -2782,6 +2783,17 @@ INFO is a plist holding contextual information.  See
      ;; No path, only description.  Try to do something useful.
      (t (format "<i>%s</i>" desc)))))
 
+;;;; Node Property
+
+(defun org-html-node-property (node-property contents info)
+  "Transcode a NODE-PROPERTY element from Org to HTML.
+CONTENTS is nil.  INFO is a plist holding contextual
+information."
+  (format "%s:%s"
+          (org-element-property :key node-property)
+          (let ((value (org-element-property :value node-property)))
+            (if value (concat " " value) ""))))
+
 ;;;; Paragraph
 
 (defun org-html-paragraph (paragraph contents info)
@@ -2930,11 +2942,10 @@ channel."
 
 (defun org-html-property-drawer (property-drawer contents info)
   "Transcode a PROPERTY-DRAWER element from Org to HTML.
-CONTENTS is nil.  INFO is a plist holding contextual
-information."
-  ;; The property drawer isn't exported but we want separating blank
-  ;; lines nonetheless.
-  "")
+CONTENTS holds the contents of the drawer.  INFO is a plist
+holding contextual information."
+  (and (org-string-nw-p contents)
+       (format "<pre class=\"example\">\n%s</pre>" contents)))
 
 ;;;; Quote Block
 

lisp/ox-latex.el

@@ -63,11 +63,12 @@
     (latex-fragment . org-latex-latex-fragment)
     (line-break . org-latex-line-break)
     (link . org-latex-link)
+    (node-property . org-latex-node-property)
     (paragraph . org-latex-paragraph)
     (plain-list . org-latex-plain-list)
     (plain-text . org-latex-plain-text)
     (planning . org-latex-planning)
-    (property-drawer . (lambda (&rest args) ""))
+    (property-drawer . org-latex-property-drawer)
     (quote-block . org-latex-quote-block)
     (quote-section . org-latex-quote-section)
     (radio-target . org-latex-radio-target)
@@ -1837,6 +1838,18 @@ INFO is a plist holding contextual information.  See
      (t (format org-latex-link-with-unknown-path-format desc)))))
 
 
+;;;; Node Property
+
+(defun org-latex-node-property (node-property contents info)
+  "Transcode a NODE-PROPERTY element from Org to LaTeX.
+CONTENTS is nil.  INFO is a plist holding contextual
+information."
+  (format "%s:%s"
+          (org-element-property :key node-property)
+          (let ((value (org-element-property :value node-property)))
+            (if value (concat " " value) ""))))
+
+
 ;;;; Paragraph
 
 (defun org-latex-paragraph (paragraph contents info)
@@ -1961,6 +1974,16 @@ information."
    "\\\\"))
 
 
+;;;; Property Drawer
+
+(defun org-latex-property-drawer (property-drawer contents info)
+  "Transcode a PROPERTY-DRAWER element from Org to LaTeX.
+CONTENTS holds the contents of the drawer.  INFO is a plist
+holding contextual information."
+  (and (org-string-nw-p contents)
+       (format "\\begin{verbatim}\n%s\\end{verbatim}" contents)))
+
+
 ;;;; Quote Block
 
 (defun org-latex-quote-block (quote-block contents info)

lisp/ox-man.el

@@ -76,11 +76,12 @@
     (keyword . org-man-keyword)
     (line-break . org-man-line-break)
     (link . org-man-link)
+    (node-property . org-man-node-property)
     (paragraph . org-man-paragraph)
     (plain-list . org-man-plain-list)
     (plain-text . org-man-plain-text)
     (planning . org-man-planning)
-    (property-drawer . (lambda (&rest args) ""))
+    (property-drawer . org-man-property-drawer)
     (quote-block . org-man-quote-block)
     (quote-section . org-man-quote-section)
     (radio-target . org-man-radio-target)
@@ -663,6 +664,16 @@ INFO is a plist holding contextual information.  See
      ;; No path, only description.  Try to do something useful.
      (t (format "\\fI%s\\fP" desc)))))
 
+;;;; Node Property
+
+(defun org-man-node-property (node-property contents info)
+  "Transcode a NODE-PROPERTY element from Org to Man.
+CONTENTS is nil.  INFO is a plist holding contextual
+information."
+  (format "%s:%s"
+          (org-element-property :key node-property)
+          (let ((value (org-element-property :value node-property)))
+            (if value (concat " " value) ""))))
 
 ;;; Paragraph
 
@@ -722,6 +733,12 @@ contextual information."
 
 ;;; Property Drawer
 
+(defun org-man-property-drawer (property-drawer contents info)
+  "Transcode a PROPERTY-DRAWER element from Org to Man.
+CONTENTS holds the contents of the drawer.  INFO is a plist
+holding contextual information."
+  (and (org-string-nw-p contents)
+       (format ".RS\n.nf\n%s\n.fi\n.RE" contents)))
 
 ;;; Quote Block
 

lisp/ox-md.el

@@ -82,9 +82,11 @@ This variable can be set to either `atx' or `setext'."
 		     (item . org-md-item)
 		     (line-break . org-md-line-break)
 		     (link . org-md-link)
+		     (node-property . org-md-node-property)
 		     (paragraph . org-md-paragraph)
 		     (plain-list . org-md-plain-list)
 		     (plain-text . org-md-plain-text)
+		     (property-drawer . org-md-property-drawer)
 		     (quote-block . org-md-quote-block)
 		     (quote-section . org-md-example-block)
 		     (section . org-md-section)
@@ -334,6 +336,18 @@ a communication channel."
 		 (format "[%s](%s)" contents path)))))))
 
 
+;;;; Node Property
+
+(defun org-md-node-property (node-property contents info)
+  "Transcode a NODE-PROPERTY element into Markdown syntax.
+CONTENTS is nil.  INFO is a plist holding contextual
+information."
+  (format "%s:%s"
+          (org-element-property :key node-property)
+          (let ((value (org-element-property :value node-property)))
+            (if value (concat " " value) ""))))
+
+
 ;;;; Paragraph
 
 (defun org-md-paragraph (paragraph contents info)
@@ -382,6 +396,16 @@ contextual information."
   text)
 
 
+;;;; Property Drawer
+
+(defun org-md-property-drawer (property-drawer contents info)
+  "Transcode a PROPERTY-DRAWER element into Markdown format.
+CONTENTS holds the contents of the drawer.  INFO is a plist
+holding contextual information."
+  (and (org-string-nw-p contents)
+       (replace-regexp-in-string "^" "    " contents)))
+
+
 ;;;; Quote Block
 
 (defun org-md-quote-block (quote-block contents info)

lisp/ox-odt.el

@@ -59,6 +59,7 @@
     (latex-fragment . org-odt-latex-fragment)
     (line-break . org-odt-line-break)
     (link . org-odt-link)
+    (node-property . org-odt-node-property)
     (paragraph . org-odt-paragraph)
     (plain-list . org-odt-plain-list)
     (plain-text . org-odt-plain-text)
@@ -2868,6 +2869,18 @@ INFO is a plist holding contextual information.  See
 		"Emphasis" desc)))))
 
 
+;;;; Node Property
+
+(defun org-odt-node-property (node-property contents info)
+  "Transcode a NODE-PROPERTY element from Org to ODT.
+CONTENTS is nil.  INFO is a plist holding contextual
+information."
+  (org-odt--encode-plain-text
+   (format "%s:%s"
+	   (org-element-property :key node-property)
+	   (let ((value (org-element-property :value node-property)))
+	     (if value (concat " " value) "")))))
+
 ;;;; Paragraph
 
 (defun org-odt--format-paragraph (paragraph contents default center quote)
@@ -3005,11 +3018,11 @@ channel."
 
 (defun org-odt-property-drawer (property-drawer contents info)
   "Transcode a PROPERTY-DRAWER element from Org to ODT.
-CONTENTS is nil.  INFO is a plist holding contextual
-information."
-  ;; The property drawer isn't exported but we want separating blank
-  ;; lines nonetheless.
-  "")
+CONTENTS holds the contents of the drawer.  INFO is a plist
+holding contextual information."
+  (and (org-string-nw-p contents)
+       (format "<text:p text:style-name=\"OrgFixedWidthBlock\">%s</text:p>"
+	       contents)))
 
 
 ;;;; Quote Block

lisp/ox-texinfo.el

@@ -89,6 +89,7 @@
     (keyword . org-texinfo-keyword)
     (line-break . org-texinfo-line-break)
     (link . org-texinfo-link)
+    (node-property . org-texinfo-node-property)
     (paragraph . org-texinfo-paragraph)
     (plain-list . org-texinfo-plain-list)
     (plain-text . org-texinfo-plain-text)
@@ -1294,6 +1295,17 @@ are generated directly."
       ;;(org-texinfo--build-detailed-menu parse top info)
       (org-texinfo--build-menu parse 1 info 'detailed)))))
 
+;;;; Node Property
+
+(defun org-texinfo-node-property (node-property contents info)
+  "Transcode a NODE-PROPERTY element from Org to Texinfo.
+CONTENTS is nil.  INFO is a plist holding contextual
+information."
+  (format "%s:%s"
+          (org-element-property :key node-property)
+          (let ((value (org-element-property :value node-property)))
+            (if value (concat " " value) ""))))
+
 ;;; Paragraph
 
 (defun org-texinfo-paragraph (paragraph contents info)
@@ -1398,11 +1410,10 @@ information."
 
 (defun org-texinfo-property-drawer (property-drawer contents info)
   "Transcode a PROPERTY-DRAWER element from Org to Texinfo.
-CONTENTS is nil.  INFO is a plist holding contextual
-information."
-  ;; The property drawer isn't exported but we want separating blank
-  ;; lines nonetheless.
-  "")
+CONTENTS holds the contents of the drawer.  INFO is a plist
+holding contextual information."
+  (and (org-string-nw-p contents)
+       (format "@verbatim\n%s@end verbatim" contents)))
 
 ;;; Quote Block
 

lisp/ox.el

@@ -128,6 +128,7 @@
     (:with-latex nil "tex" org-export-with-latex)
     (:with-planning nil "p" org-export-with-planning)
     (:with-priority nil "pri" org-export-with-priority)
+    (:with-properties nil "prop" org-export-with-properties)
     (:with-smart-quotes nil "'" org-export-with-smart-quotes)
     (:with-special-strings nil "-" org-export-with-special-strings)
     (:with-statistics-cookies nil "stat" org-export-with-statistics-cookies)
@@ -396,10 +397,11 @@ This option can also be set on with the CREATOR keyword."
   "Non-nil means export contents of standard drawers.
 
 When t, all drawers are exported.  This may also be a list of
-drawer names to export.  If that list starts with `not', only
-drawers with such names will be ignored.
+drawer names to export, as strings.  If that list starts with
+`not', only drawers with such names will be ignored.
 
-This variable doesn't apply to properties drawers.
+This variable doesn't apply to properties drawers.  See
+`org-export-with-properties' instead.
 
 This option can also be set with the OPTIONS keyword,
 e.g. \"d:nil\"."
@@ -557,6 +559,23 @@ e.g. \"pri:t\"."
   :group 'org-export-general
   :type 'boolean)
 
+(defcustom org-export-with-properties nil
+  "Non-nil means export contents of properties drawers.
+
+When t, all properties are exported.  This may also be a list of
+properties to export, as strings.
+
+This option can also be set with the OPTIONS keyword,
+e.g. \"prop:t\"."
+  :group 'org-export-general
+  :version "24.4"
+  :package-version '(Org . "8.3")
+  :type '(choice
+	  (const :tag "All properties" t)
+	  (const :tag "None" nil)
+	  (repeat :tag "Selected properties"
+		  (string :tag "Property name"))))
+
 (defcustom org-export-with-section-numbers t
   "Non-nil means add section numbers to headlines when exporting.
 
@@ -2072,7 +2091,14 @@ a tree with a select tag."
 		      (not (eq todo-type with-tasks)))
 		 (and (consp with-tasks) (not (member todo with-tasks))))))))
     ((latex-environment latex-fragment) (not (plist-get options :with-latex)))
+    (node-property
+     (let ((properties-set (plist-get options :with-properties)))
+       (cond ((null properties-set) t)
+	     ((consp properties-set)
+	      (not (member-ignore-case (org-element-property :key blob)
+				       properties-set))))))
     (planning (not (plist-get options :with-planning)))
+    (property-drawer (not (plist-get options :with-properties)))
     (statistics-cookie (not (plist-get options :with-statistics-cookies)))
     (table-cell
      (and (org-export-table-has-special-column-p

testing/lisp/test-ox.el

@@ -479,6 +479,25 @@ Paragraph"
 	    (org-test-with-temp-text "CLOSED: [2012-04-29 sun. 10:45]"
 	      (org-export-as (org-test-default-backend)
 			     nil nil nil '(:with-planning nil))))))
+  ;; Property Drawers.
+  (should
+   (equal "* H1\n"
+	  (org-test-with-temp-text
+	      "* H1\n  :PROPERTIES:\n  :PROP: value\n  :END:"
+	    (org-export-as (org-test-default-backend)
+			   nil nil nil '(:with-properties nil)))))
+  (should
+   (equal "* H1\n:PROPERTIES:\n:PROP:     value\n:END:\n"
+	  (org-test-with-temp-text
+	      "* H1\n  :PROPERTIES:\n  :PROP: value\n  :END:"
+	    (org-export-as (org-test-default-backend)
+			   nil nil nil '(:with-properties t)))))
+  (should
+   (equal "* H1\n:PROPERTIES:\n:B:        2\n:END:\n"
+	  (org-test-with-temp-text
+	      "* H1\n  :PROPERTIES:\n  :A: 1\n  :B: 2\n:END:"
+	    (org-export-as (org-test-default-backend)
+			   nil nil nil '(:with-properties ("B"))))))
   ;; Statistics cookies.
   (should
    (equal ""