ox-latex: Format-spec for hyperref and title

* ox-latex.el (org-latex--format-spec): New function with format-specs.
  (org-latex-template): Use org-latex--format-spec.
  (org-latex-hyperref-template): New defaults and use
  org-latex--format-spec.
  (org-latex-title-command): Use org-latex--format-spec.
* ORG-NEWS: Mention change.

etc/ORG-NEWS

@@ -233,6 +233,9 @@ Exact heading search for links now ignore spaces and cookies. This is
 the case for links of the form ~file:projects.org::*task title~, as
 well as links of the form ~file:projects.org::some words~
 when ~org-link-search-must-match-exact-headline~ is not nil.
+*** ~org-latex-hyperref-template~, ~org-latex-title-command~ formatting
+New formatting keys are supported.  See the respective docstrings.
+Note, ~org-latex-hyperref-template~ has a new default value.
 * Version 8.2
 
 ** Incompatible changes

lisp/ox-latex.el

@@ -383,11 +383,25 @@ are written as utf8 files."
 
 (defcustom org-latex-title-command "\\maketitle"
   "The command used to insert the title just after \\begin{document}.
-If this string contains the formatting specification \"%s\" then
-it will be used as a formatting string, passing the title as an
-argument."
+
+This format string may contain these elements:
+
+  %a for AUTHOR keyword
+  %t for TITLE keyword
+  %k for KEYWORDS line
+  %d for DESCRIPTION line
+  %c for CREATOR line
+  %l for Language keyword
+  %L for capitalized language keyword
+  %D for DATE keyword
+
+If you need to use a \"%\" character, you need to escape it
+like that: \"%%\".
+
+Setting :latex-title-command in publishing projects will take
+precedence over this variable."
   :group 'org-export-latex
-  :type 'string)
+  :type '(string :tag "Format string"))
 
 (defcustom org-latex-toc-command "\\tableofcontents\n\n"
   "LaTeX command to set the table of contents, list of figures, etc.
@@ -397,20 +411,30 @@ the toc:nil option, not to those generated with #+TOC keyword."
   :type 'string)
 
 (defcustom org-latex-hyperref-template
-  "\\hypersetup{\n pdfkeywords={%k},\n  pdfsubject={%d},\n  pdfcreator={%c}}\n"
+  "\\hypersetup{\n pdfauthor={%a},\n pdftitle={%t},\n pdfkeywords={%k},
+ pdfsubject={%d},\n pdfcreator={%c}, \n pdflang={%L}}\n"
   "Template for hyperref package options.
 
-Value is a format string, which can contain the following placeholders:
+This format string may contain these elements:
 
+  %a for AUTHOR keyword
+  %t for TITLE keyword
   %k for KEYWORDS line
   %d for DESCRIPTION line
   %c for CREATOR line
+  %l for Language keyword
+  %L for capitalized language keyword
+  %D for DATE keyword
 
-Set it to the empty string to ignore the command completely."
+If you need to use a \"%\" character, you need to escape it
+like that: \"%%\".
+
+Setting :latex-hyperref-template in publishing projects will take
+precedence over this variable."
   :group 'org-export-latex
   :version "25.1"
   :package-version '(Org . "8.3")
-  :type 'string)
+  :type '(string :tag "Format string"))
 
 ;;;; Headline
 
@@ -1193,6 +1217,33 @@ just outside of it."
 INFO is a plist used as a communication channel."
   (org-export-translate s :latex info))
 
+(defun org-latex--format-spec (info)
+  "Create a format-spec for document meta-data.
+INFO is a plist used as a communication channel."
+  (let ((objects '(bold code entity export-snippet inline-babel-call
+			inline-src-block italic latex-fragment
+			latex-math-block link macro strike-through
+			subscript superscript timestamp underline
+			verbatim))
+	(language (let ((lang (plist-get info :language)))
+		    (or (cdr (assoc lang org-latex-babel-language-alist))
+			lang ""))))
+    `((?a . ,(or (org-export-data (plist-get info :author) info) ""))
+      (?t . ,(or (org-export-data (plist-get info :title)  info) ""))
+      (?k . ,(org-export-data (org-latex--wrap-latex-math-block
+			       (org-element-parse-secondary-string
+				(plist-get info :keywords) objects)
+			       info)
+			      info))
+      (?d . ,(org-export-data (org-latex--wrap-latex-math-block
+			       (org-element-parse-secondary-string
+				(plist-get info :description) objects)
+			       info)
+			      info))
+      (?c . ,(if (plist-get info :with-creator) (plist-get info :creator) ""))
+      (?l . ,language)
+      (?L . ,(capitalize language))
+      (?D . ,(org-export-get-date info)))))
 
 
 ;;; Template
@@ -1201,7 +1252,8 @@ INFO is a plist used as a communication channel."
   "Return complete document string after LaTeX conversion.
 CONTENTS is the transcoded contents string.  INFO is a plist
 holding export options."
-  (let ((title (org-export-data (plist-get info :title) info)))
+  (let ((title (org-export-data (plist-get info :title) info))
+	(spec (org-latex--format-spec info)))
     (concat
      ;; Time-stamp.
      (and (plist-get info :time-stamp-file)
@@ -1248,17 +1300,15 @@ holding export options."
      ;; Title
      (format "\\title{%s}\n" title)
      ;; Hyperref options.
-     (format-spec (plist-get info :latex-hyperref-template)
-                  (format-spec-make
-                   ?k (or (plist-get info :keywords) "")
-                   ?d (or (plist-get info :description)"")
-                   ?c (if (plist-get info :with-creator)
-                          (plist-get info :creator)
-                        "")))
+     (let ((template (plist-get info :latex-hyperref-template)))
+       (and (stringp template)
+            (format-spec template spec)))
      ;; Document start.
      "\\begin{document}\n\n"
      ;; Title command.
-     (let ((command (plist-get info :latex-title-command)))
+     (let* ((title-command (plist-get info :latex-title-command))
+            (command (and (stringp title-command)
+                          (format-spec title-command spec))))
        (org-element-normalize-string
 	(cond ((not (plist-get info :with-title)) nil)
 	      ((string= "" title) nil)