[O] (Maybe) refactor `org-babel-insert-header-arg'?

[Thorsten Jolitz]

Hi, 

maybe make parts of `org-babel-insert-header-arg' reusable by a
refactoring like this?

;; refactored org-babel-insert-header-arg (part 1)
#+begin_src emacs-lisp
(defun tj/prompt-for-header-arg (&optional lang)
  "Prompt for header argument selecting from lists of common args and values.
Optional argument LANG specifies the Org Babel language."
  (interactive)
  (let* ((curr-block (ignore-errors
                       (org-babel-goto-src-block-head)
                       (org-element-src-block-parser
                        (point-max) nil)))
         (lang (or lang
                   (condition-case err
                       (org-element-property :language curr-block)
                     (error "Cannot determine language"))))
         (lang-headers (intern
                        (concat "org-babel-header-args:" lang)))
         (headers (org-babel-combine-header-arg-lists
                   org-babel-common-header-args-w-values
                   (when (boundp lang-headers)
                     (eval lang-headers))))
         (header-arg (org-icompleting-read
                          "Header Arg: "
                          (mapcar
                           (lambda (header-spec)
                             (symbol-name (car header-spec)))
                           headers)))
         (vals (cdr (assoc (intern header-arg) headers)))
         (value (cond
                 ((eq vals :any)
                  (read-from-minibuffer "value: "))
                 ((listp vals)
                  (mapconcat
                   (lambda (group)
                     (let ((arg (org-icompleting-read
                                 "Value: "
                                 (cons "default"
                                       (mapcar #'symbol-name
                                               group)))))
                       (if (and arg
                                (not (string= "default" arg)))
                           (concat arg " ")
                         "")))
                   vals "")))))
    (cons header-arg value)))
#+end_src

;; refactored org-babel-insert-header-arg (part 2)
#+begin_src emacs-lisp
(defun tj/insert-header-arg (header-arg &optional value keyword-p)
  "Insert HEADER-ARG with (optional) VALUE on header line.
If optional arg KEYWORD-P is non-nil, insert as separate
'#+header:' line on top of src-block."
  (when (ignore-errors (org-babel-goto-src-block-head))
    (if keyword-p
        (progn
          (newline)
          (forward-line -1)
          (insert (format "#+header: :%s%s"
                          header-arg
                          (if value (concat " " value) ""))))
      (save-excursion
        (goto-char (point-at-eol))
        (unless (= (char-before (point)) ?\ ) (insert " "))
        (insert ":" header-arg)
        (when value (insert " " value))))))
#+end_src

-- 
cheers,
Thorsten