[O] Two potentially useful functions for org-element

[Thorsten Jolitz]

Hi List, 

now that I understand the 'org-element API' a bit better, I think that
the following two functions can be very useful for creating and
modifying Org elements without the usual point movements, regexp
searches and string operations in a buffer:

#+begin_src emacs-lisp
;; might become `org-element-create'
(defun* tj/create-element (&optional insert-p &rest args &key (type 'headline) 
&allow-other-keys)
  "Create Org element, maybe insert at point."
  (let ((strg (org-element-interpret-data
               (list type args))))
    (if insert-p (insert strg) strg)))
#+end_src

#+results:
: tj/create-element


#+begin_src emacs-lisp
;; might become `org-element-rewire'
(defun* tj/rewire-element (&optional replace &rest args &key type 
&allow-other-keys)
  "Rewire element at point, maybe replace it."
  (let* ((elem (org-element-at-point))
         (plist (cadr elem))
         (beg (org-element-property :begin elem))
         (end (org-element-property :end elem))
         strg)
    (while args
          (setq plist (plist-put plist (pop args) (pop args))))
    (setq strg (org-element-interpret-data
                (list
                 (or type (org-element-type elem))
                 plist)))
    (case replace
      (append (save-excursion (goto-char end) (insert strg)))
      (prepend (goto-char beg) (insert strg))
      (t (if replace
             (let ((marker (save-excursion
                             (goto-char end) (point-marker))))
               (delete-region beg end)
               (goto-char marker)
               (save-excursion (insert strg)))
           strg)))))
#+end_src

#+results:
: tj/rewire-element

Here are a few usage examples:

#+begin_src emacs-lisp
  (tj/create-element nil
                     :type 'src-block
                     :language "emacs-lisp"
                     :value "(+ 2 2)\n"
                     :parameters ":results raw"
                     :name "myblock"
                     :header '(":var x=5"))
#+end_src

#+results:
: #+NAME: myblock
: #+HEADER: :var x=5
: #+BEGIN_SRC emacs-lisp :results raw
:   (+ 2 2)
: #+END_SRC

#+begin_src emacs-lisp :wrap org
  (tj/create-element nil
                     :type 'headline
                     :level 2
                     :todo-keyword "DONE"
                     :priority 66
                     :title "Hello World"
                     :tags '("tag1" "tag2"))
#+end_src

#+results:
#+BEGIN_org
,** DONE [#B] Hello World :tag1:tag2:
#+END_org

Now eval next src-block


#+begin_src emacs-lisp
  (defun test-fun ()
    (tj/rewire-element 'append
                       :parameters ":results table :exports both"
                       :name (format "random-block-%d" (1+ (random 11)))
                       :header '(":var x=5")
                       :value (format "%s\n%s\n" '(+ 2 2) '(* 3 x))))
#+end_src

#+results:
: test-fun

and then, with point at beginning of following src-block, eval 'M-: (test-fun)'

#+BEGIN_SRC emacs-lisp :results raw
  (+ 2 2)
#+END_SRC


#+NAME: random-block-6
#+HEADER: :var x=5
#+BEGIN_SRC emacs-lisp :results table :exports both
  (+ 2 2)
  (* 3 x)
#+END_SRC


-- 
cheers,
Thorsten