I am trying to find some ways to programatically modify org-elements that use fewer regexps and motion commands. It seems like org-dp (
https://github.com/tj64/org-dp) was intended to do that but it is not clear enough how you might use it, and it also doesn't seem to support plain-lists yet.
What I imagined happening is that I would get the element to modify as a data structure, modify the data structure, and replace the old element with an interpreted version of the modified data structure.
I want to do something like a radio list where only one box can be checked at a time. Suppose I have this:
#+attr_org: :radio
- [ ] one
- [ ] two
- [ ] three
It gets represented from org-element-context as:
(plain-list
(:type unordered :begin 579 :end 630 :contents-begin 598 :contents-end 630 :structure
((598 0 "- " nil "[ ]" nil 608)
(608 0 "- " nil "[ ]" nil 618)
(618 0 "- " nil "[ ]" nil 630))
:post-blank 0 :post-affiliated 598 :attr_org
(":radio")
:parent nil))
What I thought I could is something like (here I simulate having point in the first item):
#+BEGIN_SRC emacs-lisp :results code
(let* ((p 600) ;where current point is
n
(data '(plain-list
(:type unordered :begin 579 :end 630 :contents-begin 598 :contents-end 630 :structure
((598 0 "- " nil "[ ]" nil 608)
(608 0 "- " nil "[ ]" nil 618)
(618 0 "- " nil "[ ]" nil 630))
:post-blank 0 :post-affiliated 598 :attr_org
(":radio")
:parent nil)))
(structure (plist-get (cadr data) :structure)))
(loop for i from 0 for item in structure
do
(if (and (>= p (first item))
(< p (seventh item)))
;; in the item, toggle it
(setf (fifth item) (if (string= "[X]" (fifth item))
"[ ]"
"[X]"))
;; not on the item
(setf (fifth item) "[ ]")))
data)
#+END_SRC
Which outputs:
#+RESULTS:
#+BEGIN_SRC emacs-lisp
(plain-list
(:type unordered :begin 579 :end 630 :contents-begin 598 :contents-end 630 :structure
((598 0 "- " nil "[X]" nil 608)
(608 0 "- " nil "[ ]" nil 618)
(618 0 "- " nil "[ ]" nil 630))
:post-blank 0 :post-affiliated 598 :attr_org
(":radio")
:parent nil))
#+END_SRC
As a step towards getting to a data structure I could programmatically modify, and then reinterpret, I made this little function:
(defun ointerp ()
(interactive)
(let ((el (org-element-context)))
(kill-new (org-element-interpret-data el))))
It works on some things, e.g. headlines, src blocks. I put the point on one of those things, run this command, and then I can paste it somewhere to see that it did indeed work.
But, it does not work on plain-lists, or paragraphs. I either get an empty string, or Wrong type argument: char-or-string-p, nil
Is it possible to do what I am describing? Am I just missing how to get the element data in the right form?
Thanks,
John
-----------------------------------
Professor John Kitchin
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803