I think this is all you need to get a list of titles of level 1 headings as
strings

(org-map-entries (lambda () (fifth (org-heading-components))) "LEVEL=1")

this also works for me:

#+BEGIN_SRC emacs-lisp
(org-map-entries (lambda () (org-element-property :title
(org-element-at-point)) ) "LEVEL=1")
#+END_SRC




John

-----------------------------------
Professor John Kitchin (he/him/his)
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803
@johnkitchin
http://kitchingroup.cheme.cmu.edu



On Wed, May 19, 2021 at 3:51 AM Florian Lindner <mailinglists@xgm.de> wrote:

> Hello,
>
> I, an Emacs Lisp newbie, want to get a list of all top-level headings of
> the current buffer. My approach so far is:
>
> (defun test-org-map()
>   (interactive)
>   (setq headings '())
>   (org-map-entries (lambda ()
>                      (setq current-header-item (org-element-property
> :title (org-element-at-point))
>                      (message "Header: %s" current-header-item)
>                      (message "Is String: %s" (stringp
> (org-element-property :title (org-element-at-point))))
>                      (setq headings (append current-header-item headings))
>                      )
>                    "LEVEL=1"
>                    )
>   (dolist (heading headings)
>     (message "Header Item: %s" heading)
>     )
>   )
>
> This gives the otput:
>
> Header: AAA
> Is String: t
> Header: BBB
> Is String: t
> Header Item: 66 [3 times]
> Header Item: 65 [3 times]
>
> so basically the (org-element-property :title (org-element-at-point) does
> exactly what I want, but building the list does not what I want. I suppose
> that comes from a fundamental misunderstanding of how strings work in elisp.
>
> I would appreciate a short explanation (or pointers) why this does not
> work. And of course, I am very open to completely different, likely better,
> approches to that simply problem!
>
> Thanks,
> Florian
>