How to auto-complete links to headlines in org-mode?

Question

Given an example.org file having two headlines, I would like to auto-complete links to ¹headlines.

However hitting M-\ on [[* suggests *bold* words but not headlines.

Any ideas what I'm ²missing?

* Foo
Some *boldWord*
* Bar
Here I type [[*Fo followed by M-\ in order
to see *Foo suggested for autocompletion, though only *boldWord* is suggested.

Messages buffer returns:

M-\ runs hippie expand

M-\ on [[* runs Using try-expand-dabbrev-all-buffers

TAB runs org-cycle

Footnotes

¹ https://orgmode.org/manual/Completion.html

² https://github.com/syl20bnr/spacemacs/tree/master/layers/%2Bcompletion/auto-completion#auto-complete

Answer 1

This is how I do it - which uses Ivy. I use it in a currently 1.2 MB file containing the names of students and classes (I teach Business English online to Chinese professionals). I looked around for quite a while to find a way to efficiently insert internal links, the link completion didn't seem to work very well. This article contains the code for the technique I use. It does take a few seconds to find it given the size of the file but I can tolerate that.

http://pragmaticemacs.com/emacs/insert-internal-org-mode-links-the-ivy-way/

Edited to add code.

First, you need to install Ivy (I also installed the related tools Counsel and Swiper). I used Elpa to do this.

https://github.com/abo-abo/swiper

I also installed worf as this code uses it:

https://github.com/abo-abo/worf

Then based on the linked article, I added the following code to init.el:

(ivy-mode 1)
(counsel-mode 1)

(setq ivy-count-format "(%d/%d) ")
(global-set-key (kbd "C-s") 'swiper)

(require 'worf)

(defun bjm/worf-insert-internal-link ()
  "Use ivy to insert a link to a heading in the current `org-mode' document. Code is based on `worf-goto'."
  (interactive)
  (let ((cands (worf--goto-candidates)))
    (ivy-read "Heading: " cands
              :action 'bjm/worf-insert-internal-link-action)))


(defun bjm/worf-insert-internal-link-action (x)
  "Insert link for `bjm/worf-insert-internal-link'"
  ;; go to heading
  (save-excursion
    (goto-char (cdr x))
    ;; store link
    (call-interactively 'org-store-link)
    )
  ;; return to original point and insert link
  (org-insert-last-stored-link 1)
  ;; org-insert-last-stored-link adds a newline so delete this
  (delete-backward-char 1)
  )

;; this is the key that I decided to use to call this function

(global-set-key (kbd "C-c v") (quote bjm/worf-insert-internal-link))