Test of internal links in org and in org-ruby

1. link via CUSTOM_ID
   • CUSTOM_ID is added to heading using C-c C-x p (org-set-property)
2. link via text search in headings
   • Requires exact match to heading text
   • Not recommended
   • Very fragile against any change to the target heading
3. link via autogenerated ID
   • ID is generated by calling M-x org-store-link with point on the target heading.
   • This requires that the variable org-id-link-to-org-use-id is not nil.
     • There are various possible values for this variable.
     • I have it set to create-if-interactive-and-no-custom-id.
4. link via explicit target
   • Requires exact match to text of target
5. link via cheating
   • This only works in org-ruby, but not in org itself
   • We use an anchor that is the headline text, but converted to lower case and with spaces converted to hyphens

Test score sheets for the three different contexts

[4/5] Within emacs itself

1. [X] Works
2. [X] Works
3. [X] Works
4. [X] Works
5. [ ] Fails because the target does not exist from the emacs point of view

[2/5] Exporting HTML from emacs org-mode

Using C-c C-e h o or similar

1. [X] Works
2. [ ] Broken in org 8.2.7 if the heading contains spaces (see this thread)
3. [X] Works
4. [ ] Also broken in 8.2.7
5. [ ] Fails

[1/5] Convert to HTML using org-ruby

1. [ ] Broken because the CUSTOM_ID property does not get made into an anchor by org-ruby
2. [ ] Broken because the link is transformed into a link to a file with the name of the heading
3. [ ] Broken because no link is created at all
4. [ ] Broken because the angle bracket notation for anchors is not recognised by org-ruby
5. [X] Works because we have crafted the link to match the anchor syntax that org-ruby generates

Headings we want to link to

Via a CUSTOM_ID

Via text search

Via autogenerated ID

Via explicit target <<#mytarget2>>

Via cheating