Re: [PATCH] Allow external libraries (org-roam) to supply org-id locations

[Ihor Radchenko]

"Rick Lupton" <mail@ricklupton.name> writes:

> Since updating the org-id code [1] to use the standard org-link registered 
> functions instead of hard-coding org-id opening, I have a problem using 
> org-roam.
>
> org-roam overwrites the :follow function for "id" links from the build-in 
> `org-id-open' to its own `org-roam-id-open' 
> (https://github.com/org-roam/org-roam/blob/8667e441876cd2583fbf7282a65796ea149f0e5f/org-roam-id.el#L91).
>   The only change between these functions is to insert a call to try 
> `org-roam-id-find' before trying `org-id-find', which uses org-roam's cached 
> sqlite database to find the id 
> (https://github.com/org-roam/org-roam/blob/8667e441876cd2583fbf7282a65796ea149f0e5f/org-roam-id.el#L70-L71)
>
> As well as being messy, my specific problem is that the improvements to open 
> search strings in org-id links are no longer enabled when org-roam is loaded.
>
> It seems reasonable that a library might want to provide its own way of 
> locating org-ids.  The attached patch adds a new hook variable 
> `org-id-find-functions` which contains functions doing the same job as 
> `org-id-find' that should be tried first.  Then all org-roam needs to do is 
> add its `org-roam-id-find' to the hook.
>
> Does this seem like a good idea?

I think that we can do it simpler.

Something like

(defun yant/message-me (&rest _) (message "I am here!") nil) ; return nil to 
pass the turn
(gv-define-setter org-link-get-parameter (value type key)
  `(org-link-set-parameters ,type ,key ,value))
(add-function :before-until (org-link-get-parameter "id" :follow) 
#'yant/message-me)

The idea is to use Emacs' advice machinery to allow third-party code
alter the functions stored in link parameters.

Either way, org-roam needs to be adapted in order to support the changes
in org-id. My variant appears to be simpler. We just need to add
`gv-define-setter ...' and maybe also document the `add-function'
approach in the manual.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
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