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

[Ihor Radchenko <yantar92@posteo.net>]

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

> On Wed, 13 Mar 2024, at 12:30 PM, Ihor Radchenko wrote:
>> I think that we can do it simpler. [...]
>> The idea is to use Emacs' advice machinery to allow third-party code
>> alter the functions stored in link parameters.
>
> I was avoiding this because I thought it was only recommended (in the elisp manual) to use advice directly by users, not in libraries (like, I assume, org-roam):
>
>> If you are writing code for release, for others to use, try to avoid including advice in it. If the function you want to advise has no hook to do the job, please talk with the Emacs developers about adding a suitable hook. Especially, Emacs’s own source files should not put advice on functions in Emacs. (There are currently a few exceptions to this convention, but we aim to correct them.) It is generally cleaner to create a new hook in foo, and make bar use the hook, than to have bar put advice in foo.
>
> (https://www.gnu.org/software/emacs/manual/html_node/elisp/Advising-Named-Functions.html)

This is absolutely right, but only when advising named functions. What
we are talking about is advising the link property value. In my previous
discussions with Emacs devs, I was told that it superior to use advice
system when a library wants to modify a function stored as a value of a
variable - see
https://yhetil.org/emacs-devel/SJ0PR10MB548885B715C9875726F70F61F34FA@SJ0PR10MB5488.namprd10.prod.outlook.com/

> But I don't mind either way.  I agree your approach is simpler if it's a reasonable way for a third party library like org-roam to extend the org id functions.

I added the setter on main.
https://git.savannah.gnu.org/cgit/emacs/org-mode.git/commit/?id=d545ad606

We may also want to document the `add-function' approach in the manual.
Maybe in a new section "Modifying Hyperlink Types", right after "Adding
Hyperlink Types".

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