Load only the needed datepicker i18n files instead of all

[ZeiP]

This was originally implemented in 4b046b9, but that broke when we upgraded to Sprocket 4 in 31af1a7. e1be3b8 fixed this temporarily by compiling in all languages, but this isn't a good solution – instead should find a way to define the jquery-ui/i18n/*.js to be compiled by Sprocket in app/assets/config/manifest.js.

The main difficulty with this is that the gems aren't in the application directory, but may be in /usr/local/bundle/gems or similar, and therefore the paths relative to the configuration file that Sprocket link definition supports doesn't work. The require definition can search from all paths (which also includes the jquery-ui-rails javascripts directory), so that's easier to do but it's not useful to load the localisations in all languages for each user.

[ZeiP]

I thought I tested this well, but apparently not. It seems to always provide the Russian translation for the widget, which is kinda suboptimal. This needs to be solved before next release.

[ghost-from-the-past]

If you end having the datepicker in russian like me (because the non respect of the local language setting) you can use this very dirty patch while waiting for the final solution.

The datepicker is using the last configuration line which is
//= require jquery-ui/i18n/datepicker-ru
in the file tracks/app/assets/javascripts/applications.js

I edited the file and added after the russian one
//= require jquery-ui/i18n/datepicker-en-GB

if the language you want is already in the list, just move it to the end of the list.

In my case there was no english line but I checked and they are present at directory
/var/lib/gems/2.7.0/gems/jquery-ui-rails-6.0.1/app/assets/javascripts/jquery-ui/i18n
en-AU, en-GB, en-NZ so was safe to add the en-GB

(I use plain server, Apache , no docker)
I recompiled
bundle exec rake assets:precompile RAILS_ENV=production
adjusted the file access rights
and restart the webserver
systemctl restart apache2

now the dates are in english and I can survive until the correct solution is pushed

Regards