Version 1.0 of SubjectsPlus is using gettext to translate strings. This is a standard way of handling internationalization, and should work much better than the previous hacky way.
There is now a French version of the beta ready, thanks to Benoit H!
Make sure there is a translation for your language
Look in sp/assets/locale/ Do you see an appropriate folder for your language? If so, check inside and see if there is a messages.mo file in there. If so, you should be good. If there is just messages.po, it hasn't been translated or compiled yet. You can try sending a message to the google group to see if it has already been translated (but not yet shared back), or you can write your own translation--making sure to share it back again!
Make sure you have the gettext() extension on your server
You can try doing this to check: https://phptal.org/manual/en/split/gettext.html. Alternately, you can just try turning it on with the instructions below and seeing if it works :)
Make sure your locale (i.e., language) is on your server
One user had an issue with gettext on ubuntu. This helped: https://stackoverflow.com/questions/5257519/cant-get-gettext-php-on-ubuntu-working
They just needed to run the following to get French running on their server:
sudo locale-gen fr_FR
sudo service apache2 restart
Set up the translation in sp/control/includes/config.php
Look for the section that begins
// I18N support information here
There should be a section of commented out code.
1. Uncomment everything except the comments :)
2. Change the language to the appropriate one. If you want French, changed the $language to this:
$language = 'fr_FR';
3. Go to a page in the admin, e.g., control/admin/index.php. Do you now see the text in French?
If it isn't working:
1. Make sure there is already a translation for your desired language in assets/locale/ As of today (April, 2016), there are only 3 languages in place: French, Spanish and Russian. If you have another translation, please share it back for other SubjectsPlus users!!!
2. If there is a language, but uncommenting and changing the $language didn't work, try restarting your web server.
3. Still not working? Try hard coding the $LocalePath. E.g.,
$LocalePath = "/home/myname/www/sp/assets/locale";