Alexandre,
I know this is a quite old post, but wanted to swing back around to it a little with some of what we've been doing lately for our upcoming 4.1 release. First off, I'm not sure if you've used the Language Switcher plugin in Joomla 1.6+, but it may cover some of what you're asking for above. Basically, it will try to detect the user's browser language, and set the Joomla language accordingly for guests. Once logged in, their user language setting will be used.
For JFBConnect v4.1, we're making a few changes, mainly to accommodate the language switcher (but also fixing a few bugs along the way):
1) Properly saving the user's current language setting when the create an account. If using the language switcher, or something else, we'll properly detect what the current user's language is in Joomla, and save that to their profile.
2) When logging in, properly setting their language session variable according to their profile. We realized recently that this variable wasn't getting set in a way that all extensions would see. So, now, if the user has a language set in their profile specifically (not just 'Default'), it should get loaded right on return trips.
We're looking into using the user's Joomla language to also set the Javascript API's language so that the Like, Comment, and other widgets are automatically translated too. This is a lot tougher though, in the case that the language in their browser is not supported by Facebook (uncommon, but happens often enough).
Any feedback is appreciated!
Alex
2
Joomla Language vs FB Language
