Last modified: 2014-06-04 13:06:23 UTC
In edit phase, to help user or admin to create or maintain a template or a module, a module can display messages in the user or admin language by i18n tables. Now this is made by a special test, but if the module can get de user language this can become automatic. To see an abstract: https://fr.wikisource.org/wiki/Module:ControlArgs/Documentation#Abstract_about_multilingual_evolutions To see examples: https://fr.wikisource.org/wiki/Module:ControlArgs/Documentation#Multilingual_examples
The user language is not likely to be available in Scribunto, as it would cause cache fragmentation issues.
The ask is only to read the user language code by a value or a function getUserLanguageCode() which return "en" or "fr"... Then the module can choose the right table in its own i18n tables. Then the module can display its messages in the best language for the user or the admin who maintains the page or the module.
Bottom line: this isn't going to happen unless the feature requested in bug 2085 gets implemented, for all the reasons that feature hasn't been implemented yet.