I have created joomla module mod_my. module consists of mod_sign_up_courses.php, en-GB.mod_sign_up_courses.ini, default.php, helper.php, ...
If I write
echo JText::_('BACK_TITLE');
in default.php (template), then it works.
If I write
echo JText::_('BACK_TITLE');
in helper.php, then it doesn’t work.
How correctly use internationalization in helper.php?
You must load manually your language file, as explained here for instance.
I quote:
Source: http://dreference.blogspot.co.uk/2012/04/how-to-load-language-file-for-joomla.html