Transposh revert to original language after Ajax request

When using Transposh, the translation goes back from French to initial language each time an Ajax request is made by the theme through BuddyPress at http://ift.tt/1Vy7fP2 with the theme Sweet Date.

I was advise to modify the on_init file in Transposh, but I can’t figure out which custom handler is used to trigger the Ajax request when posting a search request to Ajax or registering a customer form - basically everything makes Transposh revert to original language...

Is there a way to use
if (isset($_POST['action']) && $_POST['action'] == 'bla_bla_bla') { $this->target_language = transposh_utils::get_language_from_url($_SERVER['HTTP_REFERER'], $this->home_url); $this->attempt_json = true; } with all Ajax requests?

via Chebli Mohamed