App\Providers\TranslationServiceProvider::boot PHP Méthode

    public function boot()
    {
        $this->app['events']->listen('locale.changed', function ($locale) {
            $this->app['xe.translator']->setLocale($locale);
        });
        $this->app['validator']->extend('LangRequired', function ($attribute, $value) {
            $fields = $this->app['request']->all();
            $protocol = 'xe_lang_preprocessor://';
            $prefix = null;
            foreach ($fields as $key => $val) {
                if (starts_with($key, $protocol)) {
                    if ($val == $attribute) {
                        $prefix = substr($key, 0, strrpos($key, '/'));
                        break;
                    }
                }
            }
            $locale = $this->app['xe.translator']->getLocale();
            $name = $prefix . '/locale/' . $locale;
            $validator = null;
            foreach ($fields as $key => $val) {
                if ($name == $key) {
                    $validator = $this->app['validator']->make([$attribute => $val], [$attribute => 'Required']);
                }
            }
            if ($validator === null) {
                return false;
            }
            return $validator->passes();
        }, 'The :attribute field is required.');
    }