ProductGroupAction::checkEmptyFloatValue

static function checkEmptyFloatValue($value)
{
	if (is_array($value) || $value === null)
		return null;
	$value = trim($value);
	if ($value === '')
		return '';
	$value = (float)(str_replace(',', '.', $value));
	return (is_finite($value) ? $value : null);
}