<?php

function smarty_function_get_delivery_dispatch_date($params, &$smarty)
{
    if (empty($params['delivery'])) {
        throw new InvalidArgumentException('Missing parameter \'delivery\'');
    }

    /** @var Delivery $delivery */
    $delivery = $params['delivery'];

    $dispatchDate = $delivery->getDispatchDate();

    if (!empty($params['assign'])) {
        $smarty->assign($params['assign'], $dispatchDate);
    } else {
        return $dispatchDate;
    }
}