public function __construct(OrderInvoice $order_invoice, $smarty)
 {
     $this->order_invoice = $order_invoice;
     $this->order = new Order((int) $this->order_invoice->id_order);
     $this->smarty = $smarty;
     // header informations
     $this->date = Tools::displayDate($order_invoice->date_add);
     $id_lang = Context::getContext()->language->id;
     $this->title = HTMLTemplateInvoice::l('Invoice ') . ' #' . Configuration::get('PS_INVOICE_PREFIX', $id_lang, null, (int) $this->order->id_shop) . sprintf('%06d', $order_invoice->number);
     // footer informations
     $this->shop = new Shop((int) $this->order->id_shop);
 }
 /**
  * Returns the template's HTML header
  *
  * @return string HTML header
  */
 public function getHeader()
 {
     $this->assignCommonHeaderData();
     $this->smarty->assign(array('header' => HTMLTemplateInvoice::l('Invoice')));
     return $this->smarty->fetch($this->getTemplate('header'));
 }