App\Ninja\Intents\UpdateInvoiceIntent::process PHP Method

    public function process()
    {
        $invoice = $this->stateInvoice();
        $invoiceItems = $this->requestInvoiceItems();
        $data = array_merge($this->requestFields(), ['public_id' => $invoice->public_id, 'invoice_items' => array_merge($invoice->invoice_items->toArray(), $invoiceItems)]);
        // map the cost and qty fields to the invoice items
        if (isset($data['cost']) || isset($data['quantity'])) {
            foreach ($data['invoice_items'] as $key => $item) {
                // if it's new or we recently created it
                if (empty($item['public_id']) || in_array($item['public_id'], $this->entities(ENTITY_INVOICE_ITEM))) {
                    $data['invoice_items'][$key]['cost'] = isset($data['cost']) ? $data['cost'] : $item['cost'];
                    $data['invoice_items'][$key]['qty'] = isset($data['quantity']) ? $data['quantity'] : $item['qty'];
                }
            }
        }
        //var_dump($data);
        $valid = EntityModel::validate($data, ENTITY_INVOICE, $invoice);
        if ($valid !== true) {
            throw new Exception($valid);
        }
        $invoice = $this->invoiceRepo->save($data, $invoice);
        $invoiceItems = array_slice($invoice->invoice_items->toArray(), count($invoiceItems) * -1);
        $invoiceItemIds = array_map(function ($item) {
            return $item['public_id'];
        }, $invoiceItems);
        $this->setStateEntities(ENTITY_INVOICE_ITEM, $invoiceItemIds);
        $response = $invoice->load('invoice_items')->present()->skypeBot;
        return $this->createResponse(SKYPE_CARD_RECEIPT, $response);
    }