Magento multiple order on one checkout or order splitting

Question

Store products are supplied from different vendors. It is required to create multiple order for every vendor based on its products in the cart during one checkout. Is there any extension to achieve this task or should I start to develop custom checkout module. What about hot points for creating such extension vision of experienced developers of Magento? Can you explain me brief checkout flow architecture Magento friendly (as possible as code level)? Thanks much more!

Answer 1

It is doable quite easily with a rewrite of the checkout/type_onepage model.
In that class override the saveOrder() method as follows:

public function saveOrder()
{
    $quote = $this->getQuote();

    // First build an array with the items split by vendor
    $sortedItems = array();
    foreach ($quote->getAllItems() as $item) {
        $vendor = $item->getProduct()->getVendor(); // <- whatever you need
        if (! isset($sortedItems[$vendor])) {
            $sortedItems[$vendor] = $item;
        }
    }
    foreach ($sortedItems as $vendor => $items) {
        // Empty quote
        foreach ($quote->getAllItems() as $item) {
            $quote->getItemsCollection()->removeItemByKey($item->getId());
        }
        foreach ($items as $item) {
            $quote->addItem($item);
        }
        // Update totals for vendor
        $quote->setTotalsCollectedFlag(false)->collectTotals();

        // Delegate to parent method to place an order for each vendor
        parent::saveOrder();
    }
    return $this;
}

But be aware that in Magento a payment is associated with an invoice, and each invoice is associated with an order.

In consequence this means that as soon as you have multiple orders, you will also have split the payments. So this is only feasible if the payment method doesn't require user interaction during the payment.

UPDATE: The orginal answer delegated to parent::save() which had to be parent:saveOrder(). It is fixed in the example code now.

Answer 2

The following is tested in CE ver 1.9.0.x

/**
 * Overwrite core
 */
class Vendor_Module_Model_Checkout_Type_Onepage extends Mage_Checkout_Model_Type_Onepage
{
    protected $_oriAddresses = array();

    /**
     * Prepare order from quote_items  
     *
     * @param   array of Mage_Sales_Model_Quote_Item 
     * @return  Mage_Sales_Model_Order
     * @throws  Mage_Checkout_Exception
     */
    protected function _prepareOrder2($quoteItems)
    {
        $quote = $this->getQuote();
        $quote->unsReservedOrderId();
        $quote->reserveOrderId();

        // new instance of quote address
        $quote->setIsMultiShipping(true); // required for new instance of Mage_Sales_Model_Quote_Address
        $address = Mage::getModel('sales/quote_address');
        $weight = 0;
        $addressType = 'billing';
        foreach ($quoteItems as $quoteItem) {
            $address->addItem($quoteItem, $quoteItem->getQty());
            $weight += $quoteItem->getWeight();
            if (!$quoteItem->getIsVirtual()) {
                $addressType = 'shipping';
            }
        }
        // get original shipping address that contains multiple quote_items
        if (!isset($this->_oriAddresses[$addressType])) {
            $this->_oriAddresses[$addressType] = Mage::getResourceModel('sales/quote_address_collection')
                ->setQuoteFilter($quote->getId())
                ->addFieldToFilter('address_type', $addressType)
                ->getFirstItem();
        }
        Mage::helper('core')->copyFieldset('sales_convert_quote_address', 'to_customer_address', $this->_oriAddresses[$addressType], $address);
        Mage::helper('core')->copyFieldset('sales_convert_quote_address', 'to_order', $this->_oriAddresses[$addressType], $address);
        $address->setQuote($quote)
            ->setWeight($weight)
            ->setSubtotal(0)
            ->setBaseSubtotal(0)
            ->setGrandTotal(0)
            ->setBaseGrandTotal(0)
            ->setCollectShippingRates(true)
            ->collectTotals()
            ->collectShippingRates()        
            ;

        $convertQuote = Mage::getSingleton('sales/convert_quote');
        $order = $convertQuote->addressToOrder($address);
        $order->setBillingAddress(
            $convertQuote->addressToOrderAddress($quote->getBillingAddress())
        );

        if ($address->getAddressType() == 'billing') {
            $order->setIsVirtual(1);
        } else {
            $order->setShippingAddress($convertQuote->addressToOrderAddress($address));
        }

        $order->setPayment($convertQuote->paymentToOrderPayment($quote->getPayment()));
        if (Mage::app()->getStore()->roundPrice($address->getGrandTotal()) == 0) {
            $order->getPayment()->setMethod('free');
        }

        foreach ($quoteItems as $quoteItem) {
            $orderItem = $convertQuote->itemToOrderItem($quoteItem);  // use quote_item to transfer is_qty_decimal
            if ($quoteItem->getParentItem()) {
                $orderItem->setParentItem($order->getItemByQuoteItemId($quoteItem->getParentItem()->getId()));
            }
            $order->addItem($orderItem);
        }

        return $order;
    }

    /**
     * Overwrite core function
     */
    public function saveOrder()
    {
        $quote = $this->getQuote();
        if ($quote->getItemsCount() > 1) {
            $items = $quote->getAllVisibleItems();
            $group = array();
            $split = array();
            foreach ($items as $item) {
                if (Mage::helper('vendor')->checkSku($item->getSku())) {
                    $split[] = array($item); // one item per order
                } else {
                    $group[] = $item; // all other items in one order
                }
            }
            if (count($split)) {
                if (count($group)) {
                    $split[] = $group;
                }
                return $this->_splitQuote($split);
            }
        }
        return parent::saveOrder();
    }

    /**
     * Split quote to multiple orders
     * 
     * @param array of Mage_Sales_Model_Quote_Item
     * @return Mage_Checkout_Model_Type_Onepage
     */
    protected function _splitQuote($split)
    {
        $this->validate();
        $isNewCustomer = false;
        switch ($this->getCheckoutMethod()) {
            case self::METHOD_GUEST:
                $this->_prepareGuestQuote();
                break;
            case self::METHOD_REGISTER:
                $this->_prepareNewCustomerQuote();
                $isNewCustomer = true;
                break;
            default:
                $this->_prepareCustomerQuote();
                break;
        }
        if ($isNewCustomer) {
            try {
                $this->_involveNewCustomer();
            } catch (Exception $e) {
                Mage::logException($e);
            }
        }

        $quote = $this->getQuote()->save();
        $orderIds = array();
        Mage::getSingleton('core/session')->unsOrderIds();
        $this->_checkoutSession->clearHelperData();

        /**
         * a flag to set that there will be redirect to third party after confirmation
         * eg: paypal standard ipn
         */
        $redirectUrl = $quote->getPayment()->getOrderPlaceRedirectUrl();

        foreach ($split as $quoteItems) {
            $order = $this->_prepareOrder2($quoteItems);
            $order->place();
            $order->save();
            Mage::dispatchEvent('checkout_type_onepage_save_order_after',
                array('order'=>$order, 'quote'=>$quote));
            /**
             * we only want to send to customer about new order when there is no redirect to third party
             */
            if (!$redirectUrl && $order->getCanSendNewEmailFlag()) {
                $order->sendNewOrderEmail();
            }
            $orderIds[$order->getId()] = $order->getIncrementId();
        }

        Mage::getSingleton('core/session')->setOrderIds($orderIds);

        // add order information to the session
        $this->_checkoutSession
            ->setLastQuoteId($quote->getId())
            ->setLastSuccessQuoteId($quote->getId())
            ->setLastOrderId($order->getId())
            ->setRedirectUrl($redirectUrl)
            ->setLastRealOrderId($order->getIncrementId());

        // as well a billing agreement can be created
        $agreement = $order->getPayment()->getBillingAgreement();
        if ($agreement) {
            $this->_checkoutSession->setLastBillingAgreementId($agreement->getId());
        }

        // add recurring profiles information to the session
        $service = Mage::getModel('sales/service_quote', $quote);
        $profiles = $service->getRecurringPaymentProfiles();
        if ($profiles) {
            $ids = array();
            foreach ($profiles as $profile) {
                $ids[] = $profile->getId();
            }
            $this->_checkoutSession->setLastRecurringProfileIds($ids);
            // TODO: send recurring profile emails
        }

        Mage::dispatchEvent(
            'checkout_submit_all_after',
            array('order' => $order, 'quote' => $quote, 'recurring_profiles' => $profiles)
        );

        return $this;
    }
}

IMPORTANT You need to customize your payment methods to retrieve the grand total from the quote.