Add to cart message when stock quantity gets below 0

[HolDenWagenHarry]

I want to show a direct message if a customer wants to buy more items of an article than I have in stock. I allow backorders but the message "%s is not available in the requested quantity. %s of the items will be backordered." is only shown in their cart. But I also want to show it directly within the normal "%s was added to your shopping cart."-message. Because some customers are going directly to checkout and do not see the backorder-message in their cart. Is there a way to add this? I think I have to modify the code

"$message = $this->__('%s was added to your shopping cart.', Mage::helper('core')->escapeHtml($product->getName()));"

in

"app/code/core/Mage/Checkout/controllers/CartController.php".

Regards,

Marcus

[Sohel · Accepted solution]

You can easily handle this using event. Don't modify core file. Try following way:

app/etc/modules/SR_MagentoCommunity.xml

<?xml version="1.0"?>
<config>
	<modules>
		<SR_MagentoCommunity>
			<active>true</active>
			<codePool>local</codePool>
		</SR_MagentoCommunity>
	</modules>
</config>

app/code/local/SR/MagentoCommunity/etc/config.xml

<?xml version="1.0"?>
<config>
    <modules>
        <SR_MagentoCommunity>
            <version>0.0.0.1</version>
        </SR_MagentoCommunity>
    </modules>
    <global>
        <models>
            <sr_magentocommunity>
                <class>SR_MagentoCommunity_Model</class>
            </sr_magentocommunity>
        </models>
    </global>
    <frontend>
        <events>
            <checkout_cart_add_product_complete>
                <observers>
                    <sr_magentocommunity_checkout_cart_add_product_complete>
                        <type>singleton</type>
                        <class>sr_magentocommunity/observer</class>
                        <method>checkoutCartAddProductComplete</method>
                    </sr_magentocommunity_checkout_cart_add_product_complete>
                </observers>
            </checkout_cart_add_product_complete>
        </events>
    </frontend>
</config>

app/code/local/SR/MagentoCommunity/Model/Observer.php

<?php

class SR_MagentoCommunity_Model_Observer
{
    public function checkoutCartAddProductComplete(Varien_Event_Observer $observer)
    {
        /** @var Mage_Catalog_Model_Product $product */
        $product = $observer->getEvent()->getData('product');

        $stock = Mage::getModel('cataloginventory/stock_item')->loadByProduct($product);
        if ($stock->getQty() <= 0) {
            $notAvailableQty = $this->getAddedProductQty($product);
            $message = Mage::helper('checkout')->__('%s is not available in the requested quantity. %s of the items will be backordered.', $product->getName(), $notAvailableQty);
            Mage::getSingleton('checkout/session')->addSuccess($message);
        } else {
            $qty = $this->getAddedProductQty($product);
            $notAvailableQty = $stock->getQty() - $qty;
            if ($notAvailableQty < 0) {
                $message = Mage::helper('checkout')->__('%s is not available in the requested quantity. %s of the items will be backordered.', $product->getName(), abs($notAvailableQty));
                Mage::getSingleton('checkout/session')->addSuccess($message);
            }
        }
    }

    /**
     * @param Mage_Catalog_Model_Product $product
     * @return int
     */
    public function getAddedProductQty($product)
    {
        $cart = Mage::getSingleton('checkout/cart');
        $quote = $cart->getQuote();
        $qty = 0;

        $items = $quote->getAllVisibleItems();
        /** @var Mage_Sales_Model_Quote_Item $item */
        foreach ($items as $item) {
            if ($item->getProductId() == $product->getId()) {
                $qty = $item->getQty();
            }
        }

        return $qty;
    }
}

[HolDenWagenHarry]

Dear Sohel, it seems to work! The backorder message appears on first place and then the normal addtocart-message on second place. Maybe it is possible to combine them?

Regards,

Marcus

[HolDenWagenHarry]

Dear Sohel,

thanks for your answer again. The message works for simple products but if a customer puts a product in his cart right from a configurable-product-page the message is also shown if the relevant simple product has enough stock. Is there a way to miodify this?

Regards,

Marcus