Set custom total row price in basket - Magento

Question

I'm developing a B2B webshop in Magento. When adding a product to basket, it will call an external API to lookup discount based on the user, product, and quantity. Problem is that the API only returns the total discounted price.

E.g. adding 10 items of $5 may return a total discountet price of $40. So ideally the shopping cart would show $5 x 10 = $40.

I've already accomplished this by overriding Mage_Sales_Model_Quote_Item in my modules config.xml:

<global>
    <models>
        <sales>
            <rewrite>
                <quote_item>Frigg_Import_Model_QuoteItem</quote_item>
            </rewrite>
        </sales>
    </models>
</global>

And then overriding the calcRowTotal()

class Frigg_Import_Model_QuoteItem extends Mage_Sales_Model_Quote_Item
{
    protected $customRowTotalPrice = null;

    public function setCustomRowTotalPrice($price)
    {
        $this->customRowTotalPrice = $price;
    }

    public function calcRowTotal()
    {
        if ($this->customRowTotalPrice !== null) {
            $this->setRowTotal($this->getStore()->roundPrice($this->customRowTotalPrice));
            $this->setBaseRowTotal($this->getStore()->roundPrice($this->customRowTotalPrice));
            return $this;
        }

        $qty = $this->getTotalQty();
        $total = $this->getStore()->roundPrice($this->getCalculationPriceOriginal()) * $qty;
        $baseTotal = $this->getStore()->roundPrice($this->getBaseCalculationPriceOriginal()) * $qty;

        $this->setRowTotal($this->getStore()->roundPrice($total));
        $this->setBaseRowTotal($this->getStore()->roundPrice($baseTotal));
        return $this;
    }

}

Then handling the event checkout_cart_product_add_after and passing this to my Observer method setPriceForItem:

<?php

class Frigg_Import_Model_Observer
{
    // Event: Price for single item
    public function setPriceForItem(Varien_Event_Observer $observer)
    {
        $customer = Mage::getSingleton('customer/session')->getCustomer();
        $item = $observer->getQuoteItem();
        if ($item->getParentItem()) {
            $item = $item->getParentItem();
        }

        $quantity = $item->getQty(); // e.g. 5
        $product = $item->getProduct();

        // Call API here and get the total price based on quantity (e.g. 40)
        // ....
        $customTotalRowPriceFromAPI = 40;

        if ($customTotalRowPriceFromAPI) {
            $item->setCustomRowTotalPrice($customTotalRowPriceFromAPI);
            $item->getProduct()->setIsSuperMode(true);
            $item->save();
        }
    }
}

Now this works, but only when adding to the basket. When I reload the browser, or go to the shopping cart page, the row prices have been reset to original price (in this case $5 x 10 = $50).

Does anyone spot my error? I hope I've explained the properly.

I'm not familiar with the quote items table (kinda new to Magento). Could you elaborate? Thank you. — frigg
There is a table with the quote items in it, check it in phpmyadmin and see what prices are coming through. — ʍǝɥʇɐɯ
When adding a product to basket, the row total is properly set in sales_flat_quote_item table, but when visiting the shopping cart, the prices have been reset. I'm guessing that I need to overwrite the method calculting the row total in shopping cart, but don't know how (yet). Any ideas? — frigg
I am not too familiar with it, however, it is loading the products in the cart and getting data from there for sensible things like the image and links. Where it is pulling the price I suspect that is from the product rather than the quote object. If you go straight to checkout is that showing expected prices? — ʍǝɥʇɐɯ

frigg frigg · Accepted Answer · 2014-06-02T10:38:11

Solved it. Just had to store the price per customer, product, and quantity in a new table when adding to cart, and then fetch the price from the new table in calcRowTotal.

Set custom total row price in basket - Magento

1 Answers