Add product to cart with custom price, using the API

Question

How can I add a product with a custom price to the cart, using the Magento API?

I found a solution where a special price is configured for one second, but this leaves the special price visible in the backend and this is not allowed.

Answer 1

The solution for me was to create a new API method, which allows to set the prices of the products in the cart. The function is based on the cart_product.remove function.

public function setCustomPrice($quoteId, $productsData, $store = null)
{
    $quote = $this->_getQuote($quoteId, $store);
    if (empty($store)) {
        $store = $quote->getStoreId();
    }

    $productsData = $this->_prepareProductsData($productsData);
    if (empty($productsData)) {
        $this->_fault('invalid_product_data');
    }

    $errors = array();
    foreach ($productsData as $productItem) {
        if (isset($productItem['product_id'])) {
            $productByItem = $this->_getProduct($productItem['product_id'], $store, "id");
        } else if (isset($productItem['sku'])) {
            $productByItem = $this->_getProduct($productItem['sku'], $store, "sku");
        } else {
            $errors[] = Mage::helper('checkout')->__("One item of products do not have identifier or sku");
            continue;
        }

        try {
            /** @var $quoteItem Mage_Sales_Model_Quote_Item */
            $quoteItem = $this->_getQuoteItemByProduct($quote, $productByItem,
                $this->_getProductRequest($productItem));
            if (is_null($quoteItem->getId())) {
                $errors[] = Mage::helper('checkout')->__("One item of products is not belong any of quote item");
                continue;
            }

            if(isset($productItem['price'])){
                $quoteItem->setCustomPrice($productItem['price']);
                $quoteItem->setOriginalCustomPrice($productItem['price']);
                $quoteItem->getProduct()->setIsSuperMode(true);
                $quoteItem->save();
            }

        } catch (Mage_Core_Exception $e) {
            $errors[] = $e->getMessage();
        }
    }

    if (!empty($errors)) {
        $this->_fault("remove_product_fault", implode(PHP_EOL, $errors));
    }

    try {
        $quote->collectTotals()->save();
    } catch (Exception $e) {
        $this->_fault("remove_product_quote_save_fault", $e->getMessage());
    }

    return true;
}