What is summaryQty Parameter in Item.php

Question

In Item.php file in app/code/core/Mage/CatalogInventory/Model/Stock/ there is the function

checkQuoteItemQty($qty, $summaryQty, $origQty = 0) ...

What is different in qty parameter and summaryQty parameter.

Answer 1

If you check the function itself, you will find the description of the parameters just above the function.

/**
 * Checking quote item quantity
 *
 * Second parameter of this method specifies quantity of this product in whole shopping cart
 * which should be checked for stock availability
 *
 * @param mixed $qty quantity of this item (item qty x parent item qty)
 * @param mixed $summaryQty quantity of this product
 * @param mixed $origQty original qty of item (not multiplied on parent item qty)
 * @return Varien_Object
 */

So, here $summaryQty is the total number of current product in whole cart. It will consist of all the instances of current product in different parent products.

Suppose you have a simple product added in multiple parent products like in configurable product, in bundle product or in grouped product and a customer buys one from configurable product and one from bundle product, $summaryQty will be the quantity of current simple product from both the parent products.

If the value of $summaryQty exceeds total number of available quantity of the product, it will display error message by below code

if (!$this->checkQty($summaryQty) || !$this->checkQty($qty)) {
    $message = Mage::helper('cataloginventory')->__('The requested quantity for "%s" is not available.', $this->getProductName());
    $result->setHasError(true)
        ->setMessage($message)
        ->setQuoteMessage($message)
        ->setQuoteMessageIndex('qty');
    return $result;
}