<?php
$curr_date = date('Y-m-d H:i:s');
$order = $observer->getEvent()->getOrder();
foreach ($order->getItemsCollection() as $item)
{
$productId = $item->getProductId();
$qty = (int)$item->getQtyOrdered();
$product = Mage::getModel('catalog/product')->load($productId);
$stock_obj = Mage::getModel('cataloginventory/stock_item')
->loadByProduct($productId);
$stockData = $stock_obj->getData();
$product_qty_before = (int)$stock_obj->getQty();
$product_qty_after = (int)($product_qty_before + $qty);
$stockData['qty'] = $product_qty_after;
/*
* it may be case that admin has enabled product add in stock,
* after product sold, he set is_in_stock = 0 and
* if order cancelled then we need to update only qty
* not is_in_stock status.
* make a note of it
*/
if($product_qty_after != 0) {
$stockData['is_in_stock'] = 1;
}else{
$stockData['is_in_stock'] = 0;
}
$productInfoData = $product->getData();
$productInfoData['updated_at'] = $curr_date;
$product->setData($productInfoData);
$product->setStockData($stockData);
$product->save();
}
