Kdjykuj

I am tring to change product collection using catalog_product_collection_load_before.
I need to sort products by in stock. Out of stock must be last.

following config.xml,

<events>

    <catalog_product_collection_load_before>

        <observers>

            <gst_sales_order_observer>

                <class>Magecomp_Sortby_Model_Observer</class>

                <method>modifyProductCollection</method>

            </gst_sales_order_observer>

        </observers>

    </catalog_product_collection_load_before>

</events>

following Observer.php

public function modifyProductCollection($observer)

{

    if (Mage::registry('current_category'))

    {   

        $products = $observer->getEvent()->getCollection();

        $_category_detail=Mage::registry('current_category');



        //Inventory Stock 

        $toolbar = Mage::getBlockSingleton('catalog/product_list_toolbar');

        if ($toolbar) {

            $products = $observer->getEvent()->getCollection();



            $stockId = Mage_CatalogInventory_Model_Stock::DEFAULT_STOCK_ID;

            $websiteId = Mage::app()->getStore($products->getStoreId())->getWebsiteId();



            $products->getSelect()->joinLeft(

                array('_inv' => $products->getResource()->getTable('cataloginventory/stock_status')),

                "_inv.product_id = e.entity_id and _inv.website_id=$websiteId and _inv.stock_id=$stockId",

                array('stock_status')

            );

            $products->addExpressionAttributeToSelect('in_stock', 'IFNULL(_inv.stock_status,0)', array());



            $products->getSelect()->reset('order');

            $products->getSelect()->order('in_stock DESC');



            if ($toolbar->getCurrentOrder()) {

                $products->addAttributeToSort($toolbar->getCurrentOrder(), $toolbar->getCurrentDirection());

            }

        }

        return $this;

    }

}

Issue When I reload category page product collection is change. any things wrong ?

your event in config.xml should be like this:

...

</global>

<frontend>

    <events>

        <catalog_product_collection_load_before>

            <observers>

                <Gst_Sales_Order_Observer>

                    <type>singleton</type>

                    <class>modelNameHere/observer</class> //exemple: sales/observer

                    <method>modifyProductCollection</method>

                </Gst_Sales_Order_Observer>

            </observers>

        </catalog_product_collection_load_before>

    </events>

</frontend>