Events in Magento when Order complete

Question

I am developing a custom module if user purchase a particular product I need to send information to a particular system. I am just searching for event where i can write my code.

Please help if someone already implemented such functionlity.

Answer 1

The event you're looking for is sales_order_invoice_save_after, this is triggered when an invoice is made so you are sure the order is paid as well.

config.xml

<config>
   [...]
   <global> 
      [...]
      <events>
         <sales_order_invoice_save_after>
            <observers>
               <[module]_order_export>
                  <type>singleton</type>
                  <class>[Namespace]_[Module]_Model_Observer</class>
                  <method>orderExport</method>
               </[module]_order_export>
            </observers>
         </sales_order_invoice_save_after>     
      </events>
      [...]
   </global>
   [...]
</config>

Observer.php

class [Namespace]_[Module]_Model_Observer
{

   public function orderExport(Varien_Event_Observer $observer)
   {
      $_event = $observer->getEvent();
      $_invoice = $_event->getInvoice();
      $_order = $_invoice->getOrder();

      [...]
      // your code to handle the export
      [...]
    }
}

Answer 2

Listen for event sales_order_payment_pay.