Question

My payment module is required to sent notifications to the payment service if an order is canceled or refunded. I assume that the “Cancel” button on the order page (in the administration backend) will cancel the order, and that the “Credit memo” button (after an invoice has been created) will refund the order.

How do I run my code on these events? I tried using the cancel() method in my payment method model, but the code did not run.

Answer 1

Seems like your payment method is not using transactions or does not create authorization transaction id. It is common beginner mistake in Payment gateways development.

To enable your payment gateway with online actions you need to implement something like this in your payment method:

class MyBest_Payment_Model_Method extends Mage_Payment_Model_Method_Abstract
{
    protected $_canAuthorize            = true; // Set true, if you have authorization step.
    protected $_canCapture              = true; // Set true, if you payment method allows to perform capture transaction (usally only credit cards methods)
    protected $_canRefund               = true; // Set true, if online refunds are available
    protected $_canVoid                 = true; // Set true, if you can cancel authorization via API online

    public function authorize(Varien_Object $payment, $amount)
    { 

        // ... You payment method authorization goes here ...
        // Here goes retrieving or generation non-zero, 
        // non-null value as transaction ID. 
        $transactionId = $api->someCall(); 
        // Setting tranasaction id to payment object
        // It is improtant, if you want perform online actions 
        // in future with this order!
        $payment->setTransactionId($transactionId); 

        // ... some other your actions ... 
        return $this;
    }

    public function void(Varien_Object $payment)
    {
        // ... some actions for sending cancel notification to your payment gateway
    }

    public function refund(Varien_Object $payment, $amount)
    {
        // ... some actions for performing an online refund ...
    }
}