Creating credit memo does not change order grand total?

Question

I have added extra fee in the checkout page and save it to the database but when I go to credit memos the extra fee is shown in Credit memo totals but the grand total is not updated

This is my config.xml file

 <blocks>
      <adminhtml>
         <rewrite>
            <sales_order_creditmemo_totals>My_Module_Block_Adminhtml_Sales_Order_Creditmemo_Totals</sales_order_creditmemo_totals>
         </rewrite>
      </adminhtml>
    </blocks>

Answer 1

Check this module on github by Adam Moss. I have used the creditmemoSaveBefore() method in observer for the same solution. (Use your extra charge fee variable at the place of $depositAmount)

https://github.com/adampmoss/magento-deposit-total/blob/master/app/code/local/Creare/Deposit/Model/Observer.php

Code:

class Creare_Deposit_Model_Observer {

    /* ... */

    public function creditmemoSaveBefore(Varien_Event_Observer $observer)
    {
        $post_data = Mage::app()->getRequest()->getPost();
        $creditmemo = $observer->getEvent()->getCreditmemo();
        $deposit_amount = $post_data['creditmemo']['deposit_amount'];
        if ($deposit_amount > 0)
        {
            $depositAmount = $creditmemo->getDepositAmount();
            $baseDepositAmount = $creditmemo->getDepositAmount();
            // Adjust Grand Total to reflect Deposit refund
            $creditmemo->setGrandTotal($creditmemo->getGrandTotal()-($depositAmount-$deposit_amount));
            $creditmemo->setBaseGrandTotal($creditmemo->getBaseGrandTotal()-($baseDepositAmount-$deposit_amount));
            // Set Deposit Total to actual refund amount
            $creditmemo->setDepositAmount($deposit_amount);
            $creditmemo->setBaseDepositAmount($deposit_amount);
        }
        return $this;
    }

    /* ... */
}