how to show custom order attribute in sales order view screen

Question

I have created custom order attribute using following script.I want to show in sales order view screen below order status. and also if order is in hold only i want to show this attribute.

<?php
$installer = new Mage_Sales_Model_Resource_Setup('core_setup');
$attribute  = array(
'type'          => 'int',
'label'         => 'Is Notified',
'default'       => 0,
'visible'       => true,
'required'      => false,
'user_defined'  => true,
'comparable'    => false );

$installer->addAttribute('order', 'is_notified', $attribute);

Answer 1

We can use event observer for this as below:

Observer code:

  /**
         * Hold Notified status display in admin order view
         * @param $observer
         */
        public function updateSalesOrderInfo($observer)
        {
            if ($observer->getBlock() instanceof Mage_Adminhtml_Block_Sales_Order_View_Info) {
                $order = Mage::registry('sales_order');
                if ($order->getState() == Mage_Sales_Model_Order::STATE_HOLDED) {
                    $isNotified = $order->getData('is_notified');
                    $html = $observer->getTransport()->getHtml();
                    if ($isNotified) {
                        $html = str_replace('<span id="order_status">On Hold</span>', '<span id="order_status">On Hold</span><div>(Notified)</div>', $html);
                    } else {
                        $html = str_replace('<span id="order_status">On Hold</span>', '<span id="order_status">On Hold</span><div>(Not Notified)</div>', $html);
                    }

                    $observer->getTransport()->setData('html', $html);
                }
            }

  }

config.xml code

<events>
  <core_block_abstract_to_html_after>
      <observers>
          <update_sales_order_info>
              <model>orderholdnotify/observer</model>
              <method>updateSalesOrderInfo</method>
          </update_sales_order_info>
      </observers>
  </core_block_abstract_to_html_after>
</events>