Magento Add telephone no in order grid using event observer - magento

Question

I want add Telephone no of customers that is used in order -> shipping or billing. in order grid. I can add the title in grid but I don't know how get the phone no. The event that used for this is sales_order_grid_collection_load_before. Even I can't get order id using this.
Here is my code.
config.xml
<?xml version="1.0"?>
<config>
<modules>
<Elavarasan_OrderGrid>
<version>0.1.0</version>
</Elavarasan_OrderGrid>
</modules>
<global>
<helpers>
<ordergrid>
<class>Elavarasan_OrderGrid_Helper</class>
</ordergrid>
</helpers>
<models>
<ordergrid>
<class>Elavarasan_OrderGrid_Model</class>
<resourceModel>ordergrid_mysql4</resourceModel>
</ordergrid>
</models>
<events>
<core_block_abstract_to_html_before> <!-- identifier of the event we want to catch -->
<observers>
<core_block_abstract_to_html_before_handler> <!-- identifier of the event handler -->
<type>model</type> <!-- class method call type; valid are model, object and singleton -->
<class>ordergrid/observer</class> <!-- observers class alias -->
<method>getGrid</method> <!-- observer's method to be called -->
<args></args> <!-- additional arguments passed to observer -->
</core_block_abstract_to_html_before_handler>
</observers>
</core_block_abstract_to_html_before>
<sales_order_grid_collection_load_before> <!-- identifier of the event we want to catch -->
<observers>
<sales_order_grid_collection_load_before_handler> <!-- identifier of the event handler -->
<type>model</type> <!-- class method call type; valid are model, object and singleton -->
<class>ordergrid/observer</class> <!-- observers class alias -->
<method>addPhoneNo</method> <!-- observer's method to be called -->
<args></args> <!-- additional arguments passed to observer -->
</sales_order_grid_collection_load_before_handler>
</observers>
</sales_order_grid_collection_load_before>
</events>
</global>
</config>
Observer.php
<?php
class Elavarasan_OrderGrid_Model_Observer
{
public function getGrid(Varien_Event_Observer $observer)
{
$block = $observer->getEvent()->getBlock();
if ($block->getId() == 'sales_order_grid') {
$block->addColumnAfter(
'telephone',
array(
'header' => Mage::helper('sales')->__('Telephone No'),
'align' => 'left',
'type' => 'options',
'options' => $paymentMethods,
'index' => 'telephone',
'filter_index' => 'telephone.telephone'
),
'shipping_name'
);
//$block->sortColumnsByOrder();
}
}
public function addPhoneNo(Varien_Event_Observer $observer)
{
echo $phone = $observer->getOrder()->getCustomer()->getPrimaryBillingAddress()->getTelephone();
}
}
Please help me guys..

Answer 1

Hope this link will help you.
http://www.ecomdev.org/2010/07/27/adding-order-attribute-to-orders-grid-in-magento-1-4-1.html