Extending A Single Method Using Depends

Question

I am trying to extend the admin order grid by adding a single column. I don't want to add all the logic again in my code, so the only method I'm calling is _prepareColumns():

protected function _prepareColumns()
{
    $this->addColumn('customer_group', array(
        'header'=> Mage::helper('sales')->__('Customer Group'),
        'width' => '80px',
        'type'  => 'text',
        'index' => 'increment_id',
    ));
    return parent::_prepareColumns();
}

I've read this article on overriding methods, but I don't know if I'm following it correctly. My module file at ~/app/etc/modules/Namespace_Module.xml includes the following:

<config>
    <modules>
        <Namespace_Module>
            <active>true</active>
            <codePool>community</codePool>
            <depends>
                <Mage_Adminhtml />
                <Mage_Core />
                <Mage_Sales />
            </depends>
        </Namespace_Module>
    </modules>
</config>

My config.xml file contains:

<config>
    ...
    <global>
        <blocks>
            <adminhtml>
                <rewrite>
                    <sales_order_grid>Namespace_Module_Block_Adminhtml_Sales_Order_Grid</sales_order_grid>
                </rewrite>
            </adminhtml>
        </blocks>
    </global>
    ...
</config>

On my testing site, I get only this Customer Group column on the grid. I am expecting all the columns AND this column. Am I wrong to think it will work like this?

My code is all in a custom module. Thanks.

A picture might help. I'm trying to edit this:

Answer 1

Thanks to @PandaWebStudio for pointing out my error. Yes, I am an idiot.

I was extending the original class Mage_Adminhtml_Block_Widget_Grid, which will add the single column. To get what I wanted, I needed to extend the class from Magento's sales order grid (which itself extends Mage_Adminhtml_Block_Widget_Grid):

Mage_Adminhtml_Block_Sales_Order_Grid

All works perfectly now. Thanks.

Answer 2

There is a better solution to add a column to the order grid, see my complete answer/solution in: Add Column to a grid (observer) - Column ‘store_id’ in where clause is ambiguous issue

Answer 3

To add customer group column in Sales Order grid. You can do it by rewriting Mage_Adminhtml_Block_Sales_Order_Grid class

 <?php
  class [CompanyName]_[ModuleName]_Block_Adminhtml_Sales_Order_Grid extends Mage_Adminhtml_Block_Sales_Order_Grid
  {
    protected function _preparePage()
    {

        $this->getCollection()
             ->getSelect()
             ->join( array('customer'=> 'customer_entity'), 'customer.entity_id = main_table.customer_id', array('customer.group_id'));
        return parent::_preparePage();
    }

    protected function _prepareColumns()
    {


        $groups = Mage::getResourceModel('customer/group_collection')
            ->addFieldToFilter('customer_group_id', array('gt'=> 0))
            ->load()
            ->toOptionHash();
        $this->addColumn('customer_group',
            array(
                'header'=> Mage::helper('sales')->__('Customer Group'),
                'width' => '70px',
                'index' => 'group_id',
                'type'  => 'options',
                'options' => $groups,
            ));

        $this->addColumnsOrder('customer_group', 'shipping_name');
        return parent::_prepareColumns();
    }
  }
?>

I hope above code will be useful.