How to get data for an entity (for example customer) from eav_attribute table to be shown in Customer Grid for admin

Question

I have extended Magento’s customer information form to store an additional attribute for customer. Lets call it ‘customer_referrer_id’.

I have a role ‘referrer ‘ who has access to customer grid and order grid only. But, I want to restrict a referrer to see only those customers in the grid who have the customer_referrer_id set as the referrer’s id who has logged in. Similarly for orders, the logged in referrer shall be able to see only those orders made by customers who have customer_referrer_id = loggedin_referrer_id.

I already know how to override a module and that I have to mainly override Adminhtml/Block/Customer/Grid::_prepareCollection and Adminhtml/Block/Sales/Order/Grid::_prepareCollection

I am using Magento 1.4.1.1

This is my module declaration file in app/etc/modules/Myproject_Adminhtml

<?xml version="1.0"?>

<config>
    <modules>
        <Myproject_Adminhtml>
            <active>true</active>
            <codePool>local</codePool>
            <depends>
                <Mage_Sales />
            </depends>
        </Myproject_Adminhtml>
    </modules>
</config>

And my modules config.xml in local/Myproject/Adminhtml/etc/ is as follows:

<config>
    <modules>
        <Myproject_Adminhtml>
            <version>1.0.0</version>
        </Myproject_Adminhtml>    
    </modules>

    <global>
          <blocks>
            <adminhtml>
                <rewrite>
                <sales_order_grid>Myproject_Adminhtml_Block_Sales_Order_Grid</sales_order_grid>
                <customer_grid>Myproject_Adminhtml_Block_Customer_Grid</customer_grid>
                </rewrite>
            </adminhtml>
        </blocks>
    </global>
</config>

And

class Myproject_Adminhtml_Block_Customer_Grid extends Mage_Adminhtml_Block_Customer_Grid
{
    protected function _prepareCollection()
    {
        $collection = Mage::getResourceModel('customer/customer_collection')
        ->addNameToSelect()
        ->addAttributeToSelect('email')
        ->addAttributeToSelect('created_at')
        ->addAttributeToSelect('group_id')
        ->joinAttribute('billing_postcode', 'customer_address/postcode', 'default_billing', null, 'left')
        ->joinAttribute('billing_city', 'customer_address/city', 'default_billing', null, 'left')
        ->joinAttribute('billing_telephone', 'customer_address/telephone', 'default_billing', null, 'left')
        ->joinAttribute('billing_region', 'customer_address/region', 'default_billing', null, 'left')
        ->joinAttribute('billing_country_id', 'customer_address/country_id', 'default_billing', null, 'left');    

        $this->setCollection($collection);

        $referrer_id = Mage::getSingleton('admin/session')->getUser()->getId();
        Mage::log('Logged in admin has id: ' . $referrer_id);

        return parent::_prepareCollection();
    }  
}

Answer 1

My first attempt would be (for both files mentioned),

$collection->addAttributeToFilter('customer_referrer_id', $referrer_id);

Where $referrer_id is the value you must retrieve from the logged in user. Since you appear to be using admin users - which are separate entities from customers - this is one way of retrieving;

$referrer_id = Mage::getSingleton('admin/session')->getUser()->getId();

Note the currently logged in admin user is not apparent from the database alone so it cannot be a table join.

On another point I would use the frontend for referrers instead of the admin. I would have the new customers and their orders shown in the referrer's customer account, similar to their own "My Orders" page. Of course I don't know what other requirements you have to attend to.

Second part

Override Mage_Adminhtml_Block_Sales_Order_Grid::_prepareCollection() to look like this:

protected function _prepareCollection()
{
    $collection = Mage::getResourceModel('customer/customer_collection');
    $collection->getSelect()->reset('columns'); // remove all customer columns
    $collection->addAttributeToFilter('entity_id', $referrer_id);
    $collection->joinTable('sales/order_grid', 'customer_id=entity_id', array('*'));

    $this->setCollection($collection);
    return parent::_prepareCollection();
}

This is necessary because the original table sales/order_grid is flat, not an entity collection, and so cannot be joined with attributes. The above works in reverse, by starting with a customer collection and then joining the flat table after.

A possibly neater method would be to override sales/order_grid_collection with your own collection class which performs all this. Although it better follows coding conventions it is more work and no more functional in the end.