Magento 1.9: How to add specific customer group in drop down list as product attribute in admin

Question

I am working on a project in which I have created a module to create custom customer in manufacturer customer group now I want to add this manufacturer customer group as a product attribute to product so that when I create a product from admin there should be an drop down list from the manufacturer customer group to add the manufacturer of the product.

Answer 1

Write your own source model for the product attribute.

Write the source model

This is a child class of Mage_Eav_Model_Entity_Attribute_Source_Abstract. The most important method to implement is getAllOptions() which returns the possible values and labels for the dropdown:

public function getAllOptions()
{
    if (is_null($this->_options)) {
        $customers = $this->_getManufacturerCustomers();
        $this->_options = [];
        foreach ($customers as $customer) {
            $this->_options[] = [
                'label' => $customer->getName(),
                'value' =>  $customer->getId(),
            ];
        }
    }
    return $this->_options;
}
protected function _getManufacturerCustomers()
{
    // take this value from configuration!
    $manufacturerGroup = 123;

    $customers = Mage::getResourceModel('customer/customer_collection');
    $customers->addAttributeToFilter('group_id', $manufacturerGroup);

    // add attributes you need to display the customer name
    $customers->addAttributeToSelect(['firstname', 'middlename' 'lastname']);

    return $customers;
}

I wrote _getManufactureCustomers() as a draft, adjust it as needed but the principle should be clear.

Use the source model

Let's say, the product attribute is manufacturer_customer and the source model alias is stack_manufacturer/attribute_source_manufacturer. Then the install script that adds the attribute looks like this:

$installer->addAttribute('catalog_product', 'manufacturer_customer', array(
    'label'             => 'Manufacturer Customer',
    'type'              => 'int',
    'input'             => 'select',
    'source'            => 'stack_manufacturer/attribute_source_manufacturer',

    // add more parameters as required

));

Flat Index

If you want the attribute to be included in the flat index (because you need it in collections in the frontend), add these methods to the source model:

public function getFlatColums()
{
    $columns = array(
        $this->getAttribute()->getAttributeCode() => array(
            'type'      => 'int',
            'unsigned'  => false,
            'is_null'   => true,
            'default'   => null,
            'extra'     => null
        )
    );
    return $columns;
}


public function getFlatUpdateSelect($store)
{
    return Mage::getResourceModel('eav/entity_attribute')
        ->getFlatUpdateSelect($this->getAttribute(), $store);
}