I am trying to add a multiselect by my install script. This is my code:
$installer = Mage::getResourceModel('catalog/setup', 'catalog_setup'); $installer->startSetup(); $options = array(); foreach(Mage::getModel('adminhtml/system_config_source_country')->toOptionArray() as $option) { $options["value"][$option["value"]] = array($option["label"]); } $installer->addAttribute('catalog_product', 'allowed_countries', array( 'group' => 'General', 'type' => 'varchar', 'input' => 'multiselect', 'label' => 'Restrict shipping to', 'backend' => 'eav/entity_attribute_backend_array', 'visible' => 1, 'required' => 0, 'user_defined' => 1, 'configurable' => 1, 'global' => Mage_Catalog_Model_Resource_Eav_Attribute::SCOPE_GLOBAL, 'option' => $options )); $installer->endSetup(); The problem is that the values of the options are not the values of the array $options.
For example: Magento changes "US" => "United States" to "8396" => "United States" 
Any ideas?
Here is the solution:
$installer = Mage::getResourceModel('catalog/setup', 'catalog_setup'); $installer->startSetup(); $installer->addAttribute('catalog_product', 'allowed_countries', array( 'group' => 'General', 'type' => 'varchar', 'input' => 'multiselect', 'label' => 'Restrict shipping to', 'backend' => 'eav/entity_attribute_backend_array', 'visible' => 1, 'required' => 0, 'user_defined' => 1, 'configurable' => 1, 'global' => Mage_Catalog_Model_Resource_Eav_Attribute::SCOPE_GLOBAL, 'source' => 'customer/entity_address_attribute_source_country' )); $installer->endSetup(); 
