Created a custom attribute via setup, but it only appears to new products

Question

Hello i have the next setup code:

$installer = new Mage_Catalog_Model_Resource_Setup('core_setup');

$installer->addAttribute('catalog_product', 'shipping_city', array(
    'group'             => 'General',
    'type'              => Varien_Db_Ddl_Table::TYPE_VARCHAR,
    'backend'           => '',
    'frontend'          => '',
    'label'             => 'Envio p/ Cidade',
    'input'             => 'text',
    'class'             => '',
    'source'            => '',
    'global'            => Mage_Catalog_Model_Resource_Eav_Attribute::SCOPE_GLOBAL,
    'visible'           => false,
    'required'          => false,
    'user_defined'      => true,
    'default'           => '',
    'searchable'        => true,
    'filterable'        => true,
    'comparable'        => false,
    'visible_on_front'  => true,
    'unique'            => false,
    'apply_to'          => 'simple,configurable,virtual',
    'is_configurable'   => false ));
$installer->endSetup();

Then i debug the products with de " and " event:

$product = $observer->getEvent()->getProduct();
Zend_Debug::dump($product->debug());die;

The problem is that if i try to save an already existing product, it gets the event and my debug brings not my attribute shipping_city. In a new product it appear in my debug but only in de save_after event, in the save_before doesnt appear aswell...

Any thoughts guys?

Answer 1

If you add a new attribute and it was added to the attribute set you want it in, everything went well with $installer->addAttribute.

The problem is, because of the EAV there is no value for your new attribute. This means querying and filtering by it, means filtering by NULL and if you call $product->getNewAttribute() you just get NULL.

But this behavior is correct and intended.

You can fix this by writing a small script and setting a default value on all products, like this:

$collection = Mage::getResourceModel('catalog/product_collection')->filterByWhateverYouWant();
foreach($collection as $product) {
    $product->setNewAttribute('myCoolValue')->save();
}

Be careful with this. This script makes one query for each product in the collection which might be a lot.