Add attribute with "appy_to" parameter does not work

Question

I am using the following function to add an attribute in an upgrade script:

$model->addAttribute('catalog_product', "LOAD TYPE", array(
    'type' => 'int',
    'input' => 'select',
    'label' => 'LOAD TYPE',
    'is_configurable' => '0',
    'user_defined'=>'1',
    'required' => false,
    'backend' => 'eav/entity_attribute_backend_array',
    'option' => array ( 'values' => array( 0 => 'white', ) ),
    'is_configurable' => false,
    'apply_to' => array('simple')
)); 

But apply_to does not work to select the product types.

Answer 1

apply_to has to be passed as comma separated list, not as array.

So the correct code is:

$model->addAttribute('catalog_product', "LOAD TYPE", array(
    'type' => 'int',
    'input' => 'select',
    'label' => 'LOAD TYPE',
    'is_configurable' => '0',
    'user_defined'=>'1',
    'required' => false,
    'backend' => 'eav/entity_attribute_backend_array',
    'option' => array ( 'values' => array( 0 => 'white', ) ),
    'is_configurable' => false,
    'apply_to' => 'simple'
));