Adding column to Wordpress Post (Specifically WP E-Commerce) - php

Question

Right, I've got WordPress E-commerce installed on WordPress and I need to add additional columns to the post type.
I've done some investigating. It appears that E-commerce just submits a post type called "Products" and changes the columns in order to add things like Price etc.
I need to add another input. Just a little checkbox that the admin can set to true or false as they add a product. The only problem for me at the moment is finding where exactly to do this.
I think I've found the WordPress E-Commerce post type column settings, but obviously just adding an additional one isn't working.
/wp-content/plugins/wp-e-commerce/wpsc-admin/display-items.page.php
function wpsc_additional_column_names( $columns ){
$columns = array();
$columns['cb'] = '';
$columns['image'] = '';
$columns['title'] = __('Name', 'wpsc');
$columns['stock'] = __('Stock', 'wpsc');
$columns['price'] = __('Price', 'wpsc');
$columns['sale_price'] = __('Sale', 'wpsc');
$columns['SKU'] = __('SKU', 'wpsc');
$columns['weight'] = __('Weight', 'wpsc');
$columns['cats'] = __('Categories', 'wpsc');
$columns['featured'] = '';
$columns['hidden_alerts'] = '';
$columns['date'] = __('Date', 'wpsc');
return $columns;
}

Answer 1

Don't edit the core files. You can add custom metaboxes to WP e-Commerce's Products post type just as you would any other post type.
My preferred solution is to use Custom Metaboxes and Fields for WordPress
This sample function will output a checkbox on products using the above plugin (note 'pages' => array('wpsc-product'), this targets products only):
function base_meta_boxes_ba($meta_boxes) {
/**
* Page Options meta box
*/
$meta_boxes[] = array(
'id' => 'product_options',
'title' => 'Extra Product Options',
'pages' => array('wpsc-product'),
'context' => 'normal',
'priority' => 'high',
'show_names' => true,
'fields' => array(
array(
'name' => 'Test Checkbox',
'desc' => 'field description (optional)',
'id' => $prefix . 'test_checkbox',
'type' => 'checkbox'
),
)
);
return $meta_boxes;
}
add_filter('cmb_meta_boxes', 'base_meta_boxes_ba');