WC_Product_Data_Store_CPT::read_attributes PHP Method

    protected function read_attributes(&$product)
    {
        $meta_values = maybe_unserialize(get_post_meta($product->get_id(), '_product_attributes', true));
        if ($meta_values) {
            $attributes = array();
            foreach ($meta_values as $meta_value) {
                if (!empty($meta_value['is_taxonomy'])) {
                    if (!taxonomy_exists($meta_value['name'])) {
                        continue;
                    }
                    $options = wc_get_object_terms($product->get_id(), $meta_value['name'], 'term_id');
                } else {
                    $options = wc_get_text_attributes($meta_value['value']);
                }
                $attribute = new WC_Product_Attribute();
                $attribute->set_id(wc_attribute_taxonomy_id_by_name($meta_value['name']));
                $attribute->set_name($meta_value['name']);
                $attribute->set_options($options);
                $attribute->set_position($meta_value['position']);
                $attribute->set_visible($meta_value['is_visible']);
                $attribute->set_variation($meta_value['is_variation']);
                $attributes[] = $attribute;
            }
            $product->set_attributes($attributes);
        }
    }