Magento Attribute working the same as weight

Question

I need another attribute for each product in Magento that works in the same way that weight does.

When the order is placed I want to be able to call the attribute but for it to already have done

product1.new_attribute + product2.new_attribute + product3.new_attribute = new_attribute

The reason I need this is for my shipping, I want to be able to tell me courier how many boxes Im sending for each order 1 box can be made up of a number of different products.

Can any one point me in the right direction as Im not sure where to start?

Answer 1

You need to create the new attribute, this can be done in the magento admin or see here:

http://www.magentocommerce.com/wiki/5_-_modules_and_development/0_-_module_development_in_magento/installing_custom_attributes_with_your_module

You can then either query this on the fly when loading the order, or a better way is to add an observer on sales_order_place_after and then calculate the total number of boxes and store that in a new column on the sales_flat_order table.

To add to sales_flat_order there are various blogs out there e.g. http://www.atwix.com/magento/custom-product-attribute-quote-order-item/