get ps_product_attribute.reference from order object

[mushu]

Hi guys, i'm a new user of prestashop with basic skills of php (i'm a python programmer)

i've created a custom module to manage hookActionObjectOrderAddAfter.

i need to catch the "reference" code of sold products to insert them in another custom table.

How can i get the reference from the the order object thought that hook?

prestashop version 1.7.3.0

Edited November 12, 2018 by mushu (see edit history)

[mushu]

that reference code is generated for each purchase (and stored in ps_orders) i need the refererence code in ps_products