I have a problem related to set data on a form on a onchange event. On saleorderline i want to set the quantity automatically when I change the product. But I have linked product to a one2many ean13 codes that have information about the quantity. So I redefine the search of the product searching on the other table linked to the products containing the quantity information, but when i type the code of the products in the onchange I have only the product_id and lost the code_id linked to the search field so I cannot retrive te quantity information. Do you have an idea how I can have in the onchange other information about the id passed???

I post the code of the onchange, the parameter ean13_id would be an ean13_id and not a product_id, or I would have to add a parameter about the code typed to search the product.

    def ean13_id_change_with_wh(self, cr, uid, ids, ean13_id, context=None):
        if context is None:
            context = {}
        res = {}  
        ean_obj = self.pool.get('product.ean13').browse(cr, uid, ean13_id, context)
        if ean13_id:           
            res = {
                   'value':{
                            'product_id':ean_obj.product_id,
                            'product_uom_qty':ean_obj.quantity
                            }
                   }
        return res