Hii,

please try this 
models/stock_rule.py

from odoo import models

class StockRule(models.Model):

    _inherit = 'stock.rule'

    def _prepare_purchase_order_line(

        self, product_id, product_qty, product_uom, company_id, values, po

    ):

        res = super()._prepare_purchase_order_line(

            product_id, product_qty, product_uom, company_id, values, po

        )

        # Pass custom field to PO line

        if values.get('x_custom_ref'):

            res['x_custom_ref'] = values['x_custom_ref']

        return res

i hope it is usefull

Hi,

You're trying to pass a custom field from the Sales Order Line to the corresponding Purchase Order Line, but during the procurement process, your custom value isn’t flowing through—even though you extended _prepare_procurement_values() and _prepare_purchase_order_line().

Try with the following.

1- Add field to sale.order.line

x_reference_code = fields.Char("Reference Code")

2-Extend _prepare_procurement_values() in sale.order.line

def _prepare_procurement_values(self, group_id=False):

    res = super()._prepare_procurement_values(group_id)

    res.update({

        'x_reference_code': self.x_reference_code,

    })

    return res

3- Extend _prepare_purchase_order_line() in purchase.order

def _prepare_purchase_order_line(self, product_id, product_qty, product_uom, company_id, values, po):

    res = super()._prepare_purchase_order_line(product_id, product_qty, product_uom, company_id, values, po)

    if 'x_reference_code' in values:

        res.update({

            'x_reference_code': values['x_reference_code'],

        })

    return res

Also, make sure purchase.order.line has this custom field.

x_reference_code = fields.Char("Reference Code")

Follow the three-step override above, and ensure the correct routes (Make To Order, Dropship, etc.) are active on your sale order line.

Hope it helps

See for example https://github.com/odoo/odoo/blob/18.0/addons/sale/models/sale_order_line.py#L1445 and https://github.com/odoo/odoo/blob/18.0/addons/sale_project/models/sale_order_line.py#L474, i.e.

def _prepare_procurement_values(self, group_id=False):
    """ Prepare specific key for moves or other components that will be created from a stock rule
        coming from a sale order line. This method could be override in order to add other custom key that could
        be used in move/po creation.
        """
        return {}

_prepare_procurement_values() must have a return value (dict). Same goes for _prepare_purchase_order_line().