Hi all,

I’m trying to expose a custom field added on pos.order so that it can be used in the POS frontend OrderReceipt QWeb/OWL template in Odoo 18.

Goal

I want a custom field defined on pos.order to be available in the POS frontend, specifically in the order_receipt template.

What I have done

I extended the pos.order model and tried to load the field using _load_pos_data_fields method , as shown below:

pos_order.py

from odoo import models, fields, api
# pos_order.py
from odoo import models, fields, api

class PosOrder(models.Model):
    _inherit = "pos.order"

    custom_field = fields.Char()

    @api.model
    def _load_pos_data_fields(self, config_id):
        fields = super()._load_pos_data_fields(config_id)
        fields.append("custom_field")
        return fields

Frontend error

After this change, the POS UI doesn't load at all, it crashes with the following error:

installHook.js:1 TypeError: Cannot read properties of undefined (reading 'filter') at get taxTotals (point_of_sale.assets_prod.min.js:8929:1016)

What I found so far

I found a couple of older forum posts and answers that suggest extending _loader_params_pos_order method on pos.session model

However, in Odoo 18, _loader_params_pos_order no longer exists, so those solutions are no longer applicable.

What is the correct way in Odoo 18 to load additional pos.order fields into the POS frontend?