Hi everyone,

I am developing a custom "Pay Later" feature for Odoo POS (Odoo 19 )

My goal is:

• Add a "Pay Later" button in the POS Payment Screen
• Allow saving POS orders without immediate payment
• Store a Boolean field is_pay_later in pos.order
• Filter Pay Later orders from backend POS Orders

I have implemented:

• Python model inheritance for pos.order
• Frontend Order model patch
• PaymentScreen patch
• XML template inheritance
• Backend form and search view inheritance

# -*- coding: utf-8 -*-
{
    'name': 'POS Pay Later',
    'version': '19.0.1.0.0',
    'category': 'Point of Sale',
    'summary': 'Allows POS orders to be paid at a later time.',
    'description': """
        This module adds a "Pay Later" functionality to the Point of Sale.
        - A "Pay Later" button is added to the payment screen.
        - Orders can be submitted without immediate payment.
        - "Pay Later" orders can be retrieved and paid for at a later time.
    """,
    'author': 'ashil',
    'website': 'https://yourwebsite.com',
    'depends': ['point_of_sale'],
    'data': [
        'views/pos_order_views.xml',
    ],
    'assets': {
        'point_of_sale.assets': [
            'zl_pos_pay_later/static/src/app/**/*',
        ],
    },
    'installable': True,
    'application': True,
}

# -*- coding: utf-8 -*-
from odoo import api, fields, models

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

    is_pay_later = fields.Boolean(
        string='Is Pay Later', 
        default=False, 
        help="Indicates if this order was marked to be paid later."
    )

    @api.model
    def _order_fields(self, ui_order):
        # Override to extract the 'is_pay_later' flag from the frontend order data
        order_fields = super(PosOrder, self)._order_fields(ui_order)
        order_fields['is_pay_later'] = ui_order.get('is_pay_later', False)
        return order_fields

/** @odoo-module */

import { PaymentScreen } from "@point_of_sale/app/screens/payment_screen/payment_screen";
import { patch } from "@web/core/utils/patch";
import { ConfirmPopup } from "@point_of_sale/app/utils/confirm_popup/confirm_popup";

patch(PaymentScreen.prototype, {
    async validateOrder(isForceValidate) {
        // If the order is marked as "Pay Later", skip payment validation
        if (this.currentOrder.is_pay_later) {
            // Bypass payment checks and directly create the order
            this.env.services.pos.push_orders(this.currentOrder, { show_error: true });
            // Show a confirmation popup
            await this.popup.add(ConfirmPopup, {
                title: this.env._t("Order Saved"),
                body: this.env._t("The order has been saved and will be paid later."),
            });
            // Go to the next screen (receipt or product screen)
            this.pos.showScreen(this.pos.getNextScreen());
            return;
        }
        // Otherwise, proceed with the standard validation
        return super.validateOrder(...arguments);
    },

    async clickPayLater() {
        // Set the 'is_pay_later' flag on the current order
        this.currentOrder.is_pay_later = true;
        // Trigger order validation
        await this.validateOrder(false);
    },
});

<?xml version="1.0" encoding="UTF-8"?>
<templates xml:space="preserve">
    <t t-name="zl_pos_pay_later.PaymentScreen" t-inherit="point_of_sale.PaymentScreen" t-inherit-mode="extension" owl="1">
        <xpath expr="//div[hasclass('payment-buttons')]" position="inside">
            <button class="btn btn-lg btn-secondary" t-on-click="clickPayLater">
                Pay Later
            </button>
        </xpath>
    </t>
</templates>

/** @odoo-module */

import { Order } from "@point_of_sale/app/models/order";
import { patch } from "@web/core/utils/patch";

patch(Order.prototype, {
    setup() {
        super.setup(...arguments);
        this.is_pay_later = this.is_pay_later || false;
    },

    export_as_JSON() {
        const json = super.export_as_JSON(...arguments);
        json.is_pay_later = this.is_pay_later;
        return json;
    },

    init_from_JSON(json) {
        super.init_from_JSON(...arguments);
        this.is_pay_later = json.is_pay_later;
    },
});

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <data>
        <!-- Add 'is_pay_later' to POS Order Form View -->
        <record id="view_pos_pos_form_inherit_pay_later" model="ir.ui.view">
            <field name="name">pos.order.form.inherit.pay.later</field>
            <field name="model">pos.order</field>
            <field name="inherit_id" ref="point_of_sale.view_pos_pos_form"/>
            <field name="arch" type="xml">
                <xpath expr="//field[@name='partner_id']" position="after">
                    <field name="is_pay_later" readonly="1"/>
                </xpath>
            </field>
        </record>

        <!-- Add filter for Pay Later orders -->
        <record id="view_pos_order_filter_inherit_pay_later" model="ir.ui.view">
            <field name="name">pos.order.list.select.inherit.pay.later</field>
            <field name="model">pos.order</field>
            <field name="inherit_id" ref="point_of_sale.view_pos_order_filter"/>
            <field name="arch" type="xml">
                <xpath expr="//filter[@name='invoiced']" position="after">
                    <filter string="Pay Later" name="pay_later" domain="[('is_pay_later', '=', True)]"/>
                </xpath>
            </field>
        </record>
    </data>
</odoo>

Could someone please review whether my implementation approach is correct.