Odoo – UoM Rounding Alert for Sale Order Quantity Input

UoM Rounding Alert for Sale Order Quantity Input

To alert or prevent users from entering a quantity that doesn’t comply with the Unit of Measure (UoM) rounding precision (e.g., whole numbers for UoMs with a 1.00 rounding), you can implement a constraint or an onchange warning on the Sale Order Line.

Scenario

Suppose you have a product “ABC” with a UoM of Roll, and:

• Rounding precision is set to 1.00
• Ratio is set to 1.00

This means the quantity should be a whole number (e.g., 12, 13).
If a user inputs 12.6, this should trigger a warning or error, because fractional quantities are not allowed.

Implementation Steps

Step 1: Create the Module Skeleton

Use the scaffold command to generate the module structure:

./odoo-bin scaffold uom_alert addons

This will create a folder structure like:

uom_alert/
├── __init__.py
├── __manifest__.py
├── models/
│   └── sale_order.py  ← Your custom logic here

Step 2: Add Logic to sale_order.py

from odoo import models, api, _
from odoo.exceptions import UserError

class SaleOrderLine(models.Model):
    _inherit = 'sale.order.line'

    @api.onchange('product_uom_qty', 'product_uom', 'product_id')
    def _onchange_uom_rounding(self):
        for line in self:
            if not line.product_uom or not line.product_id or not line.product_uom_qty:
                continue

            try:
                qty = float(line.product_uom_qty)
                rounding = float(line.product_uom.rounding)
            except (ValueError, TypeError):
                continue  # Skip invalid input

            if rounding > 0 and not self._is_multiple_of(qty, rounding):
                raise UserError(_(
                    "Quantity %.2f for product '%s' must be a multiple of the unit of measure precision (%.2f)."
                ) % (qty, line.product_id.display_name, rounding))

    def _is_multiple_of(self, qty, rounding):
        return abs(round(qty / rounding) - (qty / rounding)) < 1e-6

Step 3: __init__.py in models/ Folder

from . import sale_order

Step 4: __manifest__.py in Root Module Folder

{
    'name': "UOM Alert",
    'summary': "Alerts when product quantity input in a sale order does not match UoM rounding precision.",
    'author': "My Company",
    'website': "https://genkiware.com",
    'category': 'Sales',
    'version': '1.0',
    'depends': ['sale'],
    'data': [
        # 'security/ir.model.access.csv',
    ],
    'installable': True,
}