barcode_handler

This is one of the few Odoo widgets that deliberately draws nothing:

export class BarcodeHandlerField extends Component {
    static template = xml``;
    static props = { ...standardFieldProps };
    setup() {
        const barcode = useService("barcode");
        useBus(barcode.bus, "barcode_scanned", this.onBarcodeScanned);
    }
    onBarcodeScanned(event) {
        const { barcode } = event.detail;
        this.props.record.update({ [this.props.name]: barcode });
    }
}

The template is an empty tagged literal. Placing the field on a form adds no markup at all. What it adds is a listener: while the form is open, any barcode scanned anywhere on the page is written into this field, which then typically triggers an onchange on the server.

That pattern is how Odoo 19 turns a scan into a record change without a visible input to focus.

Warehouse and point-of-sale screens live or die on whether a scan does the right thing without anyone touching a keyboard. This widget was the mechanism: put the invisible field on the form, let the server's onchange decide what a scanned code means in that context.

If you are on Odoo 19 and this is in your views, it is working and there is nothing to fix. If you are planning an Odoo 20 upgrade and barcode scanning is part of your operation, this page is a warning: the mechanism changed, and it is not a rename.

The Odoo 19 pattern, an invisible field that catches scans:

<field name="barcode_scanned" widget="barcode_handler"/>

The field usually has an onchange on the Python side that interprets the scan for the current model.

We checked the 20.0 branch directly. The registration barcode_handler does not exist, and addons/barcodes/static/src/barcode_handler_field.js is gone.

It is tempting to read barcode_handlers in Odoo 20 as the successor, because the name is one letter away. It is not. That registration goes into a different registry:

registry.category("services").add("barcode_handlers", barcodeGenericHandlers);

A service, not a field widget. Its file is built around macros and DOM action helpers that click buttons and fill inputs, which is a different design: rather than routing a scan into a field and letting a server onchange interpret it, Odoo 20 drives the interface directly.

The practical consequence is that there is no drop-in replacement and no rename to apply. A view carrying widget="barcode_handler" in Odoo 20 finds no registration; Odoo logs a missing-widget warning in the console and falls back to rendering the field by its type, which for a char field means a visible text input appearing where nothing used to be.

So the failure is visible rather than silent, which is a small mercy. If you rely on barcode scanning, budget real time for this in an Odoo 20 upgrade: it is a rework of how scans reach your logic, not a search and replace.

Removed. The widget is not registered on the 20.0 branch and its source file is deleted. There is no field widget that replaces it.

Barcode handling moves into the services registry as barcode_handlers, built around macros that act on the interface rather than a field that receives a value. Any view using widget="barcode_handler" will render the underlying field with its default widget instead, which usually means an unexpected visible input.

Its sibling field_float_scannable was removed in the same release, so a database using both loses both at once.