code_ir_ui_view

This widget is almost entirely inherited. The source is short enough to read in full:

export class IrUiViewAceField extends AceField {
    static template = "web.IrUIViewAceField";
    static components = { IrUiViewCodeEditor };
}

export const irUiViewAceField = {
    ...aceField,
    component: IrUiViewAceField,
    additionalClasses: ["o_field_ace"],
};

Because the descriptor spreads aceField, it takes on the ace widget's declared option, mode, and its supported types of text and html. What it changes is the editor component, substituting IrUiViewCodeEditor for the generic one, and it adds a styling class.

This is the editor your technical team sees when they open a view record to inspect or patch an inherited view. It is worth knowing it exists for one reason: it is the screen where a badly formed XML edit takes a database down, and it offers highlighting rather than validation.

If people in your organization edit views through this screen, that is a change nobody can review and nothing records properly. View changes belong in a module, in version control, where they can be reviewed and rolled back. The editor is fine for reading.

The interesting example is how Odoo applies it, because it is not the usual form. In addons/web/views/ir_ui_view_views.xml, an inherited view sets the widget as an attribute:

<attribute name="widget">code_ir_ui_view</attribute>

Applying it yourself, on a text field holding markup, looks ordinary:

<field name="template_source" widget="code_ir_ui_view"
       options="{'mode': 'xml'}"/>

We scanned every XML file in Odoo 19 Community and Enterprise for widget="code_ir_ui_view". The count is zero, which would normally mean an unused registration. It is not: the widget is on a screen you can open right now.

The reason is that it is applied through view inheritance. Rather than writing the widget on the field, Odoo patches an existing field in an inherited view:

<attribute name="widget">code_ir_ui_view</attribute>

The rendered view ends up with the widget set; the source XML never contains the string widget="code_ir_ui_view".

Two things follow. First, on this site, when a widget page reports a low or zero usage count, treat it as a count of one specific spelling rather than proof the widget is dead. Second, and more usefully for your own work: if you are hunting for where a widget is applied in a database and a direct search comes up empty, search for the widget name on its own, without the widget= prefix, and you will find the attribute-based applications too.

The same trap catches widgets applied by field type with no attribute at all, such as json and many2one_reference, which Odoo resolves through the registry using the field type as the key.

No change to the registration. Diffing the 20.0 branch shows the same spread of the ace descriptor, the same component substitution and the same additional class.

The ace widget it inherits from does change in Odoo 20: it gains a lineWrapping option. Since code_ir_ui_view spreads the ace descriptor, that option comes along with it.