section_and_note_one2many

Order and invoice lines are not a plain one2many. A line can be a real product line, a section header that groups the lines below it, or a free-text note. This widget is what makes one field render all three.

It spreads the standard x2many descriptor and adds the o_field_one2many class, so everything a normal one2many supports still works. What it adds is the section and note handling, plus four settings that control how much of the line editor a given document shows.

Those four are the interesting part, because Odoo declares none of them.

This is the widget your finance and sales teams look at more than any other, even if nobody can name it. Sections and notes are what turn a flat list of products into a quote a customer can read.

The practical point for anyone customizing documents: the differences between how a sales order, a purchase order and an invoice present their lines are not separate widgets. They are the same widget with different settings, and those settings are not in Studio. If you want a document type that hides prices or suppresses the composition column, that is a view-level change, and the options exist.

Ordinary use on a document's line field:

<field name="invoice_line_ids" widget="section_and_note_one2many"/>

Hiding prices, for a document where the recipient should not see them:

<field name="order_line" widget="section_and_note_one2many"
       options="{'hide_prices': True}"/>

Aggregating columns, which is an attribute and not an option:

<field name="order_line" widget="section_and_note_one2many"
       aggregated_fields="price_subtotal, product_uom_qty"/>

This does nothing, and is the mistake worth avoiding:

<!-- wrong: aggregated_fields is an attribute, not an option -->
<field name="order_line" widget="section_and_note_one2many"
       options="{'aggregated_fields': 'price_subtotal'}"/>

The whole configuration surface is one function:

extractProps: (staticInfo, dynamicInfo) => {
    return {
        ...x2ManyField.extractProps(staticInfo, dynamicInfo),
        aggregatedFields: staticInfo.attrs.aggregated_fields
            ? staticInfo.attrs.aggregated_fields.split(/\s*,\s*/)
            : [],
        hideComposition: staticInfo.options?.hide_composition ?? false,
        hidePrices: staticInfo.options?.hide_prices ?? false,
        subsections: staticInfo.options?.subsections ?? false,
    };
},

Three come from options, one comes from attrs. That split is the trap. A developer who finds aggregated_fields in the source will reasonably assume it belongs in the options dictionary like its three neighbors, and it will be silently ignored there because the code reads staticInfo.attrs.

The splitting regex is worth noting too: /\s*,\s*/ tolerates spaces around the commas, so "a, b , c" parses correctly. Odoo is being forgiving here, which is unusual enough to rely on.

All four default to a falsy value, so omitting them gives you the full line editor. That means these options only ever subtract: there is nothing here that turns something on that was off.

This widget is unchanged. Diffing the registration between the 19.0 and 20.0 branches shows no options added or removed.

Its sibling did not survive. section_and_note_text, the widget that rendered the text of a section or note line, is removed in Odoo 20 after six uses in Odoo 19, and product_label_section_and_note_field went with it. If you inherited or referenced either of those, check them before upgrading; this one carries over untouched.