x2many_buttons

Some relations are not data the user edits but evidence the user should look at. The canonical example is Odoo's duplicate detection on vendor bills: the system computes a set of suspiciously similar moves and needs to show them inside a warning banner, compactly, with one-click access to each. A one2many list is too heavy for that, and tags are not clickable in the way needed. The x2many_buttons widget renders each related record as a small button carrying its display name.

Only the first few records get a button, three by default, and the widget appends an overflow control that opens the complete set in a list view. Both the buttons and the overflow are navigation, not editing: this widget never adds or removes records from the relation.

Duplicate vendor bills are one of the quietly expensive accounting failure modes: pay the same invoice twice and recovering the money costs far more than the original booking. Odoo's duplicate banner works because checking a suspect takes one click, right from the bill you are entering. That immediacy is this widget's whole job, and it is why the same pattern was picked up by sales and purchase for their own cross-references.

There is one behavior your accounting team must know, because the widget will not warn them: clicking any of these buttons discards unsaved changes on the current record before navigating. On an invoice that was just OCR-filled or half-corrected, that means edits are gone. Train the team to save first, or accept the widget's assumption that a record under duplicate suspicion should not be saved yet anyway.

The duplicate warning, from the invoice form

<div class="alert alert-warning" role="alert"
     invisible="not duplicated_ref_ids or state != 'draft'">
    <span>This document might be a duplicate of</span>
    <field name="duplicated_ref_ids"
           widget="x2many_buttons"
           nb_records_shown="1"
           string="Duplicated Documents"
           context="{'name_as_amount_total': True}"/>
</div>

Core shows a single inline button here and pushes everything else behind the overflow. The context key makes each duplicate's button label show its total amount, which is what you actually compare duplicates by.

On your own model

<field name="related_claim_ids"
       widget="x2many_buttons"
       nb_records_shown="5"
       string="Related Claims"/>

The target model must implement action_open_business_doc, the method the widget calls to build the destination action. Accounting documents have it; a custom model needs a one-line implementation returning its own form action.

Three source-level details define how this widget really behaves.

Discard is unconditional. Both click paths, single button and overflow, call record.discard() before navigating. The component was designed for warning banners on draft records, where pending edits are expendable. There is no option to disable it.

Single records route through action_open_business_doc. Instead of hardcoding a form action, the widget asks the target model for one. On accounting models this method resolves the true business document, so a button pointing at a payment's move opens the payment, not the raw journal entry.

The overflow is model-aware. Opening the full list builds a list-plus-form action over the relation's ids, and if the related model is account.move it injects list_view_ref: account.view_duplicated_moves_tree_js, a list view purpose-built for comparing duplicates side by side. Every other model falls back to its default list view.

The widget also declares relatedFields: display_name, which is why the buttons have labels without the view listing any subfields.

Odoo 20 is expected at Odoo Experience in Brussels, 24 to 26 September 2026. Our comparison is against the public development branch, which remains unstable until feature freeze, and this page is re-verified after release.

The report for this widget is short: the development branch file is byte-identical to Odoo 19.0 at the time of writing. The attribute surface, the discard behavior and the account.move special case all carry into Odoo 20 unchanged.