im_livechat.one2many_names

Kanban cards have no room for an embedded list, so when the livechat team wanted each session card to lead with the customers involved, they wrote this widget: it takes the records of an x2many field and prints their display names as one formatted line. The joining is done by formatList from Odoo's localization core, so an English user sees Alice, Bob, and Carol while other locales get their own separators and conjunctions.

The entire widget is one getter. It extends ListX2ManyField, the variant that renders x2many fields as plain text, and replaces its formatted value with the mapped display names. The registration adds a relatedFields hook injecting display_name, which is what makes the child names available without the kanban view loading anything explicitly.

For support managers scanning the livechat sessions board, the widget answers who was in this conversation without a click: the visitor and every agent who participated, straight on the card. The same board powers the Looking for Help queue, where seeing the customer name before grabbing a session is the difference between context and cold starts.

Beyond livechat, the widget is a pattern worth copying whenever a kanban card should mention related records by name rather than count them: attendees on a session card, participants on a case, signatories on a contract. A count says 3 records; a name list says which three, and for triage screens that specificity is usually the more useful of the two.

The core pattern: names on a kanban card

<t t-name="card">
    <field class="fw-bolder"
           name="livechat_customer_history_ids"
           widget="im_livechat.one2many_names"/>
    <span>Date: <field name="create_date"/></span>
</t>

Both core usages look like this, on the session history kanban and on the Looking for Help board. The child records' display names arrive automatically thanks to the registration's relatedFields.

The relatedFields hook is the interesting engineering. Widgets on x2many fields can declare which columns of the relation they need, and the model loader merges those into the fetch. By declaring display_name at registration time, the widget guarantees its data regardless of the view, the same mechanism many2many_tags uses for its color field. Custom widgets that read child data without declaring it work only when some other widget happened to load the column, a bug class we have documented on several core widgets; this one does it right.

Worth noting for reuse: the widget reads records from the field's list object, which respects the loaded page. An x2many with hundreds of children would print only the loaded slice's names, a non-issue on livechat cards where the participant count is small, but a real consideration before pointing it at large relations.

Odoo 20 is expected at Odoo Experience in Brussels, 24 to 26 September 2026, and the development branch keeps moving until feature freeze, so this section is provisional and re-verified after release.

For this widget the report is short: the file on the development branch is byte-identical to 19.0, registration, component, and relatedFields hook included. Even the broader Owl props migration sweeping most field widgets has not touched it at the time of writing. Views using it should carry to 20 unchanged.