Hi everyone,

I'm struggling to dynamically hide/show columns in a list view (tree) in Odoo 19 based on a boolean flag set in the parent event form.

My Goal:

I have a custom module that inherits from event.event and event.registration.

• If the event has is_internal_training = True, I want to show the employee_id and employee_number columns in the attendees registration list view.

• If it is False, these columns should be completely hidden (column_invisible).

What works:

In the Form View of event.registration, using invisible="not is_internal_training" works flawlessly.

The Problem:

In the List View (tree), I cannot find the correct syntax for column_invisible to achieve this without breaking the framework.

• If I try using parent.is_internal_training, OWL crashes with Name 'parent' is not defined when opening the list view independently (e.g., via the smart button or action menus).

• If I try reading from the context using standard evaluation, the columns don't hide or I run into circular ParseError on the backend vs EvalError on the client.

My Code Setup:

1. Models (event_event.py):

from odoo import fields, models

classEventEvent(models.Model):
    _inherit = 'event.event'

    is_internal_training = fields.Boolean(string="Internal Training", default=False)

2. Models (event_registration.py):

from odoo import fields, models

classEventRegistration(models.Model):
    _inherit = 'event.registration'

    employee_id = fields.Many2one('hr.employee', string="Employee")
    employee_number = fields.Integer(related='employee_id.employee_number', string='Employee Number', store=True, readonly=True)
    
    # Related field to expose the setting to the tree view
    is_internal_training = fields.Boolean(
        related='event_id.is_internal_training',
        string='Is Internal Training',
        readonly=True,
        store=True
    )

3. Main Event Form View (event_event_views.xml):

<xpath expr="//field[@name='tag_ids']"position="after">	​	​<fieldname="is_internal_training"string="Internal Training"/>
</xpath>

4. Target Inherited Views (event_registration_views.xml):

<recordid="view_event_registration_form_inherit_custom"model="ir.ui.view"><fieldname="name">event.registration.form.inherit.custom.website.event</field><fieldname="model">event.registration</field><fieldname="inherit_id"ref="event.view_event_registration_form"/><fieldname="arch"type="xml"><xpathexpr="//field[@name='name']"position="before"><fieldname="employee_id"placeholder="Search employee..."invisible="not is_internal_training" /><fieldname="employee_number"invisible="not is_internal_training" /></xpath></field></record><recordid="view_event_registration_tree_inherit_custom"model="ir.ui.view"><fieldname="name">event.registration.tree.inherit.custom.website.event</field><fieldname="model">event.registration</field><fieldname="inherit_id"ref="event.view_event_registration_tree"/><fieldname="arch"type="xml"><xpathexpr="//field[@name='name']"position="before"><fieldname="employee_number"optional="show"column_invisible="context.get('is_internal_training', False)"/><fieldname="employee_id"optional="show"column_invisible="context.get('is_internal_training', False)"/></xpath></field></record>

Since the attendees list view can be loaded inside the form but also globally (via smart buttons), what is the correct Odoo 19 way to dynamically evaluate column_invisible for this exact scenario using the context or the related field?

Thanks in advance!