cooperative-market/beesdoo_shift/wizard/validate_attendance_sheet.xml

<odoo>
    <record model="ir.ui.view" id="validate_attendance_sheet_form">
        <field name="name">Validate Attendance Sheet</field>
        <field name="model">beesdoo.shift.sheet.validate</field>
        <field name="arch" type="xml">
            <form>
                <label string="Beware : a validated sheet cannot be edited anymore and you won't be able to add any latecomers.
                                Emails will be sent to workers who did not attend their shift." />
                <group>
                    <field name="user" />
                </group>
                <footer>
                    <button type="object" name="validate_sheet"
                        string="Confirm" class="oe_highlight" />
                    or
                    <button special="cancel" string="Cancel" />
                </footer>
            </form>
        </field>
    </record>
</odoo>