<?xml version="1.0"?>
<data><xpath expr="//field[@name='date_deadline']" position="attributes">
                  <attribute name="invisible">activity_category == 'meeting'</attribute>
            </xpath>
            <xpath expr="//field[@name='user_id']" position="attributes">
                  <attribute name="invisible">activity_category == 'meeting'</attribute>
            </xpath>
            <xpath expr="//button[@id='mail_activity_schedule']" position="attributes">
                  <attribute name="invisible">activity_category in ['meeting', 'phonecall'] or id</attribute>
            </xpath>
            <xpath expr="//button[@id='mail_activity_save']" position="attributes">
                  <attribute name="invisible">activity_category != 'phonecall' and not id</attribute>
            </xpath>
            <xpath expr="//button[@name='action_done']" position="attributes">
                  <attribute name="invisible">activity_category == 'meeting' or chaining_type == 'trigger'</attribute>
            </xpath>
            <xpath expr="//field[@name='note']" position="attributes">
                  <attribute name="invisible">activity_category == 'meeting'</attribute>
            </xpath>
            <xpath expr="//button[@name='action_close_dialog']" position="before">
                  <field name="calendar_event_id" invisible="1"/>
                  <button string="Open Calendar" close="1" invisible="activity_category not in ['meeting', 'phonecall'] or calendar_event_id" name="action_create_calendar_event" type="object" class="btn-primary"/>
            </xpath>
        </data>