GOLEM/golem_activity_registration_export/views/golem_activity_view.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
Copyright 2016 Fabien Bourgeois <fabien@yaltik.com>

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
-->
<openerp>
  <data>

    <!-- Form -->
    <record id="export_activity_form" model="ir.ui.view">
      <field name="name">Activity Registrations CSV Export</field>
      <field name="model">golem.activity</field>
      <field name="inherit_id"
        ref="golem_activity.view_form" />
      <field name="arch" type="xml">
        <header position="inside">
          <div style="min-height: 30px;">
            <button name="do_export_csv" type="object" class="oe_button"
              string="Export members to CSV file" />
          </div>
        </header>
      </field>
    </record>

  </data>
</openerp>