golem/golem_membership/views/golem_membership_invoice.xml

<?xml version="1.0" encoding="utf-8"?>

<!--
Copyright 2016-2018 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/>.
-->

<odoo>
  <data>
    <!-- Forms -->
    <record id="golem_membership_invoice_form" model="ir.ui.view">
      <field name="name">membership.invoice.view.form</field>
      <field name="model">golem.membership.invoice</field>
      <field name="arch" type="xml">
        <form string="Membership Invoice">
          <group>
            <field name="product_id" domain="[('membership','=',True)]"
              widget="selection" />
            <field name="member_price" />
          </group>
          <footer>
            <button string="Invoice Membership" name="membership_invoice"
              type="object" class="oe_highlight"  />
            or
            <button string="Cancel" class="oe_link" special="cancel" />
          </footer>
        </form>
      </field>
    </record>

  </data>
</odoo>