Hello, I want to make a handler for button in footer area using javascript. My view model looks below :

<record id="view_rnd_history_form" model="ir.ui.view">
    <field name="name">rnd.history.form</field>
    <field name="model">rnd.batch.record.history</field>
    <field name="arch" type="xml">
        <form string="History" version="7.0">
            <group>
                <field name="br_id" colspan="2"/>
                <label for="start_date" string="Date"/>
                <div>
                    <field name="start_date" class="oe_inline"/> - 
                    <field name="end_date" class="oe_inline"/>
                </div>
                <field name="batch_number" colspan="2"/>
                <field name="parameter_id" colspan="2"/>
            </group>
            <footer>
                <button name="show_history" string="_Show" class="oe_highlight" onclick="alert('hello');"/>
            </footer>
        </form>
    </field>
</record>

I'm confuse. the onclick attribute seem removed by qweb render process. I want a simple thing, user click on show_history button, then it call a simple javascript function or action client. Any information will be appreciate. Thank you.