purchase_fast_confirm/views/purchase_view.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
        <record id="view_purchase_confirm_form" model="ir.ui.view">
            <field name="name">purchase.order.form - Confirm</field>
            <field name="model">purchase.order</field>
            <field name="inherit_id" ref="purchase.purchase_order_form"/>
            <field name="arch" type="xml">
                <button name="bid_received" states="sent" position="after">
                    <button name="purchase_process_now" string="Procesar Compra" type="object" states="draft,sent" groups="base.group_user" class="oe_highlight"/>
                </button>
                <button name="print_quotation" position="attributes">
                    <attribute name="invisible">1</attribute>
                </button>
                <button name="wkf_send_rfq" position="attributes">
                    <attribute name="invisible">1</attribute>
                </button>
                <button name="purchase_confirm" position="attributes">
                    <attribute name="invisible">1</attribute>
                </button>
                <button name="wkf_send_rfq" states="approved" position="attributes">
                    <attribute name="invisible">1</attribute>
                </button>
            </field>
        </record>
        <record id="purchase_process_now_action" model="ir.actions.server">
            <field name="name">Purchase Fast Confirm</field>
            <field name="model_id" ref="model_purchase_order"/>
            <field name="state">code</field>
            <field name="code">
                if context.get('active_model') == 'purchase.order' and context.get('active_ids'):
                    self.purchase_process_now(cr, uid, context['active_ids'], context=context)
            </field>
        </record>

        <record id="ir_purchase_process_now" model="ir.values">
            <field eval="'client_action_multi'" name="key2"/>
            <field eval="'purchase.order'" name="model"/>
            <field name="name">Purchase Fast Confirm</field>
            <field eval="'ir.actions.server,%d'%purchase_process_now_action" name="value"/>
        </record>        
    </data>
</openerp>