extra_data_dikasa/views/purchase_order.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
  <data>
    <record model="ir.ui.view" id="dikasa_purchase_form">
       <field name="name">dikasa_purchase_form</field>
       <field name="model">purchase.order</field>
       <field name="inherit_id" ref="purchase.purchase_order_form"/>
       <field name="arch" type="xml">
         <field name="partner_id" position="replace">
           <field name="partner_id" domain="[('supplier','=',True)]" options='{"always_reload": True}'/>
         </field>
         <field name="partner_id" position="after">
            <field name="ruc"/>
            <field name="street"/>
            <field name="state_id"/>
            <field name="country_id"/>
            <field name="email"/>
            <field name="phone"/>
            <field name="mobile"/>
         </field>
         <field name="validator" position="attributes">
            <attribute name="string">Confirmado por</attribute>
         </field>

         <xpath expr="//form/sheet/notebook//page[@string='RFQ &amp; Bid']" position="attributes">
           <attribute name="attrs">{'invisible':True}</attribute>
         </xpath>

         <field name="pricelist_id" position="replace"></field>
         <field name="currency_id" position="replace"></field>

         <field name="picking_type_id" position="after">
            <field name="pricelist_id"/>
            <field name="currency_id"/>
         </field>


      </field>
    </record>

</data>
</openerp>