title: How to set default field value from xml code in odoo?
body: <p>In sales order module I have created a new customised form view, in sale.py file I have created a new field 'is_sample'</p>
  
  <pre><code>'is_sample': fields.boolean("Specimen Order", store=False),
  </code></pre>
  
  <p>I want to set its default value from xml code so that it doesn't get affected in default form view. I have tried in four ways,</p>
  
  <pre><code>1)&lt;field name="is_sample" eval="True"/&gt;
  2)&lt;field name="is_sample" domain="[('is_sample','=',True)]"/&gt;
  3)&lt;record id="action_specimen_orders" model="ir.actions.act_window"&gt;
          &lt;field name="type"&gt;ir.actions.act_window&lt;/field&gt;
          &lt;field name="context"&gt;{'is_sample': 'True'}&lt;/field&gt;
         ...
  4)&lt;record id="action_specimen_orders" model="ir.actions.act_window"&gt;
          &lt;field name="type"&gt;ir.actions.act_window&lt;/field&gt;
          &lt;field name="domain"&gt;[('is_sample','=','True')]&lt;/field&gt;
         ...
  </code></pre>