title: Odoo. Function field that returns list
body: <p>We're trying to create odoo function field, that renders as list. </p>
  
  <p>We've following model:</p>
  
  <pre><code>class sale_wizard(orm.TransientModel):
      _name = 'account.bank.statement.review.wizard'
  
  
      def _orders(self, cr, uid, ids, fields, arg, context=None):
          statement = self.env['account.bank.statement'].browse(self._context.get('active_id'))
          partner_id = statement.partner_id.id
          sale_orders = self.pool.get('sale.order').search(cr, uid, [
              ('partner_id', '=', partner_id),
          ])
          print 'hiro'
          print sale_orders
          return [(1,2,3), (1,2,3)]
  
  
      _columns = { 
          'order_ids': fields.function(_orders, string="Sale Orders", type="many2many"),
      }
  </code></pre>
  
  <p>We've following view: </p>
  
  <pre><code>    &lt;?xml version="1.0" encoding="utf-8"?&gt;
      &lt;openerp&gt;
          &lt;data&gt;
              &lt;!-- Wizard Form --&gt;
              &lt;record model="ir.ui.view" id="orders_review_form"&gt;
                  &lt;field name="name"&gt;Sale Orders Review&lt;/field&gt;
                  &lt;field name="model"&gt;account.bank.statement.review.wizard&lt;/field&gt;
                  &lt;field name="arch" type="xml"&gt;
                      &lt;form string="Sale Orders Test"&gt;
                          &lt;group col="2"&gt;
                              &lt;field name="order_ids" /&gt;
                          &lt;/group&gt;
                      &lt;/form&gt;
                  &lt;/field&gt;
              &lt;/record&gt;
          &lt;/data&gt;
      &lt;/openerp&gt;
  </code></pre>
  
  <p>When I'm opening form, that contains view - it renders as empty list. And lines </p>
  
  <pre><code>print 'hiro'
  print sale_orders
  </code></pre>
  
  <p>don't execute. So function field <code>order_ids</code> don't execute function <code>orders</code>. </p>
  
  <p>Where to dig? </p>
  
  <p><strong>UPD</strong> In other module - function field works as expected and executes on model initialization. </p>