title: Call function from another class - field - Odoo v8
body: <p>I'm struggling with this and I'm not so clear about it.</p>
  
  <p>Let's say I have a function in a class:</p>
  
  <pre><code>class my_class(osv.Model):
      _name = 'my_class'
      _description = 'my description'
  
      def func (self, cr, uid, ids, name, arg, context=None):
              res = dict((id, 0) for id in ids)
      sur_res_obj = self.pool.get('contratos.user_input')
      for id in ids:
          res[id] = sur_res_obj.search(cr, uid,  # SUPERUSER_ID,
              [('contratos_id', '=', id), ('state', '=', 'done')],
              context=context, count=True)
      return res
      columns = {
          'function': fields.function(_get_func,
          string="Number of completed Contratos", type="integer"),
  my_class()
  </code></pre>
  
  <p>Now I want to call this very same function from another class-object:</p>
  
  <pre><code>class another_class(osv.Model):
      _inherit = 'my_class'
      _name = 'my_class'
  
      columns = {
          'another_field' : fields.related('function', 'state', type='char', string = "Related field which calls a function from another object"), 
      }
  </code></pre>
  
  <p>But this isn't working, I'm very confused about this, how can I call a function from another object in Odoov8?</p>
  
  <p>I've heard about <code>self.pool.get</code> but I'm not really sure on how to invoke it.</p>
  
  <p>Any ideas?</p>
  
  <p>Thanks in advance!</p>