title: Odoo: ValueError: Invalid field 'user_id' in leaf
body: <p>I am trying to create rule, to limit users to see only their records in tree view in my module, but it gives me error that 'user_id' field doesn't exist...</p>
  
  <p>Heres my model:</p>
  
  <pre><code>class help_desk(models.Model):
      _name = 'help_desk.help_desk'
  
      name = fields.Char(string="Title", required=True)
      number = fields.Char(string="Mobile", required=True)
  </code></pre>
  
  <p>Here's the rule:</p>
  
  <pre><code>&lt;record model="ir.rule" id="per_user_rule"&gt;
              &lt;field name="name"&gt;User: see the individual Record&lt;/field&gt;
              &lt;field name="model_id" ref="model_help_desk_help_desk"/&gt;
              &lt;field name="domain_force"&gt;['|',('user_id','=',False),('user_id','=',user.id)]&lt;/field&gt;
              &lt;field name="groups" eval="[(4,ref('base.group_user'))]"/&gt;
  &lt;/record&gt;
  </code></pre>
  
  <p>Here's the Error:</p>
  
  <pre><code>ValueError: Invalid field 'user_id' in leaf "&lt;osv.ExtendedLeaf: ('user_id', '=', 9) on help_desk_help_desk (ctx: )&gt;"
  </code></pre>
  
  <p>I am guessing, i have to add user_id field to my model, but how can i relate it to current user?</p>