title: before_filter :require_owner
body: <p>I have a number of resources (Trips, Schedules, etc) with actions that should be limited to just the resource's owner. </p>
  
  <p>How do you implement code with a #require_owner method defined in ApplicationController to achieve this?  Ideally, the code will look up the inheritance chain for the owner so the before_filter will work on a :comment that belongs_to :trip that belongs_to :user.</p>
  
  <pre><code>class TripsController &lt; ApplicationController
    belongs_to :member
    before_filter :require_owner
  
    ...
  
  end
  </code></pre>