title: ActiveAdmin - how to render default template in customized action
body: <p>We are using ActiveAdmin in our Rails3 application for the default models. Now we needed to overwrite the show action. The OrderProcess model is a transient (tableless) model, which means that all fields are aggregated from other data. We use an internal module that provides the necessary methods to mock the MetaSearch methods ActiveAdmin is depending on. The following is how we overwrite the show action:</p>
  
  <pre><code>ActiveAdmin.register OrderProcess do  
    member_action :show, :method =&gt; :get do
      @order_process = OrderProcess.all_orders_for_deal(params['id'])
    end
  end
  </code></pre>
  
  <p>That gives us an error complaining about a missing template "Missing template admin/order_processes/show with ..."</p>
  
  <p>We also tried to call</p>
  
  <pre><code>  render renderer_for(:show)
  </code></pre>
  
  <p>but that produced an error about a missing method model_name which may be due to our model being tableless and the regarding module.</p>
  
  <p>How can we use ActiveAdmins built in rendering methods to display our model? Any help is appreciated.</p>