title: Adding action in SonataAdminBundle
body: <p>I'm trying to add an action in sonata admin bundle. I changed my Admin class with :</p>
  
  <pre><code>protected function configureListFields(ListMapper $listMapper)
  {
      $listMapper
          -&gt;addIdentifier('id')
          -&gt;add('name')        
          // add custom action links
          -&gt;add('_action', 'actions', array(
              'actions' =&gt; array(
                  'view' =&gt; array(),
                  'calculate' =&gt; array('template' =&gt; 'myappMyBundle:Admin:list__action_calculate.html.twig'),
                  'edit' =&gt; array(),
              )
          ))
      ;
  }
  </code></pre>
  
  <p>and</p>
  
  <pre><code>protected function configureSideMenu(MenuItemInterface $menu, $action, Admin $childAdmin = null)
  {
      if (!$childAdmin &amp;&amp; !in_array($action, array('edit'))) {
          return;
      }
      $admin = $this-&gt;isChild() ? $this-&gt;getParent() : $this;
      $id = $admin-&gt;getRequest()-&gt;get('id');
      $menu-&gt;addChild('calculate', array('uri' =&gt; 'http://google.com?id=' . $id));
  }
  </code></pre>
  
  <p>and put a template called list__action_calculate.html.twig in src/myapp/MyBundle/Resources/views/Admin/ :</p>
  
  <pre><code>{% if admin.isGranted('EDIT', object) and admin.hasRoute('edit') %}
  &lt;a href="{{ admin.generateObjectUrl('calculate', object) }}" class="calculate_link" title="{{ 'action_calculate'|trans({}, 'SonataAdminBundle') }}"&gt;
      &lt;img src="{{ asset('bundles/sonataadmin/famfamfam/page_white_edit.png') }}" alt="{{ 'action_calculate'|trans({}, 'SonataAdminBundle') }}" /&gt;
  &lt;/a&gt;
  {% endif %}
  </code></pre>
  
  <p>But i got this error from symfony : </p>
  
  <pre><code>An exception has been thrown during the rendering of a template 
  ("unable to find the route `mysite.mybundle.admin.myentity.calculate`") 
  in "SonataAdminBundle:CRUD:list.html.twig"
  </code></pre>
  
  <p>What have i missed ?
  Is there a clue in the documentation than this page of the <a href="http://sonata-project.org/bundles/admin/2-0/doc/reference/batch_actions.html">Doc</a>.</p>