To add a custom column on a page list, just follow these steps. In the example, we will add a “Nombre d’annoce(s)” column.

On your admin class file (ex: /AdminBundle/Admin/SecteurAdmin.php), on your configureListFields() fonction, add a new entry on the listMapper object

    /**
     * @param \Sonata\AdminBundle\Datagrid\ListMapper $listMapper
     * @return void
     */
    protected function configureListFields(ListMapper $listMapper) {
        $listMapper
                ->addIdentifier('titre')
                ->add('Tri', 'string', array('template' => 'TripixAdminBundle:Admin:list_tri.html.twig'))
                ->add('Nb', 'string', array('label' => 'Nombre d\'annonce(s)', 'template' => 'TripixAdminBundle:Admin:list_nb_annonce.html.twig'))
                ->add('_action', 'actions', array(
                    'actions' => array(
                        'edit' => array(),
                        'delete' => array(),
                    )
                ))
        ;
    }

This new entry said to use the TripixADminBundle:Admin:list_tri.html.twig template.

Now, create your template file (list_nb_annonce.html) in the /AdminBundle/ressources/view/admin/ directory.

{% extends 'SonataAdminBundle:CRUD:base_list_field.html.twig' %}

{% block field%}
{% if admin.datagrid.results|length > 1 %}
 <div>
        <strong>{{ object.getNombreAnnonce}}</strong>
    </div>
{% endif %}
{% endblock %}

In our example, getNombreAnnonce() is not defined, let’s do it
In the /adminBundle/Entity/Secteur.php file, add

   public function getNombreAnnonce()
    {
      return count($this->getAnnonces());
    }

That’s all.