By default SonataAdminBundle doesn't come with a PDF export functionality. Since this is a nice feature to have in your application here's a way to add PDF export to the CRUD pages.

The example works with the standard Symfony2 installation and the AcmeDemoBundle. The PDF will be generated using KnpSnappyBundle (the installation process is not covered here).

The Doctrine Entity:

See [Doctrine entities in Twig templates]({{ site.baseurl }}{% post_url 2013-01-30-doctrine-entities-in-twig-templates )

The Color Admin class:

// src/Acme/DemoBundle/Admin/ColorAdmin.php
namespace Acme\DemoBundle\Admin;

  use Sonata\AdminBundle\Admin\Admin;
  use Sonata\AdminBundle\Datagrid\ListMapper;
  use Sonata\AdminBundle\Datagrid\DatagridMapper;
  use Sonata\AdminBundle\Validator\ErrorElement;
  use Sonata\AdminBundle\Form\FormMapper;

  class ColorAdmin extends Admin
  {
    public $baseRouteName = 'color';
    public $baseRoutePattern = '/color';

    protected function configureFormFields(FormMapper $formMapper)
    {
      $formMapper
         ->add('name')
         ->add('hex');
    }

    protected function configureDatagridFilters(DatagridMapper $datagridMapper)
    {
      $datagridMapper
        ->add('name')
         ->add('hex');
    }

    protected function configureListFields(ListMapper $listMapper)
    {
      $listMapper
        ->addIdentifier('name')
        ->add('hex');
    }
  }

Enable the PDF export link on list page

In order to add the PDF export option the "getExportFormats" method needs to be overridden in the ColorAdmin class:

public function getExportFormats()
{
  return array_merge(parent::getExportFormats(), array('pdf'));
}

The "pdf" options should now be displayed on the list page next to the default ones.

Create custom service to handle PDF export

First the default export service (identified by "sonata.admin.exporter") needs to be overriden. Register the service in src/Acme/DemoBundle/Resources/config/services.xml and make it aware of the knpSnappyPdf. Also the template engine will be necessary.

<service id="sonata.admin.exporter" class="Acme\DemoBundle\Export\Exporter">
  <call method="setKnpSnappyPdf">
    <argument type="service" id="knp.snappy_pdf" />
  </call>
  <call method="setTemplateEngine">
    <argument type="service" id="templating" />
  </call>
</service>

Next extend the Sonata exporter class as defined in the overridden exporter service:

// src/Acme/DemoBundle/Export/Exporter.php
namespace Acme\DemoBundle\Export;

use Exporter\Source\SourceIteratorInterface;
use Symfony\Component\HttpFoundation\Response;
use Sonata\AdminBundle\Export\Exporter as BaseExporter;

class Exporter extends BaseExporter
{
  protected $knpSnappyPdf;
  protected $templateEngine;

  public function getResponse($format, $filename, SourceIteratorInterface $source)
  {
    if ('pdf' != $format) {
      return parent::getResponse($format, $filename, $source);
    }

    $html = $this->templateEngine->renderView('AcmeDemoBundle:Export:pdf.html.twig', array(
      'source' => $source
    ));
    $content = $this->knpSnappyPdf->getOutputFromHtml($html);

    return new Response($content, 200, array(
      'Content-Type' => 'application/pdf',
       'Content-Disposition' => sprintf('attachment; filename=%s', $filename)
    ));
  }

  public function setKnpSnappyPdf($service)
  {
    $this->knpSnappyPdf = $service;
  }

  public function setTemplateEngine($service)
  {
    $this->templateEngine = $service;
  }
}

The last step is to add the Twig template used to render the PDF content, as specified in the custom exporter service. For example:

<!-- src/Acme/DemoBundle/Resources/views/Export/pdf.html.pdf" -->
<table border="1">
  <tr>
    <th>ID</th>
    <th>Name</th>
    <th>HEX</th>
  </tr>
  {% for elements in source 
    <tr>
      {% for element in elements %}
        <td>{{ element }}</td>
      {% endfor %}
    </tr>
  {% endfor 
</table>

Of course, there is room for improvement. You can do it "SonataAdmin" way with a custom PdfWriter class (similar with the built-in XlsWriter, CsvWriter or JsonWriter) to separate the PDF conversion code, instead of having the entire process in the custom Exporter class.