title: Symfony2 Knp-snappy to generate PDF from a twig view that contain an image
body: <p>I want to generate a PDF file from a twig view that contain an image.
  this is my Controller:Action  :</p>
  
  <pre><code>public function generatePdfAction(Request $request)
      {
         // initialize the $emp variable
          $html = $this-&gt;renderView('PFEEmployeesBundle:Employee:view.html.twig',
              array('employee'=&gt; $employee)
          );
  
          return new Response(
              $this-&gt;get('knp_snappy.pdf')-&gt;getOutputFromHtml($html),
              200,
              array(
                  'Content-Type'          =&gt; 'application/pdf',
                  'Content-Disposition'   =&gt; 'attachment; filename="file.pdf"'
              )
          );
      }
  </code></pre>
  
  <p>this is the configuration in the config.yml : </p>
  
  <pre><code>knp_snappy:
      pdf:
          enabled:    true
          binary:     "\"C:\\Program Files\\wkhtmltopdf\\bin\\wkhtmltopdf.exe\""
          options:    []
      image:
          enabled:    true
          binary:     "\"C:\\Program Files\\wkhtmltopdf\\bin\\wkhtmltoimage.exe\""
          options:    []
  </code></pre>
  
  <p>The code generates a pdf file including the CSS.
  I have two problems, the first is the image not displayed in the pdf file.
  the second is how to render not the whole view but just a block of the twig view ( the view extends an other).</p>