Voglio tramite codeigniter e dompdf creare file pdf da una qualsiasi view, ma non riesco.

recupero tutto il codice html
codice HTML:
<script type="text/javascript">jQuery(document).ready(function() {
   var dati = jQuery("html").html();var $modal = $('#modal');
   var richiesta  = jQuery.ajax({
    type: 'POST',
    data: 'data='+dati,
    dataType: 'html',
    url:'http://ci.dev/AR-PIB/Dompdf_test/' //MANDARE DATI PER CREARE PDF
    });
  richiesta.done(function(resp){ 
  var url = 'http://ci.dev/AR-PIB/Dompdf_test/create'    
  jQuery(location).attr('href',url);
    });
   });
Il controller
Codice PHP:
<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');class Dompdf_test extends CI_Controller { /**
  * Example: DOMPDF 
  *
  * Documentation: 
  * http://code.google.com/p/dompdf/wiki/Usage
  *
  */
  public function index()
 {
  $this->session->set_userdata('html_pdf', $this->input->post('data'));
 }
 public function create() { 
  // Load all views as normal
  $this->load->view('dompdf_v');
  // Get output html
  $html = $this->output->get_output();
  file_get_contents($this->session->userdata('html_pdf'));
  // Load library
  $this->load->library('dompdf_gen');
  
  // Convert to PDF
  $this->dompdf->load_html(utf8_decode($html));
  $this->dompdf->render();
  $this->dompdf->stream("welcome.pdf",array('Attachment'=>0));
 }
}
il file dompdf_v
Codice PHP:
<?php�
defined('BASEPATH') OR exit('No direct script access allowed');
echo $this->session->userdata('html_pdf');
?>