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   1  <?php
   2  
   3  /*
   4   * This file is part of the Symfony package.
   5   *
   6   * (c) Fabien Potencier <fabien@symfony.com>
   7   *
   8   * For the full copyright and license information, please view the LICENSE
   9   * file that was distributed with this source code.
  10   */
  11  
  12  namespace Symfony\Component\HttpKernel\HttpCache;
  13  
  14  use Symfony\Component\HttpFoundation\Request;
  15  use Symfony\Component\HttpFoundation\Response;
  16  
  17  /**
  18   * Esi implements the ESI capabilities to Request and Response instances.
  19   *
  20   * For more information, read the following W3C notes:
  21   *
  22   *  * ESI Language Specification 1.0 (http://www.w3.org/TR/esi-lang)
  23   *
  24   *  * Edge Architecture Specification (http://www.w3.org/TR/edge-arch)
  25   *
  26   * @author Fabien Potencier <fabien@symfony.com>
  27   */
  28  class Esi extends AbstractSurrogate
  29  {
  30      public function getName()
  31      {
  32          return 'esi';
  33      }
  34  
  35      /**
  36       * {@inheritdoc}
  37       */
  38      public function addSurrogateControl(Response $response)
  39      {
  40          if (false !== strpos($response->getContent(), '<esi:include')) {
  41              $response->headers->set('Surrogate-Control', 'content="ESI/1.0"');
  42          }
  43      }
  44  
  45      /**
  46       * {@inheritdoc}
  47       */
  48      public function renderIncludeTag($uri, $alt = null, $ignoreErrors = true, $comment = '')
  49      {
  50          $html = sprintf('<esi:include src="%s"%s%s />',
  51              $uri,
  52              $ignoreErrors ? ' onerror="continue"' : '',
  53              $alt ? sprintf(' alt="%s"', $alt) : ''
  54          );
  55  
  56          if (!empty($comment)) {
  57              return sprintf("<esi:comment text=\"%s\" />\n%s", $comment, $html);
  58          }
  59  
  60          return $html;
  61      }
  62  
  63      /**
  64       * {@inheritdoc}
  65       */
  66      public function process(Request $request, Response $response)
  67      {
  68          $type = $response->headers->get('Content-Type');
  69          if (empty($type)) {
  70              $type = 'text/html';
  71          }
  72  
  73          $parts = explode(';', $type);
  74          if (!\in_array($parts[0], $this->contentTypes)) {
  75              return $response;
  76          }
  77  
  78          // we don't use a proper XML parser here as we can have ESI tags in a plain text response
  79          $content = $response->getContent();
  80          $content = preg_replace('#<esi\:remove>.*?</esi\:remove>#s', '', $content);
  81          $content = preg_replace('#<esi\:comment[^>]+>#s', '', $content);
  82  
  83          $chunks = preg_split('#<esi\:include\s+(.*?)\s*(?:/|</esi\:include)>#', $content, -1, \PREG_SPLIT_DELIM_CAPTURE);
  84          $chunks[0] = str_replace($this->phpEscapeMap[0], $this->phpEscapeMap[1], $chunks[0]);
  85  
  86          $i = 1;
  87          while (isset($chunks[$i])) {
  88              $options = [];
  89              preg_match_all('/(src|onerror|alt)="([^"]*?)"/', $chunks[$i], $matches, \PREG_SET_ORDER);
  90              foreach ($matches as $set) {
  91                  $options[$set[1]] = $set[2];
  92              }
  93  
  94              if (!isset($options['src'])) {
  95                  throw new \RuntimeException('Unable to process an ESI tag without a "src" attribute.');
  96              }
  97  
  98              $chunks[$i] = sprintf('<?php echo $this->surrogate->handle($this, %s, %s, %s) ?>'."\n",
  99                  var_export($options['src'], true),
 100                  var_export(isset($options['alt']) ? $options['alt'] : '', true),
 101                  isset($options['onerror']) && 'continue' === $options['onerror'] ? 'true' : 'false'
 102              );
 103              ++$i;
 104              $chunks[$i] = str_replace($this->phpEscapeMap[0], $this->phpEscapeMap[1], $chunks[$i]);
 105              ++$i;
 106          }
 107          $content = implode('', $chunks);
 108  
 109          $response->setContent($content);
 110          $response->headers->set('X-Body-Eval', 'ESI');
 111  
 112          // remove ESI/1.0 from the Surrogate-Control header
 113          $this->removeFromControl($response);
 114  
 115          return $response;
 116      }
 117  }