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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\CssSelector\XPath\Extension;
  13  
  14  use Symfony\Component\CssSelector\Exception\ExpressionErrorException;
  15  use Symfony\Component\CssSelector\XPath\XPathExpr;
  16  
  17  /**
  18   * XPath expression translator pseudo-class extension.
  19   *
  20   * This component is a port of the Python cssselect library,
  21   * which is copyright Ian Bicking, @see https://github.com/SimonSapin/cssselect.
  22   *
  23   * @author Jean-François Simon <jeanfrancois.simon@sensiolabs.com>
  24   *
  25   * @internal
  26   */
  27  class PseudoClassExtension extends AbstractExtension
  28  {
  29      /**
  30       * {@inheritdoc}
  31       */
  32      public function getPseudoClassTranslators(): array
  33      {
  34          return [
  35              'root' => [$this, 'translateRoot'],
  36              'first-child' => [$this, 'translateFirstChild'],
  37              'last-child' => [$this, 'translateLastChild'],
  38              'first-of-type' => [$this, 'translateFirstOfType'],
  39              'last-of-type' => [$this, 'translateLastOfType'],
  40              'only-child' => [$this, 'translateOnlyChild'],
  41              'only-of-type' => [$this, 'translateOnlyOfType'],
  42              'empty' => [$this, 'translateEmpty'],
  43          ];
  44      }
  45  
  46      public function translateRoot(XPathExpr $xpath): XPathExpr
  47      {
  48          return $xpath->addCondition('not(parent::*)');
  49      }
  50  
  51      public function translateFirstChild(XPathExpr $xpath): XPathExpr
  52      {
  53          return $xpath
  54              ->addStarPrefix()
  55              ->addNameTest()
  56              ->addCondition('position() = 1');
  57      }
  58  
  59      public function translateLastChild(XPathExpr $xpath): XPathExpr
  60      {
  61          return $xpath
  62              ->addStarPrefix()
  63              ->addNameTest()
  64              ->addCondition('position() = last()');
  65      }
  66  
  67      /**
  68       * @throws ExpressionErrorException
  69       */
  70      public function translateFirstOfType(XPathExpr $xpath): XPathExpr
  71      {
  72          if ('*' === $xpath->getElement()) {
  73              throw new ExpressionErrorException('"*:first-of-type" is not implemented.');
  74          }
  75  
  76          return $xpath
  77              ->addStarPrefix()
  78              ->addCondition('position() = 1');
  79      }
  80  
  81      /**
  82       * @throws ExpressionErrorException
  83       */
  84      public function translateLastOfType(XPathExpr $xpath): XPathExpr
  85      {
  86          if ('*' === $xpath->getElement()) {
  87              throw new ExpressionErrorException('"*:last-of-type" is not implemented.');
  88          }
  89  
  90          return $xpath
  91              ->addStarPrefix()
  92              ->addCondition('position() = last()');
  93      }
  94  
  95      public function translateOnlyChild(XPathExpr $xpath): XPathExpr
  96      {
  97          return $xpath
  98              ->addStarPrefix()
  99              ->addNameTest()
 100              ->addCondition('last() = 1');
 101      }
 102  
 103      public function translateOnlyOfType(XPathExpr $xpath): XPathExpr
 104      {
 105          $element = $xpath->getElement();
 106  
 107          return $xpath->addCondition(sprintf('count(preceding-sibling::%s)=0 and count(following-sibling::%s)=0', $element, $element));
 108      }
 109  
 110      public function translateEmpty(XPathExpr $xpath): XPathExpr
 111      {
 112          return $xpath->addCondition('not(*) and not(string-length())');
 113      }
 114  
 115      /**
 116       * {@inheritdoc}
 117       */
 118      public function getName(): string
 119      {
 120          return 'pseudo-class';
 121      }
 122  }