FunctionExtension.php in Zircon Profile 8.0

Namespace

Symfony\Component\CssSelector\XPath\Extension

File

vendor/symfony/css-selector/XPath/Extension/FunctionExtension.php

<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <[e-mail]>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace Symfony\Component\CssSelector\XPath\Extension;

use Symfony\Component\CssSelector\Exception\ExpressionErrorException;
use Symfony\Component\CssSelector\Exception\SyntaxErrorException;
use Symfony\Component\CssSelector\Node\FunctionNode;
use Symfony\Component\CssSelector\Parser\Parser;
use Symfony\Component\CssSelector\XPath\Translator;
use Symfony\Component\CssSelector\XPath\XPathExpr;

/**
 * XPath expression translator function extension.
 *
 * This component is a port of the Python cssselect library,
 * which is copyright Ian Bicking, @see https://github.com/SimonSapin/cssselect.
 *
 * @author Jean-François Simon <[e-mail]>
 */
class FunctionExtension extends AbstractExtension {

  /**
   * {@inheritdoc}
   */
  public function getFunctionTranslators() {
    return array(
      'nth-child' => array(
        $this,
        'translateNthChild',
      ),
      'nth-last-child' => array(
        $this,
        'translateNthLastChild',
      ),
      'nth-of-type' => array(
        $this,
        'translateNthOfType',
      ),
      'nth-last-of-type' => array(
        $this,
        'translateNthLastOfType',
      ),
      'contains' => array(
        $this,
        'translateContains',
      ),
      'lang' => array(
        $this,
        'translateLang',
      ),
    );
  }

  /**
   * @param XPathExpr    $xpath
   * @param FunctionNode $function
   * @param bool         $last
   * @param bool         $addNameTest
   *
   * @return XPathExpr
   *
   * @throws ExpressionErrorException
   */
  public function translateNthChild(XPathExpr $xpath, FunctionNode $function, $last = false, $addNameTest = true) {
    try {
      list($a, $b) = Parser::parseSeries($function
        ->getArguments());
    } catch (SyntaxErrorException $e) {
      throw new ExpressionErrorException(sprintf('Invalid series: %s', implode(', ', $function
        ->getArguments())), 0, $e);
    }
    $xpath
      ->addStarPrefix();
    if ($addNameTest) {
      $xpath
        ->addNameTest();
    }
    if (0 === $a) {
      return $xpath
        ->addCondition('position() = ' . ($last ? 'last() - ' . ($b - 1) : $b));
    }
    if ($a < 0) {
      if ($b < 1) {
        return $xpath
          ->addCondition('false()');
      }
      $sign = '<=';
    }
    else {
      $sign = '>=';
    }
    $expr = 'position()';
    if ($last) {
      $expr = 'last() - ' . $expr;
      --$b;
    }
    if (0 !== $b) {
      $expr .= ' - ' . $b;
    }
    $conditions = array(
      sprintf('%s %s 0', $expr, $sign),
    );
    if (1 !== $a && -1 !== $a) {
      $conditions[] = sprintf('(%s) mod %d = 0', $expr, $a);
    }
    return $xpath
      ->addCondition(implode(' and ', $conditions));

    // todo: handle an+b, odd, even
    // an+b means every-a, plus b, e.g., 2n+1 means odd
    // 0n+b means b
    // n+0 means a=1, i.e., all elements
    // an means every a elements, i.e., 2n means even
    // -n means -1n
    // -1n+6 means elements 6 and previous
  }

  /**
   * @param XPathExpr    $xpath
   * @param FunctionNode $function
   *
   * @return XPathExpr
   */
  public function translateNthLastChild(XPathExpr $xpath, FunctionNode $function) {
    return $this
      ->translateNthChild($xpath, $function, true);
  }

  /**
   * @param XPathExpr    $xpath
   * @param FunctionNode $function
   *
   * @return XPathExpr
   */
  public function translateNthOfType(XPathExpr $xpath, FunctionNode $function) {
    return $this
      ->translateNthChild($xpath, $function, false, false);
  }

  /**
   * @param XPathExpr    $xpath
   * @param FunctionNode $function
   *
   * @return XPathExpr
   *
   * @throws ExpressionErrorException
   */
  public function translateNthLastOfType(XPathExpr $xpath, FunctionNode $function) {
    if ('*' === $xpath
      ->getElement()) {
      throw new ExpressionErrorException('"*:nth-of-type()" is not implemented.');
    }
    return $this
      ->translateNthChild($xpath, $function, true, false);
  }

  /**
   * @param XPathExpr    $xpath
   * @param FunctionNode $function
   *
   * @return XPathExpr
   *
   * @throws ExpressionErrorException
   */
  public function translateContains(XPathExpr $xpath, FunctionNode $function) {
    $arguments = $function
      ->getArguments();
    foreach ($arguments as $token) {
      if (!($token
        ->isString() || $token
        ->isIdentifier())) {
        throw new ExpressionErrorException('Expected a single string or identifier for :contains(), got ' . implode(', ', $arguments));
      }
    }
    return $xpath
      ->addCondition(sprintf('contains(string(.), %s)', Translator::getXpathLiteral($arguments[0]
      ->getValue())));
  }

  /**
   * @param XPathExpr    $xpath
   * @param FunctionNode $function
   *
   * @return XPathExpr
   *
   * @throws ExpressionErrorException
   */
  public function translateLang(XPathExpr $xpath, FunctionNode $function) {
    $arguments = $function
      ->getArguments();
    foreach ($arguments as $token) {
      if (!($token
        ->isString() || $token
        ->isIdentifier())) {
        throw new ExpressionErrorException('Expected a single string or identifier for :lang(), got ' . implode(', ', $arguments));
      }
    }
    return $xpath
      ->addCondition(sprintf('lang(%s)', Translator::getXpathLiteral($arguments[0]
      ->getValue())));
  }

  /**
   * {@inheritdoc}
   */
  public function getName() {
    return 'function';
  }

}

Classes

Name	Description
FunctionExtension	XPath expression translator function extension.