class XmlFileLoader

1. 8.x drupal/core/vendor/symfony/routing/Symfony/Component/Routing/Loader/XmlFileLoader.php \Symfony\Component\Routing\Loader\XmlFileLoader
2. 8.x drupal/core/vendor/symfony/dependency-injection/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php \Symfony\Component\DependencyInjection\Loader\XmlFileLoader
3. 8.x drupal/core/vendor/symfony/validator/Symfony/Component/Validator/Mapping/Loader/XmlFileLoader.php \Symfony\Component\Validator\Mapping\Loader\XmlFileLoader

ValidatorBuilder.php in drupal/core/vendor/symfony/validator/Symfony/Component/Validator/ValidatorBuilder.php

XmlFileLoaderTest.php in drupal/core/vendor/symfony/validator/Symfony/Component/Validator/Tests/Mapping/Loader/XmlFileLoaderTest.php

class XmlFileLoader extends FileLoader {

  /**
   * An array of SimpleXMLElement instances.
   *
   * @var \SimpleXMLElement[]
   */
  protected $classes = null;

  /**
   * {@inheritDoc}
   */
  public function loadClassMetadata(ClassMetadata $metadata) {
    if (null === $this->classes) {
      $this->classes = array();
      $xml = $this
        ->parseFile($this->file);
      foreach ($xml->namespace as $namespace) {
        $this
          ->addNamespaceAlias((string) $namespace['prefix'], trim((string) $namespace));
      }
      foreach ($xml->class as $class) {
        $this->classes[(string) $class['name']] = $class;
      }
    }
    if (isset($this->classes[$metadata
      ->getClassName()])) {
      $xml = $this->classes[$metadata
        ->getClassName()];
      foreach ($xml->{'group-sequence-provider'} as $provider) {
        $metadata
          ->setGroupSequenceProvider(true);
      }
      foreach ($xml->{'group-sequence'} as $groupSequence) {
        if (count($groupSequence->value) > 0) {
          $metadata
            ->setGroupSequence($this
            ->parseValues($groupSequence[0]->value));
        }
      }
      foreach ($this
        ->parseConstraints($xml->constraint) as $constraint) {
        $metadata
          ->addConstraint($constraint);
      }
      foreach ($xml->property as $property) {
        foreach ($this
          ->parseConstraints($property->constraint) as $constraint) {
          $metadata
            ->addPropertyConstraint((string) $property['name'], $constraint);
        }
      }
      foreach ($xml->getter as $getter) {
        foreach ($this
          ->parseConstraints($getter->constraint) as $constraint) {
          $metadata
            ->addGetterConstraint((string) $getter['property'], $constraint);
        }
      }
      return true;
    }
    return false;
  }

  /**
   * Parses a collection of "constraint" XML nodes.
   *
   * @param \SimpleXMLElement $nodes The XML nodes
   *
   * @return array The Constraint instances
   */
  protected function parseConstraints(\SimpleXMLElement $nodes) {
    $constraints = array();
    foreach ($nodes as $node) {
      if (count($node) > 0) {
        if (count($node->value) > 0) {
          $options = $this
            ->parseValues($node->value);
        }
        elseif (count($node->constraint) > 0) {
          $options = $this
            ->parseConstraints($node->constraint);
        }
        elseif (count($node->option) > 0) {
          $options = $this
            ->parseOptions($node->option);
        }
        else {
          $options = array();
        }
      }
      elseif (strlen((string) $node) > 0) {
        $options = trim($node);
      }
      else {
        $options = null;
      }
      $constraints[] = $this
        ->newConstraint($node['name'], $options);
    }
    return $constraints;
  }

  /**
   * Parses a collection of "value" XML nodes.
   *
   * @param \SimpleXMLElement $nodes The XML nodes
   *
   * @return array The values
   */
  protected function parseValues(\SimpleXMLElement $nodes) {
    $values = array();
    foreach ($nodes as $node) {
      if (count($node) > 0) {
        if (count($node->value) > 0) {
          $value = $this
            ->parseValues($node->value);
        }
        elseif (count($node->constraint) > 0) {
          $value = $this
            ->parseConstraints($node->constraint);
        }
        else {
          $value = array();
        }
      }
      else {
        $value = trim($node);
      }
      if (isset($node['key'])) {
        $values[(string) $node['key']] = $value;
      }
      else {
        $values[] = $value;
      }
    }
    return $values;
  }

  /**
   * Parses a collection of "option" XML nodes.
   *
   * @param \SimpleXMLElement $nodes The XML nodes
   *
   * @return array The options
   */
  protected function parseOptions(\SimpleXMLElement $nodes) {
    $options = array();
    foreach ($nodes as $node) {
      if (count($node) > 0) {
        if (count($node->value) > 0) {
          $value = $this
            ->parseValues($node->value);
        }
        elseif (count($node->constraint) > 0) {
          $value = $this
            ->parseConstraints($node->constraint);
        }
        else {
          $value = array();
        }
      }
      else {
        $value = trim($node);
      }
      $options[(string) $node['name']] = $value;
    }
    return $options;
  }

  /**
   * Parse a XML File.
   *
   * @param string $file Path of file
   *
   * @return SimpleXMLElement
   *
   * @throws MappingException
   */
  protected function parseFile($file) {
    try {
      $dom = XmlUtils::loadFile($file, __DIR__ . '/schema/dic/constraint-mapping/constraint-mapping-1.0.xsd');
    } catch (\Exception $e) {
      throw new MappingException($e
        ->getMessage(), $e
        ->getCode(), $e);
    }
    return simplexml_import_dom($dom);
  }

}