XML.php

1. 8.x drupal/core/vendor/phpunit/phpunit/PHPUnit/Util/XML.php
2. 8.x drupal/core/vendor/easyrdf/easyrdf/lib/EasyRdf/Literal/XML.php

<?php

/**
 * PHPUnit
 *
 * Copyright (c) 2001-2013, Sebastian Bergmann <sebastian@phpunit.de>.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *
 *   * Neither the name of Sebastian Bergmann nor the names of his
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * @package    PHPUnit
 * @subpackage Util
 * @author     Sebastian Bergmann <sebastian@phpunit.de>
 * @copyright  2001-2013 Sebastian Bergmann <sebastian@phpunit.de>
 * @license    http://www.opensource.org/licenses/BSD-3-Clause  The BSD 3-Clause License
 * @link       http://www.phpunit.de/
 * @since      File available since Release 3.2.0
 */

/**
 * XML helpers.
 *
 * @package    PHPUnit
 * @subpackage Util
 * @author     Sebastian Bergmann <sebastian@phpunit.de>
 * @copyright  2001-2013 Sebastian Bergmann <sebastian@phpunit.de>
 * @license    http://www.opensource.org/licenses/BSD-3-Clause  The BSD 3-Clause License
 * @link       http://www.phpunit.de/
 * @since      Class available since Release 3.2.0
 */
class PHPUnit_Util_XML {

  /**
   * @param  string $string
   * @return string
   * @author Kore Nordmann <mail@kore-nordmann.de>
   * @since  Method available since Release 3.4.6
   */
  public static function prepareString($string) {
    return preg_replace_callback('/[\\x00-\\x04\\x0b\\x0c\\x0e-\\x1f\\x7f]/', function ($matches) {
      return sprintf('&#x%02x;', ord($matches[0]));
    }, htmlspecialchars(PHPUnit_Util_String::convertToUtf8($string), ENT_COMPAT, 'UTF-8'));
  }

  /**
   * Loads an XML (or HTML) file into a DOMDocument object.
   *
   * @param  string  $filename
   * @param  boolean $isHtml
   * @param  boolean $xinclude
   * @return DOMDocument
   * @since  Method available since Release 3.3.0
   */
  public static function loadFile($filename, $isHtml = FALSE, $xinclude = FALSE) {
    $reporting = error_reporting(0);
    $contents = file_get_contents($filename);
    error_reporting($reporting);
    if ($contents === FALSE) {
      throw new PHPUnit_Framework_Exception(sprintf('Could not read "%s".', $filename));
    }
    return self::load($contents, $isHtml, $filename, $xinclude);
  }

  /**
   * Load an $actual document into a DOMDocument.  This is called
   * from the selector assertions.
   *
   * If $actual is already a DOMDocument, it is returned with
   * no changes.  Otherwise, $actual is loaded into a new DOMDocument
   * as either HTML or XML, depending on the value of $isHtml. If $isHtml is
   * false and $xinclude is true, xinclude is performed on the loaded
   * DOMDocument.
   *
   * Note: prior to PHPUnit 3.3.0, this method loaded a file and
   * not a string as it currently does.  To load a file into a
   * DOMDocument, use loadFile() instead.
   *
   * @param  string|DOMDocument  $actual
   * @param  boolean             $isHtml
   * @param  string              $filename
   * @param  boolean             $xinclude
   * @return DOMDocument
   * @since  Method available since Release 3.3.0
   * @author Mike Naberezny <mike@maintainable.com>
   * @author Derek DeVries <derek@maintainable.com>
   * @author Tobias Schlitt <toby@php.net>
   */
  public static function load($actual, $isHtml = FALSE, $filename = '', $xinclude = FALSE) {
    if ($actual instanceof DOMDocument) {
      return $actual;
    }
    $document = new DOMDocument();
    $internal = libxml_use_internal_errors(TRUE);
    $message = '';
    $reporting = error_reporting(0);
    if ($isHtml) {
      $loaded = $document
        ->loadHTML($actual);
    }
    else {
      $loaded = $document
        ->loadXML($actual);
    }
    if ('' !== $filename) {

      // Necessary for xinclude
      $document->documentURI = $filename;
    }
    if (!$isHtml && $xinclude) {
      $document
        ->xinclude();
    }
    foreach (libxml_get_errors() as $error) {
      $message .= $error->message;
    }
    libxml_use_internal_errors($internal);
    error_reporting($reporting);
    if ($loaded === FALSE) {
      if ($filename != '') {
        throw new PHPUnit_Framework_Exception(sprintf('Could not load "%s".%s', $filename, $message != '' ? "\n" . $message : ''));
      }
      else {
        throw new PHPUnit_Framework_Exception($message);
      }
    }
    return $document;
  }

  /**
   *
   *
   * @param  DOMNode $node
   * @return string
   * @since  Method available since Release 3.4.0
   */
  public static function nodeToText(DOMNode $node) {
    if ($node->childNodes->length == 1) {
      return $node->nodeValue;
    }
    $result = '';
    foreach ($node->childNodes as $childNode) {
      $result .= $node->ownerDocument
        ->saveXML($childNode);
    }
    return $result;
  }

  /**
   *
   *
   * @param  DOMNode $node
   * @since  Method available since Release 3.3.0
   * @author Mattis Stordalen Flister <mattis@xait.no>
   */
  public static function removeCharacterDataNodes(DOMNode $node) {
    if ($node
      ->hasChildNodes()) {
      for ($i = $node->childNodes->length - 1; $i >= 0; $i--) {
        if (($child = $node->childNodes
          ->item($i)) instanceof DOMCharacterData) {
          $node
            ->removeChild($child);
        }
      }
    }
  }

  /**
   * "Convert" a DOMElement object into a PHP variable.
   *
   * @param  DOMElement $element
   * @return mixed
   * @since  Method available since Release 3.4.0
   */
  public static function xmlToVariable(DOMElement $element) {
    $variable = NULL;
    switch ($element->tagName) {
      case 'array':
        $variable = array();
        foreach ($element
          ->getElementsByTagName('element') as $element) {
          $value = self::xmlToVariable($element->childNodes
            ->item(1));
          if ($element
            ->hasAttribute('key')) {
            $variable[(string) $element
              ->getAttribute('key')] = $value;
          }
          else {
            $variable[] = $value;
          }
        }
        break;
      case 'object':
        $className = $element
          ->getAttribute('class');
        if ($element
          ->hasChildNodes()) {
          $arguments = $element->childNodes
            ->item(1)->childNodes;
          $constructorArgs = array();
          foreach ($arguments as $argument) {
            if ($argument instanceof DOMElement) {
              $constructorArgs[] = self::xmlToVariable($argument);
            }
          }
          $class = new ReflectionClass($className);
          $variable = $class
            ->newInstanceArgs($constructorArgs);
        }
        else {
          $variable = new $className();
        }
        break;
      case 'boolean':
        $variable = $element->nodeValue == 'true' ? TRUE : FALSE;
        break;
      case 'integer':
      case 'double':
      case 'string':
        $variable = $element->nodeValue;
        settype($variable, $element->tagName);
        break;
    }
    return $variable;
  }

  /**
   * Validate list of keys in the associative array.
   *
   * @param  array $hash
   * @param  array $validKeys
   * @return array
   * @throws PHPUnit_Framework_Exception
   * @since  Method available since Release 3.3.0
   * @author Mike Naberezny <mike@maintainable.com>
   * @author Derek DeVries <derek@maintainable.com>
   */
  public static function assertValidKeys(array $hash, array $validKeys) {
    $valids = array();

    // Normalize validation keys so that we can use both indexed and
    // associative arrays.
    foreach ($validKeys as $key => $val) {
      is_int($key) ? $valids[$val] = NULL : ($valids[$key] = $val);
    }
    $validKeys = array_keys($valids);

    // Check for invalid keys.
    foreach ($hash as $key => $value) {
      if (!in_array($key, $validKeys)) {
        $unknown[] = $key;
      }
    }
    if (!empty($unknown)) {
      throw new PHPUnit_Framework_Exception('Unknown key(s): ' . implode(', ', $unknown));
    }

    // Add default values for any valid keys that are empty.
    foreach ($valids as $key => $value) {
      if (!isset($hash[$key])) {
        $hash[$key] = $value;
      }
    }
    return $hash;
  }

  /**
   * Parse a CSS selector into an associative array suitable for
   * use with findNodes().
   *
   * @param  string $selector
   * @param  mixed  $content
   * @return array
   * @since  Method available since Release 3.3.0
   * @author Mike Naberezny <mike@maintainable.com>
   * @author Derek DeVries <derek@maintainable.com>
   */
  public static function convertSelectToTag($selector, $content = TRUE) {
    $selector = trim(preg_replace("/\\s+/", " ", $selector));

    // substitute spaces within attribute value
    while (preg_match('/\\[[^\\]]+"[^"]+\\s[^"]+"\\]/', $selector)) {
      $selector = preg_replace('/(\\[[^\\]]+"[^"]+)\\s([^"]+"\\])/', "\$1__SPACE__\$2", $selector);
    }
    if (strstr($selector, ' ')) {
      $elements = explode(' ', $selector);
    }
    else {
      $elements = array(
        $selector,
      );
    }
    $previousTag = array();
    foreach (array_reverse($elements) as $element) {
      $element = str_replace('__SPACE__', ' ', $element);

      // child selector
      if ($element == '>') {
        $previousTag = array(
          'child' => $previousTag['descendant'],
        );
        continue;
      }
      $tag = array();

      // match element tag
      preg_match("/^([^\\.#\\[]*)/", $element, $eltMatches);
      if (!empty($eltMatches[1])) {
        $tag['tag'] = $eltMatches[1];
      }

      // match attributes (\[[^\]]*\]*), ids (#[^\.#\[]*),
      // and classes (\.[^\.#\[]*))
      preg_match_all("/(\\[[^\\]]*\\]*|#[^\\.#\\[]*|\\.[^\\.#\\[]*)/", $element, $matches);
      if (!empty($matches[1])) {
        $classes = array();
        $attrs = array();
        foreach ($matches[1] as $match) {

          // id matched
          if (substr($match, 0, 1) == '#') {
            $tag['id'] = substr($match, 1);
          }
          else {
            if (substr($match, 0, 1) == '.') {
              $classes[] = substr($match, 1);
            }
            else {
              if (substr($match, 0, 1) == '[' && substr($match, -1, 1) == ']') {
                $attribute = substr($match, 1, strlen($match) - 2);
                $attribute = str_replace('"', '', $attribute);

                // match single word
                if (strstr($attribute, '~=')) {
                  list($key, $value) = explode('~=', $attribute);
                  $value = "regexp:/.*\\b{$value}\\b.*/";
                }
                else {
                  if (strstr($attribute, '*=')) {
                    list($key, $value) = explode('*=', $attribute);
                    $value = "regexp:/.*{$value}.*/";
                  }
                  else {
                    list($key, $value) = explode('=', $attribute);
                  }
                }
                $attrs[$key] = $value;
              }
            }
          }
        }
        if ($classes) {
          $tag['class'] = join(' ', $classes);
        }
        if ($attrs) {
          $tag['attributes'] = $attrs;
        }
      }

      // tag content
      if (is_string($content)) {
        $tag['content'] = $content;
      }

      // determine previous child/descendants
      if (!empty($previousTag['descendant'])) {
        $tag['descendant'] = $previousTag['descendant'];
      }
      else {
        if (!empty($previousTag['child'])) {
          $tag['child'] = $previousTag['child'];
        }
      }
      $previousTag = array(
        'descendant' => $tag,
      );
    }
    return $tag;
  }

  /**
   * Parse an $actual document and return an array of DOMNodes
   * matching the CSS $selector.  If an error occurs, it will
   * return FALSE.
   *
   * To only return nodes containing a certain content, give
   * the $content to match as a string.  Otherwise, setting
   * $content to TRUE will return all nodes matching $selector.
   *
   * The $actual document may be a DOMDocument or a string
   * containing XML or HTML, identified by $isHtml.
   *
   * @param  array   $selector
   * @param  string  $content
   * @param  mixed   $actual
   * @param  boolean $isHtml
   * @return false|array
   * @since  Method available since Release 3.3.0
   * @author Mike Naberezny <mike@maintainable.com>
   * @author Derek DeVries <derek@maintainable.com>
   * @author Tobias Schlitt <toby@php.net>
   */
  public static function cssSelect($selector, $content, $actual, $isHtml = TRUE) {
    $matcher = self::convertSelectToTag($selector, $content);
    $dom = self::load($actual, $isHtml);
    $tags = self::findNodes($dom, $matcher, $isHtml);
    return $tags;
  }

  /**
   * Parse out the options from the tag using DOM object tree.
   *
   * @param  DOMDocument $dom
   * @param  array       $options
   * @param  boolean     $isHtml
   * @return array
   * @since  Method available since Release 3.3.0
   * @author Mike Naberezny <mike@maintainable.com>
   * @author Derek DeVries <derek@maintainable.com>
   * @author Tobias Schlitt <toby@php.net>
   */
  public static function findNodes(DOMDocument $dom, array $options, $isHtml = TRUE) {
    $valid = array(
      'id',
      'class',
      'tag',
      'content',
      'attributes',
      'parent',
      'child',
      'ancestor',
      'descendant',
      'children',
    );
    $filtered = array();
    $options = self::assertValidKeys($options, $valid);

    // find the element by id
    if ($options['id']) {
      $options['attributes']['id'] = $options['id'];
    }
    if ($options['class']) {
      $options['attributes']['class'] = $options['class'];
    }

    // find the element by a tag type
    if ($options['tag']) {
      if ($isHtml) {
        $elements = self::getElementsByCaseInsensitiveTagName($dom, $options['tag']);
      }
      else {
        $elements = $dom
          ->getElementsByTagName($options['tag']);
      }
      foreach ($elements as $element) {
        $nodes[] = $element;
      }
      if (empty($nodes)) {
        return FALSE;
      }
    }
    else {
      $tags = array(
        'a',
        'abbr',
        'acronym',
        'address',
        'area',
        'b',
        'base',
        'bdo',
        'big',
        'blockquote',
        'body',
        'br',
        'button',
        'caption',
        'cite',
        'code',
        'col',
        'colgroup',
        'dd',
        'del',
        'div',
        'dfn',
        'dl',
        'dt',
        'em',
        'fieldset',
        'form',
        'frame',
        'frameset',
        'h1',
        'h2',
        'h3',
        'h4',
        'h5',
        'h6',
        'head',
        'hr',
        'html',
        'i',
        'iframe',
        'img',
        'input',
        'ins',
        'kbd',
        'label',
        'legend',
        'li',
        'link',
        'map',
        'meta',
        'noframes',
        'noscript',
        'object',
        'ol',
        'optgroup',
        'option',
        'p',
        'param',
        'pre',
        'q',
        'samp',
        'script',
        'select',
        'small',
        'span',
        'strong',
        'style',
        'sub',
        'sup',
        'table',
        'tbody',
        'td',
        'textarea',
        'tfoot',
        'th',
        'thead',
        'title',
        'tr',
        'tt',
        'ul',
        'var',
      );
      foreach ($tags as $tag) {
        if ($isHtml) {
          $elements = self::getElementsByCaseInsensitiveTagName($dom, $tag);
        }
        else {
          $elements = $dom
            ->getElementsByTagName($tag);
        }
        foreach ($elements as $element) {
          $nodes[] = $element;
        }
      }
      if (empty($nodes)) {
        return FALSE;
      }
    }

    // filter by attributes
    if ($options['attributes']) {
      foreach ($nodes as $node) {
        $invalid = FALSE;
        foreach ($options['attributes'] as $name => $value) {

          // match by regexp if like "regexp:/foo/i"
          if (preg_match('/^regexp\\s*:\\s*(.*)/i', $value, $matches)) {
            if (!preg_match($matches[1], $node
              ->getAttribute($name))) {
              $invalid = TRUE;
            }
          }
          else {
            if ($name == 'class') {

              // split to individual classes
              $findClasses = explode(' ', preg_replace("/\\s+/", " ", $value));
              $allClasses = explode(' ', preg_replace("/\\s+/", " ", $node
                ->getAttribute($name)));

              // make sure each class given is in the actual node
              foreach ($findClasses as $findClass) {
                if (!in_array($findClass, $allClasses)) {
                  $invalid = TRUE;
                }
              }
            }
            else {
              if ($node
                ->getAttribute($name) != $value) {
                $invalid = TRUE;
              }
            }
          }
        }

        // if every attribute given matched
        if (!$invalid) {
          $filtered[] = $node;
        }
      }
      $nodes = $filtered;
      $filtered = array();
      if (empty($nodes)) {
        return FALSE;
      }
    }

    // filter by content
    if ($options['content'] !== NULL) {
      foreach ($nodes as $node) {
        $invalid = FALSE;

        // match by regexp if like "regexp:/foo/i"
        if (preg_match('/^regexp\\s*:\\s*(.*)/i', $options['content'], $matches)) {
          if (!preg_match($matches[1], self::getNodeText($node))) {
            $invalid = TRUE;
          }
        }
        else {
          if ($options['content'] === '') {
            if (self::getNodeText($node) !== '') {
              $invalid = TRUE;
            }
          }
          else {
            if (strstr(self::getNodeText($node), $options['content']) === FALSE) {
              $invalid = TRUE;
            }
          }
        }
        if (!$invalid) {
          $filtered[] = $node;
        }
      }
      $nodes = $filtered;
      $filtered = array();
      if (empty($nodes)) {
        return FALSE;
      }
    }

    // filter by parent node
    if ($options['parent']) {
      $parentNodes = self::findNodes($dom, $options['parent'], $isHtml);
      $parentNode = isset($parentNodes[0]) ? $parentNodes[0] : NULL;
      foreach ($nodes as $node) {
        if ($parentNode !== $node->parentNode) {
          continue;
        }
        $filtered[] = $node;
      }
      $nodes = $filtered;
      $filtered = array();
      if (empty($nodes)) {
        return FALSE;
      }
    }

    // filter by child node
    if ($options['child']) {
      $childNodes = self::findNodes($dom, $options['child'], $isHtml);
      $childNodes = !empty($childNodes) ? $childNodes : array();
      foreach ($nodes as $node) {
        foreach ($node->childNodes as $child) {
          foreach ($childNodes as $childNode) {
            if ($childNode === $child) {
              $filtered[] = $node;
            }
          }
        }
      }
      $nodes = $filtered;
      $filtered = array();
      if (empty($nodes)) {
        return FALSE;
      }
    }

    // filter by ancestor
    if ($options['ancestor']) {
      $ancestorNodes = self::findNodes($dom, $options['ancestor'], $isHtml);
      $ancestorNode = isset($ancestorNodes[0]) ? $ancestorNodes[0] : NULL;
      foreach ($nodes as $node) {
        $parent = $node->parentNode;
        while ($parent && $parent->nodeType != XML_HTML_DOCUMENT_NODE) {
          if ($parent === $ancestorNode) {
            $filtered[] = $node;
          }
          $parent = $parent->parentNode;
        }
      }
      $nodes = $filtered;
      $filtered = array();
      if (empty($nodes)) {
        return FALSE;
      }
    }

    // filter by descendant
    if ($options['descendant']) {
      $descendantNodes = self::findNodes($dom, $options['descendant'], $isHtml);
      $descendantNodes = !empty($descendantNodes) ? $descendantNodes : array();
      foreach ($nodes as $node) {
        foreach (self::getDescendants($node) as $descendant) {
          foreach ($descendantNodes as $descendantNode) {
            if ($descendantNode === $descendant) {
              $filtered[] = $node;
            }
          }
        }
      }
      $nodes = $filtered;
      $filtered = array();
      if (empty($nodes)) {
        return FALSE;
      }
    }

    // filter by children
    if ($options['children']) {
      $validChild = array(
        'count',
        'greater_than',
        'less_than',
        'only',
      );
      $childOptions = self::assertValidKeys($options['children'], $validChild);
      foreach ($nodes as $node) {
        $childNodes = $node->childNodes;
        foreach ($childNodes as $childNode) {
          if ($childNode->nodeType !== XML_CDATA_SECTION_NODE && $childNode->nodeType !== XML_TEXT_NODE) {
            $children[] = $childNode;
          }
        }

        // we must have children to pass this filter
        if (!empty($children)) {

          // exact count of children
          if ($childOptions['count'] !== NULL) {
            if (count($children) !== $childOptions['count']) {
              break;
            }
          }
          else {
            if ($childOptions['less_than'] !== NULL && $childOptions['greater_than'] !== NULL) {
              if (count($children) >= $childOptions['less_than'] || count($children) <= $childOptions['greater_than']) {
                break;
              }
            }
            else {
              if ($childOptions['less_than'] !== NULL) {
                if (count($children) >= $childOptions['less_than']) {
                  break;
                }
              }
              else {
                if ($childOptions['greater_than'] !== NULL) {
                  if (count($children) <= $childOptions['greater_than']) {
                    break;
                  }
                }
              }
            }
          }

          // match each child against a specific tag
          if ($childOptions['only']) {
            $onlyNodes = self::findNodes($dom, $childOptions['only'], $isHtml);

            // try to match each child to one of the 'only' nodes
            foreach ($children as $child) {
              $matched = FALSE;
              foreach ($onlyNodes as $onlyNode) {
                if ($onlyNode === $child) {
                  $matched = TRUE;
                }
              }
              if (!$matched) {
                break 2;
              }
            }
          }
          $filtered[] = $node;
        }
      }
      $nodes = $filtered;
      $filtered = array();
      if (empty($nodes)) {
        return;
      }
    }

    // return the first node that matches all criteria
    return !empty($nodes) ? $nodes : array();
  }

  /**
   * Recursively get flat array of all descendants of this node.
   *
   * @param  DOMNode $node
   * @return array
   * @since  Method available since Release 3.3.0
   * @author Mike Naberezny <mike@maintainable.com>
   * @author Derek DeVries <derek@maintainable.com>
   */
  protected static function getDescendants(DOMNode $node) {
    $allChildren = array();
    $childNodes = $node->childNodes ? $node->childNodes : array();
    foreach ($childNodes as $child) {
      if ($child->nodeType === XML_CDATA_SECTION_NODE || $child->nodeType === XML_TEXT_NODE) {
        continue;
      }
      $children = self::getDescendants($child);
      $allChildren = array_merge($allChildren, $children, array(
        $child,
      ));
    }
    return isset($allChildren) ? $allChildren : array();
  }

  /**
   * Gets elements by case insensitive tagname.
   *
   * @param  DOMDocument $dom
   * @param  string      $tag
   * @return DOMNodeList
   * @since  Method available since Release 3.4.0
   */
  protected static function getElementsByCaseInsensitiveTagName(DOMDocument $dom, $tag) {
    $elements = $dom
      ->getElementsByTagName(strtolower($tag));
    if ($elements->length == 0) {
      $elements = $dom
        ->getElementsByTagName(strtoupper($tag));
    }
    return $elements;
  }

  /**
   * Get the text value of this node's child text node.
   *
   * @param  DOMNode $node
   * @return string
   * @since  Method available since Release 3.3.0
   * @author Mike Naberezny <mike@maintainable.com>
   * @author Derek DeVries <derek@maintainable.com>
   */
  protected static function getNodeText(DOMNode $node) {
    if (!$node->childNodes instanceof DOMNodeList) {
      return '';
    }
    $result = '';
    foreach ($node->childNodes as $childNode) {
      if ($childNode->nodeType === XML_TEXT_NODE || $childNode->nodeType === XML_CDATA_SECTION_NODE) {
        $result .= trim($childNode->data) . ' ';
      }
      else {
        $result .= self::getNodeText($childNode);
      }
    }
    return str_replace('  ', ' ', $result);
  }

}