pastebin - collaborative debugging

<?php
class DomQuery {
  protected $xpath;
  function __construct($document) {
    $this->xpath = new DomXPath($document instanceOf DomDocument ? $document : $document->ownerDocument);
  }
  function getFirstElementByClassname($class_name, $node = null) {
    if (!$class_name) {
      return $node;
    }
    if ($node) {
      return $this->xpath->query("descendant::*[contains(@class,'$class_name')]", $node)->item(0);
    }
    return $this->xpath->query("descendant::*[contains(@class,'$class_name')]")->item(0);
  }
}

class Domling {
  protected $node;
  protected $query;
  protected $captures = array();
  function __construct($source) {
    if (is_string($source)) {
      $this->node = $this->parse($source);
    } else {
      $this->node = $source;
    }
    $this->query = new DomQuery($this->node);
  }
  protected function parse($html) {
    $document = new DomDocument();
    if (!preg_match('~^(<!doctype|<html)~', $html)) {
      $document->loadHtml("<html><body><div>" . $html . "</div></body></html>");
      return $document->getElementsByTagName("body")->item(0)->firstChild;
    }
    $document->loadHtml($html);
    return $document;
  }
  function purge() {
    foreach ($this->captures as $capture) {
      $capture->purge();
    }
  }
  function render() {
    $this->purge();
    if ($this->node instanceOf DOMElement) {
      preg_match('~<html>\s*<body>\s*<div>([\s\S]*)</div>\s*</body>\s*</html>\s*$~', $this->node->ownerDocument->saveHtml(), $matches);
      return $matches[1];
    }
    return $this->node->saveHtml();
  }
  function capture($class_name) {
    if (!isset($this->captures[$class_name])) {
      $this->captures[$class_name] = new Capture($this->query->getFirstElementByClassname($class_name));
    }
    return $this->captures[$class_name];
  }
  function sequence($item_class_name, $container_class_name) {
    if (!isset($this->captures[$item_class_name.":".$container_class_name])) {
      $container = $this->query->getFirstElementByClassname($container_class_name);
      $this->captures[$item_class_name.":".$container_class_name] = new Sequence(
        $this->query->getFirstElementByClassname($item_class_name, $container),
        $container);
    }
    return $this->captures[$item_class_name.":".$container_class_name];
  }
}

class Capture extends Domling {
  protected $placeholder_node;
  function __construct(DomElement $node) {
    parent::__construct($node);
    $this->placeholder_node = $this->node->ownerDocument->createComment("placeholder");
    $this->node->parentNode->replaceChild($this->placeholder_node, $this->node);
  }
  function purge() {
    parent::purge();
    if ($this->placeholder_node->parentNode) {
      $this->placeholder_node->parentNode->removeChild($this->placeholder_node);
    }
  }
  function bind($data = array()) {
    $clone = $this->node->cloneNode(true);
    $this->placeholder_node->parentNode->insertBefore($clone, $this->placeholder_node);
    if (is_string($data)) {
      $data = array('' => $data);
    }
    foreach ($data as $id => $value) {
      if (preg_match('~(.+):(.+)~', $id, $matches)) {
        $class_name = $matches[1];
        $attribute = $matches[2];
        $element = $this->query->getFirstElementByClassname($class_name, $clone);
        $element->setAttribute($attribute, $value);
      } else {
        $element = $this->query->getFirstElementByClassname($id, $clone);
        while ($element->hasChildNodes()) {
          $element->removeChild($element->firstChild);
        }
        $element->appendChild($element->ownerDocument->createTextNode($value));
      }
    }
    return $clone;
  }
}

class Sequence extends Capture {
  protected $container;
  protected $placeholder_container;
  function __construct(DomElement $node, DomElement $container) {
    parent::__construct($node);
    $this->container = $container;
    $this->placeholder_container = $container->ownerDocument->createComment("container");
    $this->container->parentNode->replaceChild($this->placeholder_container, $this->container);
  }
  function purge() {
    parent::purge();
    if ($this->placeholder_container->parentNode) {
      $this->placeholder_container->parentNode->removeChild($this->placeholder_container);
    }
  }
  function bind($data = array()) {
    if (!$this->container->parentNode) {
      $this->placeholder_container->parentNode->replaceChild($this->container, $this->placeholder_container);
    }
    return parent::bind($data);
  }
}

if (realpath($_SERVER['SCRIPT_NAME']) == __FILE__) {
  error_reporting(E_ALL);

  // simple variable binding
  $t = new Domling('<p class="hello"></p>');
  $t->capture('hello')->bind("Hello World");
  echo $t->render();
  // <p class="hello">Hello World</p>

  echo "\n---\n";

  // Switching a block out
  $t = new Domling('<p>Lorem Ipsum</p><p class="message">Hidden message</p>');
  $t->capture('message');
  echo $t->render();
  // <p>Lorem Ipsum</p>

  echo "\n---\n";

  // Putting it back in
  $t = new Domling('<p>Lorem Ipsum</p><p class="message">Hidden message</p>');
  $block = $t->capture('message');
  $block->bind();
  echo $t->render();
  // <p>Lorem Ipsum</p>
  // <p class="message">Hidden message</p>

  echo "\n---\n";

  // And looping over a block
  $t = new Domling('<ul class="links"><li class="link"><a class="anchor" href="#">title</a></li></ul>');
  $links = array(
    'Sitepoint' => 'http://www.sitepoint.com',
    'Example' => 'http://www.example.org?foo=bar&ding=dong');
  foreach ($links as $title => $link) {
    $t->sequence('link', 'links')->bind(array('anchor:href' => $link, 'anchor' => $title));
  }
  echo $t->render();
  // <ul class="links">
  // <li class="link"><a class="anchor" href="http://www.sitepoint.com">Sitepoint</a></li>
  // <li class="link"><a class="anchor" href="http://www.example.org?foo=bar&amp;ding=dong">Example</a></li>
  // </ul>

  echo "\n---\n";

  // And a full sample
  $template = "
<h1 class='title'>title</h1>
<ul class='links'>
  <li class='link'><a class='anchor' href='#'>title</a></li>
</ul>
<p class='switch'>Hide this</p>
";
  $t = new Domling($template);

  // let's bind some data to the template
  $t->capture('title')->bind("Hello World");

  // Or we can repeat a block as a sequence
  $links = array(
    'Sitepoint' => 'http://www.sitepoint.com',
    'Example' => 'http://www.example.org?foo=bar&ding=dong');
  foreach ($links as $title => $link) {
    $t->sequence('link', 'links')->bind(array('anchor:href' => $link, 'anchor' => $title));
  }

  // we can even remove a block entirely
  $t->capture('switch');

  echo $t->render();

  // <h1 class="title">Hello World</h1>
  // <ul class="links">
  // <li class="link"><a class="anchor" href="http://www.sitepoint.com">Sitepoint</a></li>
  // <li class="link"><a class="anchor" href="http://www.example.org?foo=bar&amp;ding=dong">Example</a></li>
  // </ul>
}