fb_instant_articles.module

<?php

/**
 * @file
 * Hook implementations for Facebook Instant Articles Base module.
 */

define('FB_INSTANT_ARTICLES_AD_TYPE_NONE', 'none');
define('FB_INSTANT_ARTICLES_AD_TYPE_FBAN', 'fban');
define('FB_INSTANT_ARTICLES_AD_TYPE_SOURCE_URL', 'source_url');
define('FB_INSTANT_ARTICLES_AD_TYPE_EMBED_CODE', 'embed_code');

/**
 * Get an array of possible ad types and their descriptive names
 **/
function fb_instant_articles_get_ad_types() {
  return array(
    FB_INSTANT_ARTICLES_AD_TYPE_NONE => t('None'),
    FB_INSTANT_ARTICLES_AD_TYPE_FBAN => t('Facebook Audience Network'),
    FB_INSTANT_ARTICLES_AD_TYPE_SOURCE_URL => t('Source URL'),
    FB_INSTANT_ARTICLES_AD_TYPE_EMBED_CODE => t('Embed Code'),
  );
}

/**
 * Implements hook_menu().
 */
function fb_instant_articles_menu() {
  $items['admin/config/services/fb-instant-articles'] = array(
    'title' => 'Facebook Instant Articles',
    'description' => 'Settings related to Facebook Instant Articles.',
    'page callback' => 'system_admin_menu_block_page',
    'access arguments' => array('access administration pages'),
    'file' => 'system.admin.inc',
    'file path' => drupal_get_path('module', 'system'),
  );

  $items['admin/config/services/fb-instant-articles/settings'] = array(
    'title' => 'Facebook Instant Articles Base settings',
    'description' => 'Base settings for Facebook Instant Articles.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('fb_instant_articles_settings'),
    'access arguments' => array('administer fb_instant_articles'),
    'file' => 'includes/admin.inc',
    'weight' => -10,
  );

  return $items;
}

/**
 * Implements hook_permission().
 */
function fb_instant_articles_permission() {
  $permissions = array();

  $permissions['administer fb_instant_articles'] = array(
    'title' => t('Administer Facebook Instant Articles'),
  );
  return $permissions;
}

/**
 * Implements hook_help().
 */
function fb_instant_articles_help($path, $arg) {
  switch ($path) {
    case 'admin/help#fb_instant_articles':
      $filepath = dirname(__FILE__) . '/README.md';
      if (file_exists($filepath)) {
        $string = file_get_contents($filepath);
        if ($processed = fb_instant_articles_help_markdown($string)) {
          return $processed;
        }
        return '<pre>' . $string . '</pre>';
      }
      break;
    case 'admin/config/services/fb-instant-articles':
    case 'admin/config/services/fb-instant-articles/settings':
      $page_id = (variable_get('fb_instant_articles_page_id', ''));
      $output = '';
      $output .= '<h2>' . t('Setup') . '</h2>';
      $output .= '<p>' . t('Once you\'ve activated this Drupal module, set up your Instant Articles and submit them to Facebook for a one-time review. The review is required before you can begin publishing. Follow these steps to get started:') . '</p>';
      $output .= '<ol>';
      $output .= '  <li>' . t('<a href="@sign_up_url" target="_blank">Sign up</a> for Instant Articles, if you haven\'t already, and enabled the same Facebook Page you have selected.', array('@sign_up_url' => 'https://www.facebook.com/instant_articles/signup')) . '</li>';
      $output .= '  <li>' . t('Claim the URL you will use to publish articles.</b> Right now, we think the URL for this page is: %url. ', array('%url' => $_SERVER['HTTP_HOST']));
      if ($page_id != '') {
        $claim_url = 'https://www.facebook.com/'. $page_id .'/settings/?tab=instant_articles#URL';
        $output .= t('<a href="@claim_url" target="_blank">Claim your URL here.</a>', array('@claim_url' => $claim_url));
      }
      $output .= '</li>';
      $output .= '  <li>' . t('Install the Pages Manager App to preview your articles and styles on <a href="@ios_url" target="_blank">iOS</a> or <a href="@android_url" target="_blank">Android</a>.', array('@ios_url' => 'http://itunes.apple.com/app/facebook-pages-manager/id514643583?ls=1&mt=8&ign-mscache=1', '@android_url' => 'https://play.google.com/store/apps/details?id=com.facebook.pages.app')) . '</li>';
      $output .= '  <li>' . t('Create a style template for your articles using the <a href="@style_url" target="_blank">Style Editor</a>. Be sure to provide the name of the template you want to use in the Module Configuration settings below.', array('@style_url' => 'https://developers.facebook.com/docs/instant-articles/guides/design#style')) . '</li>';
      $output .= '  <li>' . t('[Optional] Enable Audience Network, if you choose. Learn more about <a href="@audience_url" target="_blank">Audience Network</a> for Instant Articles and <a href="@sign_up_url" target="_blank">sign up here</a>.', array('@audience_url' => 'https://fbinstantarticles.files.wordpress.com/2016/03/audience-network_wp_instant-articles-2-2-web_self-serve.pdf', '@sign_up_url' => '')) . '</li>';
      $output .= '  <li>' . t('[Optional] Set up your ads and analytics, including Audience Network, in the Configuration area, below.') . '</li>';
      if ($page_id != '') {
        $article_review_url = 'https://www.facebook.com/'. $page_id .'/settings/?tab=instant_articles#Setup-Step2';
        $output .= '  <li>' . t('<a href="@article_review_url" target="_blank">Submit your articles</a> for review.', array('@article_review_url' => $article_review_url)) . '</li>';
      } else {
        $output .= '  <li>' . t('Submit your articles for review.') . '</li>';
      }
      $output .= '</ol>';
      $output .= '<p>' . t('Other Resources:') . '</p>';
      $output .= '<ol>';
      $output .= '  <li>' . t('Read the <a href="@docs_url" target="_blank">documentation</a> to answer additional questions you might have about Instant Articles.', array('@docs_url' => 'https://developers.facebook.com/docs/instant-articles')) . '</li>';
      $output .= '  <li>' . t('Check out the <a href="@blog_url" target="_blank">Instant Articles blog</a> and sign up to receive notifications of important updates.', array('@blog_url' => 'https://developers.facebook.com/ia/blog/')) . '</li>';
      if ($page_id != '') {
        $tools_url = 'https://www.facebook.com/'. $page_id .'/settings/?tab=instant_articles';
        $roles_url = 'https://www.facebook.com/'. $page_id .'/settings/?tab=admin_roles';
        $output .= '  <li>' . t('To give other members of your team access to the <a href="@tools_url" target="_blank">Instant Articles tools</a>, assign them <a href="@roles_url" target="_blank">page roles here</a>.', array('@tools_url' => $tools_url, '@roles_url' => $roles_url)) . '</li>';
      } else {
        $output .= '  <li>' . t('To give other members of your team access to the Instant Articles tools, assign them page roles.') . '</li>';
      }
      $output .= '</ol>';
      return $output;
      break;
  }
}

/**
 * Adds markdown module support for displaying README files as Drupal help text.
 *
 * @param string $string
 *   The unprocessed README file contents string.
 *
 * @return string|false
 *   A string containing the markdown filtered text, or FALSE.
 *
 * @see fb_instant_articles_help()
 */
function fb_instant_articles_help_markdown($string) {
  if (module_exists('markdown')) {
    $filters = module_invoke('markdown', 'filter_info');
    $info = $filters['filter_markdown'];
    if (function_exists($info['process callback'])) {
      return $info['process callback']($string, NULL);
    }
    return FALSE;
  }
}

/**
 * Implements hook_html_head_alter().
 */
function fb_instant_articles_html_head_alter(&$head_elements) {
  if (drupal_is_front_page() && $page_id = variable_get('fb_instant_articles_page_id', NULL)) {
    $head_elements['fb_instant_articles_page'] = array(
      '#type' => 'html_tag',
      '#tag' => 'meta',
      '#attributes' => array(
        'property' => 'fb:pages',
        'content' => $page_id,
      ),
    );
  }
}

/**
 * Implements hook_init().
 *
 * @todo Update to use a custom DrupalFBInstantArticlesLogger once
 *   @link https://github.com/facebook/facebook-instant-articles-sdk-php/issues/14 this SDK issue @endlink is in resolved.
 */
function fb_instant_articles_init() {
  $enable_transformer_logging = variable_get('fb_instant_articles_enable_logging');
  $appender = array(
    'class' => $enable_transformer_logging ? '\Drupal\fb_instant_articles\DrupalLoggerAppender' : 'LoggerAppenderNull',
    'layout' => array(
      'class' => 'LoggerLayoutSimple'
    ),
  );
  $configuration = array(
    'rootLogger' => array(
      'appenders' => array(
        'facebook-instantarticles-transformer',
        'facebook-instantarticles-client',
      ),
    ),
    'appenders' => array(
      'facebook-instantarticles-transformer' => $appender,
      'facebook-instantarticles-client' => $appender,
    ),
  );
  \Logger::configure($configuration);
}

/**
 * Implements hook_fb_instant_articles_transformer_rules().
 */
function fb_instant_articles_fb_instant_articles_transformer_rules() {
  return array(
    array(
      'class' => 'TextNodeRule',
    ),
    array(
      'class' => 'PassThroughRule',
      'selector' => 'html',
    ),
    array(
      'class' => 'PassThroughRule',
      'selector' => 'head',
    ),
    array(
      'class' => 'PassThroughRule',
      'selector' => 'body',
    ),
    array(
      'class' => 'PassThroughRule',
      'selector' => 'article',
    ),
    array(
      'class' => 'PassThroughRule',
      'selector' => 'div',
    ),
    array(
      'class' => 'PassThroughRule',
      'selector' => 'span',
    ),
    array(
      'class' => 'ParagraphRule',
      'selector' => 'p',
    ),
    array(
      'class' => 'LineBreakRule',
      'selector' => 'aside',
    ),
    array(
      'class' => 'AnchorRule',
      'selector' => 'a',
      'properties' => array(
        'anchor.href' => array(
          'type' => 'string',
          'selector' => 'a',
          'attribute' => 'href',
        ),
        'anchor.rel' => array(
          'type' => 'string',
          'selector' => 'a',
          'attribute' => 'rel',
        ),
      ),
    ),
    array(
      'class' => 'ItalicRule',
      'selector' => 'i',
    ),
    array(
      'class' => 'EmphasizedRule',
      'selector' => 'em',
    ),
    array(
      'class' => 'BoldRule',
      'selector' => 'b',
    ),
    array(
      'class' => 'BoldRule',
      'selector' => 'strong',
    ),

    array(
      'class' => 'ParagraphRule',
      'selector' => 'p',
    ),
    array(
      'class' => 'ParagraphFooterRule',
      'selector' => 'p',
    ),
    array(
      'class' => 'ListItemRule',
      'selector' => 'li',
    ),
    array(
      'class' => 'SponsorRule',
      'selector' => 'ul.op-sponsors',
      'properties' => array(
        'sponsor.page_url' => array(
          'type' => 'string',
          'selector' => 'a',
          'attribute' => 'href',
        ),
      ),
    ),
    array(
      'class' => 'ListElementRule',
      'selector' => 'ul',
    ),
    array(
      'class' => 'ListElementRule',
      'selector' => 'ol',
    ),
    array(
      'class' => 'BlockquoteRule',
      'selector' => 'blockquote',
    ),
    array(
      'class' => 'H1Rule',
      'selector' => 'h1',
      'properties' => array(
        'h1.class' => array(
          'type' => 'string',
          'selector' => 'link',
          'attribute' => 'class',
        ),
      ),
    ),
    array(
      'class' => 'H1Rule',
      'selector' => 'title',
    ),
    array(
      'class' => 'H2Rule',
      'selector' => 'h2',
      'properties' => array(
        'h2.class' => array(
          'type' => 'string',
          'selector' => 'link',
          'attribute' => 'class',
        ),
      ),
    ),
    array(
      'class' => 'HeaderRule',
      'selector' => 'header',
    ),
    array(
      'class' => 'FooterSmallRule',
      'selector' => 'small',
    ),
    array(
      'class' => 'FooterRule',
      'selector' => 'footer',
    ),
    array(
      'class' => 'RelatedArticlesRule',
      'selector' => 'ul.op-related-articles',
      'properties' => array(
        'related.title' => array(
          'type' => 'string',
          'selector' => 'ul.op-related-articles',
          'attribute' => 'title',
        ),
      ),
    ),
    array(
      'class' => 'FooterRelatedArticlesRule',
      'selector' => 'ul.op-related-articles',
    ),
    array(
      'class' => 'RelatedItemRule',
      'selector' => 'li',
      'properties' => array(
        'related.sponsored' => array(
          'type' => 'exists',
          'selector' => 'li',
          'attribute' => 'data-sponsored',
        ),
        'related.url' => array(
          'type' => 'string',
          'selector' => 'a',
          'attribute' => 'href',
        ),
      ),
    ),
    array(
      'class' => 'InstantArticleRule',
      'selector' => 'head',
      'properties' => array(
        'article.canonical' => array(
          'type' => 'string',
          'selector' => 'link',
          'attribute' => 'href',
        ),
        'article.charset' => array(
          'type' => 'xpath',
          'selector' => '//meta[@charset]',
          'attribute' => 'charset',
        ),
        'article.markup.version' => array(
          'type' => 'xpath',
          'selector' => "//meta[@property='op:markup_version']",
          'attribute' => 'content',
        ),
        'article.auto.ad' => array(
          'type' => 'xpath',
          'selector' => "//meta[@property='fb:use_automatic_ad_placement']",
          'attribute' => 'content',
        ),
        'article.style' => array(
          'type' => 'xpath',
          'selector' => "//meta[@property='fb:article_style']",
          'attribute' => 'content',
        ),
      ),
    ),
    array(
      'class' => 'HeaderTitleRule',
      'selector' => 'h1',
    ),
    array(
      'class' => 'HeaderSubTitleRule',
      'selector' => 'h2',
    ),
    array(
      'class' => 'HeaderKickerRule',
      'selector' => 'h3.op-kicker',
    ),
    array(
      'class' => 'TimeRule',
      'selector' => 'time.op-modified',
      'properties' => array(
        'article.time' => array(
          'type' => 'string',
          'selector' => 'time',
          'attribute' => 'datetime',
        ),
        'article.datetype' => array(
          'type' => 'constant',
          'value' => 'op-modified',
        ),
      ),
    ),
    array(
      'class' => 'TimeRule',
      'selector' => 'time.op-published',
      'properties' => array(
        'article.time' => array(
          'type' => 'string',
          'selector' => 'time',
          'attribute' => 'datetime',
        ),
        'article.datetype' => array(
          'type' => 'constant',
          'value' => 'op-published',
        ),
      ),
    ),
    array(
      'class' => 'AuthorRule',
      'selector' => 'address',
      'properties' => array(
        'author.name' => array(
          'type' => 'string',
        ),
      ),
    ),
    array(
      'class' => 'AuthorRule',
      'selector' => '//header/address[a]',
      'properties' => array(
        'author.url' => array(
          'type' => 'string',
          'selector' => 'a',
          'attribute' => 'href',
        ),
        'author.name' => array(
          'type' => 'string',
          'value' => 'a',
        ),
        'author.role_contribution' => array(
          'type' => 'string',
          'selector' => 'a',
          'attribute' => 'title',
        ),
        'author.description' => array(
          'type' => 'sibling',
          'value' => 'a',
        ),
      ),
    ),
    array(
      'class' => 'H1Rule',
      'selector' => 'h1',
      'properties' => array(
        'op-left' => array(
          'type' => 'exists',
          'selector' => 'h1.op-left',
        ),
        'op-center' => array(
          'type' => 'exists',
          'selector' => 'h1.op-center',
        ),
        'op-right' => array(
          'type' => 'exists',
          'selector' => 'h1.op-right',
        ),
        'op-vertical-below' => array(
          'type' => 'exists',
          'selector' => 'h1.op-vertical-below',
        ),
        'op-vertical-center' => array(
          'type' => 'exists',
          'selector' => 'h1.op-vertical-center',
        ),
        'op-vertical-above' => array(
          'type' => 'exists',
          'selector' => 'h1.op-vertical-above',
        ),
      ),
    ),
    array(
      'class' => 'H2Rule',
      'selector' => 'h2',
      'properties' => array(
        'op-left' => array(
          'type' => 'exists',
          'selector' => 'h2.op-left',
        ),
        'op-center' => array(
          'type' => 'exists',
          'selector' => 'h2.op-center',
        ),
        'op-right' => array(
          'type' => 'exists',
          'selector' => 'h2.op-right',
        ),
        'op-vertical-below' => array(
          'type' => 'exists',
          'selector' => 'h2.op-vertical-below',
        ),
        'op-vertical-center' => array(
          'type' => 'exists',
          'selector' => 'h2.op-vertical-center',
        ),
        'op-vertical-above' => array(
          'type' => 'exists',
          'selector' => 'h2.op-vertical-above',
        ),
      ),
    ),
    array(
      'class' => 'CaptionCreditRule',
      'selector' => 'cite',
      'properties' => array(
        'op-left' => array(
          'type' => 'exists',
          'selector' => 'cite.op-left',
        ),
        'op-center' => array(
          'type' => 'exists',
          'selector' => 'cite.op-center',
        ),
        'op-right' => array(
          'type' => 'exists',
          'selector' => 'cite.op-right',
        ),
        'op-vertical-below' => array(
          'type' => 'exists',
          'selector' => 'cite.op-vertical-below',
        ),
        'op-vertical-center' => array(
          'type' => 'exists',
          'selector' => 'cite.op-vertical-center',
        ),
        'op-vertical-above' => array(
          'type' => 'exists',
          'selector' => 'cite.op-vertical-above',
        ),
      ),
    ),
    array(
      'class' => 'PullquoteCiteRule',
      'selector' => 'cite',
    ),
    array(
      'class' => 'CaptionRule',
      'selector' => 'figcaption',
      'properties' => array(
        'op-medium' => array(
          'type' => 'exists',
          'selector' => 'figcaption.op-medium',
        ),
        'op-large' => array(
          'type' => 'exists',
          'selector' => 'figcaption.op-large',
        ),
        'op-extra-large' => array(
          'type' => 'exists',
          'selector' => 'figcaption.op-extra-large',
        ),
        'op-left' => array(
          'type' => 'exists',
          'selector' => 'figcaption.op-left',
        ),
        'op-center' => array(
          'type' => 'exists',
          'selector' => 'figcaption.op-center',
        ),
        'op-right' => array(
          'type' => 'exists',
          'selector' => 'figcaption.op-right',
        ),
        'op-vertical-below' => array(
          'type' => 'exists',
          'selector' => 'figcaption.op-vertical-below',
        ),
        'op-vertical-center' => array(
          'type' => 'exists',
          'selector' => 'figcaption.op-vertical-center',
        ),
        'op-vertical-above' => array(
          'type' => 'exists',
          'selector' => 'figcaption.op-vertical-above',
        ),
        'caption.default' => array(
          'type' => 'string',
          'selector' => 'img',
          'attribute' => 'alt',
        ),
      ),
    ),

    array(
      'class' => 'AudioRule',
      'selector' => 'audio',
      'properties' => array(
        'audio.url' => array(
          'type' => 'string',
          'selector' => 'source',
          'attribute' => 'src',
        ),
        'audio.title' => array(
          'type' => 'string',
          'selector' => 'audio',
          'attribute' => 'title',
        ),
        'audio.autoplay' => array(
          'type' => 'string',
          'selector' => 'audio',
          'attribute' => 'autoplay',
        ),
        'audio.muted' => array(
          'type' => 'string',
          'selector' => 'audio',
          'attribute' => 'muted',
        ),
      ),
    ),


    array(
      'class' => 'ImageRule',
      'selector' => 'figure',
      'properties' => array(
        'image.url' => array(
          'type' => 'string',
          'selector' => 'img',
          'attribute' => 'src',
        ),
        'image.like' => array(
          'type' => 'exists',
          'selector' => "figure[data-feedback*='fb:likes']",
          'attribute' => 'data-feedback',
        ),
        'aspect-fit' => array(
          'type' => 'exists',
          'selector' => "figure[data-mode=aspect-fit]",
        ),
        'aspect-fit-only' => array(
          'type' => 'exists',
          'selector' => "figure[data-mode=aspect-fit-only]",
        ),
        'fullscreen' => array(
          'type' => 'exists',
          'selector' => "figure[data-mode=fullscreen]",
        ),
        'non-interactive' => array(
          'type' => 'exists',
          'selector' => "figure[data-mode=non-interactive]",
        ),
        'image.comments' => array(
          'type' => 'exists',
          'selector' => "figure[data-feedback*='fb:comments']",
          'attribute' => 'data-feedback',
        ),
      ),
    ),


    array(
      'class' => 'VideoRule',
      'selector' => 'figure',
      'containsChild' => 'video',
      'properties' => array(
        'video.url' => array(
          'type' => 'string',
          'selector' => 'source',
          'attribute' => 'src',
        ),
        'video.type' => array(
          'type' => 'string',
          'selector' => 'source',
          'attribute' => 'type',
        ),
        'aspect-fit' => array(
          'type' => 'exists',
          'selector' => "figure[data-mode=aspect-fit]",
        ),
        'aspect-fit-only' => array(
          'type' => 'exists',
          'selector' => "figure[data-mode=aspect-fit-only]",
        ),
        'fullscreen' => array(
          'type' => 'exists',
          'selector' => "figure[data-mode=fullscreen]",
        ),
        'non-interactive' => array(
          'type' => 'exists',
          'selector' => "figure[data-mode=non-interactive]",
        ),
        'video.controls' => array(
          'type' => 'exists',
          'selector' => 'video',
          'attribute' => 'controls',
        ),
        'video.playback' => array(
          'type' => 'exists',
          'selector' => 'video',
          'attribute' => 'data-fb-disable-autoplay',
        ),
        'video.like' => array(
          'type' => 'exists',
          'selector' => "figure[data-feedback*='fb:likes']",
          'attribute' => 'data-feedback"',
        ),
        'video.comments' => array(
          'type' => 'exists',
          'selector' => "figure[data-feedback*='fb:comments']",
          'attribute' => 'data-feedback',
        ),
      ),
    ),
    array(
      'class' => 'MapRule',
      'selector' => 'figure.op-map',
    ),


    array(
      'class' => 'GeoTagRule',
      'selector' => 'script',
      'properties' => array(
        'map.geotag' => array(
          'type' => 'string',
          'selector' => 'script',
        ),
      ),
    ),
    array(
      'class' => 'InteractiveRule',
      'selector' => 'figure.op-interactive',
      'properties' => array(
        'no-margin' => array(
          'type' => 'exists',
          'selector' => 'iframe.no-margin',
        ),
        'column-width' => array(
          'type' => 'exists',
          'selector' => 'iframe.column-width',
        ),
        'interactive.url' => array(
          'type' => 'string',
          'selector' => 'iframe',
          'attribute' => 'src',
        ),
        'interactive.height' => array(
          'type' => 'int',
          'selector' => 'iframe',
          'attribute' => 'height',
        ),
        'interactive.width' => array(
          'type' => 'string',
          'selector' => 'iframe',
          'attribute' => 'width',
        ),
        'interactive.iframe' => array(
          'type' => 'children',
          'selector' => 'iframe',
        ),
      ),
    ),
    array(
      'class' => 'HeaderImageRule',
      'selector' => 'figure',
      'containsChild' => 'img',
      'properties' => array(
        'image.url' => array(
          'type' => 'string',
          'selector' => 'img',
          'attribute' => 'src',
        ),
      ),
    ),
    array(
      'class' => 'SlideshowImageRule',
      'selector' => "figure",
      'properties' => array(
        'image.url' => array(
          'type' => 'string',
          'selector' => 'img',
          'attribute' => 'src',
        ),
        'caption.title' => array(
          'type' => 'string',
          'selector' => 'figcaption',
        ),
      ),
    ),
    array(
      'class' => 'SlideshowRule',
      'selector' => "figure.op-slideshow",
    ),
    array(
      'class' => 'AdRule',
      'selector' => "figure.op-ad",
      'properties' => array(
        'ad.url' => array(
          'type' => 'string',
          'selector' => 'iframe',
          'attribute' => 'src',
        ),
        'ad.height' => array(
          'type' => 'int',
          'selector' => 'iframe',
          'attribute' => 'height',
        ),
        'ad.width' => array(
          'type' => 'int',
          'selector' => 'iframe',
          'attribute' => 'width',
        ),
        'ad.embed' => array(
          'type' => 'children',
          'selector' => 'iframe',
        ),
      ),
    ),
    array(
      'class' => 'HeaderAdRule',
      'selector' => 'figure.op-ad',
      'properties' => array(
        'ad.url' => array(
          'type' => 'string',
          'selector' => 'iframe',
          'attribute' => 'src',
        ),
        'ad.height' => array(
          'type' => 'int',
          'selector' => 'iframe',
          'attribute' => 'height',
        ),
        'ad.width' => array(
          'type' => 'int',
          'selector' => 'iframe',
          'attribute' => 'width',
        ),
        'ad.embed' => array(
          'type' => 'children',
          'selector' => 'iframe',
        ),
      ),
    ),
    array(
      'class' => 'AnalyticsRule',
      'selector' => 'figure.op-tracker',
      'properties' => array(
        'analytics.url' => array(
          'type' => 'string',
          'selector' => 'iframe',
          'attribute' => 'src',
        ),
        'analytics.embed' => array(
          'type' => 'children',
          'selector' => 'iframe',
        ),
      ),
    ),
    array(
      'class' => 'PullquoteRule',
      'selector' => 'aside',
    ),
  );
}