opengraphprotocol.module

<?php

/**
 * @file
 * Enables Open Graph protocol output for Drupal sites.
 */

/**
 * Implements hook_rdf_namespaces().
 */
function opengraphprotocol_rdf_namespaces() {
  return array(
    'og'      => 'http://ogp.me/ns#',
    'fb'      => 'http://www.facebook.com/2008/fbml',
  );
}

/**
 * Implements hook_form_FORM_ID_alter().
 *
 * Adds a vertical tab in the edit content type form to specify which Open
 * Graph protocol type should associated with each content type.
 */
function opengraphprotocol_form_node_type_form_alter(&$form, $form_state) {
  // Object types defined at http://opengraphprotocol.org/#types
  $og_types = array(
    'Activities' => array(
      'activity',
      'sport',
    ),
    'Businesses' => array(
      'bar',
      'company',
      'cafe',
      'hotel',
      'restaurant',
    ),
    'Groups' => array(
      'cause',
      'sports_league',
      'sports_team',
    ),
    'Organizations' => array(
      'band',
      'government',
      'non_profit',
      'school',
      'university',
    ),
    'People' => array(
      'actor',
      'athlete',
      'author',
      'director',
      'musician',
      'politician',
      'public_figure',
    ),
    'Places' => array(
      'city',
      'country',
      'landmark',
      'state_province',
    ),
    'Products and Entertainment' => array(
      'album',
      'book',
      'drink',
      'food',
      'game',
      'movie',
      'product',
      'song',
      'tv_show',
    ),
    'Websites' => array(
      'article',
      // website and blog are designed to represent an entire site, an og:type
      // tag with types website or blog should usually only appear on the root
      // of a domain. see http://developers.facebook.com/docs/opengraph
      //'blog',
      //'website',
    ),
  );

  // Serializes the OGP types for Drupal's Form API drop down list.
  foreach ($og_types as $name => $group) {
    foreach ($group as $type) {
      $og_types_options[$name][$type] = $type;
    }
  }

  if (isset($form['type'])) {
    $form['opengraphprotocol'] = array(
      '#type' => 'fieldset',
      '#title' => t('Open Graph protocol settings'),
      '#collapsible' => TRUE,
      '#collapsed' => TRUE,
      '#group' => 'additional_settings',
    );
    $form['opengraphprotocol']['opengraphprotocol_type'] = array(
      '#type' => 'select',
      '#title' => t('Open Graph protocol type'),
      '#description' => t('Choose the Open Graph protocol type you want to associate with this content type.'),
      '#default_value' => variable_get('opengraphprotocol_type_' . $form['#node_type']->type, ''),
      '#options' => $og_types_options,
    );
    $form['opengraphprotocol']['opengraphprotocol_fb_admins'] = array(
      '#type' => 'textfield',
      '#title' => t('Facebook Admins IDs'),
      '#description' => t('A comma-separated list of Facebook user IDs that administer the pages of this content type.'),
      '#default_value' => variable_get('opengraphprotocol_fb_admins_' . $form['#node_type']->type, ''),
    );
  }
}

/**
 * Implements MODULE_preprocess_HOOK().
 *
 * Adds the various Open Graph protocol HTML elements during page rendering.
 */
function opengraphprotocol_preprocess_node(&$variables) {
  $node = $variables['node'];

  // Uses the mapping for og:type if it has been defined by the administrator.
  $meta_tags[] = array(
    'property' => 'og:type',
    'content' => variable_get('opengraphprotocol_type_' . $node->type, $node->type),
  );
  $meta_tags[] = array(
    'property' => 'og:title',
    'content' => $node->title,
  );
  $meta_tags[] = array(
    'property' => 'og:url',
    'content' => url('node/' . $node->nid, array('absolute' => TRUE)),
  );
  $meta_tags[] = array(
    'property' => 'og:site_name',
    'content' => variable_get('site_name'),
  );
  $meta_tags[] = array(
    'property' => 'fb:admins',
    'content' => variable_get('opengraphprotocol_fb_admins_' . $node->type, ''),
  );
  // Exposes the value of any field known to og: (these are optional).
  $og_properties = array('description', 'image', 'latitude', 'longitude', 'street-address', 'locality', 'region', 'postal-code', 'country-name', 'email', 'phone_number', 'fax_number');
  foreach ($og_properties as $property) {
    $field = 'field_' . $property;
    if (isset($node->$field)) {
      $field_info = field_info_field($field);
      // We need a different logic depending on the type of data to be exposed.
      switch ($field_info['module']) {
        case 'number' :
          if (isset($node->{$field}[LANGUAGE_NONE][0]['value'])) {
            $meta_tags[] = array(
              'property' => 'og:' . $property ,
              'content' => $node->{$field}[LANGUAGE_NONE][0]['value'],
            );
          }
          break;
        case 'text' :
          if (isset($node->{$field}[LANGUAGE_NONE][0]['safe_value'])) {
            $meta_tags[] = array(
              'property' => 'og:' . $property ,
              'content' => $node->{$field}[LANGUAGE_NONE][0]['safe_value'],
            );
          }
          break;
        case 'image' :
          if (isset($node->{$field}[LANGUAGE_NONE][0]['uri'])) {
            $meta_tags[] = array(
              'property' => 'og:' . $property ,
              'content' => file_create_url($node->{$field}[LANGUAGE_NONE][0]['uri']),
            );
          }
          break;
      }
    }
  }
  // Outputs all the various metadata from above as meta tags in the head tag.
  foreach ($meta_tags as $id => $meta_tag) {
    drupal_add_html_head(array('#tag' => 'meta', '#attributes' => $meta_tag), 'opengraphprotocol_' . $id);
  }

  // Places a Facebook "Like" above the node links.
  $variables['content']['links']['node']['#prefix'] = '<div id="opengraphprotocol-like"><iframe src="http://www.facebook.com/plugins/like.php?href=' . urlencode(url('node/' . $node->nid, array('absolute' => TRUE))) . '&amp;layout=standard&amp;show_faces=true&amp;width=450&amp;action=like&amp;font&amp;colorscheme=light&amp;height=80" scrolling="no" frameborder="0" style="border:none; overflow:hidden; width:350px; height:80px;" allowTransparency="true"></iframe></div>';
}