fb_graph.module in Drupal for Facebook 6.3

Open Graph Helpers

This module adds Open Graph metadata to Drupal pages.

File

fb_graph.module

<?php

/**
 * @file
 * Open Graph Helpers
 *
 * This module adds Open Graph metadata to Drupal pages.
 */

// Permissions.
define('FB_GRAPH_PERM_DELETE_OWN', 'fb_graph delete own action');
define('FB_GRAPH_PERM_PUBLISH', 'fb_graph publish action');

// Menu paths.
define('FB_GRAPH_PATH_DELETE', 'fb_graph/delete');

// Delete item from Open Graph.
define('FB_GRAPH_PATH_DELETE_ARGS', 2);

// length of path.
// Variable names.
define('FB_GRAPH_VAR_SMART_TAGS', 'fb_graph_smart_tags');

// Add tags learned from Drupal DB.
define('FB_GRAPH_VAR_MESSAGES', 'fb_graph_messages');

// Show drupal messages when publishing.
// Variable names that will have a node type appended.
define('FB_GRAPH_VAR_OBJECT_TYPE', 'fb_graph_object_type');
define('FB_GRAPH_VAR_OBJECT_TYPE_APP', 'fb_graph_object_type_app');
define('FB_GRAPH_NOT_AN_OBJECT', 'fb_graph_none');

// deprecated
function fb_graph_perm() {
  return array(
    FB_GRAPH_PERM_PUBLISH,
    FB_GRAPH_PERM_DELETE_OWN,
  );
}

/**
 * Implements hook_menu().
 *
 * Pages for Facebook graph helper and administration.
 */
function fb_graph_menu() {
  $items = array();

  // @TODO: pages to browse graph items published this application and user.
  // Delete an item from the graph.  Will only succeed when user has necessary permission.
  $items[FB_GRAPH_PATH_DELETE . '/%'] = array(
    'title' => 'Facebook Delete',
    'description' => 'Delete an item from Facebook Open Graph',
    'page callback' => 'drupal_get_form',
    'page arguments' => array(
      'fb_graph_delete_confirm_form',
      FB_GRAPH_PATH_DELETE_ARGS,
    ),
    'access arguments' => array(
      FB_GRAPH_PERM_DELETE_OWN,
    ),
    'type' => MENU_CALLBACK,
    'file' => 'fb_graph.pages.inc',
  );
  return $items;
}

/**
 * Implements hook_fb().
 *
 * Act on ajax event 'fb_graph_publish_action' allowing third parties to use
 * ajax to publish an event.  Note FB.api() can also be used to publish events
 * directly to facebook.
 */
function fb_graph_fb($op, $data, &$return) {
  if ($op == FB_OP_AJAX_EVENT && $data['event_type'] == 'fb_graph_publish_action') {

    // As a convenience to third party modules, handle 'fb_graph_publish_action'.
    extract($data);
    fb_graph_publish_action($event_data['action'], array(
      $event_data['object_type'] => $event_data['object_url'],
    ));
  }
}

/**
 * Helper function to publish user activity to Facebook's Open Graph.
 */
function fb_graph_publish_action($action, $params, $options = array()) {
  if (!user_access(FB_GRAPH_PERM_PUBLISH)) {
    return;
  }

  // Defaults.
  if (isset($options['fb_app'])) {
    $fb_app = $options['fb_app'];
  }
  else {
    $fb_app = $GLOBALS['_fb_app'];
  }
  if (isset($options['fbu'])) {
    $fbu = $options['fbu'];
  }
  else {
    $fbu = fb_facebook_user();
  }
  if (!$fbu || !$fb_app) {

    // We don't have enough information.
    return;
  }
  if (isset($options['action_type'])) {
    $action_type = $options['action_type'];

    // Human readable verb.
  }
  else {
    $action_type = $action;
  }
  if (!isset($params['access_token'])) {
    $fb = fb_api_init($fb_app);
    $params['access_token'] = fb_get_token($fb, $fbu);
  }
  try {

    // @TODO: handle apps that have no canvas page.  how???
    // Note fb_graph() is in fb.module.
    $result = fb_graph($fbu . '/' . $fb_app->canvas . ':' . $action, $params, 'POST');
    if (isset($result['id'])) {
      $id = $result['id'];
      $message_args = array(
        '!delete_url' => url(FB_GRAPH_PATH_DELETE . '/' . $id, array(
          'destination' => $_GET['q'],
        )),
        '%action_type' => $action_type,
        '!profile_url' => 'https://www.facebook.com/' . $fbu,
      );
      if (variable_get(FB_GRAPH_VAR_MESSAGES, TRUE)) {
        $message = t('Published %action_type activity to <a href=!profile_url>Facebook</a>.', $message_args);
        if (user_access(FB_GRAPH_PERM_DELETE_OWN)) {
          $message .= '&nbsp;' . t('[<a href=!delete_url>delete from timeline</a>]');
        }
        drupal_set_message($message);
      }
      return $id;
    }
    else {
      if (fb_verbose()) {

        // This happens all the time.  I don't know why.
        watchdog('fb_graph', 'Failed to publish %action by user %fbu to facebook.  Facebook did not return an ID!', array(
          '%action' => $action,
          '%fbu' => $fbu,
        ), WATCHDOG_WARNING);
      }
    }
  } catch (Exception $e) {
    fb_log_exception($e, t('Failed to publish %action_type action', array(
      '%action_type' => $action_type,
    )));

    //$args = func_get_args();

    //watchdog('fb_graph', __FUNCTION__ . '<pre>' . dprint_r($args, 1) . '</pre>'); // debug
  }
}

/**
 * Define a metatag.  It will be published in the html header of the current page.
 *
 * @param $key
 * The property attribute of the meta tag.
 *
 * @param $value
 * The content attribute of the meta tag.
 */
function fb_graph_set_tag($key = NULL, $value = NULL, $overwrite = TRUE) {
  static $cache = array();
  if (isset($key)) {
    if ($overwrite || !isset($cache[$key])) {
      $cache[$key] = $value;
    }
  }
  else {
    return $cache;
  }
}

/**
 * Get the metatag values for the current page.
 *
 * @see fb_graph_set_tag()
 */
function fb_graph_get_tags($final = FALSE) {
  $tags = fb_graph_set_tag();

  // Allow third parties to alter.
  drupal_alter('fb_graph_tags', $tags, $final);
  if ($final) {

    // Add default tags.
    extract(fb_vars());
    if (isset($fb_app) && !isset($tags['fb:app_id'])) {
      $tags['fb:app_id'] = $fb_app->id;
    }
  }
  return $tags;
}

/**
 * Implements hook_preprocess_page().
 *
 * Adds our meta tags to the html header.
 */
function fb_graph_preprocess_page(&$vars) {
  $tags = fb_graph_get_tags(TRUE);
  if (count($tags)) {
    foreach ($tags as $key => $value) {
      if (is_array($value)) {

        // Arrays represent multiple properties for same key.  I.e. og:image
        foreach ($value as $val) {
          $markup = '<meta property="' . check_plain($key) . '" content="' . check_plain($val) . '" />';
          drupal_set_html_head($markup);
        }
      }
      else {

        // $value is a single string.
        $markup = '<meta property="' . check_plain($key) . '" content="' . check_plain($value) . '" />';
        drupal_set_html_head($markup);
      }
    }
    $vars['head'] = drupal_get_html_head();
  }
}
function fb_graph_form_alter(&$form, &$form_state, $form_id) {
  if ($form_id == 'taxonomy_form_vocabulary') {
    $vid = 0;
    if (isset($form['vid'])) {
      $vid = $form['vid']['#value'];
    }
    $form['fb_graph'] = array(
      '#type' => 'fieldset',
      '#title' => t('Open Graph'),
      '#collapsible' => TRUE,
      '#collapsed' => TRUE,
    );
    $form['fb_graph']['fb_graph_is_metadata'] = array(
      '#title' => t('Treat tags as metadata'),
      '#description' => t('Render terms as HTML header metadata.  The name of the vocabulary becomes the property, and terms become the content.  For example a vocabulary named "og:type" would have terms "article", "blog", etc...', array(
        '!url' => 'http://developers.facebook.com/docs/beta/opengraph/objects/builtin/',
      )),
      '#type' => 'checkbox',
      '#default_value' => variable_get('fb_graph_is_metadata_' . $vid, FALSE),
    );

    // @TODO add selector for application specific types.
    $form['#submit'][] = 'fb_graph_taxonomy_form_vocabulary_submit';

    // Weights on taxonomy form are screwed up.
    if (!isset($form['submit']['#weight'])) {
      $form['submit']['#weight'] = 98;
      $form['delete']['#weight'] = 99;
    }
  }
  if ($form_id == 'node_type_form') {
    $type = $form['#node_type']->type;

    // Allow administrator to configure which Object types this content type represents.
    include drupal_get_path('module', 'fb') . '/fb.admin.inc';
    $form['fb_graph'] = array(
      '#type' => 'fieldset',
      '#title' => t('Open Graph'),
      '#collapsible' => TRUE,
      '#collapsed' => TRUE,
    );
    $form['fb_graph'][FB_GRAPH_VAR_OBJECT_TYPE] = array(
      '#type' => 'textfield',
      '#title' => t('Object Type'),
      '#description' => t('Which <a href=!url target=_blank>object type</a> does this content type represent? For example, %fb_graph_type_example.', array(
        '!url' => 'http://developers.facebook.com/docs/beta/opengraph/objects/builtin/',
        '%fb_graph_type_example' => 'article',
      )),
      '#default_value' => variable_get(FB_GRAPH_VAR_OBJECT_TYPE . '_' . $type, ''),
    );
    $options = array(
      0 => t('<not a custom type>'),
    ) + fb_admin_get_app_options();
    $form['fb_graph'][FB_GRAPH_VAR_OBJECT_TYPE_APP] = array(
      '#type' => 'select',
      '#title' => t('Custom Object Type'),
      '#description' => t('If the object type is custom, as opposed to <a href=!url target=_blank>built in</a>, which application is it associated with?', array(
        '!url' => 'http://developers.facebook.com/docs/beta/opengraph/objects/builtin/',
      )),
      '#options' => $options,
      '#default_value' => variable_get(FB_GRAPH_VAR_OBJECT_TYPE_APP . '_' . $type, 0),
    );
  }
}

/**
 * Form API submit handler.
 *
 * Save settings for each vocabulary.
 */
function fb_graph_taxonomy_form_vocabulary_submit($form, &$form_state) {
  $values = $form_state['values'];
  if (!empty($values['fb_graph_is_metadata'])) {
    variable_set('fb_graph_is_metadata_' . $values['vid'], $values['fb_graph_is_metadata']);
  }
  else {

    // Delete rather than set to FALSE, because some sites will have huge numbers of vocabs.  We only need data for the few that correspond to open graph types.
    variable_del('fb_graph_is_metadata_' . $values['vid']);
  }
}

/**
 * Implements hook_nodeapi().
 *
 */
function fb_graph_nodeapi(&$node, $op, $a3 = NULL, $a4 = NULL) {
  if ($op == 'view' && $a4) {

    // Full page view
    // Some tags might come from taxonomy.
    if (!empty($node->taxonomy)) {
      foreach ($node->taxonomy as $tid => $term) {
        if (variable_get('fb_graph_is_metadata_' . $term->vid, FALSE)) {

          // Treat this tag as metadata.
          unset($node->taxonomy[$tid]);
          $v = taxonomy_vocabulary_load($term->vid);
          fb_graph_set_tag($v->name, $term->name, FALSE);

          // @TODO support multiple terms concatinated together.
        }
      }
    }

    // Some tags might come from content type.
    if ($fb_graph_type = variable_get(FB_GRAPH_VAR_OBJECT_TYPE . '_' . $node->type, '')) {
      if ($app_label = variable_get(FB_GRAPH_VAR_OBJECT_TYPE_APP . '_' . $node->type, 0)) {
        if (!empty($GLOBALS['_fb_app']) && $GLOBALS['_fb_app']->label == $app_label) {

          // Custom type applies only when app is currently active.
          fb_graph_set_tag('og:type', $GLOBALS['_fb_app']->canvas . ':' . $fb_graph_type, FALSE);
        }
      }
      else {
        fb_graph_set_tag('og:type', $fb_graph_type, FALSE);
      }
    }

    // Add additional "smart" tags.
    $tags = fb_graph_get_tags();
    fb_graph_set_tag('og:url', url('node/' . $node->nid, array(
      'absolute' => TRUE,
    )), FALSE);
    fb_graph_set_tag('og:title', t($node->title), FALSE);
    if (isset($tags['og:type']) && variable_get(FB_GRAPH_VAR_SMART_TAGS, TRUE)) {
      if ($tags['og:type'] == 'article') {
        fb_graph_set_tag('article:published_time', format_date($node->created, 'custom', 'Y-m-dTH:iZ'), FALSE);
        fb_graph_set_tag('article:modified_time', format_date($node->changed, 'custom', 'Y-m-dTH:iZ'), FALSE);

        // Only include URL to author if facebook's server will be able to view it.
        if (user_access('access user profiles', drupal_anonymous_user())) {

          // @TODO also test author profile is active.
          fb_graph_set_tag('article:author', url('user/' . $node->uid, array(
            'absolute' => TRUE,
          )), FALSE);
        }
      }
    }
  }
}
function fb_graph_user($op, &$edit, &$account, $category = NULL) {
  if ($op == 'view') {

    // Add smart default tags.
    $tags = fb_graph_get_tags();
    if (!isset($tags['og:type']) && variable_get(FB_GRAPH_VAR_SMART_TAGS, TRUE)) {
      fb_graph_set_tag('og:type', 'profile');

      // http://developers.facebook.com/docs/beta/opengraph/objects/builtin/
      fb_graph_set_tag('og:url', url('user/' . $account->uid, array(
        'absolute' => TRUE,
      )), FALSE);
      fb_graph_set_tag('profile:username', $account->name, FALSE);
    }
  }
}

Functions

Name	Description
fb_graph_fb	Implements hook_fb().
fb_graph_form_alter
fb_graph_get_tags	Get the metatag values for the current page.
fb_graph_menu	Implements hook_menu().
fb_graph_nodeapi	Implements hook_nodeapi().
fb_graph_perm
fb_graph_preprocess_page	Implements hook_preprocess_page().
fb_graph_publish_action	Helper function to publish user activity to Facebook's Open Graph.
fb_graph_set_tag	Define a metatag. It will be published in the html header of the current page.
fb_graph_taxonomy_form_vocabulary_submit	Form API submit handler.
fb_graph_user

Constants

Name	Description
FB_GRAPH_NOT_AN_OBJECT
FB_GRAPH_PATH_DELETE
FB_GRAPH_PATH_DELETE_ARGS
FB_GRAPH_PERM_DELETE_OWN
FB_GRAPH_PERM_PUBLISH
FB_GRAPH_VAR_MESSAGES
FB_GRAPH_VAR_OBJECT_TYPE
FB_GRAPH_VAR_OBJECT_TYPE_APP
FB_GRAPH_VAR_SMART_TAGS