<?php
// $Id: fb_example.module,v 1.15.2.1 2011-02-16 03:22:07 yogadex Exp $
/**
 * @file
 *
 * The code in this module provides example of common customizations to
 * modules/fb.  The code found here is used on http://drupalforfacebook.org.
 * Feel free to enable this module if you want your site to behave in just the
 * same way.  However, advanced Drupal developers may be better served copying
 * these examples into their own module, and customizing as needed.
 */

/**
 * Implements hook_link().
 *
 * Add an XFBML like button to all node pages.  The button will appear next to
 * other node links, such as "add new comment".
 */
function fb_example_link($type, $object, $teaser = FALSE) {
  if ($type == 'node' && !$teaser) {
    $items = array();
    if (variable_get('fb_example_link_add_like', TRUE)) { // Switch to control this behavior.
      $url = fb_scrub_urls(url('node/' . $object->nid, array('absolute' => TRUE)));
      $items['dff_like'] = array(
        'title' => "<fb:like href={$url}></fb:like>",
        'html' => TRUE,
      );
    }
    return $items;
  }
}


/**
 * Implements hook_fb_friend_invite_page_wrap_alter().
 *
 * @see modules/fb/contrib/fb_friend.module
 *
 * Here we customize the block which invites facebook friends to visit
 * the current page.
 *
 * By default the invite form is wrapped in serverfbml and embedded
 * within a page.  Here we alter the data before it is rendered.  We
 * change the wrapper type to fb_connect_fbml_popup.  The result is a
 * link which pops up the invite form.
 */
function fb_example_fb_friend_invite_page_wrap_alter(&$elem) {
  // Replace serverfbml with popup
  if ($elem['#type'] == 'fb_form_serverfbml') {
    $elem['#type'] = 'fb_fbml_popup';
    $elem['#title'] = t('Invite Friends to View This Page');
    $elem['#link_text'] = t('Invite friends to view this page');
    $elem['#attributes'] = array('width' => 760);
  }
}

/**
 * Implements hook_fb_friend_invite_app_alter().
 *
 * Customizes aspects of the invitation form.
 */
function fb_example_fb_friend_invite_app_alter(&$fbml) {
  $fbml['selector']['#attributes']['cols'] = 3;
  $fbml['selector']['#attributes']['email_invite'] = FALSE;
  $fbml['selector']['#attributes']['import_external_friends'] = FALSE;
}
function fb_example_fb_friend_invite_app_wrap_alter(&$elem) {
  // Replace serverfbml with popup
  if ($elem['#type'] == 'fb_form_serverfbml') {
    $elem['#type'] = 'fb_fbml_popup';
    $elem['#title'] = t('Invite Friends to install this application');
    $elem['#link_text'] = t('Invite friends to install this application');
    $elem['#attributes'] = array('width' => 760);
  }
}

/**
 * Implements hook_form_alter().
 *
 * Adds a checkbox to node edit and comment forms.  This checkbox lets
 * facebook users know that content may be published to their Wall,
 * and gives them a chance to prevent that.
 */
function fb_example_form_alter(&$form, $form_state, $form_id) {
  // Add stream publish option.
  if (isset($GLOBALS['_fb']) && fb_facebook_user()) {
    if ($form['#id'] == 'node-form') {
      // Add checkbox to control feed publish.
      $form['fb_example']['stream_publish'] = array(
        '#type' => 'checkbox',
        '#title' => t('Share on Facebook'),
        '#default_value' => TRUE,
      );
    }
    elseif ($form['form_id']['#value'] == 'comment_form') {
      // Add checkbox to control feed publish.
      $form['fb_example']['stream_publish'] = array(
        '#type' => 'checkbox',
        '#title' => t('Share on Facebook'),
        '#default_value' => TRUE,
      );
    }
  }
}

/**
 * Implements hook_nodeapi().
 *
 * Publish to facebook Walls when users submit nodes.
 *
 * @see http://developers.facebook.com/docs/reference/rest/stream.publish
 * @see http://developers.facebook.com/docs/guides/attachments
 */
function fb_example_nodeapi(&$node, $op, $a3 = NULL, $a4 = NULL) {
  if ($op == 'insert' || $op == 'update') {
    if (isset($node->stream_publish) && $node->stream_publish) {
      $attachment = array(
        'name' => $node->title,
        'href' => url('node/' . $node->nid, array('absolute' => TRUE)),
        'description' => filter_xss($node->teaser, array()),
      );

      /*
        if ($picture = $GLOBALS['user']->picture) {
        $url = url($picture, array('absolute' => TRUE));
        $attachment['media'][] = array(
        'type' => 'image',
        'src' => $url,
        'href' => $url,
        );
        }
      */
      if ($logo_path = theme_get_setting('logo_path')) {
        $url = url($logo_path, array('absolute' => TRUE));
        //dpm($logo_path, "logo_path is $logo_path and url is $url");
        $attachment['media'][] = array(
          'type' => 'image',
          'src' => $url,
          'href' => $url,
        );
      }


      $user_message = t('Check out my latest post on !site...',
                        array('!site' => variable_get('site_name', t('my Drupal for Facebook powered site'))));
      $actions = array();
      $actions[] = array(
        'text' => t('Read More'),
        'href' => url('node/' . $node->nid, array('absolute' => TRUE)),
      );
      fb_stream_publish_dialog(array('message' => $user_message,
                                     'attachment' => $attachment,
                                     'action_links' => $actions,
                               ));
    }
  }

  // Another way to add like button, as part of a node.
  if ($op == 'view' && variable_get('fb_example_nodeapi_add_like', FALSE)) {
    $url = fb_scrub_urls(url('node/' . $node->nid, array('absolute' => TRUE)));
    $node->content['dff_like'] = array(
      '#value' => "<fb:like href={$url}></fb:like>",
      '#type' => 'markup',
      '#prefix' => '<div class="dff_like_wrapper">',
      '#suffix' => '</div>',
    );
  }
}

/**
 * Implementation of hook_comment().
 *
 * Publish to facebook Walls when users submit comments.
 */
function fb_example_comment(&$a1, $op) {
  if ($op == 'insert' || $op == 'update') {
    if ($a1['stream_publish']) {
      //dpm($a1, "fb_example_comment, publishing to stream");
      $node = node_load($a1['nid']);

      // http://wiki.developers.facebook.com/index.php/Attachment_(Streams)
      $attachment = array(
        'name' => $a1['subject'],
        'href' => url('node/' . $a1['nid'], array('absolute' => TRUE, 'fragment' => 'comment-' . $a1['cid'])),
        'description' => $a1['comment'],
        //'properties' => array(t('In reply to') => array('text' => $node->title, 'href' => url("node/" . $node->nid, array('absolute' => TRUE)))),
      );

      if ($logo_path = theme_get_setting('logo_path')) {
        $url = url($logo_path, array('absolute' => TRUE));
        //dpm($logo_path, "logo_path is $logo_path and url is $url");
        $attachment['media'][] = array(
          'type' => 'image',
          'src' => $url,
          'href' => $url,
        );
      }

      $user_message = t('Check out my latest comment on !site...',
                        array('!site' => variable_get('site_name', t('my Drupal for Facebook powered site'))));
      $actions = array();
      $actions[] = array('text' => t('Read More'),
                         'href' => url('node/' . $a1['nid'], array('absolute' => TRUE)),
      );
      fb_stream_publish_dialog(array('message' => $user_message,
                                     'attachment' => $attachment,
                                     'action_links' => $actions,
                               ));
    }
  }
}


/**
 * Implements hook_fb_required_perms_alter().
 *
 * Builds a list of extended permissions required when authorizing the current facebook app.
 * @see http://developers.facebook.com/docs/authentication/permissions
 */
function fb_example_fb_required_perms_alter(&$perms) {
  if (variable_get('fb_example_require_email', TRUE)) {
    $perms[] = 'email';
  }
}


/**
 * Implements hook_fb().
 *
 * This hook provides an opportunity to customize the behavior of Facebook Applications.
 *
 * @param $op
 *   Indicates what operation is currently being performed, or which behavior
 *   can be customized.  There are a number of these.  In some cases,
 *   modules/fb is informing other modules, and in other operations it is
 *   asking for information.
 *   - FB_OP_INITIALIZE - The facebook sdk has been initialized.  This tells a
 *     facebook application is enable for the current request.
 *   - FB_OP_APP_IS_AUTHORIZED - The visitor to this page has authorized the
 *     application.
 *
 * @param $data
 *   Associative array of information specific to this operation. Usually, but not always, contains:
 *   - 'fb' - The API provided by the facebook-php-sdk.
 *   - 'fb_app' - The data about this application stored by fb_app.module.
 *   - 'fbu' - If the current user is known, their facebook id.
 *
 * @param $return
 *   An op-specific return value.  Your hook should change this reference
 *   variable, and not return it.  Some operations return an array of data,
 *   which may be collaboratively built by multiple implementations of this
 *   hook.
 *
 *
 * Note, some example code is disabled.  Change the FALSE to TRUE in
 * variable_get calls to test the code.
 */
function fb_example_fb($op, $data, &$return) {
  $fb_app = isset($data['fb_app']) ? $data['fb_app'] : NULL;
  $fb = isset($data['fb']) ? $data['fb'] : NULL;

  // Use devel module to figure out when this hook is called and what it is passed.
  //dpm(func_get_args(), "fb_example_fb($op) called"); // debug

  if ($op == FB_OP_AJAX_EVENT) {
    // We get FB_OP_AJAX_EVENT when fb.js calls us in reponse to a javascript event.
    if ($data['event_type'] == 'edge.create' && variable_get('fb_example_like_thanks', FALSE)) {
      // Facebook calls this event 'edge.create', because there's a new 'edge'
      // in the open graph.
      drupal_set_message(t('Thanks for clicking Like!'));
      // reloading allows user to see message.  This example is contrived,
      // there's no real reason to reload page here, and it prevents users
      // from adding a comment.  In practice, you could put some other javascript here.
      $return[] = "FB_JS.reload();";
    }
    if ($data['event_type'] == 'session_change' && variable_get('fb_example_session_change_redirect', FALSE)) {
      if (!isset($GLOBALS['fb_example_new_user'])) {
        // The user has clicked the connect button, or logged into/out-of
        // facebook in another browser window, then refreshed.
        if ($fbu = fb_facebook_user()) {
          // The user has connected (as opposed to logged out).  Let's redirect
          // them to our 'welcome' page.  Replace 'welcome' with the path you
          // really want.
          $url = url('welcome',
                     array('absolute' => TRUE, 'fb_canvas' => fb_is_canvas()));
          // We return javascript to be evaluated by fb.js.
          $return[] = "FB_JS.reload('$url');";
        }
      }
      elseif ($GLOBALS['fb_example_new_user']) {
        // The user has clicked the connect button and that results in a new
        // user being created.  Note this will work only when fb_example.module
        // has heavier weight than fb_user.module.  See fb_example.install.

        // Send the user to their edit page.
        $url = url('user/' . $GLOBALS['user']->uid . '/edit',
                   array('absolute' => TRUE, 'fb_canvas' => fb_is_canvas()));
        // We return javascript to be evaluated by fb.js.
        $return[] = "FB_JS.reload('$url');";
      }
    }
  }
}

/**
 * Implements hook_fb_user().
 *
 * This hook provided by fb_user.module will notify us when a new account is
 * created or a local account is logged in via facebook.
 *
 * @param $op
 *   Indicates what operation is currently being performed, or which behavior
 *   can be customized.  There are a number of these.  In some cases,
 *   modules/fb is informing other modules, and in other operations it is
 *   asking for information.
 *   - FB_USER_OP_PRE_USER - You have a chance to the name or other account
 *     attributes, before a new user account is created.
 *   - FB_OP_POST_USER - A new user account was created for a facebook user
 *     who authorized an app.
 *
 * @param $data
 *   Associative array of information specific to this operation.
 *   Usually, but not always, contains:
 *   - 'fb' - The API provided by the facebook-php-sdk.
 *   - 'fb_app' - The data about this application stored by fb_app.module.
 *   - 'fbu' - If the current user is known, their facebook id.
 *
 * @param $return
 *   An op-specific return value.  Your hook should change this reference
 *   variable, and not return it.  Some operations return an array of data,
 *   which may be collaboratively built by multiple implementations of this
 *   hook.
 *
 */
function fb_example_fb_user($op, $data, &$return) {
  $fb_app = isset($data['fb_app']) ? $data['fb_app'] : NULL;
  $fb = isset($data['fb']) ? $data['fb'] : NULL;

  if ($op == FB_USER_OP_POST_USER) {
    // Set a global that can be checked in hook_fb, above.  Note for this to
    // work properly, fb_example.module must be weighted heavier then
    // fb_user.module.  (See fb_example.install).
    $GLOBALS['fb_example_new_user'] = TRUE;
  }
}


/**
 * Implements hook_preprocess_page().
 *
 * Under admin >> site building >> facebook apps >> canvas pages, you'll find
 * some settings regarding the "processing" of canvas pages.  This processing
 * changes links for the entire page, so that all links point to
 * http://apps.facebook.com/... instead of Drupal's normal base_url.
 *
 * If instead you only want some of the links on a page to work this way, and
 * leave some unmodified, you can take the approach shown here.  In this hook
 * we process the text in some regions of the page, but not all.  So for
 * example links in the normal 'content' will not be modified.
 *
 * The code shown here could also be located in your theme's preprocess
 * function, or even in a page template.
 *
 * Note this function is only relavent when the checkboxes on admin >> site
 * building >> facebook apps >> canvas pages are disabled.
 */
function fb_example_preprocess_page(&$variables) {
  if (module_exists('fb_canvas') && fb_is_canvas()) {
    // Process links in these regions.
    foreach (array('content', 'header', 'footer', 'left', 'preface_first', 'preface_middle', 'preface_last') as $region) {
      $variables[$region] = fb_canvas_process($variables[$region], array('add_target' => TRUE, 'absolute_links' => TRUE));
    }
  }
}

/**
 * Implements hook_init().
 *
 * Workaround for a problem with Drupal where a logged in user gets access
 * denied when visiting the login or register pages.  This can easily happen
 * when clicking the facebook connect button on the login or register forms.
 * Here will simply redirect the user to the profile page when that happens.
 */
function fb_example_init() {
  global $user;
  if ($user->uid != 0) {
    if (arg(0) == 'user' &&
        (arg(1) == 'register' || arg(2) == 'login')) {
      // Avoid Drupal's awkward access denied.
      if (function_exists('fb_canvas_goto')) {
        fb_canvas_goto('user');
      }
      else {
        drupal_goto('user');
      }
    }
  }
}