Contributions API

trackback.module

<?php
// $Id: trackback.module,v 1.75.2.2 2008/04/08 15:24:14 zorac Exp $

define('TRACKBACK_WITH_SPAM', module_exists('spam'));

if (TRACKBACK_WITH_SPAM) {
  module_load_include('inc', 'trackback', 'trackback.spam');
}

/**
 * Implementation of hook_help().
 */
function trackback_help($path, $arg) {
  if ($path == 'admin/help#trackback') {
    module_load_include('inc', 'trackback', 'trackback.admin');
    return _trackback_help($path, $arg);
  }
}

/**
 * Implementation of hook_theme()
 */
function trackback_theme() {
  return array(
    'trackback' => array(
      'arguments' => array('trackback' => NULL, 'links' => array())
    ),
    'trackbacks' => array(
      'arguments' => array('trackbacks' => NULL)
    ),
    'trackback_url' => array(
      'arguments' => array('url' => NULL)
    ),
    'trackback_admin_table' => array(
      'arguments' => array('form' => NULL)
    )
  );
}

function theme_trackback($trackback, $links = array()) {
  $output  = '<div class="trackback" id="trackback-'. $trackback->trid .'">'."\n";
  $output .= '<h3 class="title">'. l($trackback->subject, $trackback->url) .'</h3>'."\n";
  $output .= '<span class="submitted">'. t('from %sitename on @date', array('%sitename' => $trackback->name, '@date' => format_date($trackback->created))) .'</span>'."\n";
  $output .= '<div class="content">'. check_markup($trackback->excerpt) .'</div>'."\n";
  if ($links) {
    $output .= '<div class="links">'. theme('links', $links) .'</div>'."\n";
  }
  $output .= '</div>'."\n";
  return $output;
}

function theme_trackbacks($trackbacks) {
  $output = '<div id="trackbacks">'."\n";
  $output .= $trackbacks ."\n";
  $output .= '</div>'."\n";
  return $output;
}

function theme_trackback_url($url) {
  return '<div id="trackback-url">'. theme('box', t('Trackback URL for this post:'), $url) .'</div>';
}

/**
 * Invoke a hook_trackback() operation in all modules.
 *
 * @param &$trackback
 *   A trackback object.
 * @param $op
 *   A string containing the name of the trackback operation.
 * @return
 *   The returned value of the invoked hooks.
 */
function trackback_invoke_trackback(&$trackback, $op) {
  $return = array();
  foreach (module_implements('trackback') as $name) {
    $function = $name .'_trackback';
    $result = $function($trackback, $op);
    if (isset($result)) {
      if (is_array($result)) {
        $return = array_merge($return, $result);
      }
      else {
        $return[] = $result;
      }
    }
  }
  return $return;
}

function trackback_render($node) {
  $result = db_query('SELECT * FROM {trackback_received} WHERE nid=%d AND status=1 ORDER BY created DESC', $node->nid);
  if ($tb = db_fetch_object($result)) {
    $link = (user_access('administer trackbacks') || node_access('update', $node));
    $received = '';
    do {
      $received .= theme('trackback', $tb, $link ? module_invoke_all('link', 'trackback', $tb, FALSE) : array());
    } while ($tb = db_fetch_object($result));
    return theme('trackbacks', $received);
  }
}

function trackback_form_alter(&$form, $form_state, $form_id) {
  if ($form_id == 'node_type_form' && isset($form['identity']['type'])) {
    $form['workflow']['trackback'] = array(
      '#type' => 'radios',
      '#title' => t('Trackbacks'),
      '#options' => array(t('Disabled'), t('Enabled')),
      '#default_value' => _trackback_node_type($form['#node_type']->type),
      '#description' => t('Enable trackbacks for this node type.')
    );
  }
  else if (isset($form['type']) && $form['type']['#value'] .'_node_form' == $form_id) {
    $node = $form['#node'];
    if (_trackback_node_type($node->type)) {
      $form['trackback'] = array(
        '#type' => 'fieldset',
        '#title' => t('Trackbacks'),
        '#collapsible' => TRUE
      );
      $form['trackback']['can_receive'] = array(
        '#type' => 'checkbox',
        '#title' => t('Allow Trackbacks'),
        '#default_value' => isset($node->can_receive) ? $node->can_receive : 1,
        '#description' => t('Allow other posts to send trackbacks to this content.')
      );
      $form['trackback']['trackback_urls'] = array(
        '#type' => 'textarea',
        '#title' => t('Send Trackbacks'),
        '#default_value' => isset($node->trackback_urls) ? $node->trackback_urls : '',
        '#cols' => 80,
        '#rows' => 4,
        '#description' => t('Enter one URL per line for each trackback you wish to send.')
      );

      // if there are any past successful trackbacks from this posting, add them to the node editing page.
      // if there are any past unsuccessful trackbacks from this posting, add checkmarks to enable resending them
      $past_successes_listing = array();
      $options = array();
      if (isset($node->nid)) {
        $result = db_query('SELECT url, successful FROM {trackback_sent} WHERE nid = %d', $node->nid);
        while ($url = db_fetch_object($result)) {
          if ($url->successful) {
            $past_successes_listing[] = $url->url;
          }
          else {
            $options[$url->url] = $url->url;
          }
        }
      }

      // add listing of successfully trackbacked URLs
      if (count($past_successes_listing)) {
        $form['trackback'][] = array(
          '#value' => theme('item_list', $past_successes_listing, t('Successful URLs'))
        );
        //t('These URLs have been successfuly pinged by this post.')
      }

      // add listing of unsuccessfully trackbacked URLs
      if (count($options)) {
        $form['trackback']['trackback_urls_to_retry'] = array(
          '#type' => 'checkboxes',
          '#title' => t('Unsuccessful URLs'),
          '#default_value' => array(),
          '#options' => $options,
          '#description' => t('Attempts to ping these URLs with this post have failed. Mark a check next to the trackback URLs you wish to retry for this post.')
        );
      }
    }
  }
}

function trackback_nodeapi(&$node, $op, $teaser = NULL, $page = NULL) {
  switch ($op) {
    case 'load':
      if (_trackback_node_type($node->type)) {
        $q = db_fetch_object(db_query('SELECT * FROM {trackback_node} WHERE nid=%d', $node->nid));
        return array('can_receive' => $q ? $q->can_receive : 1);
      }
      break;

    case 'view':
      if (isset($node->can_receive) && empty($node->in_preview)) {
        $node->content['trackback'] = array('#weight' => 12);
        if ($node->can_receive) {
          $url = url('node/'. $node->nid, array('absolute' => TRUE));
          $tb_url = url('trackback/'. $node->nid, array('absolute' => TRUE));
          $autodetect = "\n<!--\n";
          $autodetect .= '<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:trackback="http://madskills.com/public/xml/rss/module/trackback/">'."\n";
          $autodetect .= '<rdf:Description rdf:about="'. $url .'" dc:identifier="'. $url .'" dc:title="'. strtr(check_plain($node->title), array('--' => '&mdash;')) .'" trackback:ping="'. $tb_url .'" />'."\n";
          $autodetect .= '</rdf:RDF>';
          $autodetect .= "\n-->\n";
          $node->content['trackback']['autodetect'] = array('#value' => $autodetect, '#weight' => -2);
          if (!$teaser) {
            $node->content['trackback']['url'] = array('#value' => theme('trackback_url', $tb_url), '#weight' => -1);
          }
        }
        if (!$teaser && variable_get('trackback_view', 0) == 0) {
          $node->content['trackback']['received'] = array('#value' => trackback_render($node));
        }
      }
      break;

    case 'validate':
      if (!empty($node->trackback_urls)) {
        foreach (explode("\n", $node->trackback_urls) as $url) {
          $url = trim($url);
          if ($url && !_trackback_valid_url($url)) {
            form_set_error('trackback_urls', t('The trackback url %url is not a valid url.', array('%url' => $url)));
          }
        }
      }
      break;

    case 'insert':
    case 'update':
      if (_trackback_node_type($node->type)) {
        module_load_include('inc', 'trackback', 'trackback.ping');
        register_shutdown_function('_trackback_send', $node);
        $cron = ($node->status && variable_get('trackback_auto_detection_enabled', 0) == 2);
        db_lock_table('trackback_node');
        db_query("UPDATE {trackback_node} SET awaiting_cron=%d, can_receive=%d WHERE nid=%d", $cron, $node->can_receive, $node->nid);
        if (!db_affected_rows()) {
          db_query("INSERT INTO {trackback_node}(nid, awaiting_cron, can_receive) VALUES(%d, %d, %d)", $node->nid, $cron, $node->can_receive);
        }
        db_unlock_tables();
      }
      break;

    case 'delete':
      if (TRACKBACK_WITH_SPAM) {
        db_query("DELETE FROM {spam_tracker} USING ({spam_tracker}, {trackback_received}) WHERE {spam_tracker}.source='trackback' AND {spam_tracker}.id={trackback_received}.trid AND {trackback_received}.nid=%d", $node->nid);
      }
      db_query("DELETE FROM {trackback_node} WHERE nid=%d", $node->nid);
      db_query("DELETE FROM {trackback_sent} WHERE nid=%d", $node->nid);
      db_query("DELETE FROM {trackback_received} WHERE nid=%d", $node->nid);
      break;
  }
}

function trackback_link($type, $node = NULL, $teaser = FALSE) {
  $links = array();
  switch ($type) {
    case 'node':
      if ($teaser && isset($node->can_receive)) {
        $count = db_result(db_query("SELECT count(*) FROM {trackback_received} WHERE nid=%d AND status=1", $node->nid));
        if ($count) {
          $links[] = array(
            'title' => format_plural($count, '1 trackback', '@count trackbacks'),
            'href' => _trackback_path($node),
            'fragment' => 'trackbacks'
          );
        }
      }
      break;

    case 'trackback':
      if (!$teaser) {
        $links['trackback_edit'] = array(
          'title' => t('edit'),
          'href' => 'trackback/edit/'. $node->trid
        );
      }
      $links['trackback_delete'] = array(
        'title' => t('delete'),
        'href' => 'trackback/delete/'. $node->trid
      );
      if (TRACKBACK_WITH_SPAM) {
        $links += _trackback_spam_link($node);
      }
      break;
  }
  return $links;
}

function trackback_menu() {
  $items['admin/content/trackback'] = array(
    'title' => 'Trackbacks',
    'description' => 'List and edit site trackbacks and the trackback moderation queue.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('trackback_admin_overview'),
    'access arguments' => array('administer trackbacks'),
    'file' => 'trackback.admin.inc'
  );

  // Tabs:
  $items['admin/content/trackback/list'] = array(
    'title' => 'List',
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => -10
  );

  // Subtabs:
  $items['admin/content/trackback/list/new'] = array(
    'title' => 'Published trackbacks',
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => -10
  );
  $items['admin/content/trackback/list/approval'] = array(
    'title' => 'Approval queue',
    'page arguments' => array('trackback_admin_overview', 'approval'),
    'access arguments' => array('administer trackbacks'),
    'type' => MENU_LOCAL_TASK
  );
  $items['admin/content/trackback/list/spam'] = array(
    'title' => 'Spam',
    'page arguments' => array('trackback_admin_overview', 'spam'),
    'access callback' => '_trackback_spam_access',
    'weight' => 10,
    'type' => MENU_LOCAL_TASK
  );
  $items['admin/content/trackback/settings'] = array(
    'title' => 'Settings',
    'page arguments' => array('trackback_configure'),
    'access arguments' => array('administer trackbacks'),
    'weight' => 10,
    'type' => MENU_LOCAL_TASK
  );

  // Other stuff:
  $items['trackback/%node'] = array(
    'title' => 'Trackbacks',
    'page callback' => 'trackback_page',
    'page arguments' => array(1),
    'access callback' => '_trackback_access',
    'access arguments' => array('receive', 1),
    'type' => MENU_CALLBACK,
    'file' => 'trackback.ping.inc'
  );
  $items['trackback/edit/%trackback'] = array(
    'title' => 'Moderate trackback',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('trackback_edit', 2),
    'access callback' => '_trackback_access',
    'access arguments' => array('edit', NULL, 2),
    'type' => MENU_CALLBACK,
    'file' => 'trackback.admin.inc'
  );
  $items['trackback/delete/%trackback'] = array(
    'title' => 'Delete trackback',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('trackback_delete', 2),
    'access callback' => '_trackback_access',
    'access arguments' => array('edit', NULL, 2),
    'type' => MENU_CALLBACK,
    'file' => 'trackback.admin.inc'
  );
  $items['node/%node/trackback'] = array(
    'title' => 'Trackbacks',
    'page callback' => 'trackback_view_page',
    'page arguments' => array(1),
    'access callback' => '_trackback_access',
    'access arguments' => array('page', 1),
    'weight' => 2,
    'type' => MENU_LOCAL_TASK
  );
  return $items;
}

function trackback_perm() {
  return array('administer trackbacks');
}

function _trackback_access($op, $node, $trackback = NULL) {
  switch ($op) {
    case 'page':
      return isset($node->can_receive) && variable_get('trackback_view', 0) == 1 && node_access('view', $node) && db_result(db_query('SELECT count(*) FROM {trackback_received} WHERE nid=%d AND status=1', $node->nid));
    case 'edit':
      if (user_access('administer trackbacks')) {
        return TRUE;
      }
      if (empty($node) && !empty($trackback->nid)) {
        $node = node_load($trackback->nid);
      }
      return node_access('update', $node);
    case 'receive':
      return !empty($node->can_receive) && node_access('view', $node);
  }
}

function _trackback_spam_access() {
  return TRACKBACK_WITH_SPAM && user_access('administer trackbacks');
}

function trackback_load($trid) {
  return db_fetch_object(db_query('SELECT * FROM {trackback_received} WHERE trid=%d', $trid));
}

function trackback_view_page($node) {
  drupal_set_title(check_plain($node->title));
  return trackback_render($node);
}

function trackback_cron() {
  // query for all nodes where
  $result = db_query('SELECT t.nid, n.status FROM {trackback_node} t INNER JOIN {node} n ON t.nid = n.nid WHERE t.awaiting_cron = 1');

  while ($node = db_fetch_object($result)) {
    // First things first, let's unset the 'awaiting_cron' bit in the {trackback_node} table.
    db_query('UPDATE {trackback_node} SET awaiting_cron = 0 WHERE nid = %d', $node->nid);
    if ($node->status) {
      module_load_include('inc', 'trackback', 'trackback.ping');
      $node = node_load($node->nid);
      _trackback_ping($node, trackback_urls_via_nodebody($node));
    }
  }
}

function trackback_block($op = 'list', $delta = 0, $edit = array()) {
  if ($op == 'list') {
    $blocks[0]['info'] = t('Recent trackbacks');
    if (variable_get('trackback_view', 0) == 2) {
      $blocks[1]['info'] = t('Trackbacks');
      $blocks[1]['cache'] = BLOCK_CACHE_PER_PAGE | BLOCK_CACHE_PER_ROLE;
    }
    return $blocks;
  }

  if ($delta == 0) {
    switch ($op) {
      case 'configure':
        $form['trackback_display_number'] = array(
          '#type' => 'select',
          '#title' => t('Number of trackbacks to display'),
          '#default_value' => variable_get('trackback_display_number', 10),
          '#options' => drupal_map_assoc(array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30)),
          '#description' => t('How many trackbacks are displayed in the recent trackbacks block')
        );
        return $form;

      case 'save':
        variable_set('trackback_display_number', $edit['trackback_display_number']);
        break;

      case 'view':
        $result = db_query_range('SELECT * FROM {trackback_received} WHERE status=1 ORDER BY created DESC', 0, variable_get('trackback_display_number', 10));
        $items = array();
        while ($tb = db_fetch_object($result)) {
          $items[] = _trackback_path($tb, truncate_utf8($tb->subject, 128, FALSE, TRUE)) .'<br />'. t('%time ago', array('%time' => format_interval(time() - $tb->created)));
        }
        $block['subject'] = t('Recent trackbacks');
        $block['content'] = theme('item_list', $items);
        return $block;
    }
  }
  else if ($op == 'view' && variable_get('trackback_view', 0) == 2) {
    if (arg(0) == 'node' && is_numeric(arg(1)) && is_null(arg(2))) {
      $node = node_load(arg(1));
      if (isset($node->can_receive) and node_access('view', $node) and $block['content'] = trackback_render($node)) {
        $block['subject'] = t('Trackbacks');
        return $block;
      }
    }
  }
}

function _trackback_valid_url($url) {
  $uc = '[a-z0-9;/?:@&=+$,_.!~*\'()%-]';
  return preg_match('`^(http|https)://'. $uc .'+(#'. $uc .'*)?$`i', $url);
}

// Code that adds configurability for trackback features.
function _trackback_node_type($type) {
  static $types = array('story', 'forum', 'blog');
  return variable_get('trackback_'. $type, in_array($type, $types) ? 1 : 0);
}

function _trackback_path($obj, $text = NULL, $opt = array()) {
  static $prefix;

  if (!isset($prefix)) {
    $prefix = variable_get('trackback_view', 0) == 1 ? '/trackback' : '';
  }
  if (!isset($text)) {
    return 'node/'. $obj->nid . $prefix;
  }
  if ($obj->status) {
    $opt += array('fragment' => 'trackback-'. $obj->trid);
    return l($text, 'node/'. $obj->nid . $prefix, $opt);
  }
  return l($text, 'trackback/edit/'. $obj->trid, $opt);
}

function _trackback_build_content($node, $teaser = FALSE) {
  if (isset($node->can_receive)) {
    $can_receive = $node->can_receive;
    unset($node->can_receive);
  }
  $node = node_build_content($node, $teaser);
  if (isset($can_receive)) {
    $node->can_receive = $can_receive;
  }
  return $node;
}

function _trackback_operation($action, $trackback, $clear = TRUE) {
  if (is_numeric($trackback)) {
    $trackback = trackback_load($trackback);
  }
  if ($trackback) {
    switch ($action) {
      case 'publish':
        db_query('UPDATE {trackback_received} SET status=1 WHERE trid=%d', $trackback->trid);
        $trackback->status = 1;
        trackback_invoke_trackback($trackback, $action);
        watchdog('trackback', 'Published trackback %subject.', array('%subject' => $trackback->subject), WATCHDOG_NOTICE, _trackback_path($trackback, t('view')));
        break;

      case 'unpublish':
        db_query('UPDATE {trackback_received} SET status=0 WHERE trid=%d', $trackback->trid);
        $trackback->status = 0;
        trackback_invoke_trackback($trackback, $action);
        watchdog('trackback', 'Unpublished trackback %subject.', array('%subject' => $trackback->subject), WATCHDOG_NOTICE, _trackback_path($trackback, t('view')));
        break;

      case 'delete':
        db_query('DELETE FROM {trackback_received} WHERE trid=%d', $trackback->trid);
        trackback_invoke_trackback($trackback, $action);
        watchdog('trackback', 'Deleted trackback %subject. The trackback was posted to !link.', array('%subject' => $trackback->subject, '!link' => l(url('node/'. $trackback->nid, array('absolute' => TRUE)), 'node/'. $trackback->nid)));
        break;

      default:
        $action($trackback);
        break;
    }
    if ($clear) {
      cache_clear_all();
    }
  }
  return $trackback;
}