List of Active Channels on block

Jason,
I guess you can not create a site wide chatroom. You can have nodes with chats, accessible from any where in the site.

My requirement is similar to yours. I am approaching the problem by adding chatroom name just under the "Chat room users" (or something similar) block. Or another approach could be to add a new block just to display the available chatrooms and number of users in it.

I solved the problem partially. I added another block for active channels. But I would like to add a link to the correct node where the channel is. I don't know how to do it.

Heres is the modified phpfreechat_block function

/**
 * Implementation of hook_block().
 * S M Mahbub Murshed, June 26, 2007
 */
function phpfreechat_block($op = 'list', $delta = 0, $edit = array()) {
  global $user, $base_url;
  if ($op == 'list') {
    $block[0]['info'] = t('Who is chatting');
    $block[1]['info'] = t('Who is chatting on...');
    $block[2]['info'] = t('Latest from...');
    $block[3]['info'] = t('Active channels');
    return $block;
  }
  else if ($op == 'configure' && $delta > 0) {
    $form['phpfreechat_block'] = array(
      '#type' => 'textfield',
      '#title' => t('Channel Name'),
      '#default_value' => variable_get('phpfreechat_block_channel_'.$delta, ''),
      '#description' => t('Enter the channel name to use')
    );
    return $form;
  }
  else if ($op == 'save' && $delta > 0) {
    variable_set('phpfreechat_block_channel_'.$delta, $edit['phpfreechat_block']);
  }
  else if ($op == 'view') {
    if (user_access('access content')) {
      if (!phpfreechat_check_install()) {
        $block['content'] = phpfreechat_not_found();
        return $block;
      }
      $params = phpfreechat_load_params();
      require_once 'phpfreechat/src/pfcinfo.class.php';
      $info  = new pfcInfo(md5($base_url), $params['data_private_path']);

      if ($delta == 0) {
        $users = $info->getOnlineNick(NULL);
        $nd_users = count($users);
        $block['content'] .= theme_item_list($users);
        $block['subject'] = t('who is chatting').' ('.t($nd_users).')';
      }
      if ($delta == 1) {
        $channel = variable_get('phpfreechat_block_channel_1', '');
        $users = $info->getOnlineNick($channel);
        $nd_users = count($users);
        $block['content'] .= theme_item_list($users);
        $block['subject'] = t('who is chatting on ').$channel.' ('.t($nd_users).')';
      }
      if ($delta == 2) {
        $channel = variable_get('phpfreechat_block_channel_2', '');
        $lastmsg_raw = $info->getLastMsg($channel, 10);
        $output = '';
        foreach($lastmsg_raw["data"] as $m) {
          $output .= $m["sender"].': ';
          $output .= '<em>' . $m["param"].'</em><br />';
          $date = $m["date"];
          $time = $m["time"];
        }
        $output .= t('Last chat: ');
        // Convert to US style date
        $date = preg_replace("/^\s*([0-9]{1,2})[\/\. -]+([0-9]{1,2})[\/\. -]+([0-9]{1,4})/", "\\2/\\1/\\3", $date);
        $output .= format_interval(time() - strtotime($date.' '.$time));
        $output .= t(' ago');
        $block['content'] .= $output;
        $block['subject'] = t('latest from ').$channel;
      }
      if ($delta == 3) {
        if(is_array($params['channels'])) {
          $nd_chan = count($params['channels']);
          for($i = 0; $i < $nd_chan; $i++) {
            $users = $info->getOnlineNick($params['channels'][$i]);
            $nd_users = count($users);
            $block['content'] .= $params['channels'][$i].' ('.t($nd_users).')';
            $block['content'] .= theme_item_list($users);
            if($i!=$nd_chan-1)
              $block['content'] .= '<br />';
          }
        }
        else {
            $users = $info->getOnlineNick($params['channels']);
            $nd_users = count($users);
            $block['content'] .= $params['channels'].' ('.t($nd_users).')';
            $block['content'] .= theme_item_list($users);
        }
        $block['subject'] = t('Active channels');
      }
      return $block;
    }
  }
}

There is a small correction. I don't know why it is happening, but the $params['channels'] is not and array! That why I did what I did in my previous code. I have only one active channel.

        else {
            $users = $info->getOnlineNick($params[0]['channels']);
            $nd_users = count($users);

Alright this one works perfectly

/**
 * Implementation of hook_block().
 * S M Mahbub Murshed June 26, 2007
 * udvranto@yahoo.com  
 */
function phpfreechat_block($op = 'list', $delta = 0, $edit = array()) {
  global $user, $base_url;
  if ($op == 'list') {
    $block[0]['info'] = t('Who is chatting');
    $block[1]['info'] = t('Who is chatting on...');
    $block[2]['info'] = t('Latest from...');
    $block[3]['info'] = t('Active channels');
    return $block;
  }
  else if ($op == 'configure' && $delta > 0) {
    $form['phpfreechat_block'] = array(
      '#type' => 'textfield',
      '#title' => t('Channel Name'),
      '#default_value' => variable_get('phpfreechat_block_channel_'.$delta, ''),
      '#description' => t('Enter the channel name to use')
    );
    return $form;
  }
  else if ($op == 'save' && $delta > 0) {
    variable_set('phpfreechat_block_channel_'.$delta, $edit['phpfreechat_block']);
  }
  else if ($op == 'view') {
    if (user_access('access content')) {
      if (!phpfreechat_check_install()) {
        $block['content'] = phpfreechat_not_found();
        return $block;
      }
      $params = phpfreechat_load_params();
      require_once 'phpfreechat/src/pfcinfo.class.php';
      $info  = new pfcInfo(md5($base_url), $params['data_private_path']);

      if ($delta == 0) {
        $users = $info->getOnlineNick(NULL);
        $nd_users = count($users);
        $block['content'] .= theme_item_list($users);
        $block['subject'] = t('who is chatting').' ('.t($nd_users).')';
      }
      if ($delta == 1) {
        $channel = variable_get('phpfreechat_block_channel_1', '');
        $users = $info->getOnlineNick($channel);
        $nd_users = count($users);
        $block['content'] .= theme_item_list($users);
        $block['subject'] = t('who is chatting on ').$channel.' ('.t($nd_users).')';
      }
      if ($delta == 2) {
        $channel = variable_get('phpfreechat_block_channel_2', '');
        $lastmsg_raw = $info->getLastMsg($channel, 10);
        $output = '';
        foreach($lastmsg_raw["data"] as $m) {
          $output .= $m["sender"].': ';
          $output .= '<em>' . $m["param"].'</em><br />';
          $date = $m["date"];
          $time = $m["time"];
        }
        $output .= t('Last chat: ');
        // Convert to US style date
        $date = preg_replace("/^\s*([0-9]{1,2})[\/\. -]+([0-9]{1,2})[\/\. -]+([0-9]{1,4})/", "\\2/\\1/\\3", $date);
        $output .= format_interval(time() - strtotime($date.' '.$time));
        $output .= t(' ago');
        $block['content'] .= $output;
        $block['subject'] = t('latest from ').$channel;
      }
      if ($delta == 3) {
        $channels = db_query('SELECT nid, phpfreechat_title FROM {phpfreechat} WHERE phpfreechat_enabled = 1 ORDER BY nid DESC');
        while ($channel = db_fetch_object($channels)) {
          $users = $info->getOnlineNick($channel->phpfreechat_title);
          $nd_users = count($users);
          $block['content'] .= l($channel->phpfreechat_title, 'node/'. $channel->nid, array('title' => t('Chat on %channel',array('%channel' => $channel->phpfreechat_title)))).' ('.t($nd_users).')';
          $block['content'] .= theme_item_list($users);              
        }
        
        $block['subject'] = t('Active channels');
      }
      return $block;
    }
  }
}

A patch

      if ($delta == 3) {
        $channels = db_query('SELECT nid, phpfreechat_title, phpfreechat_channels FROM {phpfreechat} WHERE phpfreechat_enabled = 1 ORDER BY nid DESC');
        while ($channel = db_fetch_object($channels)) {
          $block['content'] .= l($channel->phpfreechat_title, 'node/'. $channel->nid, array('target'=> '_blank', 'title' => t('Chat on %channel',array('%channel' => $channel->phpfreechat_title))));
          $block['content'] .= "<br>";
          $ichannels = explode(",", $channel->phpfreechat_channels);
          $nc = count(ichannels);
          for($i=0; $i<$nc; $i++) {            
            $users = $info->getOnlineNick($ichannels[$i]);
            $nd_users = count($users);
            $block['content'] .= $ichannels[$i].' ('.t($nd_users).')';
            $block['content'] .= theme_item_list($users);
          }              
        }
        
        $block['subject'] = t('Active channels');
      }

This is an update. Another block is added for unique users

/**
 * Implementation of hook_block().
 * Updated by 
 * S M Mahbub Murshed June 26, 2007
 * udvranto@yahoo.com  
 */
function phpfreechat_block($op = 'list', $delta = 0, $edit = array()) {
  global $user, $base_url;
  if ($op == 'list') {
    $block[0]['info'] = t('Who is chatting');
    $block[1]['info'] = t('Who is chatting on...');
    $block[2]['info'] = t('Latest from...');
    $block[3]['info'] = t('Active channels');
    $block[4]['info'] = t('Unique users of active channels');
    return $block;
  }
  else if ($op == 'configure' && $delta > 0) {
    $form['phpfreechat_block'] = array(
      '#type' => 'textfield',
      '#title' => t('Channel Name'),
      '#default_value' => variable_get('phpfreechat_block_channel_'.$delta, ''),
      '#description' => t('Enter the channel name to use')
    );
    return $form;
  }
  else if ($op == 'save' && $delta > 0) {
    variable_set('phpfreechat_block_channel_'.$delta, $edit['phpfreechat_block']);
  }
  else if ($op == 'view') {
    if (user_access('access content')) {
      if (!phpfreechat_check_install()) {
        $block['content'] = phpfreechat_not_found();
        return $block;
      }
      $params = phpfreechat_load_params();
      require_once 'phpfreechat/src/pfcinfo.class.php';
      $info  = new pfcInfo(md5($base_url), $params['data_private_path']);

      if ($delta == 0) {
        $users = $info->getOnlineNick(NULL);
        $nd_users = count($users);
        $block['content'] .= theme_item_list($users);
        $block['subject'] = t('who is chatting').' ('.t($nd_users).')';
      }
      if ($delta == 1) {
        $channel = variable_get('phpfreechat_block_channel_1', '');
        $users = $info->getOnlineNick($channel);
        $nd_users = count($users);
        $block['content'] .= theme_item_list($users);
        $block['subject'] = t('who is chatting on ').$channel.' ('.t($nd_users).')';
      }
      if ($delta == 2) {
        $channel = variable_get('phpfreechat_block_channel_2', '');
        $lastmsg_raw = $info->getLastMsg($channel, 10);
        $output = '';
        foreach($lastmsg_raw["data"] as $m) {
          $output .= $m["sender"].': ';
          $output .= '<em>' . $m["param"].'</em><br />';
          $date = $m["date"];
          $time = $m["time"];
        }
        $output .= t('Last chat: ');
        // Convert to US style date
        $date = preg_replace("/^\s*([0-9]{1,2})[\/\. -]+([0-9]{1,2})[\/\. -]+([0-9]{1,4})/", "\\2/\\1/\\3", $date);
        $output .= format_interval(time() - strtotime($date.' '.$time));
        $output .= t(' ago');
        $block['content'] .= $output;
        $block['subject'] = t('latest from ').$channel;
      }
      if ($delta == 3) {
        $channels = db_query('SELECT nid, phpfreechat_title, phpfreechat_channels FROM {phpfreechat} WHERE phpfreechat_enabled = 1 ORDER BY nid DESC');        
        while ($channel = db_fetch_object($channels)) {
          $channel_line = l($channel->phpfreechat_title, 'node/'. $channel->nid, array('target'=> '_blank', 'title' => t('Chat on %channel',array('%channel' => $channel->phpfreechat_title))));
          $channel_line .= "<br>";
          $ichannels = strtok($channel->phpfreechat_channels, ", \n\t");
          while ($ichannels !== false) {
            $users = $info->getOnlineNick($ichannels);
            $nd_users = count($users);
            $channel_line .= $ichannels.' ('.t($nd_users).')';
            $channel_line .= theme_item_list($users);
            $ichannels = strtok(", \n\t");
          }
          $channels_list[] = $channel_line;            
        }
        $block['content'] .= theme_item_list($channels_list);        
        $block['subject'] = t('Active channels');
      }
      if ($delta == 4) {
        $channels = db_query('SELECT nid, phpfreechat_title, phpfreechat_channels FROM {phpfreechat} WHERE phpfreechat_enabled = 1 ORDER BY nid DESC');        
        while ($channel = db_fetch_object($channels)) {
          $ichannels = strtok($channel->phpfreechat_channels, ", \n\t");
          $users = array();
          while ($ichannels !== false) {
            $users = array_merge($users, $info->getOnlineNick($ichannels));
            $ichannels = strtok(", \n\t");
          }
          $users = array_unique ($users);
          $nd_users = count($users);
          $channels_display[] .= l($channel->phpfreechat_title.' ('.t($nd_users).')', 'node/'. $channel->nid, array('target'=> '_blank', 'title' => t('Chat on %channel',array('%channel' => $channel->phpfreechat_title))))
          . theme_item_list($users);                  
        }
        $block['content'] .= theme_item_list($channels_display);
        $block['subject'] = t('Unique users of active channels');
      }
      return $block;
    }
  }
}