index.js

function loadMoreChatMessage(func) {
  if (!PreviousMessageListQuery) {
    PreviousMessageListQuery = currChannelInfo.createPreviousMessageListQuery();
  }

  PreviousMessageListQuery.load(50, false, function(messages, error){
    if (error) {
      return;
    }

    var moreMessage = messages;
    var msgList = '';
    messages.forEach(function(message){
      switch (message.MESSAGE_TYPE) {
        case message.MESSAGE_TYPE_USER:
          msgList += messageList(message);
          break;
        default:
      }
    });
  });
}

function messageList(obj) {
  var message = obj;
  var user = message.sender;

  if (user.connectionStatus == "online") {
    msgList += '<span class="user-online-icon"></span>';
  } else {
    msgList += '<span class="user-offline-icon"></span>';
  }
}