简单介绍下思路： ajax到对象，然后从子到父依次创建对象，设置样式，添加层级。 然后代码长这样：

function Activity(obj) {
  var activityContent = document.createElement('a');
  activityContent.innerHTML = obj.post.c;
  activityContent.className = 'activity-content';
  activityContent.style.overflow = 'hidden';
  activityContent.href = '/t/'+obj.tid+'#'+obj.pid;
  var activityTitleText = document.createElement('span');
  activityTitleText.innerHTML = obj.oc.t;
  activityTitleText.style.overflow = 'hidden';
  var activityTitle = document.createElement('div');
  activityTitle.className = 'activity-title';
  var activityTitleA = document.createElement('a');
  activityTitleA.appendChild(activityTitleText);
  activityTitleA.href = '/t/'+obj.tid;
  var activityInfo = document.createElement('span');
  activityInfo.className = 'activity-info';
  if(obj.forum) {
    var color = obj.forum.color || 'orange';
    var forum = document.createElement('a');
    forum.href= '/f/'+obj.fid;
    var forumText = document.createElement('span');
    forumText.className = 'activity-title-forum';
    forumText.style.backgroundColor = color;
    forumText.innerHTML = ' '+obj.forum.abbr+' ';
    forum.appendChild(forumText);
    activityTitle.appendChild(forum);
  }
  if(obj.toMyForum) {
    var color = obj.toMyForum.color || 'orange';
    var toMyForum = document.createElement('a');
    toMyForum.href= '/m/'+obj.toMyForum._key;
    var toMyForumText = document.createElement('span');
    toMyForumText.className = 'activity-title-forum';
    toMyForumText.style.backgroundColor = color;
    toMyForumText.innerHTML = ' '+obj.toMyForum.abbr+' ';
    toMyForum.appendChild(toMyForumText);
    activityTitle.appendChild(toMyForum);
  }
  if(obj.myForum) {
    var color = obj.myForum.color || 'orange';
    var myForum = document.createElement('a');
    myForum.href= '/m/'+obj.myForum._key;
    var myForumText = document.createElement('span');
    myForumText.className = 'activity-title-forum';
    myForumText.style.backgroundColor = color;
    myForumText.innerHTML = ' '+obj.myForum.abbr+' ';
    myForum.appendChild(myForumText);
    activityTitle.appendChild(myForum);
  }
  activityTitle.appendChild(activityTitleA);
  activityInfo.appendChild(activityTitle);
  activityInfo.appendChild(activityContent);
  var activityUser = document.createElement('div');
  activityUser.className = 'activity-user';
  activityUserA = document.createElement('a');
  activityUserA.href = '/activities/'+obj.uid;
  var activityUserAvatar = document.createElement('img');
  activityUserAvatar.className = 'activity-user-avatar';
  activityUserAvatar.src = '/avatar/'+ obj.uid;
  activityUserA.appendChild(activityUserAvatar);
  var username = document.createElement('a');
  username.href = '/activities/'+obj.uid;
  username.innerHTML = obj.user.username;
  activityUser.appendChild(activityUserA);
  activityUser.appendChild(username);
  var type;
  switch (obj.type) {
    case 1:
      type = 'Po';
      break;
    case 2:
      type = 'Re';
      break;
    case 4:
      type = 'Rc';
      break;
    default:
      type = 'X';
  }
  var activityType = document.createElement('div');
  activityType.className = 'activity-type';
  var activityTypeText = document.createElement('div');
  activityTypeText.className = 'activity-type-text';
  activityTypeText.innerHTML = type;
  var activityTypeDate = document.createElement('div');
  activityTypeDate.className = 'activity-type-date';
  activityTypeDate.innerHTML = moment(obj.time).fromNow();
  activityType.appendChild(activityTypeText);
  activityType.appendChild(activityTypeDate);
  var activity = document.createElement('div');
  activity.className = 'activity';
  activity.appendChild(activityType);
  activity.appendChild(activityUser);
  activity.appendChild(activityInfo);
  return activity;
}

辣不辣？ 就这种玩意儿。。。咋优化呢？ 前端对ES6的支持不理想，所以字符串模板不能用，又不好添加框架，硬写的话，应该怎么做？ 这样写对比字符串拼接然后直接innerHTML有什么劣势？