<view
  class="dm-textfold {{className}}  "
  onTap="onDmTap"
>
  <text>{{isExpand?text:text.slice(0,max)}}</text><text
    onTap="onDmExpand"
    a:if="{{!isExpand}}"
    class="dm-textfold-button"
  >{{placeholder}}</text>
</view>