reader/pages/user/mycourse/mycourse.wxml

<view class='my-course'>
  <block wx:for="{{ bookList }}" wx:key="{{ index }}">
    <view class="book-item">
      <view class='book-box' bindtap='toCourse' data-productId='{{ item.productId }}' data-productTitle='{{ item.productTitle }}'>
        <image class="item-img" src="{{ item.iconImg }}"></image>
      </view>
      <view class='item-title'>{{ item.groupTitle }}</view>
    </view>    
  </block> 
  <myPlacerholder line1="{{line1}}" line2="{{line2}}" wx:if="{{bookList.length <= 0}}" />            
</view>