html 和css 和js结合实现折叠菜单的代码

<script id="templateNavBar" type="text/html">
    <p class="nav-bar-logo">

    </p>
    {{each $data as item i}}
        <p class="nav-item {{item.class}}">{{item.name}}</p>
        {{if item.child != null}}
            <p class="childgroup">
                {{each item.child as child i}}
                    <p class="nav-item {{child.class}} child">{{child.name}}</p>
                {{/each}}
            </p>
        {{/if}}
    {{/each}}
</script>

               $(document).on('click','.nav-item:not(.child)',function () {
              console.log("choosing");
              var that = $(this);
              var next =that.next();
              if(next.hasClass('childgroup')){
                  if (that.hasClass('open'))
                  {
                      // 收起当前菜单项
                      that.removeClass('open');
                      next.slideUp();
                  }
                  else{
                      // 将其他打开的菜单项收起来
                      if($('.nav-item:not(.child).open').next().hasClass('childgroup'))
                      {
                          $('.nav-item:not(.child).open').next().slideUp();
                          $('.nav-item:not(.child).open').removeClass('open');
                      }
                      // 激活当前菜单项
                      that.addClass('open');
                      next.slideDown();
                  }
              }
              // 监听一级菜单结束