页面懒加载滑动调用接口

data() {
    return {
        homeCate: [
        {
          name: 'Jewelry & Watches',
          category_id: 110,
          url: '',
          product: [],
          is_cate: false,
        }
      ],
      homeCateLoading: true,
    }
    },
mounted() {
    window.addEventListener('scroll', this.onScrollFunc, true)
  },
  methods: {
  onScrollFunc(event) {
      if (this.homeCateLoading) {
        this.homeCateLoading = false;
        const scrollTop = event.target.documentElement.scrollTop;
        const viewPortHeight = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
        const that = this;
        this.homeCate.forEach(function (item, index) {
          if (!(item.product.length > 0) && !item.is_cate) {
            var offsetTop = document.getElementById('categoryProduct' + index).offsetTop;
            var top = offsetTop - scrollTop;
            if (top <= viewPortHeight + 100) {
              let params = {
                limit: 4,
                page: 1,
                category_id: item.category_id,
              }
              that.$set(that.homeCate[index], 'is_cate', true);
              setTimeout(function () {
                getGoodList(params).then(response => {
                  that.$set(that.homeCate[index], 'product', response.data);
                });
              }, 1000);
            }
          }
          if (that.homeCate.length == (index + 1)) {
            that.$nextTick(() => {
              that.homeCateLoading = true;
            })
          }
        });
      }
    },
     }