处理可见区域加载class

      //封装动画
        apiIntersectionObserver(items) {

            const observer = new IntersectionObserver((entries) => {
                entries.forEach((entry, index) => {
                    console.log(55);
                    if (entry.isIntersecting) {
                        // 处理元素可见的逻辑
                    } else {
                        // 处理元素不可见的逻辑
                    }
                });
            });
            this.$nextTick(() => {

                const element = this.$el.querySelector(`.footer`);
                console.log(this.$refs.footer);
                observer.observe(element);

            });

        }