封装 resize 指令

const map = new WeakMap()

const ob = new ResizeObserver((entries) => {
  for(const entry of entries) {
    // 运行 entry.target 对应的回调函数
    const handler = map.get(entry.target);
    if (handler) {
      handler({
        width: entry.borderBoxSize[0].inlineSize,
        height: entry.borderBoxSize[0].inlineSize,
      })
    }
  }
})

export default {
  mounted(el, binding) {
    // 监听el元素尺寸的变化
    map.set(el, binding.value);
    ob.observer(el);
  }
  unmounted(el) {
    // 取消监听
  }
}