vue中watch computed属性，会有冲突吗？

Question

今天用了升级vux到2.7.5，发现里边的previewer组件有bug，点击图片查看放大图片，会提示Cannot read property 'w' of undefined错误，看了里边的实现，发现watch了computed属性imgs，imgs只返回了个空数组。

computed: {

imgs () {
  return this.list.map(one => {
    if (!one.msrc) {
      one.msrc = one.src
    }
    if (typeof one.w === 'undefined') {
      one.w = 0
      one.h = 0
    }
    return one
  })
}

},
watch: {

imgs (newVal, oldVal) {
  if (!this.photoswipe) {
    return
  }
  if (newVal.length && newVal.length - oldVal.length === -1) {
    const index = this.photoswipe.getCurrentIndex()
    this.photoswipe.invalidateCurrItems()
    this.photoswipe.items.splice(index, 1)
    let goToIndex = index
    if (goToIndex > this.photoswipe.items.length - 1) {
      goToIndex = 0
    }
    this.photoswipe.goTo(goToIndex)
    this.photoswipe.updateSize(true)
    this.photoswipe.ui.update()
  } else if (!newVal.length) {
    this.close()
  }
}

}

Answer 1

computed 是你用a计算出b，a变了，他就会重新计算，
watch 是你watch的那个东西变了会触发的方法