vue瀑布流组件实现上拉加载更多

<template>
 <div class="loadmore">
 <div class="loadmore__body">
  <slot></slot>
 </div>
 <div class="loadmore__footer">
  <span v-if="loading">
  <i class="tc-loading"></i>
  <span>正在加载</span>
  </span>
  <span v-else-if="loadable">上拉加载更多</span>
  <span v-else>没有更多了</span>
 </div>
 </div>
</template>

export default {
 mounted() {
  // 确定容器
  // 容器绑定事件
 },
 beforeDestory() {
  // 解绑事件
 },
}

export default {
 ???
 methods：{
  /**
  * 加载一组数据的方法
  */
  load() {
   // 设置options
  this.$axios.request(options).then((res) => {
   // 获取数据后的处理
  }).catch((e) => {
   // 异常处理
  })
  },
  /**
  * 鼠标按下事件处理函数
  * @param {Object} e - 事件对象
  */
  pointerdown(e) {
  // 获取按下的位置
  this.pageY = e.changedTouches ? e.changedTouches[0].pageY : e.pageY
  },
  /**
  * 鼠标移动事件处理函数
  * @param {Object} e - 事件对象
  */
  pointermove(e) {
  const container = this.$container
  const pageY = e.changedTouches ? e.changedTouches[0].pageY : e.pageY
  const moveY = pageY - this.pageY

  // 如果已经向下滚动到页面最底部
  if (moveY < 0 && (container.scrollTop + Math.min(
   global.innerHeight,
   container.clientHeight,
  )) >= container.scrollHeight) {
   // 阻止原生的上拉拖动会露出页面底部空白区域的行为（主要针对iOS版微信）
   e.preventDefault()

   // 如果上拉距离超过50像素，则加载下一页
   if (moveY < -50) {
   this.pageY = pageY
   this.load()
   }
  }
  },
  /**
  * 鼠标松开事件处理函数
  */
  pointerup() {
  // 这边就是取消拖动状态，需要注意在拖动过程中不要再次触发一些事件回调，否侧乱套
  this.dragging = false
  },
 },
 ???
}

<template>
 <div class="loadmore">
 <!-- <div class="loadmore__header"></div> -->
 <div class="loadmore__body">
  <slot></slot>
 </div>
 <div class="loadmore__footer">
  <span v-if="loading">
  <i class="tc-loading"></i>
  <span>正在加载</span>
  </span>
  <span v-else-if="loadable">上拉加载更多</span>
  <span v-else>没有更多了</span>
 </div>
 </div>
</template>

<script type="text/babel">
 import axios from 'axios'

 const CancelToken = axios.CancelToken

 export default {
 data() {
  return {
  /**
   * 总页数（由服务端返回）
   * @type {number}
   */
  count: 0,

  /**
   * 是否正在拖拽中
   * @type {boolean}
   */
  dragging: false,

  /**
   * 已加载次数
   * @type {number}
   */
  times: 0,

  /**
   * 已开始记载
   * @type {boolean}
   */
  started: false,

  /**
   * 正在加载中
   * @type {boolean}
   */
  loading: false,
  }
 },

 props: {
  /**
  * 初始化后自动开始加载数据
  */
  autoload: {
  type: Boolean,
  default: true,
  },

  /**
  * 离组件最近的可滚动父级元素（用于监听事件及获取滚动条位置）
  */
  container: {
  // Selector or Element
  default: 'body',
  },

  /**
  * 禁用组件
  */
  disabled: {
  type: Boolean,
  default: false,
  },

  /**
  * Axios请求参数配置对象
  * {@link https://github.com/mzabriskie/axios#request-config}
  */
  options: {
  type: Object,
  default: null,
  },

  /**
  * 起始页码
  */
  page: {
  type: Number,
  default: 1,
  },

  /**
  * 每页加载数据条数
  */
  rows: {
  type: Number,
  default: 10,
  },

  /**
  * 数据加载请求地址
  */
  url: {
  type: String,
  default: '',
  },
 },

 computed: {
  /**
  * 是否可以加载
  * @returns {boolean} 是与否
  */
  loadable() {
  return !this.disabled && (!this.started || (this.page + this.times) <= this.count)
  },
 },

 mounted() {
  let container = this.container

  if (container) {
  if (typeof container === 'string') {
   container = document.querySelector(container)
  } else if (!container.querySelector) {
   container = document.body
  }
  }

  if (!container) {
  container = document.body
  }

  this.$container = container
  this.onPointerDown = this.pointerdown.bind(this)
  this.onPointerMove = this.pointermove.bind(this)
  this.onPointerUp = this.pointerup.bind(this)

  if (global.PointerEvent) {
  container.addEventListener('pointerdown', this.onPointerDown, false)
  container.addEventListener('pointermove', this.onPointerMove, false)
  container.addEventListener('pointerup', this.onPointerUp, false)
  container.addEventListener('pointercancel', this.onPointerUp, false)
  } else {
  container.addEventListener('touchstart', this.onPointerDown, false)
  container.addEventListener('touchmove', this.onPointerMove, false)
  container.addEventListener('touchend', this.onPointerUp, false)
  container.addEventListener('touchcancel', this.onPointerUp, false)
  container.addEventListener('mousedown', this.onPointerDown, false)
  container.addEventListener('mousemove', this.onPointerMove, false)
  container.addEventListener('mouseup', this.onPointerUp, false)
  }

  if (this.autoload) {
  this.load()
  }
 },

 // eslint-disable-next-line
 beforeDestroy() {
  const container = this.$container

  if (global.PointerEvent) {
  container.removeEventListener('pointerdown', this.onPointerDown, false)
  container.removeEventListener('pointermove', this.onPointerMove, false)
  container.removeEventListener('pointerup', this.onPointerUp, false)
  container.removeEventListener('pointercancel', this.onPointerUp, false)
  } else {
  container.removeEventListener('touchstart', this.onPointerDown, false)
  container.removeEventListener('touchmove', this.onPointerMove, false)
  container.removeEventListener('touchend', this.onPointerUp, false)
  container.removeEventListener('touchcancel', this.onPointerUp, false)
  container.removeEventListener('mousedown', this.onPointerDown, false)
  container.removeEventListener('mousemove', this.onPointerMove, false)
  container.removeEventListener('mouseup', this.onPointerUp, false)
  }

  if (this.loading && this.cancel) {
  this.cancel()
  }
 },

 methods: {
  /**
  * 加载一组数据的方法
  */
  load() {
  if (this.disabled || this.loading) {
   return
  }

  this.started = true
  this.loading = true

  const params = {
   currentPage: this.page + this.times,
   pageSize: this.rows,
  }
  const options = Object.assign({}, this.options, {
   url: this.url,
   cancelToken: new CancelToken((cancel) => {
   this.cancel = cancel
   }),
  })

  if (String(options.method).toUpperCase() === 'POST') {
   options.data = Object.assign({}, options.data, params)
  } else {
   options.params = Object.assign({}, options.params, params)
  }

  this.$axios.request(options).then((res) => {
   const data = res.result

   this.times += 1
   this.loading = false
   this.count = data.pageCount
   this.$emit('success', data.list)
   this.$emit('complete')
  }).catch((e) => {
   this.loading = false
   this.$emit('error', e)
   this.$emit('complete')
  })
  },

  /**
  * 重置加载相关变量
  */
  reset() {
  this.count = 0
  this.times = 0
  this.started = false
  this.loading = false
  },

  /**
  *重新开始加载
  */
  restart() {
  this.reset()
  this.load()
  },

  /**
  * 鼠标按下事件处理函数
  * @param {Object} e - 事件对象
  */
  pointerdown(e) {
  if (this.disabled || !this.loadable || this.loading) {
   return
  }

  this.dragging = true
  this.pageY = e.changedTouches ? e.changedTouches[0].pageY : e.pageY
  },

  /**
  * 鼠标移动事件处理函数
  * @param {Object} e - 事件对象
  */
  pointermove(e) {
  if (!this.dragging) {
   return
  }

  const container = this.$container
  const pageY = e.changedTouches ? e.changedTouches[0].pageY : e.pageY
  const moveY = pageY - this.pageY

  // 如果已经向下滚动到页面最底部
  if (moveY < 0 && (container.scrollTop + Math.min(
   global.innerHeight,
   container.clientHeight,
  )) >= container.scrollHeight) {
   // 阻止原生的上拉拖动会露出页面底部空白区域的行为（主要针对iOS版微信）
   e.preventDefault()

   // 如果上拉距离超过50像素，则加载下一页
   if (moveY < -50) {
   this.pageY = pageY
   this.load()
   }
  }
  },

  /**
  * 鼠标松开事件处理函数
  */
  pointerup() {
  this.dragging = false
  },
 },
 }
</script>