vue实现瀑布流组件滑动加载更多

mounted() {
 ···
 this.dom.addEventListener('scroll', this.scroll, false)
 ···
 },

 beforeDestroy() {
 ···
 this.dom.removeEventListener('scroll', this.scroll, false)
 ···
 },

 /**
 * 滚动钩子
 */
 scroll() {
 const viewHeight = global.innerHeight
 let parentNode
 if (this.container !== global) {
  parentNode = this.$el
 } else {
  parentNode = this.$el.parentNode
 }
 if (parentNode) {
  // 获取Vue实例使用的根 DOM 元素相对于视口的位置
  const rect = parentNode.getBoundingClientRect()
  // this.distance 离底部多少距离开始加载
  // 如果此元素底边距离视口顶部的距离小于视口高度加上distance之和，就加载下一页
  if ((rect.bottom <= viewHeight + this.distance) && this.loadable && !this.loading) {
  this.load()
  }
 }
 },

<template>
 <div class="loadmore" ref="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">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,

 dom: null,
 }
 },

 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: () => (global),
 },

 /**
 * 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: '',
 },

 /**
 * 距离底部多远加载
 */
 distance: {
 type: Number,
 default: 200,
 },
 },

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

 mounted() {
 if (this.container !== global) {
 this.dom = document.querySelector(this.container)
 } else {
 this.dom = this.container
 }
 if (!this.dom) {
 return
 }
 this.dom.addEventListener('scroll', this.scroll, false)
 if (this.autoload && !this.loading) {
 this.load()
 }
 },

 // eslint-disable-next-line
 beforeDestroy() {
 if (this.dom) {
 this.dom.removeEventListener('scroll', this.scroll, false)
 }
 },

 methods: {
 /**
 * 滚动钩子
 */
 scroll() {
 const viewHeight = global.innerHeight
 let parentNode
 if (this.container !== global) {
  parentNode = this.$el
 } else {
  parentNode = this.$el.parentNode
 }
 if (parentNode) {
  const rect = parentNode.getBoundingClientRect()
  if ((rect.bottom <= viewHeight + this.distance) && this.loadable && !this.loading) {
  this.load()
  }
 }
 },
 /**
 * 加载一组数据的方法
 */
 load() {
 if (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()
 },
 },
 }
</script>

<template>
 <div class="loadmore" ref="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="loading">正在加载...</span>
 <span v-else>没有更多了</span>
 </div>
 </div>
</template>

<script>
export default {
 props: {
 /**
 * 是否加载
 */
 loading: {
 type: Boolean,
 default: false,
 },

 /**
 * 滚动外部容器, 选择器字符串
 */
 container: {
 default: () => (global),
 },

 /**
 * 距离底部多远加载
 */
 distance: {
 type: Number,
 default: 200,
 },
 },

 data() {
 return {
 dom: null, // 外部容器dom
 }
 },
 mounted() {
 if (this.container !== global) {
 this.dom = document.querySelector(this.container)
 } else {
 this.dom = this.container
 }
 if (!this.dom) {
 return
 }
 this.dom.addEventListener('scroll', this.scroll, false)
 if (this.autoload && !this.loading) {
 this.load()
 }
 },

 methods: {
 /**
 * 滚动钩子
 */
 scroll() {
 if (!this.loading) {
 return
 }
 const viewHeight = global.innerHeight
 let parentNode
 if (this.container !== global) {
 parentNode = this.$el
 } else {
 parentNode = this.$el.parentNode
 }
 if (parentNode) {
 const rect = parentNode.getBoundingClientRect()
 if ((rect.bottom <= viewHeight + this.distance)) {
  this.load()
 }
 }
 },
 /**
 * 加载一组数据的方法
 */
 load() {
 this.$emit('load')
 },
 },
 beforeDestroy() {
 if (this.dom) {
 this.dom.removeEventListener('scroll', this.scroll, false)
 }
 },
}
</script>
<style lang="stylus" rel="stylesheet/stylus" scoped>
.loadmore {
 user-select: none;

 &__footer {
 color: #e4e4e4;
 padding: 20px;
 text-align: center;
 }

 .tc-loading {
 ~ span {
 vertical-align: middle;
 }
 }
}
</style>