vue底部加载更多

<template>
<div class="newsList">
<div v-for="(items, index) in newsList">
<div class="date">{{showDay(index)}}</div>
<div class="list" >
<ul>
<li class="list-item" v-for="item in items">
<span class="text">{{item.title}}</span>
<img :src="attachImageUrl(item.images[0])" class="image"/>
</li>
</ul>
</div>
</div>
<div class="infinite-scroll" v-show="loading">
<svg class="loader-circular" viewBox="25 25 50 50">
<circle class="loader-path" cx="50" cy="50" r="20" fill="none" stroke="rgb(53, 157, 218)" stroke-width="5"></circle>
</svg>
<span class="infinite-scroll-text">{{tips}}</span>
</div>
</div>
</template>

<script>
import axios from 'axios';

export default {
data () {
return {
newsList: [],
date: [],
todayDate: '',
REQUIRE: true,
loading: false,
tips: '努力加载中...'
}
},
created () {
// 获取今日新闻
axios.get('http://zhihuapi.herokuapp.com/api/4/news/latest')
.then( (res) => {
this.newsList.push(res.data['stories'])
this.date.push(res.data['date']);
this.todayDate = res.data['date']
})
},
mounted () {
// 添加滚动事件，检测滚动到页面底部
window.addEventListener('scroll', this.scrollBottom)
},
methods: {
scrollBottom() {
// 滚动到页面底部时，请求前一天的文章内容
if (((window.screen.height + document.body.scrollTop) > (document.body.clientHeight)) && this.REQUIRE) {
// 请求
4000
的数据未加载完成时，滚动到底部不再请求前一天的数据
this.REQUIRE = false;
this.loading = true;
this.tips = '努力加载中...';
axios.get('http://zhihuapi.herokuapp.com/api/4/news/before/' + this.todayDate).then((res) => {
this.newsList.push(res.data['stories']);
this.date.push(res.data['date']);
this.todayDate = res.data['date'];
// 请求的数据加载完成后，再次滚动到底部时，允许请求前一天数据
this.$nextTick(() => {
this.REQUIRE = true;
this.loading = false;
});
}).catch(() => {
this.tips = '连接失败，请稍后重试';
// 请求失败时，将 REQUIRE 置为 true，滚动到底部时，再次请求
this.REQUIRE = true;
});
}
},
showDay (index) {
if (index === 0) {
return '今日新闻'
} else {
return this.getToday(index)
}
},
getToday (index) {
let year = this.date[index].slice(0, 4);
let month = this.date[index].slice(4, 6);
let day = this.date[index].slice(6);
let today = new Date(year + '/' + month + '/' + day);
let week = ['日', '一', '二', '三', '四', '五', '六'];
return month + '月' + day + '日' + ' 星期' + week[today.getDay()];
},
attachImageUrl (srcUrl) {
if (srcUrl !== undefined) {
return 'http://read.html5.qq.com/image?src=forum&q=5&r=0&imgflag=7&imageUrl=' + srcUrl.slice(0, 4) + srcUrl.slice(5);
}
}
}
}
</script>