简介
设想一下，如果商品条目数量很多，假设有100条，如果我们一次性拉下来，是很影响性能的。所以我们需要为商品列表添加分页功能。本篇主要实现以下目的：
- 后端分页功能逻辑实现
- 前端分页功能逻辑实现
1. 后端分页功能逻辑实现
这里我们有如下约定;
- 后端需要接收参数page和pageSize。
- page表示请求第几页数据。
- pageSize表示每页返回的数目。
- 按pageSize分页并返回指定页数的数据。
修改routes/goods.js文件如下：
/* GET goods */
router.get('/', function (req, res, next) {
// 只有接口请求带参数sort=priceDown才会按价格降序
let sort = req.query['sort'] === 'priceDown'?-1:1;
let startPrice = req.query['startPrice'];
let endPrice = req.query['endPrice'];
let page = parseInt(req.query['page']);
let pageSize = parseInt(req.query['pageSize']);
// 价格筛选处理逻辑
startPrice = startPrice? parseInt(startPrice):0;
endPrice = endPrice?parseInt(endPrice):undefined;
console.log(startPrice, endPrice);
let params = {};
if (endPrice) {
params = {salePrice: {$gt: startPrice, $lte: endPrice}};
} else {
params = {salePrice: {$gt: startPrice}};
}
// 分页处理逻辑
if (!(page > 0 && pageSize > 0)) {
res.json({
code: '801',
msg: '请求参数有误'
});
return;
}
let skip = (page - 1)*pageSize;
// 查询起始价（不包含）到结尾价（包含）区间的商品,并分页返回
let query = Good.find(params).skip(skip).limit(pageSize);
query.sort({salePrice: sort});
query.exec((err, doc) => {
if (err) {
res.json({
code: '900',
msg: err.message || '服务器错误'
})
} else {
res.json({
code: '000',
msg: '',
result: {
count: doc.length,
list: doc
}
})
}
});
});
2. 前端分页功能逻辑实现
这里我们不再详述与后端分离开发的逻辑，直接使用已经开发好的后端接口来看效果。
step1 在前端写死分页参数请求数据并展示
此处由于后端返回的数据结构有了变化，为了看到效果，我们首先要更改一下前端数据处理逻辑。
export default {
data () {
return {
prdList: [], // 产品列表
// 价格过滤列表
priceFilterList: [
{
startPrice: 0,
endPrice: 100
},
{
startPrice: 100,
endPrice: 500
},
{
startPrice: 500,
endPrice: 2000
},
{
startPrice: 2000
}
],
priceChecked: 'all', // 选中的价格过滤列表项
filterPrice: null, // 选中的价格过滤列表对象
isShowFilterBy: false, // 是否展示过滤列表弹窗
isShowOverLay: false, // 是否展示遮罩层
page: 1,
pageSize: 8,
sortChecked: 'default',
isPriceUp: true
}
},
computed: {
isPriceArrowUp () {
return !this.isPriceUp
}
},
components: {
PageHeader,
PageBread,
PageFooter
},
created () {
this.getPrdList()
},
methods: {
// 请求接口获取产品列表数据
getPrdList () {
queryPrdObj = Object.assign({}, this.filterPrice, {page: this.page, pageSize: this.pageSize, sort: this.sortChecked})
axios.get('/api/goods', {params: queryPrdObj}).then((res) => {
console.log('res', res)
let data = (res && res.data) || {}
if (data.code === '000') {
let result = data.result || {}
this.prdList = result.list || []
console.log('prdList', this.prdList)
} else {
alert(`err:${data.msg || '系统错误'}`)
}
})
},
// 选取价格过滤列表项
checkPriceFilter (index) {
this.priceChecked = index
this.filterPrice = index === 'all' ? null : this.priceFilterList[index]
this.getPrdList()
this.closeFilterBy()
},
// 展示过滤列表弹窗
showFilterBy () {
this.isShowFilterBy = true
this.isShowOverLay = true
},
// 关闭过滤列表弹窗
closeFilterBy () {
this.isShowFilterBy = false
this.isShowOverLay = false
},
checkSort (val) {
this.sortChecked = val
if (val === 'priceUp' || val === 'priceDown') {
this.isPriceUp = !this.isPriceUp
} else {
this.isPriceUp = true
}
this.getPrdList()
}
}
}
step2 使用vue-infinite-loading进行上拉加载
关于vue-infinite-loading使用方法见官网。
安装;
npm install vue-infinite-loading --save
six-tao-1301.gif
修改GoodsList.vue文件如下：
<template>
<div>
<PageHeader></PageHeader>
<PageBread>
<span>Goods</span>
</PageBread>
<div class="accessory-result-page accessory-page">
<div class="container">
<div class="filter-nav">
<span class="sortby">Sort by:</span>
<a href="javascript:void(0)" class="default" :class="{'cur': sortChecked === 'default'}" @click="checkSort('default')">Default</a>
<a href="javascript:void(0)" class="price" :class="{'cur': sortChecked === 'priceUp' || sortChecked === 'priceDown'}" @click="checkSort(isPriceUp?'priceDown':'priceUp')">Price
<span v-if="isPriceArrowUp">↑</span>
<span v-else>↓</span>
<!--<svg class="icon icon-arrow-short">-->
<!--<symbol id="icon-arrow-short" viewBox="0 0 25 32">-->
<!--<title>arrow-short</title>-->
<!--<path class="path1" d="M24.487 18.922l-1.948-1.948-8.904 8.904v-25.878h-2.783v25.878l-8.904-8.904-1.948 1.948 12.243 12.243z"></path>-->
<!--</symbol>-->
<!--<use xlink:href="#icon-arrow-short"></use>-->
<!--</svg>-->
</a>
<a href="javascript:void(0)" class="filterby stopPop" @click="showFilterBy">Filter by</a>
</div>
<div class="accessory-result">
<!-- filter -->
<div class="filter stopPop" id="filter" :class="{'filterby-show': isShowFilterBy}">
<dl class="filter-price">
<dt>Price:</dt>
<dd><a href="javascript:void(0)" :class="{'cur': priceChecked === 'all'}" @click="checkPriceFilter('all')">All</a></dd>
<dd v-for="(item, index) in priceFilterList" :key="index">
<a v-if="item.endPrice" href="javascript:void(0)" :class="{'cur': priceChecked === index}" @click="checkPriceFilter(index)">{{item.startPrice}} - {{item.endPrice}}</a>
<a v-else href="javascript:void(0)" :class="{'cur': priceChecked === index}" @click="checkPriceFilter(index)">> {{item.startPrice}}</a>
</dd>
</dl>
</div>
<!-- search result accessories list -->
<div class="accessory-list-wrap">
<div class="accessory-list col-4">
<ul>
<li v-for="item in prdList" :key="item.productId">
<div class="pic">
<a href="#"><img v-lazy="`../../../static/${item.productImage}`" alt=""></a>
</div>
<div class="main">
<div class="name">{{item.productName}}</div>
<div class="price">{{item.salePrice}}</div>
<div class="btn-area">
<a href="javascript:;" class="btn btn--m">加入购物车</a>
</div>
</div>
</li>
</ul>
</div>
<infinite-loading @infinite="infiniteHandler">
<span slot="no-more">
No more ...
</span>
</infinite-loading>
</div>
</div>
</div>
</div>
<div class="md-overlay" v-show="isShowOverLay" @click="closeFilterBy"></div>
<PageFooter></PageFooter>
</div>
</template>
<script>
import PageHeader from '../../components/PageHeader'
import PageBread from '../../components/PageBread'
import PageFooter from '../../components/PageFooter'
import axios from 'axios'
import InfiniteLoading from 'vue-infinite-loading'
let queryPrdObj = {}
export default {
data () {
return {
prdList: [], // 产品列表
// 价格过滤列表
priceFilterList: [
{
startPrice: 0,
endPrice: 100
},
{
startPrice: 100,
endPrice: 500
},
{
startPrice: 500,
endPrice: 2000
},
{
startPrice: 2000
}
],
priceChecked: 'all', // 选中的价格过滤列表项
filterPrice: null, // 选中的价格过滤列表对象
isShowFilterBy: false, // 是否展示过滤列表弹窗
isShowOverLay: false, // 是否展示遮罩层
page: 1,
pageSize: 8,
sortChecked: 'default',
isPriceUp: true
}
},
computed: {
isPriceArrowUp () {
return !this.isPriceUp
}
},
components: {
PageHeader,
PageBread,
PageFooter,
InfiniteLoading
},
created () {
// this.getPrdList()
},
methods: {
// 请求接口获取产品列表数据
getPrdList ($state) {
queryPrdObj = Object.assign({}, this.filterPrice, {page: this.page, pageSize: this.pageSize, sort: this.sortChecked})
axios.get('/api/goods', {params: queryPrdObj}).then((res) => {
console.log('res', res)
this.page++
let data = (res && res.data) || {}
if (data.code === '000') {
let result = data.result || {}
this.prdList = this.prdList.concat(result.list || [])
if (result.count === this.pageSize) {
$state.loaded()
} else {
$state.complete()
}
} else {
alert(`err:${data.msg || '系统错误'}`)
$state.complete()
}
})
},
// 选取价格过滤列表项
checkPriceFilter (index) {
this.priceChecked = index
this.filterPrice = index === 'all' ? null : this.priceFilterList[index]
this.getPrdList()
this.closeFilterBy()
},
// 展示过滤列表弹窗
showFilterBy () {
this.isShowFilterBy = true
this.isShowOverLay = true
},
// 关闭过滤列表弹窗
closeFilterBy () {
this.isShowFilterBy = false
this.isShowOverLay = false
},
checkSort (val) {
this.sortChecked = val
if (val === 'priceUp' || val === 'priceDown') {
this.isPriceUp = !this.isPriceUp
} else {
this.isPriceUp = true
}
this.getPrdList()
},
infiniteHandler ($state) {
this.getPrdList($state)
}
}
}
</script>
总结
到此，商品列表页的查询展示逻辑基本上完成了。
我们提交代码：
- six-tao
git status
git diff
git commit -am 'add vue-infinite-loading'
git push
- six-tao-server
git status
git diff
git commit -am 'paging logic done'
git push
