官方代码:
<template> <div> <el-autocomplete v-model="state" :fetch-suggestions="querySearchAsync" placeholder="请输入内容" @select="handleSelect" ></el-autocomplete> </div> </template> <script> export default { data() { return { restaurants: [], state: '', timeout: null }; }, methods: { loadAll() { return [ { "value": "三全鲜食(北新泾店)", "address": "长宁区新渔路144号" }, { "value": "Hot honey 首尔炸鸡(仙霞路)", "address": "上海市长宁区淞虹路661号" }, { "value": "新旺角茶餐厅", "address": "上海市普陀区真北路988号创邑金沙谷6号楼113" }, { "value": "泷千家(天山西路店)", "address": "天山西路438号" }, { "value": "胖仙女纸杯蛋糕(上海凌空店)", "address": "上海市长宁区金钟路968号1幢18号楼一层商铺18-101" }, { "value": "贡茶", "address": "上海市长宁区金钟路633号" }, { "value": "豪大大香鸡排超级奶爸", "address": "上海市嘉定区曹安公路曹安路1685号" }, { "value": "茶芝兰(奶茶,手抓饼)", "address": "上海市普陀区同普路1435号" }, { "value": "十二泷町", "address": "上海市北翟路1444弄81号B幢-107" }, { "value": "星移浓缩咖啡", "address": "上海市嘉定区新郁路817号" }, { "value": "阿姨奶茶/豪大大", "address": "嘉定区曹安路1611号" }, { "value": "新麦甜四季甜品炸鸡", "address": "嘉定区曹安公路2383弄55号" }, { "value": "Monica摩托主题咖啡店", "address": "嘉定区江桥镇曹安公路2409号1F,2383弄62号1F" }, { "value": "浮生若茶(凌空soho店)", "address": "上海长宁区金钟路968号9号楼地下一层" }, { "value": "NONO JUICE 鲜榨果汁", "address": "上海市长宁区天山西路119号" }, { "value": "CoCo都可(北新泾店)", "address": "上海市长宁区仙霞西路" }, { "value": "快乐柠檬(神州智慧店)", "address": "上海市长宁区天山西路567号1层R117号店铺" }, { "value": "Merci Paul cafe", "address": "上海市普陀区光复西路丹巴路28弄6号楼819" }, { "value": "猫山王(西郊百联店)", "address": "上海市长宁区仙霞西路88号第一层G05-F01-1-306" }, { "value": "枪会山", "address": "上海市普陀区棕榈路" }, { "value": "纵食", "address": "元丰天山花园(东门) 双流路267号" }, { "value": "钱记", "address": "上海市长宁区天山西路" }, { "value": "壹杯加", "address": "上海市长宁区通协路" }, { "value": "唦哇嘀咖", "address": "上海市长宁区新泾镇金钟路999号2幢(B幢)第01层第1-02A单元" }, { "value": "爱茜茜里(西郊百联)", "address": "长宁区仙霞西路88号1305室" }, { "value": "爱茜茜里(近铁广场)", "address": "上海市普陀区真北路818号近铁城市广场北区地下二楼N-B2-O2-C商铺" }, { "value": "鲜果榨汁(金沙江路和美广店)", "address": "普陀区金沙江路2239号金沙和美广场B1-10-6" }, { "value": "开心丽果(缤谷店)", "address": "上海市长宁区威宁路天山路341号" }, { "value": "超级鸡车(丰庄路店)", "address": "上海市嘉定区丰庄路240号" }, { "value": "妙生活果园(北新泾店)", "address": "长宁区新渔路144号" }, { "value": "香宜度麻辣香锅", "address": "长宁区淞虹路148号" }, { "value": "凡仔汉堡(老真北路店)", "address": "上海市普陀区老真北路160号" }, { "value": "港式小铺", "address": "上海市长宁区金钟路968号15楼15-105室" }, { "value": "蜀香源麻辣香锅(剑河路店)", "address": "剑河路443-1" }, { "value": "北京饺子馆", "address": "长宁区北新泾街道天山西路490-1号" }, { "value": "饭典*新简餐(凌空SOHO店)", "address": "上海市长宁区金钟路968号9号楼地下一层9-83室" }, { "value": "焦耳·川式快餐(金钟路店)", "address": "上海市金钟路633号地下一层甲部" }, { "value": "动力鸡车", "address": "长宁区仙霞西路299弄3号101B" }, { "value": "浏阳蒸菜", "address": "天山西路430号" }, { "value": "四海游龙(天山西路店)", "address": "上海市长宁区天山西路" }, { "value": "樱花食堂(凌空店)", "address": "上海市长宁区金钟路968号15楼15-105室" }, { "value": "壹分米客家传统调制米粉(天山店)", "address": "天山西路428号" }, { "value": "福荣祥烧腊(平溪路店)", "address": "上海市长宁区协和路福泉路255弄57-73号" }, { "value": "速记黄焖鸡米饭", "address": "上海市长宁区北新泾街道金钟路180号1层01号摊位" }, { "value": "红辣椒麻辣烫", "address": "上海市长宁区天山西路492号" }, { "value": "(小杨生煎)西郊百联餐厅", "address": "长宁区仙霞西路88号百联2楼" }, { "value": "阳阳麻辣烫", "address": "天山西路389号" }, { "value": "南拳妈妈龙虾盖浇饭", "address": "普陀区金沙江路1699号鑫乐惠美食广场A13" } ]; }, querySearchAsync(queryString, cb) { var restaurants = this.restaurants; var results = queryString ? restaurants.filter(this.createStateFilter(queryString)) : restaurants; clearTimeout(this.timeout); this.timeout = setTimeout(() => { cb(results); }, 3000 * Math.random()); }, // 过滤出state.value中包含queryString的记录 createStateFilter(queryString) { return (state) => { return (state.value.toLowerCase().indexOf(queryString.toLowerCase()) === 0); }; }, handleSelect(item) { // console.log(item); } }, mounted() { this.restaurants = this.loadAll(); } }; </script>
页面渲染完成后,就模拟从后台获取的数据赋值给this.restaurants。当你点击输入框,此时还没输入数据,queryString为空字符串,results为restaurants,当你输入字符,如“港式”,则queryString就是“港式”,此时queryString不为空,此时results为{ "value": "港式小铺", "address": "上海市长宁区金钟路968号15楼15-105室" }
使用el-autocomplete标签,fetch-suggestions属性:返回输入建议的方法,仅当你的输入建议数据 resolve 时,通过调用 callback(data:[]) 来返回它。
callback 是一种特殊的函数,这个函数被作为参数传给另一个函数去调用。这样的函数就是回调函数。callback 就是传给另一个函数调用的函数
实现的机制
[1]定义一个回调函数;
[2]提供函数实现的一方在初始化的时候,将回调函数的函数指针注册给调用者;
[3]当特定的事件或条件发生的时候,调用者使用函数指针调用回调函数对事件进行处理。
自己的理解:
[1]定义一个回调函数 (cb);
[2]提供函数实现的一方在初始化的时候,将回调函数的函数指针注册给调用者(fetch-suggestions);
[3]当特定的事件或条件发生的时候,调用者(fetch-suggestions)使用函数指针调用回调函数 (cb)对事件进行处理。
实际工程中应用:
<el-form-item label="药品通用名" prop="commonName">
<el-autocomplete v-model="ruleForm.commonName" :fetch-suggestions="querySearch" placeholder="请输入药品通用名"></el-autocomplete>
</el-form-item>
//查询搜索处理
querySearch(name, callback) {
if (name != null && name.length > 0) {
//获取搜索数据
medicineListApi.getListByLike({ name }).then(res => {
const list = []
//封装要显示的数据
for (let v of res) {
list.push({ value: v.drugname })
}
// 调用 callback 返回建议列表的数据,是一个数组类型
callback(list)
}, err => {
console.log(err)
})
}
},
在medicineList.js中的代码
//根据名字进行模糊查询,实现搜索提示
getListByLike(params) {
return request.get(baseUrl + "/listByName", { params });
},
后台代码:
controller
@GetMapping("/listByName")
public List<DrugData> getList(@RequestParam String name) {
QueryWrapper<DrugData> wrapper = new QueryWrapper<>();
wrapper.like("drugname",name);
return medicineListService.list(wrapper);
}
service接口:
public interface MedicineListService extends IService<DrugData> { }
service实现类
@Service public class MedicineListServiceImpl extends ServiceImpl<MedicineListMapper,DrugData> implements MedicineListService { @Resource private MedicineListMapper medicineListMapper; }
Dao接口
public interface MedicineListMapper extends BaseMapper<DrugData> { }