Vue实现typeahead组件功能(非常靠谱)

<select-search 
style="max-width:195px" 
placeholder="请选择广告主" 
:asyncData.sync="adHostData" 
:mapData="adHostDataList" 
:mapDataFormat="{label:'userName',value:'userId'}">
</select-search>

<template>
 <div class="select-search" v-if="typeaheadData" ref="selectSearch" @click.native="showHideMenu($event)">
 <div class="select-header">
 <input type="text" autocomplete="off" readonly :placeholder="placeholder" :value="placeholderValue" @keydown.down.prevent="selectChildWidthArrowDown" @keydown.up.prevent="selectChildWidthArrowUp" @keydown.enter="selectChildWidthEnter">
 <i class="fzicon " :class="isExpand?'fz-ad-jiantou1':'fz-ad-jiantou'"></i>
 </div>
 <div class="select-body" v-if="isExpand && typeaheadData">
 <input type="text" placeholder="关键字" v-model="searchVal" autocomplete="off" @keydown.esc="resetDefaultStatus" @keydown.down.prevent="selectChildWidthArrowDown" @keydown.up.prevent="selectChildWidthArrowUp" @keydown.enter="selectChildWidthEnter">
 <transition name="el-fade-in-linear" mode="out-in">
 <div class="typeahead-filter">
 <transition-group tag="ul" name="el-fade-in-linear" v-show="typeaheadData.length>0">
 <li v-for="(item,index) in typeaheadData" :key="index" :class="item.active ? 'active':''" @mouseenter="setActiveClass(index)" @mouseleave="setActiveClass(index)" @click="selectChild(index)">
 <a href="javascript:;" rel="external nofollow" >
 {{item[mapDataFormat.label]}}
 </a>
 </li>
 </transition-group>
 <p class="noFound" v-show="typeaheadData && typeaheadData.length === 0">未能查询到,请重新输入!</p>
 </div>
 </transition>
 </div>
 </div>
</template>
<script>
 export default {
 name: 'selectSearch',
 data: function () {
 return {
 placeholderValue: '',// 给看到选择内容的
 isExpand: false,
 searchVal: '', // 搜索关键字
 resultVal: '', // 保存搜索到的值
 searchList: [], //保存过滤的结果集
 currentIndex: -1, // 当前默认选中的index,
 }
 },
 computed: {
 mapFormatData () { // 外部有传入格式的时候映射mapData
 return this.mapData.map(item => {
 item[this.mapDataFormat.value] = item[this.mapDataFormat.value];
 return item;
 });
 },
 typeaheadData () {
 let temp = [];
 if (this.searchVal && this.searchVal === '') {
 return this.mapFormatData;
 } else {
 this.currentIndex = -1; // 重置特殊情况下的索引
 this.mapFormatData.map(item => {
 if (item[this.mapDataFormat.label].indexOf(this.searchVal.toLowerCase().trim()) !== -1) {
 temp.push(item)
 }
 return item;
 })
 return temp;
 }
 }
 },
 props: {
 placeholder: {
 type: String,
 default: '--请选择--'
 },
 emptyText: {
 type: String,
 default: '暂无数据'
 },
 mapData: { // 外部传入的列表数据
 type: Array,
 default: function () {
 return []
 }
 },
 mapDataFormat: { // 映射传入数据的格式
 type: Object,
 default: function () {
 return {
 label: 'text',
 value: 'value',
 extraText: 'extraText'
 }
 }
 },
 asyncData: { // 实时响应的值
 type: [Object, String],
 default: function () {
 return {}
 }
 }
 },
 methods: {
 showHideMenu (e) { // 点击其他区域关闭下拉列表
 if (e) {
 if (this.$refs.selectSearch && this.$refs.selectSearch.contains(e.target)) {
 this.isExpand = true;
 } else {
 this.isExpand = false;
 }
 }
 },
 resetDefaultStatus () { // 清除所有选中状态
 this.searchVal = '';
 this.currentIndex = -1;
 this.typeaheadData.map(item => {
 this.$delete(item, 'active');
 })
 },
 setActiveClass (index) { // 设置样式活动类
 this.typeaheadData.map((item, innerIndex) => {
 if (index === innerIndex) {
 this.$set(item, 'active', true);
 this.currentIndex = index; // 这句话是用来修正index,就是键盘上下键的索引,不然会跳位
 } else {
 this.$set(item, 'active', false)
 }
 })
 },
 selectChildWidthArrowDown () {
 // 判断index选中子项
 if (this.currentIndex < this.typeaheadData.length) {
 this.currentIndex++;
 this.typeaheadData.map((item, index) => {
 this.currentIndex === index ? this.$set(item, 'active', true) : this.$set(item, 'active', false);
 })
 }
 },
 selectChildWidthArrowUp () {
 // 判断index选中子项
 if (this.currentIndex > 0) {
 this.currentIndex--;
 this.typeaheadData.map((item, index) => {
 this.currentIndex === index ? this.$set(item, 'active', true) : this.$set(item, 'active', false);
 })
 }
 },
 selectChildWidthEnter () {
 // 若是结果集只有一个,则默认选中
 if (this.typeaheadData.length === 1) {
 this.$emit('update:asyncData', this.typeaheadData[0]); // emit响应的值
 this.placeholderValue = this.typeaheadData[0][this.mapDataFormat.label];
 } else {
 // 若是搜索的内容完全匹配到项内的内容,则默认选中
 this.typeaheadData.map(item => {
 if (this.searchVal === item[this.mapDataFormat.label] || item.active === true) {
 this.$emit('update:asyncData', item); // emit响应的值
 this.placeholderValue = item[this.mapDataFormat.label];
 }
 })
 }
 this.isExpand = false;
 },
 selectChild (index) {
 // 鼠标点击选择子项
 this.typeaheadData.map((item, innerIndex) => {
 if (index === innerIndex || item.active) {
 this.placeholderValue = item[this.mapDataFormat.label];
 this.$emit('update:asyncData', item); // emit响应的值
 }
 });
 this.isExpand = false;
 },
 },
 mounted () {
 window.addEventListener('click', this.showHideMenu);
 },
 beforeDestroy () {
 window.removeEventListener('click', this.showHideMenu);
 },
 watch: {
 'isExpand' (newValue) {
 if (newValue === false) {
 this.resetDefaultStatus();
 }
 }
 }
 }
</script>
<style scoped lang="scss">
 .el-fade-in-linear-enter-active,
 .el-fade-in-linear-leave-active,
 .fade-in-linear-enter-active,
 .fade-in-linear-leave-active {
 transition: opacity .2s linear;
 }
 .el-fade-in-enter,
 .el-fade-in-leave-active,
 .el-fade-in-linear-enter,
 .el-fade-in-linear-leave,
 .el-fade-in-linear-leave-active,
 .fade-in-linear-enter,
 .fade-in-linear-leave,
 .fade-in-linear-leave-active {
 opacity: 0;
 }
 .noFound {
 text-align: center;
 }
 .select-search {
 position: relative;
 z-index: 1000;
 a {
 color: #333;
 text-decoration: none;
 padding: 5px;
 }
 ul {
 list-style: none;
 padding: 6px 0;
 margin: 0;
 max-height: 200px;
 overflow-x: hidden;
 overflow-y: auto;
 li {
 display: block;
 width: 100%;
 padding: 5px;
 font-size: 14px;
 padding: 8px 10px;
 position: relative;
 white-space: nowrap;
 overflow: hidden;
 text-overflow: ellipsis;
 color: #48576a;
 height: 36px;
 line-height: 1.5;
 box-sizing: border-box;
 cursor: pointer;
 &.active {
 background-color: #20a0ff;
 a {
 color: #fff;
 }
 }
 }
 }
 .select-header {
 position: relative;
 border-radius: 4px;
 border: 1px solid #bfcbd9;
 outline: 0;
 padding: 0 8px;
 >input {
 border: none;
 -webkit-appearance: none;
 -moz-appearance: none;
 appearance: none;
 width: 100%;
 outline: 0;
 box-sizing: border-box;
 color: #1f2d3d;
 font-size: inherit;
 height: 36px;
 line-height: 1;
 }
 >i {
 transition: all .3s linear;
 display: inline-block;
 position: absolute;
 right: 3%;
 top: 50%;
 transform: translateY(-50%);
 }
 }
 .select-body {
 position: absolute;
 border-radius: 2px;
 background-color: #fff;
 box-sizing: border-box;
 margin: 5px 0;
 padding: 8px;
 width: 100%;
 box-shadow: 0 2px 4px rgba(0, 0, 0, .12), 0 0 6px rgba(0, 0, 0, .04);
 >input {
 -webkit-appearance: none;
 -moz-appearance: none;
 appearance: none;
 background-color: #fff;
 background-image: none;
 border-radius: 4px;
 border: 1px solid #bfcbd9;
 box-sizing: border-box;
 color: #1f2d3d;
 font-size: inherit;
 height: 36px;
 line-height: 1;
 outline: 0;
 padding: 3px 10px;
 transition: border-color .2s cubic-bezier(.645, .045, .355, 1);
 width: 100%;
 display: inline-block;
 &:focus {
 outline: 0;
 border-color: #20a0ff;
 }
 }
 }
 }
</style>