基于element-ui中el-select下拉框选项过多的优化方案

<el-select
  v-model="userId"
  filterable
  :filter-method="userFilter"
  clearable>
  <el-option
    v-for="item in userList"
    :key="item.userId"
    :label="item.username"
    :value="item.userId"
  ></el-option>
</el-select>

props: {
        value: {
            type: [String, Number],
            default: ''
        }
    },
computed: {
        userId: {
            get () {
                return this.value || ''
            },
            set (value) {
                this.$emit('input', value)
            }
        }
    },

userFilter(query = '') {
  let arr = this.allUserList.filter((item) => {
    return item.username.includes(query) || item.userId.includes(query)
  })
  if (arr.length > 50) {
    this.userList = arr.slice(0, 50)
  } else {
    this.userList = arr
  }
},
getUserWhiteList() {
  HttpRequest.post("/api/admin/community/getUserWhiteList").then(
    response => {
      this.allUserList = response.data.list;
      this.userFilter()
    }
  );
},

addValueOptions () {
            if (this.userId) {
                let target = this.allUserList.find((item) => { // 从大option中找到当前条
                    return item.value === this.userId
                })
                if (target) { // 将当前条与小option比对，没有则加入
                    if (this.userList.every(item => item.value !== target.value)) {
                        this.userList.unshift(target)
                    }
                }
            }
        },

// 安装 pinyin-match npm install pinyin-match --save

<template>
	<el-select v-model="formInline.brandId" @change="changeBrand" filterable :filter-method="pinyingMatch" placeholder="请选择"  style="width: 180px" >
	   <el-option :label="item.label" :value="item.value" v-for="(item,index ) in brand" :key="item.value"></el-option>
	</el-select>
</template>

<script>
    export default{
        data(){
          return{
          brand:[],//下拉框所有数据
          copyBrand:[]
          }
        },
        methods:{
            //获取所有的品牌
             async getBrand(){
	            const response = await reqLimitBranch()
	            this.brand = response.data
	            //把所有的品牌在赋值copyBrand
	            this.copyBrand = this.brand
              },
		          //下拉框设置拼音模糊搜索
		      pinyingMatch(val){
		         const pinyingMatch = require('pinyin-match')
		         if(val){
		             var result = []
		             //
		             this.copyBrand.forEach( e => {
		               var m = pinyingMatch.match(e.label, val)
		               if( m){
		                   result.push(e)
		               }
		             })
		             //搜索到相应的数据就把符合条件的n个数据赋值brand 
		             this.brand = result
		         }else{
		           //没有搜索到数据，就还展示所有的brand 
		           this.brand = this.copyBrand
		         }
		      },
        }
    }
    
</script>