需求
页面中上面搜索项有获取字典枚举接口,table表格中也有根据key匹配字典中的value
方案一
需要做到的要求
- 这里上面下拉列表是一个组件获取的字典,下面也是通过字典匹配,所以尽量统一封装一个函数,每个组件保证最少变动
- table表格中如果filters中更改,会获取多次接口,—使用闭包让只获取一次接口,节省性能
- filter中又是必须同步函数,异步函数报错,所以不能使用async,await
- 最好请求接口之后存储起来下次直接拿不用请求了
综上
utils/dictionary.js
import { getDicValue } from '@/api/systemManage'
import store from '@/store'
/*** 获取字典数据* @param {Boolean} hasAllOption 是否包含全部选项*/
export function getDicValueList(dictClassCode, hasAllOption = true) {const dictionaryCache = store.state.dictionary.dictionaryCache || {}return new Promise((resolve, reject) => {let optionList = []if (dictionaryCache[dictClassCode]) {const dicList = JSON.parse(JSON.stringify(dictionaryCache[dictClassCode]))if (hasAllOption) {optionList = [ { value: '', label: '全部' }, ...dicList]} else {optionList = [...dicList]}resolve(optionList)} else {getDicValue(dictClassCode).then(response => {console.log('字典调用', dictClassCode)const dicList = response.value || []store.dispatch('dictionary/setDictionaryCache', { key: dictClassCode, value: dicList })if (hasAllOption) {optionList = [ { value: '', label: '全部' }, ...dicList]} else {optionList = [...dicList]}resolve(optionList)}).catch(error => {reject([])})}})
}/*** 获取字典数据并返回一个闭包函数* @param {string} dictClassCode 字典类代码* @param {string} noTitle 默认值,当找不到匹配项时返回* @returns {Promise<Function>} 返回一个闭包函数,该函数可以根据 value 获取 label*/
export async function getDicValueName(dictClassCode, noTitle = "--") {try {const response = await getDicValueList(dictClassCode, false)const listData = response || []return (value) => {let label = noTitlelistData.some(item => {if (item.value === value) {label = item.labelreturn true}})return label}} catch (err) {console.error(err)return (value) => noTitle}
}
下拉框组件
created () {this.getOptionLists()},getOptionLists() {if (this.dictClassCode) {getDicValueList(this.dictClassCode).then(res => {this.optionLists = res})} else {this.optionLists = this.options}},
table组件中
<span>{{ filterStateName(scope.row.state) }}</span>import { getDicValueName } from '@/utils/dictionary'created() {this.initDictionary()},methods: {
async initDictionary() {try {this.filterStateName = await getDicValueName('DC_DICTIONARY_STATE')} catch (error) {console.error('Failed to fetch dictionary:', error)this.filterStateName = (value) => '--'}},}
问题: 但是这种因为一进页面这两个组件都是去获取字典,所以还是从接口拿的数据,会调用两次接口
方案二(建议)
方案:接下来优化可以通过路由导航预加载,先获取字典之后,在加载页面
router.js
// 预加载字典
export function preloadDictionary(dictClassCodeList) {const pList = []dictClassCodeList.forEach(dictClassCode => {const p = getDicValueList(dictClassCode)pList.push(p)})return Promise.all(pList)
}// 预加载字典
router.beforeEach((to, from, next) => {if(to.meta && to.meta.dictClassCodeList&& to.meta.dictClassCodeList.length > 0) {preloadDictionary(to.meta.dictClassCodeList).then(res => {next()})} else {next()}
})
总结:其实这里都可以规定直接预加载字典,到页面直接使用加载后的字典,注册个全局filters就行,根本不用上面那些,先都记录上,后期根据需求灵活应用吧