前景提要：
ts 简易封装 axios，统一 API
实现在 config 中配置开关拦截器

loading 分为全屏 loading 和局部 loading。
axios 中设置 loading 只能设置全屏 loading，因为局部 loading 需要当前局部的 dom，在 axios 中显然拿不到发起请求的元素 dom。

封装 loading 拦截器

1. 请求拦截器开启 loading
2. 响应拦截器关闭 loading
   • 注意：无论请求成功或失败都应关闭 loading，因此在响应拦截器两个回调中都要关闭 loading。

import { AxiosError, AxiosResponse } from "axios";
import { ElLoading } from "element-plus";
import { MyInternalAxiosRequestConfig } from "./request";/*** el-loading 有两种方式调用：指令和服务。* 指令可以绑定到元素上，局部loading* 此处以服务方式调用loading，并且根据请求配置 showLoading 来决定请求是否开启loading* 此loading在全局拦截器生效，服务方式默认就是全屏*//* 全局请求 loading(服务方式调用) */
let loadingInstance: ReturnType<typeof ElLoading.service>;const startElementLoading = () => {loadingInstance = ElLoading.service({fullscreen: true,lock: true,text: "Loading",background: "rgba(0, 0, 0, 0.7)"// spinner:	自定义加载图标类名// customClass:	Loading 的自定义类名});
};const endElementLoading = (loadingInstance: ReturnType<typeof ElLoading.service>) => loadingInstance.close();/*** 开启loading* @param {import("..").AxiosRequestConfig} config* @returns*/
export function showLoading(config: MyInternalAxiosRequestConfig) {if (config.showLoading === false) return config;startElementLoading();return config;
}/*** 请求成功关闭 loading* @param {import("axios").AxiosResponse} res* @returns*/
export function closeLoadingOnFulfilled(res: AxiosResponse) {if (loadingInstance) endElementLoading(loadingInstance);return res;
}/*** 请求失败关闭 loading* @param {import("axios").AxiosError} err* @returns*/
export function closeLoadingOnRejected(err: AxiosError) {if (loadingInstance) endElementLoading(loadingInstance);throw err;
}

在 config 中配置 loading 开关

const DEFAULT_EXTRA_FEATURE_CONFIG = { showLoading: true, showMessage: true, retry: true };/** 扩展 axios 的请求配置类型 */
export interface MyAxiosRequestConfig<TReqBodyData = any> extends AxiosRequestConfig<TReqBodyData> {showLoading?: boolean;showMessage?: boolean;retry?: boolean;
}/** 给拦截器使用 */
export interface MyInternalAxiosRequestConfig extends InternalAxiosRequestConfig {showLoading?: boolean;showMessage?: boolean;retry?: boolean;
}

axios 实例化后注册 loading 拦截器

import HttpRequest from "./http/request";
import { compareUrl, filterFulfilledUrlOnFulfilled, filterFulfilledUrlOnRejected } from "./http/debounceReq";
import { closeLoadingOnFulfilled, closeLoadingOnRejected, showLoading } from "./http/loading";
import { responseMessageOnFulfilled } from "./http/message";
import { getTokenResponseInterceptor, setAccessTokenRequestInterceptor } from "./http/token";
import { retryRequest } from "./http/retryRequest";const httpRequest = new HttpRequest({baseURL: import.meta.env.VITE_APP_API_BASE_URL,timeout: import.meta.env.VITE_APP_API_TIMEOUT
});// loading
httpRequest.getInstance().interceptors.request.use(showLoading);
httpRequest.getInstance().interceptors.response.use(closeLoadingOnFulfilled, closeLoadingOnRejected);export default httpRequest;
```