[前端] axios网络请求二次封装

一、场景描述

为什么要对axios网络请求进行二次封装?
解决代码的复用，提高可维护性。 —这个有两个方案：一个是二次封装一个是实例化。（设置一些公共的参数，然后进行请求）
为什么可以解决代码的复用：
这是最简单格式的代码，需要定义url和请求方式。

axios({
  method: "get",
  url: "http://codercba.com:9002/banner",
}).then(function (response) {
    console.log(response);
}).catch(function (error) {
    console.log(error);
});

封装之后的请求方式，减少了点代码

    hyRequest.get({ url: "/banner" }).then((res) => {
      console.log(res);
      setImg(res.banners);
      console.log(img);
    });

Axios实例化的输出

const instance = axios.create({
  baseURL: "http://codercba.com:9002",
});

instance.get("banner").then((response) => {
  console.log("实例化请求输出");
  console.log(response);
});

二、二次封装的代码实现

type.ts //定义一些类型

import type {
  InternalAxiosRequestConfig,
  AxiosRequestConfig,
  AxiosResponse,
  AxiosRequestHeaders,
} from "axios";
 
export interface HYInterceptors<T = AxiosResponse> {   //定义拦截器类型
  requestSuccessFn?: (
    config: InternalAxiosRequestConfig
  ) => InternalAxiosRequestConfig;
  requestFailureFn?: (err: any) => any;
  responseSuccessFn?: (res: T) => T;
  responseFailureFn?: (err: any) => any;
}
 
export interface HYRequestConfig<T = AxiosResponse> extends AxiosRequestConfig {      //定义请求体的配置   
  interceptors?: HYInterceptors<T>;
  headers?: AxiosRequestHeaders;
}

request.ts //封装axios

import axios, { InternalAxiosRequestConfig } from "axios";
import type { AxiosInstance } from "axios";
import type { HYRequestConfig } from "./type";
 
class HYRequest {
  instance: AxiosInstance;     //实例
  constructor(config: HYRequestConfig) {   
    this.instance = axios.create(config);     //实例化axios
    this.instance.interceptors.response.use(
      (config) => {
        return config;
      },
      (err) => {
        return err;
      }
    );
    this.instance.interceptors.response.use(
      (res) => {
        return res.data;
      },
      (err) => {
        return err;
      }
    );
    this.instance.interceptors.request.use(
      config.interceptors?.requestSuccessFn,
      config.interceptors?.requestFailureFn
    );
    this.instance.interceptors.response.use(
      config.interceptors?.responseSuccessFn,
      config.interceptors?.responseFailureFn
    );
  }
  request<T = any>(config: HYRequestConfig<T>) {
    if (config.interceptors?.requestSuccessFn) {
      config = config.interceptors.requestSuccessFn(
        config as InternalAxiosRequestConfig
      );
    }
    return new Promise<T>((resolve, reject) => {
      this.instance      //实例请求 
        .request<any, T>(config)
        .then((res) => {
          if (config.interceptors?.responseSuccessFn) {
            res = config.interceptors.responseSuccessFn(res);
          }
          resolve(res);
        })
        .catch((err) => {
          reject(err);
        });
    });
  }
 
  get<T = any>(config: HYRequestConfig<T>) {
    return this.request({ ...config, method: "GET" });
  }
  post<T = any>(config: HYRequestConfig<T>) {
    return this.request({ ...config, method: "POST" });
  }
  delete<T = any>(config: HYRequestConfig<T>) {
    return this.request({ ...config, method: "DELETE" });
  }
  patch<T = any>(config: HYRequestConfig<T>) {
    return this.request({ ...config, method: "PATCH" });
  }
}
 
export default HYRequest;

index.ts //实例化

import { BASE_URL, TIME_OUT } from "./config";
import HYRequest from "./request";
 
const hyRequest = new HYRequest({
  baseURL: BASE_URL,
  timeout: TIME_OUT,
  interceptors: {
    requestSuccessFn: (config) => {
      return config;
    },
  },
});
 
export default hyRequest;

可以看到其实封装也是先实例化之后再进行封装。为什么要这么做，实例化的东西不太好维护。包括对拦截器的更新。

三、axios相关内容