Vue+Element UI封装Axios请求，支持PayLoad、Form Data两种方式

由于Element的Loading是全局等待条，每次请求都需要显示，有时候不太方便。 

下面做了一个处理，根据情况，在请求参数中添加showLoading=true，自行显示全局等待条。

import Axios from 'axios'
import qs from 'qs'
import { Message, Loading } from 'element-ui';

let loading;        //定义loading变量

function startLoading() {    //使用Element loading-start 方法
    loading = Loading.service({
        lock: true,
        text: '加载数据中……',
        background: 'rgba(0, 0, 0, 0.3)'
    })
}
function endLoading() {    //使用Element loading-close 方法
    loading.close()
}
//那么 showFullScreenLoading() tryHideFullScreenLoading() 要干的事儿就是将同一时刻的请求合并。
//声明一个变量 needLoadingRequestCount，每次调用showFullScreenLoading方法 needLoadingRequestCount + 1。
//调用tryHideFullScreenLoading()方法，needLoadingRequestCount - 1。needLoadingRequestCount为 0 时，结束 loading。
let needLoadingRequestCount = 0
export function showFullScreenLoading() {
    if (needLoadingRequestCount === 0) {
        startLoading()
    }
    needLoadingRequestCount++
}

export function tryHideFullScreenLoading() {
    if (needLoadingRequestCount <= 0) return
    needLoadingRequestCount--
    if (needLoadingRequestCount === 0) {
        endLoading()
    }
}

Axios.defaults.timeout = 60000
Axios.defaults.baseURL = ''


//http request 拦截器
Axios.interceptors.request.use(
  config => {
    if(config.method === 'post') { //支持2种方法，默认使用Form Data
      if(config.data.useRequestBody) {
        //参数需要带上useRequestBody
        //如果useRequestBody=true, 支持Request Payload，
        //SpringMVC Controller 中需要使用@RequestBody
        delete config.data.useRequestBody;
        config.headers = {
          'Content-Type': 'application/json;charset=UTF-8'
        }
      } else { 
        //如果useRequestBody=false, 默认支持Form Data
        //SpringMVC Controller 中不需要使用@RequestBody，默认使用@RequestParam
        config.data = qs.stringify(config.data); 
        config.headers = {
          'Content-Type': 'application/x-www-form-urlencoded;charset=UTF-8'
        }
      }
      
    } else if(config.method === 'get') {
      let newParams = {}
      for(let key in config.params) {
        newParams[key] = encodeURIComponent(config.params[key])
      }
      config.params = newParams
 
      config.headers = {
        'Content-Type': 'application/json;charset=UTF-8'
      }
    }

    //显示等待框
    showFullScreenLoading();

    return config
  },
  error => {
    return Promise.reject(error)
  }
)

//http response 拦截器
Axios.interceptors.response.use(
  response => {
    let data = response.data
    
    //隐藏等待框
    //tryHideFullScreenLoading()

    if(data.successFlag === 1) {
      return Promise.resolve(data)
    } else {
      return Promise.reject(data)
    }
  },
  error => {
    return Promise.reject(error)
  }
)

/**
 * 封装get方法
 * @param url
 * @param data
 * @returns {Promise}
 */

const get = function get(url, params = {}) {
  return new Promise((resolve, reject) => {
    params.showLoading && showFullScreenLoading() //显示等待框

    Axios.get(url, {
        params: params
      })
      .then(response => {
        params.showLoading && tryHideFullScreenLoading() //隐藏等待框

        resolve(response);
      })
      .catch(err => {
        params.showLoading && tryHideFullScreenLoading() //隐藏等待框

        reject(err)
      })
  })
}


/**
 * 封装post请求
 * @param url
 * @param params
 * @returns {Promise}
 */

const post = function post(url, params = {}) {
  return new Promise((resolve, reject) => {
    params.showLoading && showFullScreenLoading() //显示等待框

    Axios.post(url, params)
      .then(response => {
        params.showLoading && tryHideFullScreenLoading() //隐藏等待框

        resolve(response);
      }, err => {
        params.showLoading && tryHideFullScreenLoading() //隐藏等待框

        reject(err)
      })
  })
}

/**
 * 封装patch请求
 * @param url
 * @param data
 * @returns {Promise}
 */

const patch = function patch(url, data = {}) {
  return new Promise((resolve, reject) => {
    Axios.patch(url, data)
      .then(response => {
        resolve(response);
      }, err => {
        reject(err)
      })
  })
}

/**
 * 封装put请求
 * @param url
 * @param data
 * @returns {Promise}
 */

const put = function put(url, data = {}) {
  return new Promise((resolve, reject) => {
    Axios.put(url, data)
      .then(response => {
        resolve(response);
      }, err => {
        reject(err)
      })
  })
}


export default {
  post,
  get,
  patch,
  put
}