前端axios取消请求总结详解

const { CancelToken, isCanCel } = axios;
const source = CancelToken.source();
axios.get('/user/12345', {
  cancelToken: source.token
}).catch(thrown => {
  if (isCancel(thrown)) {
    // 获取 取消请求 的相关信息
    console.log('Request canceled', thrown.message);
  } else {
    // 处理其他异常
  }
});
axios.post('/user/12345', {
  name: 'new name'
}, {
  cancelToken: source.token
})
// 取消请求。参数是可选的，参数传递一个取消请求的相关信息，在 catch 钩子函数里能获取到
source.cancel('Operation canceled by the user.');

const CancelToken = axios.CancelToken;
let cancel;
axios.get('/user/12345', {
  cancelToken: new CancelToken(function executor(c) {
    // 参数 c 也是个函数
    cancel = c;
  })
});
// 取消请求，参数用法同上
cancel();

import axios from 'axios'
import store from '@/store'
import { getToken } from '@/utils/auth'
// 创建一个 axios 实例，并改变默认配置
const service = axios.create({
  baseURL: process.env.BASE_API, // api 的 base_url
  timeout: 5000 // request timeout
})
// 请求拦截
service.interceptors.request.use(
  config => {
    // Do something before request is sent
    if (store.getters.token) {
      // 让每个请求携带token-- ['X-Token']为自定义key 请根据实际情况自行修改
      config.headers['X-Token'] = getToken()
    }
    return config
  },
  error => {
    // Do something with request error
    console.log(error) // for debug
    Promise.reject(error)
  }
)
// 响应拦截
service.interceptors.response.use(
  response => response,
  error => {
    alert(error)
    return Promise.reject(error)
  }
)
export default service

// api.js
import request from 'request'
export function getUsers(page, options) {
  return request({
    url: 'api/users',
    params: {
      page
    },
    ...options
  })
}

// User.vue
import { CancelToken, isCancel } from 'axios'
import { getUsers } from 'api'
...
cancel: null
...
toCancel() {
  this.cancel('取消请求')
}
getUsers(1,
  {
    cancelToken:  new CancelToken(c => (this.cancel = c))
  }
)
.then(...)
.catch(err => {
  if (isCancel) {
    console.log(err.message)
  } else {
    ...
  }
})

// User.vue
import { CancelToken, isCancel } from 'axios'
import { getUsers } from 'api'
...
cancel: []
...
toCancel() {
  while (this.cancel.length > 0) {
    this.cancel.pop()('取消请求')
  }
}
getUser1(1,
  {
    cancelToken:  new CancelToken(c1 => (this.cancel.push(c1)))
  }
)
getUser2(2,
 {
  cancelTokem: new CancleTokem(c2 => (this.cancel.push(c2)))
 }
)

http.interceptors.request.use(config => {
    config.cancelToken = store.source.token
    return config
}, err => {
    return Promise.reject(err)
})
router.beforeEach((to, from, next) => {
    const CancelToken = axios.CancelToken
    store.source.cancel && store.source.cancel()
    store.source = CancelToken.source()
    next()
})
// 全局变量
store = {
    source: {
        token: null,
        cancel: null
  }
}

var CancelToken = axios.CancelToken;
var source = CancelToken.source();
axios.get('/get?name=xmz', {
    cancelToken : source.token
}).then((response)=>{
    console.log('response', response)
}).catch((error)=>{
    if(axios.isCancel(error)){
        console.log('取消请求传递的消息', error.message)
    }else{
        console.log('error', error)
    }
})
// 取消请求
source.cancel('取消请求传递这条消息');

axios.CancelToken = require('./cancel/CancelToken');

CancelToken.source = function(){
    var cancel;
    var token = new CancelToken(function executor(c) {
        cancel = c
    })
    return {
        token : token,
        cancel : cancel
    }
}

function CancelToken (executor){
    // ...
    // 判断executor是一个函数，不然就报错
    var resolvePromise;
    this.promise = new Promise(function(resolve){
        resolvePromise = resolve;
    })
    var token = this;
    // 以上token现在有一个promise属性，是一个未成功的promise对象；
    executor(function cancel(message){
        if(token.reason){
            return;
        }
        token.reason = new Cancel(message);
        resolvePromise(token.reason);
    })
    // 这个cancel函数就是 上面函数中的cancel，也就是source.cancel；
}

function Cancel(message){
    this.message = message
}

// 在发送请求之前，验证了cancelToken，看来此处就是用来取消请求的；
if(config.cancelToken){
    // 具体是如何取消的，是在这个判断内定义的；
    config.cancelToken.promise.then(function(cancel){
        request.abort();
        reject(cancel);
        request = null;
    })
}
// 发送请求
request.send(requestData);