import axios from 'axios'

let cancelToken = axios.CancelToken

const cancel = []

const removePending = config => {
  for(let p in cancel){
    if (cancel[p].u === config.url) {
      cancel[p].f()
    }
  }
}

// 请求拦截器 发送一个请求之前
axios.interceptors.request.use(config => {
  //在一个ajax发送前执行一下取消操作
  removePending(config)
  config.cancelToken = new cancelToken(c => {
    cancel.push({ 
      f: c,
      u: config.url,
    })
  })
  
  return config
}, error => {
  return Promise.reject(error)
})

//添加响应拦截器
axios.interceptors.response.use(response => {
  return response
}, error => {
  return Promise.reject(error)
})

qs字符串转对象

qs.parse(参数, { ignoreQueryPrefix: true })