前端实现轮询

/**
 *
 * @param callback 需要轮询的函数
 * @param interval 轮询的间隔时间
 * @returns
 */
export function pollFn(callback, interval = 1000) {
  let timerId;
  //是否停止轮询
  let isStop = false;
  //轮询请求
  const pollFetch = async () => {
    await callback();
    if (isStop) return;
    timerId = setTimeout(pollFetch, interval);
    return;
  };
  //开始轮询
  const start = async () => {
    await pollFetch();
  };
  //停止轮询
  const stop = () => {
    isStop = true;
    clearTimeout(timerId);
  };
  return {
    start,
    stop,
  };
}

　　

//使用方法
mounted(){
 this.pollManager = pollFn(this.pollQuery, 5000 );
//开始轮询
 this.pollManager&&this.pollManager.start&&this.pollManager.start();
//7秒之后清楚轮询
setTimeout(()=>{

this.pollManager&&this.pollManager.stop&&this.pollManager.stop(); 
this.pollManager=null; },
7000) } 
//http请求 
async pollQuery(){ 
 await new Promise((resolve, reject) => {
 setTimeout(()=>{ resolve(true) },5000) 
   })  
}