import { NetWorkError } from '../common/errors.js'let jsonpId = 1;export function jsonpCallbackId() {    return jsonpId ++;}export function jsonpRequest(url, params) {    let pStr;    let reqUrl = url + '?' + '_=' + Date.now() + ((pStr = param2String(params)) ? '&' + pStr : '');    return sendJsonp(reqUrl);}// 将键数据转换成get请求的参数形式function param2String(params) {    if (typeof params === 'string') {        return params;    }    return objectToParamString(params);}// 将对象转换成键值对形式，只支持单层function objectToParamString(params) {    let ret = '';    for (let key in params) {        ret = ret + key + '=' + encodeURIComponent(params[key]) + '&';    }    ret = ret.substr(0, ret.length-1); // 去除最后的'&'    return ret;}function sendJsonp(reqUrl) {    return new Promise((resolve, reject)=>{        let callbackName = 'jsonp_cb_' + jsonpCallbackId();        let script = document.createElement('script');        let respData = null;        let isTimeout = false;        let timeout = setTimeout(()=>{            isTimeout = true;            reject(new NetWorkError('timeout'));        }, 5000);        let loadCallback = ()=>{            clearTimeout(timeout);            if(!isTimeout) {                respData ? resolve(respData) : reject(new NetWorkError('error'));            }            delete window[callbackName];            script.removeEventListener('load', loadCallback);            script.removeEventListener('error', loadCallback);            document.head.removeChild(script);        }        script.addEventListener('load',loadCallback);        script.addEventListener('error', loadCallback);            window[callbackName] = function(resp){            respData = resp;        }        script.src = reqUrl + '&callback=' + callbackName;        document.head.appendChild(script);    });}

 

 

errors.js

export class NetWorkError extends Error {    constructor(message) {        super(message)            this.errorType = 'NetWorkError'    }}