手写 jsonp

let jsonp = (url, data = {}, callback = "callback") => {
  //准备好带有padding的请求url
  let dataStr = url.indexOf("?") === -1 ? "?" : "&";
  // console.log(dataStr);
  for (let key in data) {
    dataStr += `${key}=${data[key]}&`;
  }
  dataStr += `callback=` + callback;

  //构造 script
  let oScript = document.createElement("script");
  oScript.src = url + dataStr;
  //appendChild () 方法可向节点的子节点列表的末尾添加新的子节点
  document.body.appendChild(oScript);

  // window[callback]=(data)=>{
  //     console.log(data);
  // }
  return new Promise((resolve, reject) => {
    window[callback] = (data) => {
      try {
        resolve(data);
      } catch (e) {
        reject(e);
      } finally {
        oScript.parentNode.removeChild(oScript); // 注意这句代码，OScript移除,细节
      }
    };
  });
};

jsonp("https://www.zijieyuan.com/index?a=1", {
  page: 1,
  cate: "recommend",
}).then((response) => {
  console.log(response);
});