JS uses the generator function to perform AJAX tasks synchronously

function request(url, callback) {    fetch(url, {mode: ‘cors‘ , credentials: ‘include‘ , headers: new Headers({ ‘X-Requested-With‘ : ‘XMLHttpRequest‘ })})    .then(response => response.text())    .then(text => {      console.log(url);      console.log(text);      callback(text);    })    . catch ((e) => console.log(e)); } var iterator = null ; function getData(src){    request(src, function (response){      iterator.next(JSON.parse(response));    }) } function getTpl(src){    request(src, function (response){      iterator.next(response);    }); } // 同步任务 function render(data, tpl){    for ( var i in data) {      tpl = tpl.replace( "${" +i+ "}" , data[i]);    }    return tpl; } // 主逻辑 var getArticles = function * (src){    console.log( ‘begin‘ )    var data = yield getData(src)    var tpl = yield getTpl(data.tpl)    var res = render(data, tpl)    console.log(res) } iterator = getArticles( ‘data.json‘ ) // 开始执行 iterator.next() // 异步任务模型

JS uses the generator function to perform AJAX tasks synchronously