eventproxy 帮你管理到底这些异步操作是否完成
源代码：
var eventproxy = require('eventproxy'); var superagent = require('superagent'); var cheerio = require('cheerio'); var url = require('url'); var cnodeUrl = 'https://cnodejs.org/'; superagent.get(cnodeUrl) .end(function (err, res) { if (err) { return console.error(err); } var topicUrls = []; var $ = cheerio.load(res.text); $('#topic_list .topic_title').each(function (idx, element) { var $element = $(element); var href = url.resolve(cnodeUrl, $element.attr('href')); topicUrls.push(href); }); var ep = new eventproxy(); ep.after('topic_html', topicUrls.length, function (topics) { topics = topics.map(function (topicPair) { var topicUrl = topicPair[0]; var topicHtml = topicPair[1]; var $ = cheerio.load(topicHtml); return ({ title: $('.topic_full_title').text().trim(), href: topicUrl, comment1: $('.reply_content').eq(0).text().trim(), }); }); console.log('final:'); console.log(topics); }); topicUrls.forEach(function (topicUrl) { superagent.get(topicUrl) .end(function (err, res) { console.log('fetch ' + topicUrl + ' successful'); ep.emit('topic_html', [topicUrl, res.text]); }); }); }); 效果演示图： 