如何熟练掌握NPM模块，改写node-lessons包教不包会代码？
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本文共计457个文字，预计阅读时间需要2分钟。
`topicUrl` 是一个对象集合，如何在 `after` 方法中读取 `topic[i].href` 的链接并请求？
javascriptvar cnodeTitle={ id: index, title: title, href: href};topicUrls.push(cnodeTitle); // 如何读取 topic[i].href 的链接并推送到请求？
topicUrl是对象集合, 则如何在after方法中读取topic[i].href的链接然后请求?var cnodeTitle = { id: index; title: title; href: href } topicUrls.push(cnodeTitle); //how to read the topic[i].href 's anchor and push request? ep.after('topic_title', topicUrls.length, function(topics) { topics = topics.map(function () { ```` }); console.log(topics.title); }); 不是请求之后,计数完成才会触发after回调方法吗? 如果要遍历一个对象集合,一样可以用foreach,然后用item.href取链接即可.
/* topics.forEach(function (item) { //item is an object console.log(item.href); // get the Object's href's value }) */ // but if you want to control the concurrency, the code showing above won't work // Eg: a concurrent queue, load 5 pair each time, (if one of them complete, them load another) 解决方法: 完整代码
// 引入外部模块 var superagent = require('superagent'); //cnodejs.org/"; superagent.get(cnodeUrl) .end(function(err, res) { if(err) { console.error(err); } var cnodeUrls = []; var $ = cheerio.load(res.text); $('#topic_list .topic_title').each(function(i, element) { //console.log($(element).attr('href')); //$(element).attr('href') 获取href的所有内容 if(i < 5) { //防止过度请求 var href = url.resolve(cnodeUrl, $(element).attr('href')); //整合成整个url cnodeUrls.push(hred); } }); /* 获取每个URL中的页面 */ var ep = new eventproxy(); ep.after('topic_html', cnodeUrls.length, function(topics) { topics = topics.map(function(em) { var topicUrl = em[0]; var score0 = em[1]; var title = em[2]; var commment0 = em[3]; var author0 = em[4]; return ({ title: title, href: topicUrl, comment0: comment0, author0: author0, score0: score0 }); }); console.log(topics); }); cnode.Urls.forEach(function(topicUrl) { superagent.get(topicUrl) //针对每一个页面进行get请求 .end(function(error, tres) { console.log('fetch' + 'topicUrl' + '-successful'); var $ = cheerio.load(tres.text); /*获取author的链接*/ var score0 = null; var title = $('.topic_full_title').text().trim(); var comment0 = $('.reply_content').eq(0).text().trim(); var author0 = $('.reply_author').eq(0).text().trim(); var author0href = $('.reply_author').eq(0).attr('href'); /*获取页面过多会存在undefined的*/ if(typeof(author0href) != 'undefined') { var author0Url = url.resolve(cnodeUrl, $('.reply_author').eq(0).attr('href')); console.log('|-author fetch ' + author0Url + '-successful'); superagent.get(author0Url) .end(function(auerr, aures) { var $ = cheero.load(aures.text); score0 = $('.floor').text().trim(); ep.emit('topic_html', [topicUrl, score0, title, comment0, author0]); }); } }); }); });
本文共计457个文字，预计阅读时间需要2分钟。
`topicUrl` 是一个对象集合，如何在 `after` 方法中读取 `topic[i].href` 的链接并请求？
javascriptvar cnodeTitle={ id: index, title: title, href: href};topicUrls.push(cnodeTitle); // 如何读取 topic[i].href 的链接并推送到请求？
topicUrl是对象集合, 则如何在after方法中读取topic[i].href的链接然后请求?var cnodeTitle = { id: index; title: title; href: href } topicUrls.push(cnodeTitle); //how to read the topic[i].href 's anchor and push request? ep.after('topic_title', topicUrls.length, function(topics) { topics = topics.map(function () { ```` }); console.log(topics.title); }); 不是请求之后,计数完成才会触发after回调方法吗? 如果要遍历一个对象集合,一样可以用foreach,然后用item.href取链接即可.
/* topics.forEach(function (item) { //item is an object console.log(item.href); // get the Object's href's value }) */ // but if you want to control the concurrency, the code showing above won't work // Eg: a concurrent queue, load 5 pair each time, (if one of them complete, them load another) 解决方法: 完整代码
// 引入外部模块 var superagent = require('superagent'); //cnodejs.org/"; superagent.get(cnodeUrl) .end(function(err, res) { if(err) { console.error(err); } var cnodeUrls = []; var $ = cheerio.load(res.text); $('#topic_list .topic_title').each(function(i, element) { //console.log($(element).attr('href')); //$(element).attr('href') 获取href的所有内容 if(i < 5) { //防止过度请求 var href = url.resolve(cnodeUrl, $(element).attr('href')); //整合成整个url cnodeUrls.push(hred); } }); /* 获取每个URL中的页面 */ var ep = new eventproxy(); ep.after('topic_html', cnodeUrls.length, function(topics) { topics = topics.map(function(em) { var topicUrl = em[0]; var score0 = em[1]; var title = em[2]; var commment0 = em[3]; var author0 = em[4]; return ({ title: title, href: topicUrl, comment0: comment0, author0: author0, score0: score0 }); }); console.log(topics); }); cnode.Urls.forEach(function(topicUrl) { superagent.get(topicUrl) //针对每一个页面进行get请求 .end(function(error, tres) { console.log('fetch' + 'topicUrl' + '-successful'); var $ = cheerio.load(tres.text); /*获取author的链接*/ var score0 = null; var title = $('.topic_full_title').text().trim(); var comment0 = $('.reply_content').eq(0).text().trim(); var author0 = $('.reply_author').eq(0).text().trim(); var author0href = $('.reply_author').eq(0).attr('href'); /*获取页面过多会存在undefined的*/ if(typeof(author0href) != 'undefined') { var author0Url = url.resolve(cnodeUrl, $('.reply_author').eq(0).attr('href')); console.log('|-author fetch ' + author0Url + '-successful'); superagent.get(author0Url) .end(function(auerr, aures) { var $ = cheero.load(aures.text); score0 = $('.floor').text().trim(); ep.emit('topic_html', [topicUrl, score0, title, comment0, author0]); }); } }); }); });