javascript - Node.js 和 Express : How to create many app. 通过 "for loop"与 Express.js 进行调用？

Question

在我的 server.js 中，我尝试循环遍历具有不同 url 的数组，并将这些 url 用于 app.get 请求函数。

这是我的代码:

let articleUrlArray = [ 'https://techcrunch.com/2018/05/19/shared-housing-startups-are-taking-off/',
  'https://techcrunch.com/2018/05/19/shared-housing-startups-are-taking-off/',
  'https://techcrunch.com/2018/05/19/my-data-request-lists-guides-to-get-data-about-you/',
  'https://techcrunch.com/2018/05/19/siempos-new-app-will-break-your-smartphone-addiction/',
  'https://techcrunch.com/2018/05/19/la-belle-vie-wants-to-compete-with-amazon-prime-now-in-paris/',
  'https://techcrunch.com/2018/05/19/apple-started-paying-15-billion-european-tax-fine/',
  'https://techcrunch.com/2018/05/19/original-content-dear-white-people/',
  'https://techcrunch.com/2018/05/19/meet-the-judges-for-the-tc-startup-battlefield-europe-at-vivatech/',
  'https://techcrunch.com/2018/05/18/nasas-newest-planet-hunting-satellite-takes-a-stellar-first-test-image/',
  'https://techcrunch.com/video-article/turning-your-toys-into-robots-with-circuit-cubes/',
  'https://techcrunch.com/2018/05/18/does-googles-duplex-violate-two-party-consent-laws/' ];

for(var i = 0; i < articleUrlArray.length-1; i++) {
  app.get('/news/news-desc', function(req, res) {

    var data = '';
    
    var techCrunchNewsItems = [];

    request( articleUrlArray[i], function(err, response, html) {
      var $ = cheerio.load(html);

      if($('.article-content').children('p').eq(0).text().split(' ').length > 50) {

        techCrunchNewsItems.push({
          bodyOne: $('.article-content').children('p').eq(0).text()
        });
      } else {

        techCrunchNewsItems.push({
          bodyOne: $('.article-content').children('p').eq(0).text(),
          bodyTwo: $('.article-content').children('p').eq(1).text()
        });
      }
        
      data = techCrunchNewsItems;

      res.send(JSON.stringify(data));
    });
  })
}

正如您在我的代码中看到的，我有一个数组调用“articleUrlArray”，并创建了“for 循环”来循环该数组以获取每个“articleUrl”。然后使用该“articleUrl”作为请求函数并获取该 url 的正文内容。

无论发生什么，我总是“只”获取最后一个网址的正文内容。它没有获取“articleUrlArray”中每个网址的正文内容。

我做错了什么？

这是我运行 Hugo Nasciutti 的解决方案后得到的屏幕截图:

Answer 1

const articleUrlArray = [
    'https://techcrunch.com/2018/05/19/shared-housing-startups-are-taking-off/',
    'https://techcrunch.com/2018/05/19/shared-housing-startups-are-taking-off/',
    'https://techcrunch.com/2018/05/19/my-data-request-lists-guides-to-get-data-about-you/',
    'https://techcrunch.com/2018/05/19/siempos-new-app-will-break-your-smartphone-addiction/',
    'https://techcrunch.com/2018/05/19/la-belle-vie-wants-to-compete-with-amazon-prime-now-in-paris/',
    'https://techcrunch.com/2018/05/19/apple-started-paying-15-billion-european-tax-fine/',
    'https://techcrunch.com/2018/05/19/original-content-dear-white-people/',
    'https://techcrunch.com/2018/05/19/meet-the-judges-for-the-tc-startup-battlefield-europe-at-vivatech/',
    'https://techcrunch.com/2018/05/18/nasas-newest-planet-hunting-satellite-takes-a-stellar-first-test-image/',
    'https://techcrunch.com/video-article/turning-your-toys-into-robots-with-circuit-cubes/',
    'https://techcrunch.com/2018/05/18/does-googles-duplex-violate-two-party-consent-laws/'
];

const checkBody = res => (err, response, html) => {
    const $ = cheerio.load(html);
    const articleContent = $('.article-content').children('p')
    const bodyOne = articleContent.eq(0).text()
    const bodyTwo = articleContent.eq(1).text()
    const isExtensive = bodyOne.split(' ').length > 50
    res(isExtensive ? { bodyOne } : { bodyOne, bodyTwo })
}

const getArticle = article => new Promise(res => request(article, checkBody(res)))

app.get('/news/news-desc', (req, res) => {
    Promise.all(articleUrlArray.map(getArticle)).then(data => res.send(JSON.stringify(data)))
})

这里真正发生的事情是，我使用一个函数来带来一个 Promise 数组，当所有 Promise 都得到解决时，然后用字符串化的对象数组响应请求。我擅自实现了箭头函数和常量。