nightmare - 未定义nightmarejs参数

Question

我想抓取并通过页面中的每个herf获取html，然后输出到csv。现在我第一次使用 Nightmare 。所以我对未定义的段落有疑问。

var Nightmare = require('nightmare');
    var nightmare = Nightmare({ show: true });
    var fs  = require('fs');
    var result ;
    nightmare
      .goto('http://football-system.jp/fss/pub_kaijyolist.php?lid=h0xYuxqKQ+M=')
      .wait(1000)
      .evaluate(function () {
        var divs = document.querySelectorAll('a[target="_blank"]'),i;
        for (i = 0,result = ""; i < divs.length; ++i) {
            result += divs[i].href.toString()+"\n";
            }
        return divs;
      })
      .end()
      .then(function (divs) {
        console.log(divs)
        ///////////////////////////////////////////////////
        fs.writeFile('8.csv', result, function (err) {
      if (err) throw err;
      console.log('It\'s saved!');
    });
    ////////////////////////////////////////////////////
      })
      .then(function() {
        //since Nightmare has an internal `.then()`, return the instance returned by the final call in the chain
        return nightmare
          //click the next button to get the next page of search results
          .goto(divs[0].href)
          //get the first HREF from the second page of results
          .evaluate(function() {
            return document.querySelector('div[class="outputDate"]');
          })
      })
      .catch(function (error) {
        console.error('Search failed:', error);
      });

第二个goto()有一个错误:未定义divs。非常感谢。

Answer 1

错误消息说明了一切:divs未定义。这意味着在第二个divs回调的范围内没有then变量。

您可以将其中的两个then回调“合并”为一个，并具有如下所示的内容:

var Nightmare = require('nightmare');
    var nightmare = Nightmare({ show: true });
    var fs  = require('fs');
    var result ;
    nightmare
      .goto('http://football-system.jp/fss/pub_kaijyolist.php?lid=h0xYuxqKQ+M=')
      .wait(1000)
      .evaluate(function () {
        var divs = document.querySelectorAll('a[target="_blank"]'),i;
        for (i = 0,result = ""; i < divs.length; ++i) {
            result += divs[i].href.toString()+"\n";
            }
        return divs;
      })
      .then(function (divs) {
        console.log(divs)
        ///////////////////////////////////////////////////
        fs.writeFile('8.csv', result, function (err) {
          if (err) throw err;
          console.log('It\'s saved!');
        });
        ////////////////////////////////////////////////////
        nightmare
          //click the next button to get the next page of search results
          console.log('this is the link I want to navigate to', divs[0].href)
          .goto(divs[0].href)
          //get the first HREF from the second page of results
          .evaluate(function() {
            return document.querySelector('div[class="outputDate"]');
          })
          .then(function(div) {
            console.log('I got the "div", now Ill do something with it', div)
          })
      })
      .catch(function (error) {
        console.error('Search failed:', error);
      });

      nightmare.end()

但是此代码也将失败，因为您的 divs列表中充满了空对象。我更改了一些代码以使其对您有用一半:

var Nightmare = require('nightmare');
    var nightmare = Nightmare({ show: true });
    var fs  = require('fs');
    var result ;
    nightmare
      .goto('http://football-system.jp/fss/pub_kaijyolist.php?lid=h0xYuxqKQ+M=')
      .wait(1000)
      .evaluate(function () {
        var divs = document.querySelectorAll('a[target="_blank"]'),i;
        var links = []
        for (i = 0,result = ""; i < divs.length; ++i) {
            links.push(divs[i].href)
            result += divs[i].href.toString()+"\n";
            }
        return links;
      })
      .then(function (links) {
        console.log(links)
        ///////////////////////////////////////////////////
        fs.writeFile('8.csv', links.join('\n'), function (err) {
          if (err) throw err;
          console.log('It\'s saved!');
        });
        ////////////////////////////////////////////////////
        console.log('this is the link I want to navigate to', links[0])
        nightmare
          //click the next button to get the next page of search results
          .goto(links[0])
          .wait(5000)
          //get the first HREF from the second page of results
          .evaluate(function() {
            return document.querySelector('div[class="outputDate"]');
          })
          .end()
          .then(function(div) {
            console.log('I got the "div", now Ill do something with it', div)
          })
      })
      .catch(function (error) {
        console.error('Search failed:', error);
      });

现在，您将不得不遍历链接列表并导航到每个链接。这与Nightmare有点棘手，请查看 this资源和 this答案。我相信您会发现它们很有帮助。