如何遍历 DataTable 中列的每个单元格以检查其文本？

Question

我有一个使用 jquery DataTables API 创建的表。我有一列表示我的数据表中每个单词的单词频率。如果频率

所以我需要遍历该列中的每个单元格以检查其中的文本。最好的方法是什么？

我在网上查找了一些问题并尝试编写以下内容，但这告诉我我正在尝试查找未定义对象的属性“.each”

    words_table.column("corpus_rank").nodes().each( function(cell, i) {
    console.log(words_table.cell(i, 2).data());
});

我也可能不应该使用我不理解的代码......我不知道“i”应该是什么意思。因此，如果有人能以简单的方式解释这一点，那将会很有帮助。

添加更多代码。生成此 DataTable 有很多内容，这就是为什么我不一定认为代码有帮助的原因。但是，确实有人询问了代码的上下文，这让我想到了一些事情。

        var filter_states = determineFilterState(); 
var word_data_filtered = filterWordData(filter_states); //This line and the one above are responsible for determining which columns are displayed.
words_table = $("#words_generated").DataTable({
    "data" : word_data_filtered,
    "columns" : columns,    
    "aLengthMenu": [[25, 50, 100, 200, -1],
            [25, 50, 100, 250, "All"]],
    "pageLength": 100,
});

当这个数据表被初始化时，我隐藏了包含词频的列。不久之后，我运行我最初发布的代码来遍历词频列的每个单元格。

column.nodes()根据文档获取https://datatables.net/reference/api/column().nodes()列对应的<th>和<td>标签

我已经使用 DataTables 足够长的时间来想知道是否......也许words_table.column("corpus_rank").nodes()` 返回一个未定义的值，因为我没有显示该列，所以它和标签不存在。我很确定这个 API 不仅仅是让不可见的列“显示隐藏”。

编辑：我将我的代码行移动到我的 js 文件的另一部分，以确保显示词频列。但是表达式words_table.column("corpus_rank").nodes() 返回一个未定义的值。删除 .nodes() 方法会返回正确的列对象。 “corpus_rank”是该列的名称设置（同样，使用 DataTables API）。

Answer 1

根据您提供的引用链接，该集合不是 jQuery 对象，示例显示链接 .to$() 以将其转换为 jQuery 对象。

each() 的参数也颠倒了

试试：

 words_table.column("corpus_rank").nodes().to$().each( function(i,cell) {
    console.log(words_table.cell(i, 2).data());
});

Answer 2

您可以使用draw event 来获取感兴趣的列（参考nTBody）：

draw 事件：在牌桌完成抽奖后触发。

这个事件有两个参数：

• 事件对象
• 设置：DataTables 设置对象

您可以从 settings 参数获取 nTBody 属性。此属性包含对 tbody 元素的永久引用。

您可以将其转换为 jQuery 对象，这样您就可以根据列位置使用:nth-child() 或:last-child 选择器选择您感兴趣的列。

对于列中包含的每个单元格（即：.each()），您可以测试元素是否大于 40。

在示例中，我使用了标准数据表示例，并使用了第 4 列。

$('#example').on('draw.dt', function (e, settings) {
    $(settings.nTBody).find('tr td:nth-child(4)').each(function(idx, ele) {
        if (+ele.textContent < 40) {
            ele.textContent = 'unranked';
        }
    })
}).DataTable();

$('#example').on('draw.dt', function (e, settings) {
    $(settings.nTBody).find('tr td:nth-child(4)').each(function(idx, ele) {
        if (+ele.textContent < 40) {
            ele.textContent = 'unranked';
        }
    })
}).DataTable();

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<link rel="stylesheet" href="https://cdn.datatables.net/1.10.15/css/jquery.dataTables.min.css">
<script src="https://cdn.datatables.net/1.10.15/js/jquery.dataTables.min.js"></script>


<table id="example" class="display" cellspacing="0" width="100%">
<thead>
<tr>
    <th>Name</th>
    <th>Position</th>
    <th>Office</th>
    <th>Age</th>
    <th>Start date</th>
    <th>Salary</th>
</tr>
</thead>
<tfoot>
<tr>
    <th>Name</th>
    <th>Position</th>
    <th>Office</th>
    <th>Age</th>
    <th>Start date</th>
    <th>Salary</th>
</tr>
</tfoot>
<tbody>
<tr>
    <td>Tiger Nixon</td>
    <td>System Architect</td>
    <td>Edinburgh</td>
    <td>61</td>
    <td>2011/04/25</td>
    <td>$320,800</td>
</tr>
<tr>
    <td>Garrett Winters</td>
    <td>Accountant</td>
    <td>Tokyo</td>
    <td>63</td>
    <td>2011/07/25</td>
    <td>$170,750</td>
</tr>
<tr>
    <td>Ashton Cox</td>
    <td>Junior Technical Author</td>
    <td>San Francisco</td>
    <td>66</td>
    <td>2009/01/12</td>
    <td>$86,000</td>
</tr>
<tr>
    <td>Cedric Kelly</td>
    <td>Senior Javascript Developer</td>
    <td>Edinburgh</td>
    <td>22</td>
    <td>2012/03/29</td>
    <td>$433,060</td>
</tr>
<tr>
    <td>Airi Satou</td>
    <td>Accountant</td>
    <td>Tokyo</td>
    <td>33</td>
    <td>2008/11/28</td>
    <td>$162,700</td>
</tr>
<tr>
    <td>Brielle Williamson</td>
    <td>Integration Specialist</td>
    <td>New York</td>
    <td>61</td>
    <td>2012/12/02</td>
    <td>$372,000</td>
</tr>
<tr>
    <td>Herrod Chandler</td>
    <td>Sales Assistant</td>
    <td>San Francisco</td>
    <td>59</td>
    <td>2012/08/06</td>
    <td>$137,500</td>
</tr>
<tr>
    <td>Rhona Davidson</td>
    <td>Integration Specialist</td>
    <td>Tokyo</td>
    <td>55</td>
    <td>2010/10/14</td>
    <td>$327,900</td>
</tr>
<tr>
    <td>Colleen Hurst</td>
    <td>Javascript Developer</td>
    <td>San Francisco</td>
    <td>39</td>
    <td>2009/09/15</td>
    <td>$205,500</td>
</tr>
<tr>
    <td>Sonya Frost</td>
    <td>Software Engineer</td>
    <td>Edinburgh</td>
    <td>23</td>
    <td>2008/12/13</td>
    <td>$103,600</td>
</tr>
<tr>
    <td>Jena Gaines</td>
    <td>Office Manager</td>
    <td>London</td>
    <td>30</td>
    <td>2008/12/19</td>
    <td>$90,560</td>
</tr>
<tr>
    <td>Quinn Flynn</td>
    <td>Support Lead</td>
    <td>Edinburgh</td>
    <td>22</td>
    <td>2013/03/03</td>
    <td>$342,000</td>
</tr>
<tr>
    <td>Charde Marshall</td>
    <td>Regional Director</td>
    <td>San Francisco</td>
    <td>36</td>
    <td>2008/10/16</td>
    <td>$470,600</td>
</tr>
<tr>
    <td>Haley Kennedy</td>
    <td>Senior Marketing Designer</td>
    <td>London</td>
    <td>43</td>
    <td>2012/12/18</td>
    <td>$313,500</td>
</tr>
<tr>
    <td>Tatyana Fitzpatrick</td>
    <td>Regional Director</td>
    <td>London</td>
    <td>19</td>
    <td>2010/03/17</td>
    <td>$385,750</td>
</tr>
<tr>
    <td>Michael Silva</td>
    <td>Marketing Designer</td>
    <td>London</td>
    <td>66</td>
    <td>2012/11/27</td>
    <td>$198,500</td>
</tr>
<tr>
    <td>Paul Byrd</td>
    <td>Chief Financial Officer (CFO)</td>
    <td>New York</td>
    <td>64</td>
    <td>2010/06/09</td>
    <td>$725,000</td>
</tr>
<tr>
    <td>Gloria Little</td>
    <td>Systems Administrator</td>
    <td>New York</td>
    <td>59</td>
    <td>2009/04/10</td>
    <td>$237,500</td>
</tr>
<tr>
    <td>Bradley Greer</td>
    <td>Software Engineer</td>
    <td>London</td>
    <td>41</td>
    <td>2012/10/13</td>
    <td>$132,000</td>
</tr>
<tr>
    <td>Dai Rios</td>
    <td>Personnel Lead</td>
    <td>Edinburgh</td>
    <td>35</td>
    <td>2012/09/26</td>
    <td>$217,500</td>
</tr>
<tr>
    <td>Jenette Caldwell</td>
    <td>Development Lead</td>
    <td>New York</td>
    <td>30</td>
    <td>2011/09/03</td>
    <td>$345,000</td>
</tr>
<tr>
    <td>Yuri Berry</td>
    <td>Chief Marketing Officer (CMO)</td>
    <td>New York</td>
    <td>40</td>
    <td>2009/06/25</td>
    <td>$675,000</td>
</tr>
<tr>
    <td>Caesar Vance</td>
    <td>Pre-Sales Support</td>
    <td>New York</td>
    <td>21</td>
    <td>2011/12/12</td>
    <td>$106,450</td>
</tr>
<tr>
    <td>Doris Wilder</td>
    <td>Sales Assistant</td>
    <td>Sidney</td>
    <td>23</td>
    <td>2010/09/20</td>
    <td>$85,600</td>
</tr>
<tr>
    <td>Angelica Ramos</td>
    <td>Chief Executive Officer (CEO)</td>
    <td>London</td>
    <td>47</td>
    <td>2009/10/09</td>
    <td>$1,200,000</td>
</tr>
<tr>
    <td>Gavin Joyce</td>
    <td>Developer</td>
    <td>Edinburgh</td>
    <td>42</td>
    <td>2010/12/22</td>
    <td>$92,575</td>
</tr>
<tr>
    <td>Jennifer Chang</td>
    <td>Regional Director</td>
    <td>Singapore</td>
    <td>28</td>
    <td>2010/11/14</td>
    <td>$357,650</td>
</tr>
<tr>
    <td>Brenden Wagner</td>
    <td>Software Engineer</td>
    <td>San Francisco</td>
    <td>28</td>
    <td>2011/06/07</td>
    <td>$206,850</td>
</tr>
<tr>
    <td>Fiona Green</td>
    <td>Chief Operating Officer (COO)</td>
    <td>San Francisco</td>
    <td>48</td>
    <td>2010/03/11</td>
    <td>$850,000</td>
</tr>
<tr>
    <td>Shou Itou</td>
    <td>Regional Marketing</td>
    <td>Tokyo</td>
    <td>20</td>
    <td>2011/08/14</td>
    <td>$163,000</td>
</tr>
<tr>
    <td>Michelle House</td>
    <td>Integration Specialist</td>
    <td>Sidney</td>
    <td>37</td>
    <td>2011/06/02</td>
    <td>$95,400</td>
</tr>
<tr>
    <td>Suki Burks</td>
    <td>Developer</td>
    <td>London</td>
    <td>53</td>
    <td>2009/10/22</td>
    <td>$114,500</td>
</tr>
<tr>
    <td>Prescott Bartlett</td>
    <td>Technical Author</td>
    <td>London</td>
    <td>27</td>
    <td>2011/05/07</td>
    <td>$145,000</td>
</tr>
<tr>
    <td>Gavin Cortez</td>
    <td>Team Leader</td>
    <td>San Francisco</td>
    <td>22</td>
    <td>2008/10/26</td>
    <td>$235,500</td>
</tr>
<tr>
    <td>Martena Mccray</td>
    <td>Post-Sales support</td>
    <td>Edinburgh</td>
    <td>46</td>
    <td>2011/03/09</td>
    <td>$324,050</td>
</tr>
<tr>
    <td>Unity Butler</td>
    <td>Marketing Designer</td>
    <td>San Francisco</td>
    <td>47</td>
    <td>2009/12/09</td>
    <td>$85,675</td>
</tr>
<tr>
    <td>Howard Hatfield</td>
    <td>Office Manager</td>
    <td>San Francisco</td>
    <td>51</td>
    <td>2008/12/16</td>
    <td>$164,500</td>
</tr>
<tr>
    <td>Hope Fuentes</td>
    <td>Secretary</td>
    <td>San Francisco</td>
    <td>41</td>
    <td>2010/02/12</td>
    <td>$109,850</td>
</tr>
<tr>
    <td>Vivian Harrell</td>
    <td>Financial Controller</td>
    <td>San Francisco</td>
    <td>62</td>
    <td>2009/02/14</td>
    <td>$452,500</td>
</tr>
<tr>
    <td>Timothy Mooney</td>
    <td>Office Manager</td>
    <td>London</td>
    <td>37</td>
    <td>2008/12/11</td>
    <td>$136,200</td>
</tr>
<tr>
    <td>Jackson Bradshaw</td>
    <td>Director</td>
    <td>New York</td>
    <td>65</td>
    <td>2008/09/26</td>
    <td>$645,750</td>
</tr>
<tr>
    <td>Olivia Liang</td>
    <td>Support Engineer</td>
    <td>Singapore</td>
    <td>64</td>
    <td>2011/02/03</td>
    <td>$234,500</td>
</tr>
<tr>
    <td>Bruno Nash</td>
    <td>Software Engineer</td>
    <td>London</td>
    <td>38</td>
    <td>2011/05/03</td>
    <td>$163,500</td>
</tr>
<tr>
    <td>Sakura Yamamoto</td>
    <td>Support Engineer</td>
    <td>Tokyo</td>
    <td>37</td>
    <td>2009/08/19</td>
    <td>$139,575</td>
</tr>
<tr>
    <td>Thor Walton</td>
    <td>Developer</td>
    <td>New York</td>
    <td>61</td>
    <td>2013/08/11</td>
    <td>$98,540</td>
</tr>
<tr>
    <td>Finn Camacho</td>
    <td>Support Engineer</td>
    <td>San Francisco</td>
    <td>47</td>
    <td>2009/07/07</td>
    <td>$87,500</td>
</tr>
<tr>
    <td>Serge Baldwin</td>
    <td>Data Coordinator</td>
    <td>Singapore</td>
    <td>64</td>
    <td>2012/04/09</td>
    <td>$138,575</td>
</tr>
<tr>
    <td>Zenaida Frank</td>
    <td>Software Engineer</td>
    <td>New York</td>
    <td>63</td>
    <td>2010/01/04</td>
    <td>$125,250</td>
</tr>
<tr>
    <td>Zorita Serrano</td>
    <td>Software Engineer</td>
    <td>San Francisco</td>
    <td>56</td>
    <td>2012/06/01</td>
    <td>$115,000</td>
</tr>
<tr>
    <td>Jennifer Acosta</td>
    <td>Junior Javascript Developer</td>
    <td>Edinburgh</td>
    <td>43</td>
    <td>2013/02/01</td>
    <td>$75,650</td>
</tr>
<tr>
    <td>Cara Stevens</td>
    <td>Sales Assistant</td>
    <td>New York</td>
    <td>46</td>
    <td>2011/12/06</td>
    <td>$145,600</td>
</tr>
<tr>
    <td>Hermione Butler</td>
    <td>Regional Director</td>
    <td>London</td>
    <td>47</td>
    <td>2011/03/21</td>
    <td>$356,250</td>
</tr>
<tr>
    <td>Lael Greer</td>
    <td>Systems Administrator</td>
    <td>London</td>
    <td>21</td>
    <td>2009/02/27</td>
    <td>$103,500</td>
</tr>
<tr>
    <td>Jonas Alexander</td>
    <td>Developer</td>
    <td>San Francisco</td>
    <td>30</td>
    <td>2010/07/14</td>
    <td>$86,500</td>
</tr>
<tr>
    <td>Shad Decker</td>
    <td>Regional Director</td>
    <td>Edinburgh</td>
    <td>51</td>
    <td>2008/11/13</td>
    <td>$183,000</td>
</tr>
<tr>
    <td>Michael Bruce</td>
    <td>Javascript Developer</td>
    <td>Singapore</td>
    <td>29</td>
    <td>2011/06/27</td>
    <td>$183,000</td>
</tr>
<tr>
    <td>Donna Snider</td>
    <td>Customer Support</td>
    <td>New York</td>
    <td>27</td>
    <td>2011/01/25</td>
    <td>$112,000</td>
</tr>
</tbody>
</table>