javascript - 表格单元格(td)子项？

Question

我正在尝试搜索其中包含子项(文本区域)的表格单元格。我努力了 td.children.value, td.childNodes.value, td.firstChild.value, td.lastChild.value, td.textarea.value...这些都不起作用。这是我的片段:

addCell = function() {
  var table = document.getElementById('myTable');

  var tr = document.createElement('tr');
  var td = document.createElement('td');
  var txt = document.createElement('textarea');

  table.appendChild(tr);
  tr.appendChild(td);
  td.appendChild(txt);
}

searchT = function() {
  var table = document.getElementById('myTable');
  var search = document.getElementById('search');
  var tr = document.getElementsByTagName('tr');
  var td = document.getElementsByTagName('td');

  if (search.value === td.textarea.value) {
    alert('hello');
  }

  /* I have tried:
  
  	td.childNodes.value
    td.children.value
    td.firstChild.value
    td.lastChild.value
    td.textarea.value
  */

}

td {
  background-color: #ccc;
  width: 100px;
  height: 20px;
}

textarea {
  resize: none;
}

.search {
  width: 100px;
}

<button onclick="addCell()">
  add
</button>

<input id="search" placeholder="search">
<button onclick="searchT()">
  search
</button>

<table id="myTable">
  <tr>
    <td>
      <textarea></textarea>
    </td>
  </tr>
</table>

Answer 1

当你这样做时document.getElementsByTagName() ，这将返回 document 上所有项目的列表。其中包含该标签名称。为了查明它是否存在于该列表中(我假设这就是您想要的)，那么您必须循环查找 getElementsByTagName() 返回的列表。

我还假设您想要添加一个表格，其中包含您在 <input> 中输入的内容所以我在addCell()中添加了这一点.

addCell = function() {
  var table = document.getElementById('myTable');

  var tr = document.createElement('tr');
  var td = document.createElement('td');
  var txt = document.createElement('textarea');
  var search = document.getElementById('search'); // Get value in input field
  
  table.appendChild(tr);
  tr.appendChild(td);
  txt.innerHTML = search.value; // Set value to table
  td.appendChild(txt);
  
}

searchT = function() {
  var search = document.getElementById('search');
  var textareas = document.getElementsByTagName('textarea'); // Get the textareas instead
  
  for(var i = 0; i < textareas.length; i++) {
    if(search.value === textareas[i].innerHTML) { // If the text matches the search field
      console.log("Found: " + search.value + " at index: " + i);
    }
  }
}

td {
  background-color: #ccc;
  width: 100px;
  height: 20px;
}

textarea {
  resize: none;
}

.search {
  width: 100px;
}

<button onclick="addCell()">
  add
</button>

<input id="search" placeholder="search">
<button onclick="searchT()">
  search
</button>

<table id="myTable">
  <tr>
    <td>
      <textarea readonly="readonly">Template</textarea> <!-- This doesn't have to be readonly but I made it Note: readonly="readonly" is only for valid XHTML. It could be left as readonly without the assignment for valid HTML -->
    </td>
  </tr>
</table>

如果您好奇，可以阅读有关 getElementsByTagName() 的更多信息。 here.