javascript - XPath 表达式中的变量

Question

我在将变量放入我的 XPath 表达式时遇到困难。

我想创建一个可以从输入中修改的搜索词，并在 XPath 表达式中使用它，但下面的第二个示例失败了。

<强>1。这行得通

var nodesSnapshot = document.evaluate("//option[text()[not(contains(., 'test'))]]", document, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);

for (var i = 0; i < nodesSnapshot.snapshotLength; i++) {
  console.log(nodesSnapshot.snapshotItem(i));
}

<select>
  <option>cat</option>
  <option>test</option>
  <option>dog</option>
</select>

<强>2。这失败了

var searchTerm = 'test';
var xPath = '"' + "//option[text()[not(contains(.,'" + searchTerm + "'))]]" + '"';
console.log(xPath);

var nodesSnapshot = document.evaluate(xPath, document, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);

for (var i = 0; i < nodesSnapshot.snapshotLength; i++) {
  console.log(nodesSnapshot.snapshotItem(i));
}

<select>
  <option>cat</option>
  <option>test</option>
  <option>dog</option>
</select>

Answer 1

很难跟踪开盘价和收盘价。相反，您可以使用 template literals :

var searchTerm = 'test';
var xPath = `//option[text()[not(contains(., '${searchTerm}'))]]`;
console.log(xPath);

var nodesSnapshot = document.evaluate(xPath, document, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);

for (var i = 0; i < nodesSnapshot.snapshotLength; i++) {
  console.log(nodesSnapshot.snapshotItem(i));
}

<select>
  <option>cat</option>
  <option>test</option>
  <option>dog</option>
</select>

这是 ES2015+ 语法。如果你想要 ES5 解决方案，请使用:

var xPath = "//option[text()[not(contains(., '" + searchTerm + "'))]]"