XPathEvaluator

XPathEvaluator interface allows to compile and evaluate XPath expressions.

It is implemented by the Document 接口。

方法

XPathEvaluator.createExpression()
Creates a parsed XPath expression with resolved namespaces.
XPathEvaluator.createNSResolver()
Adapts any DOM node to resolve namespaces allowing the XPath expression to be evaluated relative to the context of the node where it appeared within the document.
XPathEvaluator.evaluate()
Evaluates an XPath expression string and returns a result of the specified type if possible.

范例

The following example shows the use of the XPathEvaluator 接口。

HTML

<div>XPath example</div>
<div>Number of <div>s: <output></output></div>
					

JavaScript

var xpath = "//div";
var evaluator = new XPathEvaluator();
var expression = evaluator.createExpression("//div");
var result = expression.evaluate(document, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE);
document.querySelector("output").textContent = result.snapshotLength;
					

结果

规范

规范 状态 Comment
Document Object Model (DOM) Level 3 XPath Specification
The definition of 'XPathEvaluator' in that specification.
Recommendation 初始定义

浏览器兼容性

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另请参阅