From 33058f2b292b3a581333bdfb21b8f671898c5060 Mon Sep 17 00:00:00 2001 From: Peter Bengtsson Date: Tue, 8 Dec 2020 14:40:17 -0500 Subject: initial commit --- files/zh-cn/web/api/xpathevaluator/index.html | 88 +++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 files/zh-cn/web/api/xpathevaluator/index.html (limited to 'files/zh-cn/web/api/xpathevaluator') diff --git a/files/zh-cn/web/api/xpathevaluator/index.html b/files/zh-cn/web/api/xpathevaluator/index.html new file mode 100644 index 0000000000..7ce04064f3 --- /dev/null +++ b/files/zh-cn/web/api/xpathevaluator/index.html @@ -0,0 +1,88 @@ +--- +title: XPathEvaluator +slug: Web/API/XPathEvaluator +tags: + - API + - DOM + - DOM XPath API + - Document + - Interface + - NeedsTranslation + - Reference + - TopicStub + - XML + - XPath + - XPathEvaluator +translation_of: Web/API/XPathEvaluator +--- +

{{APIRef("DOM XPath")}}

+ +

 XPathEvaluator  接口能够对 {{Glossary("XPath")}} 表达式进行编译和求值。

+ +

该接口实现自{{domxref("Document")}}的接口。

+ +

方法

+ +
+
{{DOMxRef("XPathEvaluator.createExpression()")}}
+
创建一个解析过的XPath和解析后的namespaces
+
{{DOMxRef("XPathEvaluator.createNSResolver()")}}
+
任意DOM节点能够通过该方法来解析namespaces,允许通过节点出现在文档中的相对上下文对XPath表达式进行求值。
+
{{DOMxRef("XPathEvaluator.evaluate()")}}
+
对XPath字符串求值,返回可能的确切类型的匹配结果。
+
+ +

例子

+ +

下面的实例展示了如何使用XPathEvaluator接口。

+ +

HTML

+ +
<div>XPath example</div>
+<div>Number of &lt;div&gt;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

+ + + +

{{EmbedLiveSample('Example', 400, 70)}}

+ +

规范

+ + + + + + + + + + + + + + +
SpecificationStatusComment
{{SpecName("DOM3 XPath", "xpath.html#XPathEvaluator", "XPathEvaluator")}}{{Spec2("DOM3 XPath")}}Initial definition
+ +

浏览器兼容性

+ + + +

{{Compat("api.XPathEvaluator")}}

+ +

相关链接

+ + -- cgit v1.2.3-54-g00ecf