nsIDOMXPathExpression 编辑

dom/interfaces/xpath/nsIDOMXPathExpression.idlScriptable Represents a compiled XPath query returned from nsIDOMXPathEvaluator.createExpression or document.createExpression Inherits from: nsISupports Last changed in Gecko 1.7

Method overview

nsISupports evaluate(in nsIDOMNode contextNode, in unsigned short type, in nsISupports result)

Methods

evaluate()

Evaluate the XPath expression.

nsISupports evaluate(
  in nsIDOMNode contextNode,
  in unsigned short type,
  in nsISupports result
);

Parameters

contextNode

A DOM node to evaluate the XPath expression against. To evaluate against a whole document, use the document.documentElement method to get the node to evaluate against.

type

A number that corresponds to one of the type constants of nsIDOMXPathResult.

result

An existing nsIDOMXPathResult to use for the result. Using null will create a new nsIDOMXPathResult.

Return value

An XPath result.

See also

• Introduction to using XPath in JavaScript
• nsIDOMXPathEvaluator
• document.evaluate
• Document Object Model (DOM) Level 3 XPath Specification
• nsIDOMXPathResult