JavaScript: The Definitive Guide, 5th Edition

Name

Document.createExpression( ): create an XPath expression for later evaluation — Firefox 1.0, Safari 2.01, Opera 9:

Synopsis

XPathExpression createExpression(StringxpathText,
                                 Function namespaceURLMapper)
    throws XPathException

Arguments

xpathText

The string representing the XPath expression to compile.

namespaceURLMapper

A function that will map from a namespace prefix to a full namespace URL, or null if no such mapping is required.

Returns

An XPathExpression object.

Throws

This method throws an exception if the xpathText contains a syntax error or if it uses a namespace prefix that cannot be resolved by namespaceURLMapper.

Description

This method takes a string representation of an XPath expression and converts it to a compiled representation, an XPathExpression. In addition to the expression, this method takes a function of the form function(prefix) that resolves a namespace prefix string and returns it as a full namespace URL string.

Internet Explorer does not support this API. See Node.selectNodes( ) for an IE-specific alternative.

See Also

Document.evaluate( ), Node.selectNodes( ), XPathExpression, XPathResult