net.sf.saxon.sxpath
Class XPathDynamicContext

java.lang.Object
  net.sf.saxon.sxpath.XPathDynamicContext

public class XPathDynamicContext
extends Object

This object represents the dynamic XPath execution context for use in the free-standing Saxon XPath API. The dynamic context holds the context item and the values of external variables used by the XPath expression.

This object is always created via the method XPathExpression.createDynamicContext(net.sf.saxon.om.Item)

Method Summary

Item	getContextItem() Get the context item
void	setContextItem(Item item) Set the context item for evaluation of the XPath Expression
void	setContextNode(Source source) Set the context item to a node derived from a supplied Source object.
void	setVariable(XPathVariable variable, ValueRepresentation value) Set the value of an external variable used within the XPath expression

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

setContextNode

public void setContextNode(Source source)
                    throws XPathException

Set the context item to a node derived from a supplied Source object. This may be any implementation of the Source interface recognized by Saxon. Note that the Saxon NodeInfo interface, representing a node in a tree, is one such implementation; others include StreamSource, SAXSource, and DOMSource

Parameters:

source - The source object representing the node that will be used as the context item

Throws:

XPathException - if a failure occurs reading or parsing a Source object to build an input tree, or if the source is a document that was built under the wrong configuration

setContextItem

public void setContextItem(Item item)
                    throws XPathException

Set the context item for evaluation of the XPath Expression

Parameters:

item - the context item

Throws:

XPathException - if the node is in a document that was built under the wrong configuration

getContextItem

public Item getContextItem()

Get the context item

Returns:

the context item if there is one, or null otherwise

setVariable

public void setVariable(XPathVariable variable,
                        ValueRepresentation value)
                 throws XPathException

Set the value of an external variable used within the XPath expression

Parameters:

variable - the object representing the variable, as returned by the XPathEvaluator.declareVariable(String, String) method. Note that setting the value of a variable does not modify the XPathVariable object itself, which means that this method is thread-safe.

value - The value of the variable.

Throws:

XPathException - if the supplied value does not conform to the required type of the variable