com.novell.xml.xpath
Class Predicate

java.lang.Object
  com.novell.xml.xpath.Predicate

All Implemented Interfaces:

ContextNodeList

public class Predicate

extends Object

implements ContextNodeList

Class that represents a predicate in a Step or in a FilterExpr

Field Summary

Fields inherited from interface com.novell.xml.xpath.ContextNodeList

DOCUMENT_ORDER, REVERSE_DOCUMENT_ORDER, UNKNOWN_ORDER

Constructor Summary

Predicate(Expression expr)
Create a Predicate with the given expression

Method Summary

int	count() Return a count of nodes in the context node list that match the predicate expression
void	done() stop referencing resources that are no longer needed
Node	first() Return the first node from the context node list that matches the predicate expression
ContextListMark	getMark() Return a marker to a position in a ContextNodeList.
Node	next() Return subsequent nodesfrom the context node list that match the predicate expression
int	order() Return order in which nodes are returned from first()-next()
int	position() Return the position of the last node returned by a call to first() or next()
Node	returnToMark(ContextListMark mark) Go to a position in a ContextNodeList previously marked with getMark()
void	setup(ExpressionContext context) Setup the Predicate for first()/next() calls The Predicate uses the ContextNodeList interface of the ExpressionContext to get the nodes to test.
String	toString() Provide a readable description for debugging.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Predicate

public Predicate(Expression expr)

Create a Predicate with the given expression

Parameters:

expr - The PredicateExpr expression

Method Detail

toString

public String toString()

Provide a readable description for debugging.

Returns:

String representation

setup

public void setup(ExpressionContext context)

Setup the Predicate for first()/next() calls The Predicate uses the ContextNodeList interface of the ExpressionContext to get the nodes to test.

Parameters:

context - The expression context for evalulating the PredicateExpr.

done

public void done()

stop referencing resources that are no longer needed

first

public Node first()
           throws XPathEvaluationException

Return the first node from the context node list that matches the predicate expression

Specified by:

first in interface ContextNodeList

Returns:

a node

Throws:

XPathEvaluationException

next

public Node next()
          throws XPathEvaluationException

Return subsequent nodesfrom the context node list that match the predicate expression

Specified by:

next in interface ContextNodeList

Returns:

a node

Throws:

XPathEvaluationException

position

public int position()

Return the position of the last node returned by a call to first() or next()

Specified by:

position in interface ContextNodeList

Returns:

Node position in node list. 0 is returned if no nodes have been returned. Once first() or next() return null (indicating no more nodes in list) the return will be the position of the last node in the list.

count

public int count()
          throws XPathEvaluationException

Return a count of nodes in the context node list that match the predicate expression

Specified by:

count in interface ContextNodeList

Returns:

Count of nodes in the context node list.

Throws:

XPathEvaluationException

order

public int order()

Return order in which nodes are returned from first()-next()

Specified by:

order in interface ContextNodeList

Returns:

DOCUMENT_ORDER or REVERSE_DOCUMENT_ORDER

getMark

public ContextListMark getMark()

Return a marker to a position in a ContextNodeList. This marker can be used later in a call to returnToMark() to return to a particular position in the list.

Specified by:

getMark in interface ContextNodeList

Returns:

an opaque marker

returnToMark

public Node returnToMark(ContextListMark mark)

Go to a position in a ContextNodeList previously marked with getMark()

Specified by:

returnToMark in interface ContextNodeList

Parameters:

mark - mark returned from getMark()

Returns:

The node at the mark