com.novell.xml.xpath
Class Step

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

public class Step

extends Object

class that represents an XPath LocationPath Step The nodes returned from this class will always be in document order. The reason for this is that a Step is defined by XPath as returning a node-set, rather than a list. However, the only way node-sets are used is in document order.

Constructor Summary

Step(Basis basis)
Construct a Step without a predicate

Step(Basis basis, Predicate predicate)
Construct a Step with a single predicate

Step(Basis basis, Predicate[] predicates)
Construct a Step with multiple predicates, e.g., child::*[1][2][3]

Step(Step step, Predicate predicate)
Construct a Step based on an exising step and an additional predicate.

Method Summary

void	done() Undo any state changes that may have occurred in the expression context due to evaluation of the Step
Node	first() Return the first node in the node-set resulting from evaluation of the Step with the expression context set in the setup() call
Node	next() Return subsequent nodes in the node-set resulting from the evaluation of the Step with the context setup by setup()
void	setup(Node contextNode, ExpressionContext context) Initialize the Step to enable it to return the resulting node-set based on the passed expression context.
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

Step

public Step(Basis basis)

Construct a Step without a predicate

Parameters:

basis - The axis-name::node-test

Step

public Step(Basis basis,
            Predicate predicate)

Construct a Step with a single predicate

Parameters:

basis - The axis-name::node-test

predicate - The predicate expression

Step

public Step(Basis basis,
            Predicate[] predicates)

Construct a Step with multiple predicates, e.g., child::*[1][2][3]

Parameters:

basis - The axis-name::node-test

predicates - Array of predicates

Step

public Step(Step step,
            Predicate predicate)

Construct a Step based on an exising step and an additional predicate.

Parameters:

step - The existing Step

predicate - The additional predicate

Method Detail

setup

public void setup(Node contextNode,
                  ExpressionContext context)

Initialize the Step to enable it to return the resulting node-set based on the passed expression context. Call first()-next() to get the members of the node-set

Parameters:

contextNode - The node from which evaluation starts

context - The collection of things that make up the expression context for the step and for subexpressions in the step

done

public void done()

Undo any state changes that may have occurred in the expression context due to evaluation of the Step

first

public Node first()
           throws XPathEvaluationException

Return the first node in the node-set resulting from evaluation of the Step with the expression context set in the setup() call

Returns:

a node or null, if resulting node-set is empty

Throws:

XPathEvaluationException

next

public Node next()
          throws XPathEvaluationException

Return subsequent nodes in the node-set resulting from the evaluation of the Step with the context setup by setup()

Returns:

a node or null, if the last node in the resulting node-set has already been returned

Throws:

XPathEvaluationException

toString

public String toString()

Provide a readable description for debugging.

Returns:

String representation