com.novell.xml.xpath
Class Axis

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

All Implemented Interfaces:

ContextNodeList

Direct Known Subclasses:

AxisAttribute, AxisElement, AxisNamespace

public abstract class Axis

extends Object

implements ContextNodeList

This class represents a generic XPath axis. Derived classes must override first() and next() to provide navigation among the nodes specified by the particular axis.

See Also:

Basis

Nested Class Summary

protected class

Axis.AxisMark

Field Summary

protected WhitespaceStripper

stripper

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

DOCUMENT_ORDER, REVERSE_DOCUMENT_ORDER, UNKNOWN_ORDER

Constructor Summary

protected

Axis()

Method Summary

int	count() Return the number of nodes in the axis.
void	done() stop referencing resources that are no longer needed
protected Node	getContextNode() Access to context node setup by init()
protected Node	incPosition(Node node) Increment the "last node" position.
protected void	init() Initialization of common code.
int	order() Return order in which nodes are returned from first()-next() NOTE: derived classes that are in reverse document order MUST override this
int	position() Return the position in the axis of the last node returned by first() or next().
abstract int	principalNodeType() Return the principal node type for the axis.
void	setup(Node contextNode, WhitespaceStripper stripper) Initialize an axis instance for a context node
protected boolean	stripNode(Node node) Return whether an arbitrary node should be stripped
abstract String	toString() Provide a readable description of the axis for debugging.

Methods inherited from class java.lang.Object

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

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

first, getMark, next, returnToMark

Field Detail

stripper

protected WhitespaceStripper stripper

Constructor Detail

Axis

protected Axis()

Method Detail

setup

public void setup(Node contextNode,
                  WhitespaceStripper stripper)

Initialize an axis instance for a context node

Parameters:

contextNode - the context node

stripper - The WhitespaceStripper implementation for stripping whitespace nodes

done

public void done()

stop referencing resources that are no longer needed

principalNodeType

public abstract int principalNodeType()

Return the principal node type for the axis. For the attribute axis, this is org.w3c.dom.Node.ATTRIBUTE_NODE For the namespace axis, this is com.novell.xml.xpath.XPathAttributeNode.NAMESPACE_NODE For all other axes, this is org.w3c.dom.Node.ELEMENT_NODE

Returns:

node type for axis

toString

public abstract String toString()

Provide a readable description of the axis for debugging.

Returns:

String representation of the axis (the axis name)

count

public int count()
          throws XPathEvaluationException

Return the number of nodes in the axis. This is implemented in terms of the derived class's first() and next() functions and caches the resulting number. NOTE: first() must have been called previous for meaningful results

Specified by:

count in interface ContextNodeList

Returns:

the number of nodes in the axis

Throws:

XPathEvaluationException

position

public int position()

Return the position in the axis of the last node returned by first() or next(). Note: this will continue to return the position of the last node returned even if next() is called again.

Specified by:

position in interface ContextNodeList

Returns:

The 1-based position of the node in the axis

order

public int order()

Return order in which nodes are returned from first()-next() NOTE: derived classes that are in reverse document order MUST override this

Specified by:

order in interface ContextNodeList

Returns:

ContextNodeList.DOCUMENT_ORDER

init

protected void init()

Initialization of common code. Derived classes must call this at beginning of their first() implementations

incPosition

protected Node incPosition(Node node)

Increment the "last node" position. Derived classes must call this before returning the result of first() and next()

Parameters:

node - Node to be returned from first() or next() (may be null)

Returns:

The passed node (so derived class can write "return incPosition(node)"

getContextNode

protected Node getContextNode()

Access to context node setup by init()

Returns:

The context node

stripNode

protected boolean stripNode(Node node)

Return whether an arbitrary node should be stripped

Parameters:

node - The node to test

Returns:

True if the node is a text or cdata section node and the WhitespaceStripper object passed to setup() returns true.