net.sourceforge.htmlunit.xpath.axes

Class WalkingIterator

java.lang.Object

net.sourceforge.htmlunit.xpath.Expression

net.sourceforge.htmlunit.xpath.patterns.NodeTest

net.sourceforge.htmlunit.xpath.axes.PredicatedNodeTest

net.sourceforge.htmlunit.xpath.axes.LocPathIterator

net.sourceforge.htmlunit.xpath.axes.WalkingIterator

All Implemented Interfaces:

Cloneable, SourceLocator, PathComponent, SubContextList, ExpressionNode, DTMIterator, XPathVisitable

Direct Known Subclasses:

WalkingIteratorSorted

public class WalkingIterator
extends LocPathIterator

Location path iterator that uses Walkers.

Field Summary

Fields

Modifier and Type	Field and Description
protected AxesWalker	m_firstWalker The head of the step walker list.
protected AxesWalker	m_lastUsedWalker The last used step walker in the walker list.

Fields inherited from class net.sourceforge.htmlunit.xpath.axes.LocPathIterator

m_allowDetach, m_cdtm, m_clones, m_context, m_currentContextNode, m_execContext, m_lastFetched, m_length, m_pos

Fields inherited from class net.sourceforge.htmlunit.xpath.axes.PredicatedNodeTest

m_foundLast, m_lpi, m_predCount, m_proximityPositions

Fields inherited from class net.sourceforge.htmlunit.xpath.patterns.NodeTest

m_name, m_whatToShow, SCORE_NODETEST, SCORE_NONE, SCORE_NSWILD, SCORE_OTHER, SCORE_QNAME, SHOW_BYFUNCTION, WILD

Fields inherited from interface net.sourceforge.htmlunit.xpath.xml.dtm.DTMIterator

FILTER_ACCEPT, FILTER_SKIP

Constructor Summary

Constructors

Constructor and Description
WalkingIterator(PrefixResolver nscontext) Create a WalkingIterator object.

Method Summary

Modifier and Type	Method and Description
void	callVisitors(XPathVisitor visitor) This will traverse the hierarchy, calling the visitor for each member.
Object	clone()
boolean	deepEquals(Expression expr) Compare this object with another object and see if they are equal, include the sub heararchy.
void	detach() Detaches the DTMIterator from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state.
int	getAnalysisBits() Get the analysis bits for this path component, as defined in the WalkerFactory.
AxesWalker	getLastUsedWalker() Get the last used walker.
int	nextNode() Returns the next node in the set and advances the position of the iterator in the set.
void	reset() Reset the iterator to the start.
void	setLastUsedWalker(AxesWalker walker) Set the last used walker.
void	setRoot(int context, Object environment) Reset the root node of the DTMIterator, overriding the value specified when it was created.

Methods inherited from class net.sourceforge.htmlunit.xpath.axes.LocPathIterator

allowDetachToRelease, asIterator, asNode, bool, cloneWithReset, execute, getAxis, getCurrentNode, getCurrentPos, getDTM, getDTMManager, getExpandEntityReferences, getIsTopLevel, getLastPos, getLength, getPrefixResolver, getRoot, getWhatToShow, getXPathContext, incrementCurrentPos, isDocOrdered, isFresh, item, previousNode, returnNextNode, runTo, setCurrentPos, setIsTopLevel, setShouldCacheNodes

Methods inherited from class net.sourceforge.htmlunit.xpath.axes.PredicatedNodeTest

acceptNode, callPredicateVisitors, canTraverseOutsideSubtree, countProximityPosition, getPredicate, getPredicateCount, getProximityPosition, getProximityPosition, getProximityPosition, initPredicateInfo, initProximityPosition, isReverseAxes, nodeToString, resetProximityPositions, setLocPathIterator, setPredicateCount

Methods inherited from class net.sourceforge.htmlunit.xpath.patterns.NodeTest

calcScore, execute, execute, getLocalName, getNamespace, getNodeTypeTest, getStaticScore, initNodeTest, initNodeTest, setLocalName, setNamespace, setStaticScore, setWhatToShow

Methods inherited from class net.sourceforge.htmlunit.xpath.Expression

assertion, error, execute, exprGetParent, exprSetParent, getColumnNumber, getExpressionOwner, getLineNumber, getPublicId, getSystemId, isSameClass, isStableNumber, num

Methods inherited from class java.lang.Object

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

Field Detail

m_lastUsedWalker

protected AxesWalker m_lastUsedWalker

The last used step walker in the walker list.

m_firstWalker

protected AxesWalker m_firstWalker

The head of the step walker list.

Constructor Detail

WalkingIterator

public WalkingIterator(PrefixResolver nscontext)

Create a WalkingIterator object.

Parameters:

nscontext - The namespace context for this iterator, should be OK if null.

Method Detail

getAnalysisBits

public int getAnalysisBits()

Get the analysis bits for this path component, as defined in the WalkerFactory.

Specified by:

getAnalysisBits in interface PathComponent

Overrides:

getAnalysisBits in class LocPathIterator

Returns:

One of WalkerFactory#BIT_DESCENDANT, etc.

clone

public Object clone()
             throws CloneNotSupportedException

Specified by:

clone in interface DTMIterator

Overrides:

clone in class PredicatedNodeTest

Returns:

A clone of this object.

Throws:

CloneNotSupportedException - if any

reset

public void reset()

Reset the iterator to the start. After resetting, the next node returned will be the root node -- or, if that's filtered out, the first node within the root's subtree which is _not_ skipped by the filters.

Specified by:

reset in interface DTMIterator

Overrides:

reset in class LocPathIterator

setRoot

public void setRoot(int context,
                    Object environment)

Reset the root node of the DTMIterator, overriding the value specified when it was created. Note the root node is not the root node of the document tree, but the context node from where the iteration begins.

Specified by:

setRoot in interface DTMIterator

Overrides:

setRoot in class LocPathIterator

Parameters:

context - int Handle of the context node.

environment - The environment object. The environment in which this iterator operates, which should provide:

• a node (the context node... same value as "root" defined below)
• a pair of non-zero positive integers (the context position and the context size)
• a set of variable bindings
• a function library
• the set of namespace declarations in scope for the expression.

  At this time the exact implementation of this environment is application dependent. Probably a proper interface will be created fairly soon.

nextNode

public int nextNode()

Returns the next node in the set and advances the position of the iterator in the set. After a DTMIterator has setRoot called, the first call to nextNode() returns that root or (if it is rejected by the filters) the first node within its subtree which is not filtered out.

Specified by:

nextNode in interface DTMIterator

Specified by:

nextNode in class LocPathIterator

Returns:

The next node handle in the set being iterated over, or DTM.NULL if there are no more members in that set.

setLastUsedWalker

public final void setLastUsedWalker(AxesWalker walker)

Set the last used walker.

Parameters:

walker - The last used walker, or null.

getLastUsedWalker

public final AxesWalker getLastUsedWalker()

Get the last used walker.

Returns:

The last used walker, or null.

detach

public void detach()

Detaches the DTMIterator from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state. After detach has been invoked, calls to nextNode or previousNode will raise a runtime exception.

Specified by:

detach in interface DTMIterator

Overrides:

detach in class LocPathIterator

callVisitors

public void callVisitors(XPathVisitor visitor)

This will traverse the hierarchy, calling the visitor for each member. If the called visitor method returns false, the subtree should not be called.

Specified by:

callVisitors in interface XPathVisitable

Overrides:

callVisitors in class LocPathIterator

Parameters:

visitor - The visitor whose appropriate method will be called.

deepEquals

public boolean deepEquals(Expression expr)

Compare this object with another object and see if they are equal, include the sub heararchy.

Overrides:

deepEquals in class PredicatedNodeTest

Parameters:

expr - Another expression object.

Returns:

true if this objects class and the expr object's class are the same, and the data contained within both objects are considered equal.