Class OneStepIterator

java.lang.Object

org.htmlunit.xpath.Expression

org.htmlunit.xpath.patterns.NodeTest

org.htmlunit.xpath.axes.PredicatedNodeTest

org.htmlunit.xpath.axes.LocPathIterator

org.htmlunit.xpath.axes.BasicTestIterator

org.htmlunit.xpath.axes.ChildTestIterator

org.htmlunit.xpath.axes.OneStepIterator

All Implemented Interfaces:

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

public class OneStepIterator
extends ChildTestIterator

This class implements a general iterator for those LocationSteps with only one step, and perhaps a predicate.

Field Summary

Fields

Modifier and Type	Field	Description
protected int	m_axis	The traversal axis from where the nodes will be filtered.
protected DTMAxisIterator	m_iterator	The DTM inner traversal class, that corresponds to the super axis.

Fields inherited from class ChildTestIterator

m_traverser

Fields inherited from class LocPathIterator

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

Fields inherited from class PredicatedNodeTest

DEBUG_PREDICATECOUNTING, m_foundLast, m_lpi, m_predCount, m_predicateIndex, m_proximityPositions

Fields inherited from class NodeTest

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

Fields inherited from interface DTMIterator

FILTER_ACCEPT, FILTER_SKIP

Constructor Summary

Constructors

Constructor	Description
OneStepIterator(Compiler compiler, int opPos, int analysis)	Create a OneStepIterator object.

Method Summary

Modifier and Type	Method	Description
Object	clone()
DTMIterator	cloneWithReset()	Get a cloned Iterator that is reset to the start of the iteration.
protected void	countProximityPosition(int i)	Count forward one proximity position.
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	getAxis()	Returns the axis being iterated, if it is known.
int	getLength()	The number of nodes in the list.
protected int	getNextNode()	Get the next node via getNextXXX.
protected int	getProximityPosition(int predicateIndex)	Get the current sub-context position.
boolean	isReverseAxes()	Tells if this is a reverse axes.
void	reset()	Reset the iterator to the start.
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 BasicTestIterator

nextNode

Methods inherited from class LocPathIterator

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

Methods inherited from class PredicatedNodeTest

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

Methods inherited from class NodeTest

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

Methods inherited from class Expression

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

Methods inherited from class Object

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

Field Details

m_axis

protected int m_axis

The traversal axis from where the nodes will be filtered.

m_iterator

protected DTMAxisIterator m_iterator

The DTM inner traversal class, that corresponds to the super axis.

Constructor Details

OneStepIterator

OneStepIterator(Compiler compiler,
 int opPos,
 int analysis)
         throws TransformerException

Create a OneStepIterator object.

Parameters:

compiler - A reference to the Compiler that contains the op map.

opPos - The position within the op map, which contains the location path expression for this itterator.

Throws:

TransformerException - if any

Method Details

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 ChildTestIterator

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.

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 ChildTestIterator

getNextNode

protected int getNextNode()

Get the next node via getNextXXX. Bottlenecked for derived class override.

Overrides:

getNextNode in class ChildTestIterator

Returns:

The next node on the axis, or DTM.NULL.

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

cloneWithReset

public DTMIterator cloneWithReset()
                           throws CloneNotSupportedException

Get a cloned Iterator that is reset to the start of the iteration.

Specified by:

cloneWithReset in interface DTMIterator

Overrides:

cloneWithReset in class ChildTestIterator

Returns:

A clone of this iteration that has been reset.

Throws:

CloneNotSupportedException - if any

isReverseAxes

public boolean isReverseAxes()

Tells if this is a reverse axes.

Overrides:

isReverseAxes in class PredicatedNodeTest

Returns:

false, unless a derived class overrides.

getProximityPosition

protected int getProximityPosition(int predicateIndex)

Get the current sub-context position.

Overrides:

getProximityPosition in class PredicatedNodeTest

Parameters:

predicateIndex - The index of the predicate where the proximity should be taken from.

Returns:

The node position of this walker in the sub-context node list.

getLength

public int getLength()

The number of nodes in the list. The range of valid child node indices is 0 to length-1 inclusive. Note that this requires running the iterator to completion, and presumably filling the cache.

Specified by:

getLength in interface DTMIterator

Overrides:

getLength in class LocPathIterator

Returns:

The number of nodes in the list.

countProximityPosition

protected void countProximityPosition(int i)

Count forward one proximity position.

Overrides:

countProximityPosition in class PredicatedNodeTest

Parameters:

i - The index into the m_proximityPositions array, where the increment will occur.

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

getAxis

public int getAxis()

Returns the axis being iterated, if it is known.

Specified by:

getAxis in interface DTMIterator

Overrides:

getAxis in class ChildTestIterator

Returns:

Axis.CHILD, etc., or -1 if the axis is not known or is of multiple types.

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.