org.htmlunit.xpath.axes

Class FilterExprWalker

java.lang.Object

org.htmlunit.xpath.Expression

org.htmlunit.xpath.patterns.NodeTest

org.htmlunit.xpath.axes.PredicatedNodeTest

org.htmlunit.xpath.axes.AxesWalker

org.htmlunit.xpath.axes.FilterExprWalker

All Implemented Interfaces:

Cloneable, SourceLocator, PathComponent, SubContextList, ExpressionNode, XPathVisitable

public class FilterExprWalker
extends AxesWalker

Walker for the OP_VARIABLE, or OP_FUNCTION, or OP_GROUP, op codes.

See Also:

XPath FilterExpr descriptions

Field Summary

Fields inherited from class org.htmlunit.xpath.axes.AxesWalker

m_axis, m_nextWalker, m_traverser

Fields inherited from class org.htmlunit.xpath.axes.PredicatedNodeTest

m_foundLast, m_lpi, m_predCount, m_proximityPositions

Fields inherited from class org.htmlunit.xpath.patterns.NodeTest

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

Constructor Summary

Constructors

Constructor and Description
FilterExprWalker(WalkingIterator locPathIterator) Construct a FilterExprWalker using a LocPathIterator.

Method Summary

Modifier and Type	Method and Description
short	acceptNode(int n) Test whether a specified node is visible in the logical view of a TreeWalker or NodeIterator.
void	callPredicateVisitors(XPathVisitor visitor) This will traverse the heararchy, 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 walker from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state.
static XNodeSet	executeFilterExpr(int context, XPathContext xctxt, PrefixResolver prefixResolver, boolean isTopLevel, Expression expr) Execute the expression.
int	getAnalysisBits() Get the analysis bits for this path component, as defined in the WalkerFactory.
int	getAxis() Returns the axis being iterated, if it is known.
int	getLastPos(XPathContext xctxt) Get the number of nodes in the node list, which, in the XSLT 1 based counting system, is the last index position.
int	getNextNode() Get the next node in document order on the axes.
void	init(Compiler compiler, int opPos, int stepType) Initialize an AxesWalker during the parse of the XPath expression.
void	setRoot(int root) Set the root node of the TreeWalker.

Methods inherited from class org.htmlunit.xpath.axes.AxesWalker

callVisitors, getDTM, getNextWalker, getRoot, nextNode, setNextWalker, setPrevWalker, wi

Methods inherited from class org.htmlunit.xpath.axes.PredicatedNodeTest

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

Methods inherited from class org.htmlunit.xpath.patterns.NodeTest

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

Methods inherited from class org.htmlunit.xpath.Expression

asIterator, asNode, assertion, bool, 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

Constructor Detail

FilterExprWalker

public FilterExprWalker(WalkingIterator locPathIterator)

Construct a FilterExprWalker using a LocPathIterator.

Parameters:

locPathIterator - non-null reference to the parent iterator.

Method Detail

init

public void init(Compiler compiler,
                 int opPos,
                 int stepType)
          throws TransformerException

Initialize an AxesWalker during the parse of the XPath expression.

Overrides:

init in class AxesWalker

Parameters:

compiler - The Compiler object that has information about this walker in the op map.

opPos - The op code position of this location step.

stepType - The type of location step.

Throws:

TransformerException - if any

detach

public void detach()

Detaches the walker from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state.

Overrides:

detach in class AxesWalker

setRoot

public void setRoot(int root)

Set the root node of the TreeWalker. (Not part of the DOM2 TreeWalker interface).

Overrides:

setRoot in class AxesWalker

Parameters:

root - The context node of this step.

executeFilterExpr

public static XNodeSet executeFilterExpr(int context,
                                         XPathContext xctxt,
                                         PrefixResolver prefixResolver,
                                         boolean isTopLevel,
                                         Expression expr)
                                  throws WrappedRuntimeException

Execute the expression. Meant for reuse by other FilterExpr iterators that are not derived from this object.

Throws:

WrappedRuntimeException

clone

public Object clone()
             throws CloneNotSupportedException

Overrides:

clone in class AxesWalker

Throws:

CloneNotSupportedException

acceptNode

public short acceptNode(int n)

Test whether a specified node is visible in the logical view of a TreeWalker or NodeIterator. This function will be called by the implementation of TreeWalker and NodeIterator; it is not intended to be called directly from user code.

Overrides:

acceptNode in class PredicatedNodeTest

Parameters:

n - The node to check to see if it passes the filter or not.

Returns:

a constant to determine whether the node is accepted, rejected, or skipped, as defined above .

getNextNode

public int getNextNode()

Get the next node in document order on the axes.

Overrides:

getNextNode in class AxesWalker

Returns:

the next node in document order on the axes, or null.

getLastPos

public int getLastPos(XPathContext xctxt)

Get the number of nodes in the node list, which, in the XSLT 1 based counting system, is the last index position.

Specified by:

getLastPos in interface SubContextList

Overrides:

getLastPos in class AxesWalker

Parameters:

xctxt - The XPath runtime context.

Returns:

the number of nodes in the node list.

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 AxesWalker

Returns:

One of WalkerFactory#BIT_DESCENDANT, etc.

getAxis

public int getAxis()

Returns the axis being iterated, if it is known.

Overrides:

getAxis in class AxesWalker

Returns:

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

callPredicateVisitors

public void callPredicateVisitors(XPathVisitor visitor)

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

Overrides:

callPredicateVisitors in class PredicatedNodeTest

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 AxesWalker

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.