org.apache.xpath.axes
Class DescendantIterator

java.lang.Object
  |
  +--org.apache.xpath.Expression
        |
        +--org.apache.xpath.patterns.NodeTest
              |
              +--org.apache.xpath.axes.PredicatedNodeTest
                    |
                    +--org.apache.xpath.axes.LocPathIterator
                          |
                          +--org.apache.xpath.axes.DescendantIterator

public class DescendantIterator

extends LocPathIterator

**For advanced use only** This class implements an optimized iterator for descendant, descendant-or-self, or "//foo" patterns.

See Also:

org.apache.xpath.axes.WalkerFactory#newLocPathIterator, Serialized Form

Fields inherited from class org.apache.xpath.axes.LocPathIterator

m_lastFetched

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

SCORE_NODETEST, SCORE_NONE, SCORE_NSWILD, SCORE_OTHER, SCORE_QNAME, SHOW_BYFUNCTION, SUPPORTS_PRE_STRIPPING, WILD

Constructor Summary

DescendantIterator()
Create a DescendantIterator object.

Method Summary

int	asNode(XPathContext xctxt) Return the first node out of the nodeset, if this expression is a nodeset expression.
DTMIterator	cloneWithReset() Get a cloned Iterator that is reset to the beginning of the query.
boolean	deepEquals(Expression expr)
void	detach() Detaches the iterator 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	nextNode() Returns the next node in the set and advances the position of the iterator in the set.
void	setRoot(int context, java.lang.Object environment) Initialize the context values for this expression after it is cloned.

Methods inherited from class org.apache.xpath.axes.LocPathIterator

allowDetachToRelease, asIterator, bool, callVisitors, execute, executeCharsToContentHandler, getAnalysisBits, getContext, getCurrentContextNode, getCurrentNode, getCurrentPos, getDTM, getDTMManager, getExpandEntityReferences, getFilter, getFoundLast, getIsTopLevel, getLastPos, getLength, getPrefixResolver, getRoot, getWhatToShow, getXPathContext, incrementCurrentPos, isDocOrdered, isFresh, isMutable, isNodesetExpr, item, previousNode, reset, runTo, setCurrentContextNode, setCurrentPos, setEnvironment, setIsTopLevel, setItem, setShouldCacheNodes, size

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

acceptNode, callPredicateVisitors, canTraverseOutsideSubtree, clone, fixupVariables, getLocPathIterator, getPredicate, getPredicateCount, getPredicateIndex, getProximityPosition, getProximityPosition, initProximityPosition, isReverseAxes, resetProximityPositions, setLocPathIterator, setPredicateCount

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

debugWhatToShow, execute, execute, getDefaultScore, getLocalName, getNamespace, getNodeTypeTest, getStaticScore, initNodeTest, initNodeTest, setLocalName, setNamespace, setStaticScore, setWhatToShow

Methods inherited from class org.apache.xpath.Expression

asIteratorRaw, assertion, error, execute, exprAddChild, exprGetChild, exprGetNumChildren, exprGetParent, exprSetParent, getColumnNumber, getExpressionOwner, getLineNumber, getPublicId, getSystemId, isStableNumber, num, warn, xstr

Methods inherited from class java.lang.Object

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

Constructor Detail

DescendantIterator

public DescendantIterator()

Create a DescendantIterator 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 -

Method Detail

cloneWithReset

public DTMIterator cloneWithReset()
                           throws java.lang.CloneNotSupportedException

Get a cloned Iterator that is reset to the beginning of the query.

Returns:

A cloned NodeIterator set of the start of the query.

Throws:

java.lang.CloneNotSupportedException -

Overrides:

cloneWithReset in class LocPathIterator

nextNode

public int nextNode()

Returns the next node in the set and advances the position of the iterator in the set. After a NodeIterator is created, the first call to nextNode() returns the first node in the set.

Returns:

The next Node in the set being iterated over, or null if there are no more members in that set.

Throws:

DOMException - INVALID_STATE_ERR: Raised if this method is called after the detach method was invoked.

Overrides:

nextNode in class LocPathIterator

setRoot

public void setRoot(int context,
                    java.lang.Object environment)

Initialize the context values for this expression after it is cloned.

Parameters:

execContext - The XPath runtime context for this transformation.

Overrides:

setRoot in class LocPathIterator

asNode

public int asNode(XPathContext xctxt)
           throws TransformerException

Return the first node out of the nodeset, if this expression is a nodeset expression. This is the default implementation for nodesets.

WARNING: Do not mutate this class from this function!

Parameters:

xctxt - The XPath runtime context.

Returns:

the first node out of the nodeset, or DTM.NULL.

Overrides:

asNode in class LocPathIterator

detach

public void detach()

Detaches the iterator from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state. Afterdetach has been invoked, calls to nextNode orpreviousNode will raise the exception INVALID_STATE_ERR.

Overrides:

detach in class LocPathIterator

getAxis

public int getAxis()

Returns the axis being iterated, if it is known.

Returns:

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

Overrides:

getAxis in class LocPathIterator

deepEquals

public boolean deepEquals(Expression expr)

Overrides:

deepEquals in class PredicatedNodeTest

See Also:

Expression.deepEquals(Expression)