org.apache.xpath.axes
Class ChildTestIterator

java.lang.Object
  extended by org.apache.xpath.Expression
      extended by org.apache.xpath.patterns.NodeTest
          extended by org.apache.xpath.axes.PredicatedNodeTest
              extended by org.apache.xpath.axes.LocPathIterator
                  extended by org.apache.xpath.axes.BasicTestIterator
                      extended by org.apache.xpath.axes.ChildTestIterator
All Implemented Interfaces:
java.io.Serializable, java.lang.Cloneable, javax.xml.transform.SourceLocator, DTMIterator, PathComponent, SubContextList, ExpressionNode, XPathVisitable
Direct Known Subclasses:
AttributeIterator, KeyRefIterator, OneStepIterator, OneStepIteratorForward, UnionChildIterator

public class ChildTestIterator
extends BasicTestIterator

This class implements an optimized iterator for children patterns that have a node test, and possibly a predicate.

See Also:
BasicTestIterator, Serialized Form

Nested Class Summary
 
Nested classes/interfaces inherited from class org.apache.xpath.axes.PredicatedNodeTest
PredicatedNodeTest.PredOwner
 
Field Summary
protected  DTMAxisTraverser m_traverser
          The traverser to use to navigate over the descendants.
(package private) static long serialVersionUID
           
 
Fields inherited from class org.apache.xpath.axes.LocPathIterator
m_allowDetach, m_cdtm, m_clones, m_context, m_currentContextNode, m_execContext, m_lastFetched, m_length, m_pos, m_stackFrame
 
Fields inherited from class org.apache.xpath.axes.PredicatedNodeTest
DEBUG_PREDICATECOUNTING, m_foundLast, m_lpi, m_predCount, m_predicateIndex, m_proximityPositions
 
Fields inherited from class org.apache.xpath.patterns.NodeTest
m_name, m_whatToShow, SCORE_NODETEST, SCORE_NONE, SCORE_NSWILD, SCORE_OTHER, SCORE_QNAME, SHOW_BYFUNCTION, SUPPORTS_PRE_STRIPPING, WILD
 
Fields inherited from interface org.apache.xml.dtm.DTMIterator
FILTER_ACCEPT, FILTER_REJECT, FILTER_SKIP
 
Constructor Summary
ChildTestIterator(Compiler compiler, int opPos, int analysis)
          Create a ChildTestIterator object.
ChildTestIterator(DTMAxisTraverser traverser)
          Create a ChildTestIterator object.
 
Method Summary
 DTMIterator cloneWithReset()
          Get a cloned Iterator that is reset to the beginning of the query.
 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.
protected  int getNextNode()
          Get the next node via getNextXXX.
 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.BasicTestIterator
nextNode
 
Methods inherited from class org.apache.xpath.axes.LocPathIterator
allowDetachToRelease, asIterator, asNode, 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, returnNextNode, runTo, setCurrentContextNode, setCurrentPos, setEnvironment, setIsTopLevel, setItem, setNextPosition, setShouldCacheNodes, size
 
Methods inherited from class org.apache.xpath.axes.PredicatedNodeTest
acceptNode, callPredicateVisitors, canTraverseOutsideSubtree, clone, countProximityPosition, deepEquals, executePredicates, fixupVariables, getLocPathIterator, getPredicate, getPredicateCount, getPredicateIndex, getProximityPosition, getProximityPosition, getProximityPosition, initPredicateInfo, initProximityPosition, isReverseAxes, nodeToString, resetProximityPositions, setLocPathIterator, setPredicateCount
 
Methods inherited from class org.apache.xpath.patterns.NodeTest
calcScore, 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, isSameClass, isStableNumber, num, warn, xstr
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface org.apache.xml.dtm.DTMIterator
clone
 

Field Detail

serialVersionUID

static final long serialVersionUID
See Also:
Constant Field Values

m_traverser

protected transient DTMAxisTraverser m_traverser
The traverser to use to navigate over the descendants.

Constructor Detail

ChildTestIterator

ChildTestIterator(Compiler compiler,
                  int opPos,
                  int analysis)
            throws javax.xml.transform.TransformerException
Create a ChildTestIterator 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:
javax.xml.transform.TransformerException

ChildTestIterator

public ChildTestIterator(DTMAxisTraverser traverser)
Create a ChildTestIterator object.

Parameters:
traverser - Traverser that tells how the KeyIterator is to be handled.
Throws:
javax.xml.transform.TransformerException
Method Detail

getNextNode

protected int getNextNode()
Get the next node via getNextXXX. Bottlenecked for derived class override.

Specified by:
getNextNode in class BasicTestIterator
Returns:
The next node on the axis, or DTM.NULL.

cloneWithReset

public DTMIterator cloneWithReset()
                           throws java.lang.CloneNotSupportedException
Get a cloned Iterator that is reset to the beginning of the query.

Specified by:
cloneWithReset in interface DTMIterator
Overrides:
cloneWithReset in class BasicTestIterator
Returns:
A cloned NodeIterator set of the start of the query.
Throws:
java.lang.CloneNotSupportedException

setRoot

public void setRoot(int context,
                    java.lang.Object environment)
Initialize the context values for this expression after it is cloned.

Specified by:
setRoot in interface DTMIterator
Overrides:
setRoot in class LocPathIterator
Parameters:
context - The XPath runtime context for this transformation.
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.


getAxis

public int getAxis()
Returns the axis being iterated, if it is known.

Specified by:
getAxis in interface DTMIterator
Overrides:
getAxis in class LocPathIterator
Returns:
Axis.CHILD, etc., or -1 if the axis is not known or is of multiple types.

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.

Specified by:
detach in interface DTMIterator
Overrides:
detach in class LocPathIterator