org.apache.xpath.axes
Class OneStepIterator

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
                          extended by org.apache.xpath.axes.OneStepIterator
All Implemented Interfaces:
java.io.Serializable, java.lang.Cloneable, javax.xml.transform.SourceLocator, DTMIterator, PathComponent, SubContextList, ExpressionNode, XPathVisitable

public class OneStepIterator
extends ChildTestIterator

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

See Also:
org.apache.xpath.axes, Serialized Form
Usage:
**For advanced use only**

Field Summary
 
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
 
Fields inherited from interface org.apache.xml.dtm.DTMIterator
FILTER_ACCEPT, FILTER_REJECT, FILTER_SKIP
 
Constructor Summary
OneStepIterator(DTMAxisIterator iterator, int axis)
          Create a OneStepIterator object.
 
Method Summary
 java.lang.Object clone()
          Get a cloned iterator.
 DTMIterator cloneWithReset()
          Get a cloned Iterator that is reset to the beginning of the query.
 boolean deepEquals(Expression expr)
          Compare this object with another object and see if they are equal, include the sub heararchy.
 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 getLength()
          The number of nodes in the list.
 boolean isReverseAxes()
          Tells if this is a reverse axes.
 void reset()
          Reset the iterator.
 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, getPrefixResolver, getRoot, getWhatToShow, getXPathContext, incrementCurrentPos, isDocOrdered, isFresh, isMutable, isNodesetExpr, item, previousNode, runTo, setCurrentContextNode, setCurrentPos, setEnvironment, setIsTopLevel, setItem, setShouldCacheNodes, size
 
Methods inherited from class org.apache.xpath.axes.PredicatedNodeTest
acceptNode, callPredicateVisitors, canTraverseOutsideSubtree, fixupVariables, getLocPathIterator, getPredicate, getPredicateCount, getPredicateIndex, getProximityPosition, getProximityPosition, initProximityPosition, 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

OneStepIterator

public OneStepIterator(DTMAxisIterator iterator,
                       int axis)
                throws javax.xml.transform.TransformerException
Create a OneStepIterator object.

Parameters:
iterator - The DTM iterator which this iterator will use.
axis - One of Axis.Child, etc., or -1 if the axis is unknown.
Throws:
javax.xml.transform.TransformerException
Method Detail

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 ChildTestIterator
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.


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 ChildTestIterator

clone

public java.lang.Object clone()
                       throws java.lang.CloneNotSupportedException
Get a cloned iterator.

Specified by:
clone in interface DTMIterator
Overrides:
clone in class PredicatedNodeTest
Returns:
A new iterator that can be used without mutating this one.
Throws:
java.lang.CloneNotSupportedException

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 ChildTestIterator
Returns:
A cloned NodeIterator set of the start of the query.
Throws:
java.lang.CloneNotSupportedException

isReverseAxes

public boolean isReverseAxes()
Tells if this is a reverse axes. Overrides AxesWalker#isReverseAxes.

Overrides:
isReverseAxes in class PredicatedNodeTest
Returns:
true for this class.

getLength

public int getLength()
The number of nodes in the list. The range of valid child node indices is 0 to length-1 inclusive.

Specified by:
getLength in interface DTMIterator
Overrides:
getLength in class LocPathIterator
Returns:
The number of nodes in the list, always greater or equal to zero.

reset

public void reset()
Reset the iterator.

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)
Description copied from class: Expression
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.
See Also:
Expression.deepEquals(Expression)


Copyright ? 2005 Apache XML Project. All Rights Reserved.