## 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

This class implements an optimized iterator for descendant, descendant-or-self, or "//foo" patterns.

See Also:
  `LocPathIterator`, Serialized Form
Usage:
  **For advanced use only**

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.

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:
    `context` - 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. After`detach` has been invoked, calls to `nextNode` or`previousNode` 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)`

Copyright © 2006 Apache XML Project. All Rights Reserved.