org.apache.xpath.axes
Class MatchPatternIterator

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.MatchPatternIterator
All Implemented Interfaces:
java.io.Serializable, java.lang.Cloneable, javax.xml.transform.SourceLocator, DTMIterator, PathComponent, SubContextList, ExpressionNode, XPathVisitable

public class MatchPatternIterator
extends LocPathIterator

This class treats a LocationPath as a filtered iteration over the tree, evaluating each node in a super axis traversal against the LocationPath interpreted as a match pattern. This class is useful to find nodes in document order that are complex paths whose steps probably criss-cross each other.

See Also:
Serialized Form

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
 
Method Summary
 short acceptNode(int n, XPathContext xctxt)
          Test whether a specified node is visible in the logical view of a TreeWalker or NodeIterator.
 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 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, asNode, bool, callVisitors, cloneWithReset, execute, executeCharsToContentHandler, getAnalysisBits, getAxis, 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, deepEquals, 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
 
Methods inherited from interface org.apache.xml.dtm.DTMIterator
clone
 

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 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.


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

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.

Specified by:
nextNode in interface DTMIterator
Specified by:
nextNode in class LocPathIterator
Returns:
The next Node in the set being iterated over, or null if there are no more members in that set.

acceptNode

public short acceptNode(int n,
                        XPathContext xctxt)
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.

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 .


Copyright ? 2005 Apache XML Project. All Rights Reserved.