Package org.apache.xpath.axes

Class MatchPatternIterator

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.MatchPatternIterator
All Implemented Interfaces:
Serializable, Cloneable, 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 Details

    • m_pattern

      protected StepPattern m_pattern
      This is the select pattern, translated into a match pattern.

    • m_superAxis

      protected int m_superAxis
      The traversal axis from where the nodes will be filtered.

    • m_traverser

      protected DTMAxisTraverser m_traverser
      The DTM inner traversal class, that corresponds to the super axis.

  • Method Details

    • setRoot

      public void setRoot​(int context, 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

    • getNextNode

      protected int getNextNode()
      Get the next node via getNextXXX. Bottlenecked for derived class override.
      Returns:
      The next node on the axis, or DTM.NULL.

    • 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 .