Package org.apache.xpath.patterns

Class StepPattern

java.lang.Object
org.apache.xpath.Expression
org.apache.xpath.patterns.NodeTest
org.apache.xpath.patterns.StepPattern
All Implemented Interfaces:
Serializable, SourceLocator, SubContextList, ExpressionNode, ExpressionOwner, XPathVisitable
Direct Known Subclasses:
ContextMatchStepPattern, FunctionPattern
public class StepPattern
extends NodeTest
implements SubContextList, ExpressionOwner
This class represents a single pattern match step.
See Also:
Serialized Form

  • Field Details

    • m_axis

      protected int m_axis
      The axis for this test.

  • Constructor Details

    • StepPattern

      public StepPattern​(int whatToShow, String namespace, String name, int axis, int axisForPredicate)
      Construct a StepPattern that tests for namespaces and node names.
      Parameters:
      whatToShow - Bit set defined mainly by NodeFilter.
      namespace - The namespace to be tested.
      name - The local name to be tested.
      axis - The Axis for this test, one of of Axes.ANCESTORORSELF, etc.
      axisForPredicate - No longer used.

    • StepPattern

      public StepPattern​(int whatToShow, int axis, int axisForPredicate)
      Construct a StepPattern that doesn't test for node names.
      Parameters:
      whatToShow - Bit set defined mainly by NodeFilter.
      axis - The Axis for this test, one of of Axes.ANCESTORORSELF, etc.
      axisForPredicate - No longer used.

  • Method Details

    • calcTargetString

      public void calcTargetString()
      Calculate the local name or psuedo name of the node that this pattern will test, for hash table lookup optimization.
      See Also:
      PsuedoNames

    • getTargetString

      public String getTargetString()
      Get the local name or psuedo name of the node that this pattern will test, for hash table lookup optimization.
      Returns:
      local name or psuedo name of the node.
      See Also:
      PsuedoNames

    • fixupVariables

      public void fixupVariables​(Vector vars, int globalsSize)
      This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time.
      Overrides:
      fixupVariables in class NodeTest
      Parameters:
      vars - List of QNames that correspond to variables. This list should be searched backwards for the first qualified name that corresponds to the variable reference qname. The position of the QName in the vector from the start of the vector will be its position in the stack frame (but variables above the globalsTop value will need to be offset to the current stack frame).
      globalsSize - The number of variables in the global variable area.

    • setRelativePathPattern

      public void setRelativePathPattern​(StepPattern expr)
      Set the reference to nodetest and predicate for parent or ancestor.
      Parameters:
      expr - The relative pattern expression.

    • getRelativePathPattern

      public StepPattern getRelativePathPattern()
      Get the reference to nodetest and predicate for parent or ancestor.
      Returns:
      The relative pattern expression.

    • getPredicates

      public Expression[] getPredicates()
      Set the list of predicate expressions for this pattern step.
      Returns:
      List of expression objects.

    • canTraverseOutsideSubtree

      public boolean canTraverseOutsideSubtree()
      Tell if this expression or it's subexpressions can traverse outside the current subtree. NOTE: Ancestors tests with predicates are problematic, and will require special treatment.
      Overrides:
      canTraverseOutsideSubtree in class Expression
      Returns:
      true if traversal outside the context node's subtree can occur.

    • getPredicate

      public Expression getPredicate​(int i)
      Get a predicate expression.
      Parameters:
      i - The index of the predicate.
      Returns:
      A predicate expression.

    • getPredicateCount

      public final int getPredicateCount()
      Get the number of predicates for this match pattern step.
      Returns:
      the number of predicates for this match pattern step.

    • setPredicates

      public void setPredicates​(Expression[] predicates)
      Set the predicates for this match pattern step.
      Parameters:
      predicates - An array of expressions that define predicates for this step.

    • calcScore

      public void calcScore()
      Static calc of match score.
      Overrides:
      calcScore in class NodeTest

    • execute

      public XObject execute​(XPathContext xctxt, int currentNode) throws TransformerException
      Execute this pattern step, including predicates.
      Overrides:
      execute in class NodeTest
      Parameters:
      xctxt - XPath runtime context.
      currentNode - The current node context.
      Returns:
      NodeTest.SCORE_NODETEST, NodeTest.SCORE_NONE, NodeTest.SCORE_NSWILD, NodeTest.SCORE_QNAME, or NodeTest.SCORE_OTHER.
      Throws:
      TransformerException

    • execute

      public XObject execute​(XPathContext xctxt) throws TransformerException
      Execute this pattern step, including predicates.
      Overrides:
      execute in class NodeTest
      Parameters:
      xctxt - XPath runtime context.
      Returns:
      NodeTest.SCORE_NODETEST, NodeTest.SCORE_NONE, NodeTest.SCORE_NSWILD, NodeTest.SCORE_QNAME, or NodeTest.SCORE_OTHER.
      Throws:
      TransformerException

    • execute

      public XObject execute​(XPathContext xctxt, int currentNode, DTM dtm, int expType) throws TransformerException
      Execute an expression in the XPath runtime context, and return the result of the expression.
      Overrides:
      execute in class NodeTest
      Parameters:
      xctxt - The XPath runtime context.
      currentNode - The currentNode.
      dtm - The DTM of the current node.
      expType - The expanded type ID of the current node.
      Returns:
      The result of the expression in the form of a XObject.
      Throws:
      TransformerException - if a runtime exception occurs.

    • getProximityPosition

      public int getProximityPosition​(XPathContext xctxt)
      Get the proximity position index of the current node based on this node test.
      Specified by:
      getProximityPosition in interface SubContextList
      Parameters:
      xctxt - XPath runtime context.
      Returns:
      the proximity position index of the current node based on the node test.

    • getLastPos

      public int getLastPos​(XPathContext xctxt)
      Get the count of the nodes that match the test, which is the proximity position of the last node that can pass this test in the sub context selection. In XSLT 1-based indexing, this count is the index of the last node.
      Specified by:
      getLastPos in interface SubContextList
      Parameters:
      xctxt - XPath runtime context.
      Returns:
      the count of the nodes that match the test.

    • executeRelativePathPattern

      protected final XObject executeRelativePathPattern​(XPathContext xctxt, DTM dtm, int currentNode) throws TransformerException
      Execute the match pattern step relative to another step.
      Parameters:
      xctxt - The XPath runtime context.
      dtm - The DTM of the current node.
      currentNode - The current node context.
      Returns:
      NodeTest.SCORE_NODETEST, NodeTest.SCORE_NONE, NodeTest.SCORE_NSWILD, NodeTest.SCORE_QNAME, or NodeTest.SCORE_OTHER.
      Throws:
      TransformerException

    • executePredicates

      protected final boolean executePredicates​(XPathContext xctxt, DTM dtm, int currentNode) throws TransformerException
      Execute the predicates on this step to determine if the current node should be filtered or accepted.
      Parameters:
      xctxt - The XPath runtime context.
      dtm - The DTM of the current node.
      currentNode - The current node context.
      Returns:
      true if the node should be accepted, false otherwise.
      Throws:
      TransformerException

    • toString

      public String toString()
      Get the string represenentation of this step for diagnostic purposes.
      Overrides:
      toString in class Object
      Returns:
      A string representation of this step, built by reverse-engineering the contained info.

    • getMatchScore

      public double getMatchScore​(XPathContext xctxt, int context) throws TransformerException
      Get the match score of the given node.
      Parameters:
      xctxt - The XPath runtime context.
      context - The node to be tested.
      Returns:
      NodeTest.SCORE_NODETEST, NodeTest.SCORE_NONE, NodeTest.SCORE_NSWILD, NodeTest.SCORE_QNAME, or NodeTest.SCORE_OTHER.
      Throws:
      TransformerException

    • setAxis

      public void setAxis​(int axis)
      Set the axis that this step should follow.
      Parameters:
      axis - The Axis for this test, one of of Axes.ANCESTORORSELF, etc.

    • getAxis

      public int getAxis()
      Get the axis that this step follows.
      Returns:
      The Axis for this test, one of of Axes.ANCESTORORSELF, etc.

    • callVisitors

      public void callVisitors​(ExpressionOwner owner, XPathVisitor visitor)
      Description copied from interface: XPathVisitable
      This will traverse the heararchy, calling the visitor for each member. If the called visitor method returns false, the subtree should not be called.
      Specified by:
      callVisitors in interface XPathVisitable
      Overrides:
      callVisitors in class NodeTest
      Parameters:
      owner - The owner of the visitor, where that path may be rewritten if needed.
      visitor - The visitor whose appropriate method will be called.
      See Also:
      XPathVisitable.callVisitors(ExpressionOwner, XPathVisitor)

    • callSubtreeVisitors

      protected void callSubtreeVisitors​(XPathVisitor visitor)
      Call the visitors on the subtree. Factored out from callVisitors so it may be called by derived classes.

    • getExpression

      public Expression getExpression()
      Description copied from interface: ExpressionOwner
      Get the raw Expression object that this class wraps.
      Specified by:
      getExpression in interface ExpressionOwner
      Returns:
      the raw Expression object, which should not normally be null.
      See Also:
      ExpressionOwner.getExpression()

    • setExpression

      public void setExpression​(Expression exp)
      Description copied from interface: ExpressionOwner
      Set the raw expression object for this object.
      Specified by:
      setExpression in interface ExpressionOwner
      Parameters:
      exp - the raw Expression object, which should not normally be null.
      See Also:
      ExpressionOwner.setExpression(Expression)

    • 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 NodeTest
      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)