Class XPath

  • All Implemented Interfaces:
    java.io.Serializable, ExpressionOwner

    public class XPath
    extends java.lang.Object
    implements java.io.Serializable, ExpressionOwner
    The XPath class wraps an expression object and provides general services for execution of that expression.
    See Also:
    Serialized Form
    • Field Summary

      Fields 
      Modifier and Type Field Description
      static int MATCH
      Represents a match type expression.
      static double MATCH_SCORE_NODETEST
      The match score if the pattern consists of just a NodeTest.
      static double MATCH_SCORE_NONE
      The match score if no match is made.
      static double MATCH_SCORE_NSWILD
      The match score if the pattern pattern has the form NCName:*.
      static double MATCH_SCORE_OTHER
      The match score if the pattern consists of something other than just a NodeTest or just a qname.
      static double MATCH_SCORE_QNAME
      The match score if the pattern has the form of a QName optionally preceded by an @ character.
      static int SELECT
      Represents a select type expression.
    • Constructor Summary

      Constructors 
      Constructor Description
      XPath​(java.lang.String exprString, javax.xml.transform.SourceLocator locator, PrefixResolver prefixResolver, int type)
      Construct an XPath object.
      XPath​(java.lang.String exprString, javax.xml.transform.SourceLocator locator, PrefixResolver prefixResolver, int type, javax.xml.transform.ErrorListener errorListener)
      Construct an XPath object.
      XPath​(java.lang.String exprString, javax.xml.transform.SourceLocator locator, PrefixResolver prefixResolver, int type, javax.xml.transform.ErrorListener errorListener, FunctionTable aTable)
      Construct an XPath object.
      XPath​(Expression expr)
      Construct an XPath object.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void assertion​(boolean b, java.lang.String msg)
      Tell the user of an assertion error, and probably throw an exception.
      boolean bool​(XPathContext xctxt, int contextNode, PrefixResolver namespaceContext)
      Given an expression and a context, evaluate the XPath and return the result.
      void callVisitors​(ExpressionOwner owner, XPathVisitor visitor)
      This will traverse the heararchy, calling the visitor for each member.
      void error​(XPathContext xctxt, int sourceNode, java.lang.String msg, java.lang.Object[] args)
      Tell the user of an error, and probably throw an exception.
      XObject execute​(XPathContext xctxt, int contextNode, PrefixResolver namespaceContext)
      Given an expression and a context, evaluate the XPath and return the result.
      XObject execute​(XPathContext xctxt, org.w3c.dom.Node contextNode, PrefixResolver namespaceContext)
      Given an expression and a context, evaluate the XPath and return the result.
      void fixupVariables​(java.util.Vector vars, int globalsSize)
      This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time.
      Expression getExpression()
      Get the raw Expression object that this class wraps.
      javax.xml.transform.SourceLocator getLocator()
      Get the SourceLocator on the expression object.
      double getMatchScore​(XPathContext xctxt, int context)
      Get the match score of the given node.
      java.lang.String getPatternString()
      Return the XPath string associated with this object.
      void setExpression​(Expression exp)
      Set the raw expression object for this object.
      void warn​(XPathContext xctxt, int sourceNode, java.lang.String msg, java.lang.Object[] args)
      Warn the user of an problem.
      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • SELECT

        public static final int SELECT
        Represents a select type expression.
        See Also:
        Constant Field Values
      • MATCH

        public static final int MATCH
        Represents a match type expression.
        See Also:
        Constant Field Values
      • MATCH_SCORE_NONE

        public static final double MATCH_SCORE_NONE
        The match score if no match is made.
        See Also:
        Constant Field Values
      • MATCH_SCORE_QNAME

        public static final double MATCH_SCORE_QNAME
        The match score if the pattern has the form of a QName optionally preceded by an @ character.
        See Also:
        Constant Field Values
      • MATCH_SCORE_NSWILD

        public static final double MATCH_SCORE_NSWILD
        The match score if the pattern pattern has the form NCName:*.
        See Also:
        Constant Field Values
      • MATCH_SCORE_NODETEST

        public static final double MATCH_SCORE_NODETEST
        The match score if the pattern consists of just a NodeTest.
        See Also:
        Constant Field Values
      • MATCH_SCORE_OTHER

        public static final double MATCH_SCORE_OTHER
        The match score if the pattern consists of something other than just a NodeTest or just a qname.
        See Also:
        Constant Field Values
    • Constructor Detail

      • XPath

        public XPath​(java.lang.String exprString,
                     javax.xml.transform.SourceLocator locator,
                     PrefixResolver prefixResolver,
                     int type,
                     javax.xml.transform.ErrorListener errorListener)
              throws javax.xml.transform.TransformerException
        Construct an XPath object. (Needs review -sc) This method initializes an XPathParser/ Compiler and compiles the expression.
        Parameters:
        exprString - The XPath expression.
        locator - The location of the expression, may be null.
        prefixResolver - A prefix resolver to use to resolve prefixes to namespace URIs.
        type - one of SELECT or MATCH.
        errorListener - The error listener, or null if default should be used.
        Throws:
        javax.xml.transform.TransformerException - if syntax or other error.
      • XPath

        public XPath​(java.lang.String exprString,
                     javax.xml.transform.SourceLocator locator,
                     PrefixResolver prefixResolver,
                     int type,
                     javax.xml.transform.ErrorListener errorListener,
                     FunctionTable aTable)
              throws javax.xml.transform.TransformerException
        Construct an XPath object. (Needs review -sc) This method initializes an XPathParser/ Compiler and compiles the expression.
        Parameters:
        exprString - The XPath expression.
        locator - The location of the expression, may be null.
        prefixResolver - A prefix resolver to use to resolve prefixes to namespace URIs.
        type - one of SELECT or MATCH.
        errorListener - The error listener, or null if default should be used.
        Throws:
        javax.xml.transform.TransformerException - if syntax or other error.
      • XPath

        public XPath​(java.lang.String exprString,
                     javax.xml.transform.SourceLocator locator,
                     PrefixResolver prefixResolver,
                     int type)
              throws javax.xml.transform.TransformerException
        Construct an XPath object. (Needs review -sc) This method initializes an XPathParser/ Compiler and compiles the expression.
        Parameters:
        exprString - The XPath expression.
        locator - The location of the expression, may be null.
        prefixResolver - A prefix resolver to use to resolve prefixes to namespace URIs.
        type - one of SELECT or MATCH.
        Throws:
        javax.xml.transform.TransformerException - if syntax or other error.
      • XPath

        public XPath​(Expression expr)
        Construct an XPath object.
        Parameters:
        expr - The Expression object.
        Throws:
        javax.xml.transform.TransformerException - if syntax or other error.
    • Method Detail

      • getExpression

        public Expression getExpression()
        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.
      • fixupVariables

        public void fixupVariables​(java.util.Vector vars,
                                   int globalsSize)
        This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time.
        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).
      • setExpression

        public void setExpression​(Expression exp)
        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.
      • getLocator

        public javax.xml.transform.SourceLocator getLocator()
        Get the SourceLocator on the expression object.
        Returns:
        the SourceLocator on the expression object, which may be null.
      • getPatternString

        public java.lang.String getPatternString()
        Return the XPath string associated with this object.
        Returns:
        the XPath string associated with this object.
      • execute

        public XObject execute​(XPathContext xctxt,
                               org.w3c.dom.Node contextNode,
                               PrefixResolver namespaceContext)
                        throws javax.xml.transform.TransformerException
        Given an expression and a context, evaluate the XPath and return the result.
        Parameters:
        xctxt - The execution context.
        contextNode - The node that "." expresses.
        namespaceContext - The context in which namespaces in the XPath are supposed to be expanded.
        Returns:
        The result of the XPath or null if callbacks are used.
        Throws:
        javax.xml.transform.TransformerException - thrown if the error condition is severe enough to halt processing.
        javax.xml.transform.TransformerException
      • execute

        public XObject execute​(XPathContext xctxt,
                               int contextNode,
                               PrefixResolver namespaceContext)
                        throws javax.xml.transform.TransformerException
        Given an expression and a context, evaluate the XPath and return the result.
        Parameters:
        xctxt - The execution context.
        contextNode - The node that "." expresses.
        namespaceContext - The context in which namespaces in the XPath are supposed to be expanded.
        Throws:
        javax.xml.transform.TransformerException - thrown if the active ProblemListener decides the error condition is severe enough to halt processing.
        javax.xml.transform.TransformerException
      • bool

        public boolean bool​(XPathContext xctxt,
                            int contextNode,
                            PrefixResolver namespaceContext)
                     throws javax.xml.transform.TransformerException
        Given an expression and a context, evaluate the XPath and return the result.
        Parameters:
        xctxt - The execution context.
        contextNode - The node that "." expresses.
        namespaceContext - The context in which namespaces in the XPath are supposed to be expanded.
        Throws:
        javax.xml.transform.TransformerException - thrown if the active ProblemListener decides the error condition is severe enough to halt processing.
        javax.xml.transform.TransformerException
      • getMatchScore

        public double getMatchScore​(XPathContext xctxt,
                                    int context)
                             throws javax.xml.transform.TransformerException
        Get the match score of the given node.
        Parameters:
        xctxt - XPath runtime context.
        context - The current source tree context node.
        Returns:
        score, one of MATCH_SCORE_NODETEST, MATCH_SCORE_NONE, MATCH_SCORE_OTHER, or MATCH_SCORE_QNAME.
        Throws:
        javax.xml.transform.TransformerException
      • warn

        public void warn​(XPathContext xctxt,
                         int sourceNode,
                         java.lang.String msg,
                         java.lang.Object[] args)
                  throws javax.xml.transform.TransformerException
        Warn the user of an problem.
        Parameters:
        xctxt - The XPath runtime context.
        sourceNode - Not used.
        msg - An error msgkey that corresponds to one of the constants found in XPATHErrorResources, which is a key for a format string.
        args - An array of arguments represented in the format string, which may be null.
        Throws:
        javax.xml.transform.TransformerException - if the current ErrorListoner determines to throw an exception.
      • assertion

        public void assertion​(boolean b,
                              java.lang.String msg)
        Tell the user of an assertion error, and probably throw an exception.
        Parameters:
        b - If false, a runtime exception will be thrown.
        msg - The assertion message, which should be informative.
        Throws:
        java.lang.RuntimeException - if the b argument is false.
      • error

        public void error​(XPathContext xctxt,
                          int sourceNode,
                          java.lang.String msg,
                          java.lang.Object[] args)
                   throws javax.xml.transform.TransformerException
        Tell the user of an error, and probably throw an exception.
        Parameters:
        xctxt - The XPath runtime context.
        sourceNode - Not used.
        msg - An error msgkey that corresponds to one of the constants found in XPATHErrorResources, which is a key for a format string.
        args - An array of arguments represented in the format string, which may be null.
        Throws:
        javax.xml.transform.TransformerException - if the current ErrorListoner determines to throw an exception.
      • callVisitors

        public void callVisitors​(ExpressionOwner owner,
                                 XPathVisitor visitor)
        This will traverse the heararchy, calling the visitor for each member. If the called visitor method returns false, the subtree should not be called.
        Parameters:
        owner - The owner of the visitor, where that path may be rewritten if needed.
        visitor - The visitor whose appropriate method will be called.