///*--
//
// $Id: JaxenXPath.java,v 1.20 2007/11/10 05:29:02 jhunter Exp $
//
// Copyright (C) 2000-2007 Jason Hunter & Brett McLaughlin.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions, and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions, and the disclaimer that follows
//    these conditions in the documentation and/or other materials
//    provided with the distribution.
//
// 3. The name "JDOM" must not be used to endorse or promote products
//    derived from this software without prior written permission.  For
//    written permission, please contact <request_AT_jdom_DOT_org>.
//
// 4. Products derived from this software may not be called "JDOM", nor
//    may "JDOM" appear in their name, without prior written permission
//    from the JDOM Project Management <request_AT_jdom_DOT_org>.
//
// In addition, we request (but do not require) that you include in the
// end-user documentation provided with the redistribution and/or in the
// software itself an acknowledgement equivalent to the following:
//     "This product includes software developed by the
//      JDOM Project (http://www.jdom.org/)."
// Alternatively, the acknowledgment may be graphical using the logos
// available at http://www.jdom.org/images/logos.
//
// THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
// OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED.  IN NO EVENT SHALL THE JDOM AUTHORS OR THE PROJECT
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
// USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE.
//
// This software consists of voluntary contributions made by many
// individuals on behalf of the JDOM Project and was originally
// created by Jason Hunter <jhunter_AT_jdom_DOT_org> and
// Brett McLaughlin <brett_AT_jdom_DOT_org>.  For more information
// on the JDOM Project, please see <http://www.jdom.org/>.
//
// */
//
//package org.jdom.xpath;
//
//
//import java.util.*;
//
//import org.jaxen.*;
//import org.jaxen.jdom.*;
//import org.jdom.*;
//
//
///**
// * A non-public concrete XPath implementation for Jaxen.
// *
// * @version $Revision: 1.20 $, $Date: 2007/11/10 05:29:02 $
// * @author  Laurent Bihanic
// */
//class JaxenXPath extends    XPath {             // package protected
//
//    private static final String CVS_ID =
//    "@(#) $RCSfile: JaxenXPath.java,v $ $Revision: 1.20 $ $Date: 2007/11/10 05:29:02 $ $Name: jdom_1_1_1 $";
//
//   /**
//    * The compiled XPath object to select nodes.  This attribute can
//    * not be made final as it needs to be set upon object
//    * deserialization.
//    */
//   private transient JDOMXPath xPath;
//
//   /**
//    * The current context for XPath expression evaluation.
//    */
//   private           Object    currentContext;
//
//   /**
//    * Creates a new XPath wrapper object, compiling the specified
//    * XPath expression.
//    *
//    * @param  expr   the XPath expression to wrap.
//    *
//    * @throws JDOMException   if the XPath expression is invalid.
//    */
//   public JaxenXPath(String expr) throws JDOMException {
//      setXPath(expr);
//   }
//
//   /**
//    * Evaluates the wrapped XPath expression and returns the list
//    * of selected items.
//    *
//    * @param  context   the node to use as context for evaluating
//    *                   the XPath expression.
//    *
//    * @return the list of selected items, which may be of types: {@link Element},
//    *         {@link Attribute}, {@link Text}, {@link CDATA},
//    *         {@link Comment}, {@link ProcessingInstruction}, Boolean,
//    *         Double, or String.
//    *
//    * @throws JDOMException   if the evaluation of the XPath
//    *                         expression on the specified context
//    *                         failed.
//    */
//   public List selectNodes(Object context) throws JDOMException {
//      try {
//         currentContext = context;
//
//         return xPath.selectNodes(context);
//      }
//      catch (JaxenException ex1) {
//         throw new JDOMException("XPath error while evaluating \"" +
//                        xPath.toString() + "\": " + ex1.getMessage(), ex1);
//      }
//      finally {
//         currentContext = null;
//      }
//   }
//
//   /**
//    * Evaluates the wrapped XPath expression and returns the first
//    * entry in the list of selected nodes (or atomics).
//    *
//    * @param  context   the node to use as context for evaluating
//    *                   the XPath expression.
//    *
//    * @return the first selected item, which may be of types: {@link Element},
//    *         {@link Attribute}, {@link Text}, {@link CDATA},
//    *         {@link Comment}, {@link ProcessingInstruction}, Boolean,
//    *         Double, String, or <code>null</code> if no item was selected.
//    *
//    * @throws JDOMException   if the evaluation of the XPath
//    *                         expression on the specified context
//    *                         failed.
//    */
//   public Object selectSingleNode(Object context) throws JDOMException {
//      try {
//         currentContext = context;
//
//         return xPath.selectSingleNode(context);
//      }
//      catch (JaxenException ex1) {
//         throw new JDOMException("XPath error while evaluating \"" +
//                        xPath.toString() + "\": " + ex1.getMessage(), ex1);
//      }
//      finally {
//         currentContext = null;
//      }
//   }
//
//   /**
//    * Returns the string value of the first node selected by applying
//    * the wrapped XPath expression to the given context.
//    *
//    * @param  context   the element to use as context for evaluating
//    *                   the XPath expression.
//    *
//    * @return the string value of the first node selected by applying
//    *         the wrapped XPath expression to the given context.
//    *
//    * @throws JDOMException   if the XPath expression is invalid or
//    *                         its evaluation on the specified context
//    *                         failed.
//    */
//   public String valueOf(Object context) throws JDOMException {
//      try {
//         currentContext = context;
//
//         return xPath.stringValueOf(context);
//      }
//      catch (JaxenException ex1) {
//         throw new JDOMException("XPath error while evaluating \"" +
//                        xPath.toString() + "\": " + ex1.getMessage(), ex1);
//      }
//      finally {
//         currentContext = null;
//      }
//   }
//
//   /**
//    * Returns the number value of the first item selected by applying
//    * the wrapped XPath expression to the given context.
//    *
//    * @param  context   the element to use as context for evaluating
//    *                   the XPath expression.
//    *
//    * @return the number value of the first item selected by applying
//    *         the wrapped XPath expression to the given context,
//    *         <code>null</code> if no node was selected or the
//    *         special value {@link java.lang.Double#NaN}
//    *         (Not-a-Number) if the selected value can not be
//    *         converted into a number value.
//    *
//    * @throws JDOMException   if the XPath expression is invalid or
//    *                         its evaluation on the specified context
//    *                         failed.
//    */
//   public Number numberValueOf(Object context) throws JDOMException {
//      try {
//         currentContext = context;
//
//         return xPath.numberValueOf(context);
//      }
//      catch (JaxenException ex1) {
//         throw new JDOMException("XPath error while evaluating \"" +
//                        xPath.toString() + "\": " + ex1.getMessage(), ex1);
//      }
//      finally {
//         currentContext = null;
//      }
//   }
//
//   /**
//    * Defines an XPath variable and sets its value.
//    *
//    * @param  name    the variable name.
//    * @param  value   the variable value.
//    *
//    * @throws IllegalArgumentException   if <code>name</code> is not
//    *                                    a valid XPath variable name
//    *                                    or if the value type is not
//    *                                    supported by the underlying
//    *                                    implementation
//    */
//   public void setVariable(String name, Object value)
//                                        throws IllegalArgumentException {
//      Object o = xPath.getVariableContext();
//      if (o instanceof SimpleVariableContext) {
//           ((SimpleVariableContext)o).setVariableValue(null, name, value);
//      }
//   }
//
//   /**
//    * Adds a namespace definition to the list of namespaces known of
//    * this XPath expression.
//    * <p>
//    * <strong>Note</strong>: In XPath, there is no such thing as a
//    * 'default namespace'.  The empty prefix <b>always</b> resolves
//    * to the empty namespace URI.</p>
//    *
//    * @param  namespace   the namespace.
//    */
//   public void addNamespace(Namespace namespace) {
//      try {
//         xPath.addNamespace(namespace.getPrefix(), namespace.getURI());
//      }
//      catch (JaxenException ex1) { /* Can't happen here. */ }
//   }
//
//   /**
//    * Returns the wrapped XPath expression as a string.
//    *
//    * @return the wrapped XPath expression as a string.
//    */
//   public String getXPath() {
//      return (xPath.toString());
//   }
//
//   /**
//    * Compiles and sets the XPath expression wrapped by this object.
//    *
//    * @param  expr   the XPath expression to wrap.
//    *
//    * @throws JDOMException   if the XPath expression is invalid.
//    */
//   private void setXPath(String expr) throws JDOMException {
//      try {
//         xPath = new JDOMXPath(expr);
//         xPath.setNamespaceContext(new NSContext());
//      }
//      catch (Exception ex1) {
//         throw new JDOMException(
//                        "Invalid XPath expression: \"" + expr + "\"", ex1);
//      }
//   }
//
//   public String toString() {
//      return (xPath.toString());
//   }
//
//   public boolean equals(Object o) {
//      if (o instanceof JaxenXPath) {
//         JaxenXPath x = (JaxenXPath)o;
//
//         return (super.equals(o) &&
//                 xPath.toString().equals(x.xPath.toString()));
//      }
//      return false;
//   }
//
//   public int hashCode() {
//      return xPath.hashCode();
//   }
//
//   private class NSContext extends SimpleNamespaceContext {
//      public NSContext() {
//         super();
//      }
//
//      /**
//       * <i>[Jaxen NamespaceContext interface support]</i> Translates
//       * the provided namespace prefix into the matching bound
//       * namespace URI.
//       *
//       * @param  prefix   the namespace prefix to resolve.
//       *
//       * @return the namespace URI matching the prefix.
//       */
//      public String translateNamespacePrefixToUri(String prefix) {
//         if ((prefix == null) || (prefix.length() == 0)) {
//            return null;
//         }
//
//         String uri = super.translateNamespacePrefixToUri(prefix);
//         if (uri == null) {
//            Object ctx = currentContext;
//            if (ctx != null) {
//               Element elt = null;
//
//               // Get closer element node
//               if (ctx instanceof Element) {
//                  elt = (Element)ctx;
//               } else if (ctx instanceof Attribute) {
//                  elt = ((Attribute)ctx).getParent();
//               } else if (ctx instanceof Content) {
//                  elt = ((Content) ctx).getParentElement();
//               } else if (ctx instanceof Document) {
//                  elt = ((Document)ctx).getRootElement();
//               }
//
//               if (elt != null) {
//                  Namespace ns = elt.getNamespace(prefix);
//                  if (ns != null) {
//                     uri = ns.getURI();
//                  }
//               }
//            }
//         }
//         return uri;
//      }
//   }
//}