/*

  * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/javabean/JavaBeanXPath.java,v 1.6 2006/06/03 20:36:00 elharo Exp $

  * $Revision: 1.6 $

  * $Date: 2006/06/03 20:36:00 $

  *

  * ====================================================================

  *

  * Copyright 2000-2002 bob mcwhirter & James Strachan.

  * All rights reserved.

  *

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions are

  * met:

  * 

  *   * Redistributions of source code must retain the above copyright

  *     notice, this list of conditions and the following disclaimer.

  * 

  *   * Redistributions in binary form must reproduce the above copyright

  *     notice, this list of conditions and the following disclaimer in the

  *     documentation and/or other materials provided with the distribution.

  * 

  *   * Neither the name of the Jaxen Project nor the names of its

  *     contributors may be used to endorse or promote products derived 

  *     from this software without specific prior written permission.

  * 

  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS

  * IS" AND ANY EXPRESS 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 COPYRIGHT OWNER

  * OR 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 Jaxen Project and was originally 

  * created by bob mcwhirter <bob@werken.com> and 

  * James Strachan <jstrachan@apache.org>.  For more information on the 

  * Jaxen Project, please see <http://www.jaxen.org/>.

  * 

  * $Id: JavaBeanXPath.java,v 1.6 2006/06/03 20:36:00 elharo Exp $

  */

 package org.jaxen.javabean;

 import org.jaxen.Context;

 import org.jaxen.BaseXPath;

 import org.jaxen.JaxenException;

 import java.util.List;

 import java.util.ArrayList;

 import java.util.Collection;

 import java.util.Iterator;

 /** An XPath implementation for JavaBeans.

  *

  * <p>This is the main entry point for matching an XPath against a JavaBean

  * tree.  You create a compiled XPath object, then match it against

  * one or more context nodes using the {@link #selectNodes(Object)}

  * method, as in the following example:</p>

  *

  * <pre>

  * Node node = ...;

  * XPath path = new JavaBeanXPath("a/b/c");

  * List results = path.selectNodes(node);

  * </pre>

  *

  * @see BaseXPath

  *

  * @author <a href="mailto:bob@werken.com">bob mcwhirter</a>

  *

  * @version $Revision: 1.6 $

  */

 public class JavaBeanXPath extends BaseXPath

 {

     /**

      * 

      */

     private static final long serialVersionUID = -1567521943360266313L;

     /** Construct given an XPath expression string.

      *

      *  @param xpathExpr The XPath expression.

      *

      *  @throws JaxenException if there is a syntax error while

      *          parsing the expression

      */

     public JavaBeanXPath(String xpathExpr) throws JaxenException

     {

         super( xpathExpr, DocumentNavigator.getInstance() );

     }

     protected Context getContext(Object node)

     {

         if ( node instanceof Context )

         {

             return (Context) node;

         }

         if ( node instanceof Element )

         {

             return super.getContext( node );

         }

         if ( node instanceof List )

         {

             List newList = new ArrayList();

             for ( Iterator listIter = ((List)node).iterator();

                   listIter.hasNext(); )

             {

                 newList.add( new Element( null, "root", listIter.next() ) );

             }

             return super.getContext( newList );

         }

         return super.getContext( new Element( null, "root", node ) );

     }

     public Object evaluate(Object node)

         throws JaxenException

     {

         Object result = super.evaluate( node );

         if ( result instanceof Element )

         {

             return ((Element)result).getObject();

         }

         else if ( result instanceof Collection )

         {

             List newList = new ArrayList();

             for ( Iterator listIter = ((Collection)result).iterator();

                   listIter.hasNext(); )

             {

                 Object member = listIter.next();

                 if ( member instanceof Element )

                 {

                     newList.add( ((Element)member).getObject() );

                 }

                 else

                 {

                     newList.add( member );

                 }

             }

             return newList;

         }

         return result;

     }

 }