content: /*
   * $Header$
   * $Revision$
   * $Date$
   *
   * ====================================================================
   *
   * 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/>.
   * 
   * $Id$
   */
  
  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 $Revision$
   */
  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;
      }
  } 
  