package org.jaxen.dom4j;

 /*

  * $Header$

  * $Revision: 1171 $

  * $Date: 2006-07-03 06:17:30 -0700 (Mon, 03 Jul 2006) $

  *

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

  *

  * Copyright 2000-2005 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: DocumentNavigator.java 1171 2006-07-03 13:17:30Z elharo $

 */

 import java.util.ArrayList;

 import java.util.HashSet;

 import java.util.Iterator;

 import java.util.List;

 import org.dom4j.Attribute;

 import org.dom4j.Branch;

 import org.dom4j.CDATA;

 import org.dom4j.Comment;

 import org.dom4j.Document;

 import org.dom4j.DocumentException;

 import org.dom4j.Element;

 import org.dom4j.Namespace;

 import org.dom4j.Node;

 import org.dom4j.ProcessingInstruction;

 import org.dom4j.QName;

 import org.dom4j.Text;

 import org.dom4j.io.SAXReader;

 import org.jaxen.DefaultNavigator;

 import org.jaxen.FunctionCallException;

 import org.jaxen.NamedAccessNavigator;

 import org.jaxen.Navigator;

 import org.jaxen.XPath;

 import org.jaxen.JaxenConstants;

 import org.jaxen.saxpath.SAXPathException;

 import org.jaxen.util.SingleObjectIterator;

 /** 

  * Interface for navigating around the DOM4J object model.

  *

  * <p>

  * This class is not intended for direct usage, but is

  * used by the Jaxen engine during evaluation.

  * </p>

  *

  * @see XPath

  *

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

  * @author Stephen Colebourne

  */

 public class DocumentNavigator extends DefaultNavigator implements NamedAccessNavigator

 {

     /**

      * 

      */

     private static final long serialVersionUID = 5582300797286535936L;

     private transient SAXReader reader;

     /** Singleton implementation.

      */

     private static class Singleton

     {

         /** Singleton instance.

          */

         private static DocumentNavigator instance = new DocumentNavigator();

     }

     /** Retrieve the singleton instance of this <code>DocumentNavigator</code>.

      */

     public static Navigator getInstance()

     {

         return Singleton.instance;

     }

     public boolean isElement(Object obj)

     {

         return obj instanceof Element;

     }

     public boolean isComment(Object obj)

     {

         return obj instanceof Comment;

     }

     public boolean isText(Object obj)

     {

         return ( obj instanceof Text 

                  ||

                  obj instanceof CDATA );

     }

     public boolean isAttribute(Object obj)

     {

         return obj instanceof Attribute;

     }

     public boolean isProcessingInstruction(Object obj)

     {

         return obj instanceof ProcessingInstruction;

     }

     public boolean isDocument(Object obj)

     {

         return obj instanceof Document;

     }

     public boolean isNamespace(Object obj)

     {

         return obj instanceof Namespace;

     }

     public String getElementName(Object obj)

     {

         Element elem = (Element) obj;

         return elem.getName();

     }

     public String getElementNamespaceUri(Object obj)

     {

         Element elem = (Element) obj;

         String uri = elem.getNamespaceURI();

         if ( uri == null)

             return "";

         else

             return uri;

     }

     public String getElementQName(Object obj)

     {

         Element elem = (Element) obj;

         return elem.getQualifiedName();

     }

     public String getAttributeName(Object obj)

     {

         Attribute attr = (Attribute) obj;

         return attr.getName();

     }

     public String getAttributeNamespaceUri(Object obj)

     {

         Attribute attr = (Attribute) obj;

         String uri = attr.getNamespaceURI();

         if ( uri == null)

             return "";

         else

             return uri;

     }

     public String getAttributeQName(Object obj)

     {

         Attribute attr = (Attribute) obj;

         return attr.getQualifiedName();

     }

     public Iterator getChildAxisIterator(Object contextNode)

     {

         Iterator result = null;

         if ( contextNode instanceof Branch )

         {

             Branch node = (Branch) contextNode;

             result = node.nodeIterator();

         }

         if (result != null) {

             return result;

         }

         return JaxenConstants.EMPTY_ITERATOR;

     }

     /**

      * Retrieves an <code>Iterator</code> over the child elements that

      * match the supplied name.

      *

      * @param contextNode      the origin context node

      * @param localName        the local name of the children to return, always present

      * @param namespacePrefix  the prefix of the namespace of the children to return

      * @param namespaceURI     the uri of the namespace of the children to return

      * 

      * @return an Iterator that traverses the named children, or null if none

      */

     public Iterator getChildAxisIterator(

             Object contextNode, String localName, String namespacePrefix, String namespaceURI) {

         if ( contextNode instanceof Element ) {

             Element node = (Element) contextNode;

             return node.elementIterator(QName.get(localName, namespacePrefix, namespaceURI));

         }

         if ( contextNode instanceof Document ) {

             Document node = (Document) contextNode;

             Element el = node.getRootElement();

             if (el == null || el.getName().equals(localName) == false) {

                 return JaxenConstants.EMPTY_ITERATOR;

             }

             if (namespaceURI != null) {

                 if (namespaceURI.equals(el.getNamespaceURI()) == false) {

                     return JaxenConstants.EMPTY_ITERATOR;

                 }

             }

             return new SingleObjectIterator(el);

         }

         return JaxenConstants.EMPTY_ITERATOR;

     }

     public Iterator getParentAxisIterator(Object contextNode)

     {

         if ( contextNode instanceof Document )

         {

             return JaxenConstants.EMPTY_ITERATOR;

         }

         Node node = (Node) contextNode;

         Object parent = node.getParent();

         if ( parent == null )

         {

             parent = node.getDocument();

         }

         return new SingleObjectIterator( parent );

     }

     public Iterator getAttributeAxisIterator(Object contextNode)

     {

         if ( ! ( contextNode instanceof Element ) )

         {

             return JaxenConstants.EMPTY_ITERATOR;

         }

         Element elem = (Element) contextNode;

         return elem.attributeIterator();

     }

     /**

      * Retrieves an <code>Iterator</code> over the attribute elements that

      * match the supplied name.

      *

      * @param contextNode  the origin context node

      * @param localName  the local name of the attributes to return, always present

      * @param namespacePrefix  the prefix of the namespace of the attributes to return

      * @param namespaceURI  the URI of the namespace of the attributes to return

      * @return an Iterator that traverses the named attributes, not null

      */

     public Iterator getAttributeAxisIterator(

             Object contextNode, String localName, String namespacePrefix, String namespaceURI) {

         if ( contextNode instanceof Element ) {

             Element node = (Element) contextNode;

             Attribute attr = node.attribute(QName.get(localName, namespacePrefix, namespaceURI));

             if (attr == null) {

                 return JaxenConstants.EMPTY_ITERATOR;

             }

             return new SingleObjectIterator(attr);

         }

         return JaxenConstants.EMPTY_ITERATOR;

     }

     public Iterator getNamespaceAxisIterator(Object contextNode)

     {

         if ( ! ( contextNode instanceof Element ) )

         {

             return JaxenConstants.EMPTY_ITERATOR;

         }

         Element element = (Element) contextNode;

         List nsList = new ArrayList();

         HashSet prefixes = new HashSet();

         for ( Element context = element; context != null; context = context.getParent() ) {

             List declaredNS = new ArrayList(context.declaredNamespaces());

             declaredNS.add(context.getNamespace());

             for ( Iterator iter = context.attributes().iterator(); iter.hasNext(); )

             {

                 Attribute attr = (Attribute) iter.next();

                 declaredNS.add(attr.getNamespace());

             }

             for ( Iterator iter = declaredNS.iterator(); iter.hasNext(); )

             {

                 Namespace namespace = (Namespace) iter.next();

                 if (namespace != Namespace.NO_NAMESPACE)

                 {

                     String prefix = namespace.getPrefix();

                     if ( ! prefixes.contains( prefix ) ) {

                         prefixes.add( prefix );

                         nsList.add( namespace.asXPathResult( element ) );

                     }

                 }

             }

         }

         nsList.add( Namespace.XML_NAMESPACE.asXPathResult( element ) );

         return nsList.iterator();

     }

     public Object getDocumentNode(Object contextNode)

     {

         if ( contextNode instanceof Document ) 

         {

             return contextNode;

         }

         else if ( contextNode instanceof Node ) 

         {

             Node node = (Node) contextNode;

             return node.getDocument();

         }

         return null;

     }

     /** Returns a parsed form of the given XPath string, which will be suitable

      *  for queries on DOM4J documents.

      */

     public XPath parseXPath (String xpath) throws SAXPathException

     {

         return new Dom4jXPath(xpath);

     }

     public Object getParentNode(Object contextNode)

     {

         if ( contextNode instanceof Node ) 

         {

             Node node = (Node) contextNode;

             Object answer = node.getParent();

             if ( answer == null ) 

             {

                 answer = node.getDocument();

                 if (answer == contextNode) {

                     return null;

                 }

             }

             return answer;            

         }

         return null;

     }

     public String getTextStringValue(Object obj)

     {

         return getNodeStringValue( (Node) obj );

     }

     public String getElementStringValue(Object obj)

     {

         return getNodeStringValue( (Node) obj );

     }

     public String getAttributeStringValue(Object obj)

     {

         return getNodeStringValue( (Node) obj );

     }

     private String getNodeStringValue(Node node)

     {

         return node.getStringValue();

     }

     public String getNamespaceStringValue(Object obj)

     {

         Namespace ns = (Namespace) obj;

         return ns.getURI();

     }

     public String getNamespacePrefix(Object obj)

     {

         Namespace ns = (Namespace) obj;

         return ns.getPrefix();

     }

     public String getCommentStringValue(Object obj)

     {

         Comment cmt = (Comment) obj;

         return cmt.getText();

     }

     public String translateNamespacePrefixToUri(String prefix, Object context)

     {

         Element element = null;

         if ( context instanceof Element ) 

         {

             element = (Element) context;

         }

         else if ( context instanceof Node )

         {

             Node node = (Node) context;

             element = node.getParent();

         }

         if ( element != null )

         {

             Namespace namespace = element.getNamespaceForPrefix( prefix );

             if ( namespace != null ) 

             {

                 return namespace.getURI();

             }

         }

         return null;

     }

     public short getNodeType(Object node) 

     {

         if ( node instanceof Node )

         {

             return ((Node) node).getNodeType();

         }

         return 0;

     }

     public Object getDocument(String uri) throws FunctionCallException

     {

         try

         {

             return getSAXReader().read( uri );

         }

         catch (DocumentException e)

         {

             throw new FunctionCallException("Failed to parse document for URI: " + uri, e);

         }

     }

     public String getProcessingInstructionTarget(Object obj)

     {

         ProcessingInstruction pi = (ProcessingInstruction) obj;

         return pi.getTarget();

     }

     public String getProcessingInstructionData(Object obj)

     {

         ProcessingInstruction pi = (ProcessingInstruction) obj;

         return pi.getText();

     }

     // Properties

     //-------------------------------------------------------------------------    

     public SAXReader getSAXReader()

     {

         if ( reader == null ) 

         {

             reader = new SAXReader();

             reader.setMergeAdjacentText( true );

         }

         return reader;

     }

     public void setSAXReader(SAXReader reader)

     {

         this.reader = reader;

     }

 }