/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: DOM2DTMdefaultNamespaceDeclarationNode.java,v 1.2.4.1 2005/09/15 08:15:11 suresh_emailid Exp $
 */

// This is copied directly out of the original
// com.sun.org.apache.xml.internal.dtm.ref.dom2dtm path to allow modifying
// DOM2DTM and working around package private constructors.  Other than the
// package declaration, this class is unmodified

package nokogiri.internals.dom2dtm;

import org.apache.xml.dtm.DTMException;

import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.TypeInfo;
import org.w3c.dom.UserDataHandler;
import org.w3c.dom.DOMException;

/** This is a kluge to let us shove a declaration for xml: into the
 * DOM2DTM model.  Basically, it creates a proxy node in DOM space to
 * carry the additional information. This is _NOT_ a full DOM
 * implementation, and shouldn't be one since it sits alongside the
 * DOM rather than becoming part of the DOM model.
 *
 * (This used to be an internal class within DOM2DTM. Moved out because
 * I need to perform an instanceof operation on it to support a temporary
 * workaround in DTMManagerDefault.)
 *
 * %REVIEW% What if the DOM2DTM was built around a DocumentFragment and
 * there isn't a single root element? I think this fails that case...
 *
 * %REVIEW% An alternative solution would be to create the node _only_
 * in DTM space, but given how DOM2DTM is currently written I think
 * this is simplest.
 * */
public class DOM2DTMdefaultNamespaceDeclarationNode implements Attr, TypeInfo
{
  final String NOT_SUPPORTED_ERR = "Unsupported operation on pseudonode";

  Element pseudoparent;
  String prefix, uri, nodename;
  int handle;
  DOM2DTMdefaultNamespaceDeclarationNode(Element pseudoparent, String prefix, String uri, int handle)
  {
    this.pseudoparent = pseudoparent;
    this.prefix = prefix;
    this.uri = uri;
    this.handle = handle;
    this.nodename = "xmlns:" + prefix;
  }
  public String
  getNodeName() {return nodename;}
  public String
  getName() {return nodename;}
  public String
  getNamespaceURI() {return "http://www.w3.org/2000/xmlns/";}
  public String
  getPrefix() {return prefix;}
  public String
  getLocalName() {return prefix;}
  public String
  getNodeValue() {return uri;}
  public String
  getValue() {return uri;}
  public Element
  getOwnerElement() {return pseudoparent;}

  public boolean
  isSupported(String feature, String version) {return false;}
  public boolean
  hasChildNodes() {return false;}
  public boolean
  hasAttributes() {return false;}
  public Node
  getParentNode() {return null;}
  public Node
  getFirstChild() {return null;}
  public Node
  getLastChild() {return null;}
  public Node
  getPreviousSibling() {return null;}
  public Node
  getNextSibling() {return null;}
  public boolean
  getSpecified() {return false;}
  public void
  normalize() {return;}
  public NodeList
  getChildNodes() {return null;}
  public NamedNodeMap
  getAttributes() {return null;}
  public short
  getNodeType() {return Node.ATTRIBUTE_NODE;}
  public void
  setNodeValue(String value) {throw new DTMException(NOT_SUPPORTED_ERR);}
  public void
  setValue(String value) {throw new DTMException(NOT_SUPPORTED_ERR);}
  public void
  setPrefix(String value) {throw new DTMException(NOT_SUPPORTED_ERR);}
  public Node
  insertBefore(Node a, Node b) {throw new DTMException(NOT_SUPPORTED_ERR);}
  public Node
  replaceChild(Node a, Node b) {throw new DTMException(NOT_SUPPORTED_ERR);}
  public Node
  appendChild(Node a) {throw new DTMException(NOT_SUPPORTED_ERR);}
  public Node
  removeChild(Node a) {throw new DTMException(NOT_SUPPORTED_ERR);}
  public Document
  getOwnerDocument() {return pseudoparent.getOwnerDocument();}
  public Node
  cloneNode(boolean deep) {throw new DTMException(NOT_SUPPORTED_ERR);}

  /** Non-DOM method, part of the temporary kluge
   * %REVIEW% This would be a pruning problem, but since it will always be
   * added to the root element and we prune on elements, we shouldn't have
   * to worry.
   */
  public int
  getHandleOfNode()
  {
    return handle;
  }

  //RAMESH: PENDING=> Add proper implementation for the below DOM L3 additions

  /**
   * @see org.w3c.dom.TypeInfo#getTypeName()
   */
  public String
  getTypeName() {return null; }

  /**
   * @see org.w3c.dom.TypeInfo#getTypeNamespace()
   */
  public String
  getTypeNamespace() { return null;}

  /**
   * @see or.gw3c.dom.TypeInfo#isDerivedFrom(String,String,int)
   */
  public boolean
  isDerivedFrom(String ns, String localName, int derivationMethod)
  {
    return false;
  }

  public TypeInfo
  getSchemaTypeInfo() { return this; }

  public boolean
  isId() { return false; }

  /**
   * Associate an object to a key on this node. The object can later be
   * retrieved from this node by calling <code>getUserData</code> with the
   * same key.
   * @param key The key to associate the object to.
   * @param data The object to associate to the given key, or
   *   <code>null</code> to remove any existing association to that key.
   * @param handler The handler to associate to that key, or
   *   <code>null</code>.
   * @return Returns the <code>DOMObject</code> previously associated to
   *   the given key on this node, or <code>null</code> if there was none.
   * @since DOM Level 3
   */
  public Object
  setUserData(String key,
              Object data,
              UserDataHandler handler)
  {
    return getOwnerDocument().setUserData(key, data, handler);
  }

  /**
   * Retrieves the object associated to a key on a this node. The object
   * must first have been set to this node by calling
   * <code>setUserData</code> with the same key.
   * @param key The key the object is associated to.
   * @return Returns the <code>DOMObject</code> associated to the given key
   *   on this node, or <code>null</code> if there was none.
   * @since DOM Level 3
   */
  public Object
  getUserData(String key)
  {
    return getOwnerDocument().getUserData(key);
  }

  /**
   *  This method returns a specialized object which implements the
   * specialized APIs of the specified feature and version. The
   * specialized object may also be obtained by using binding-specific
   * casting methods but is not necessarily expected to, as discussed in Mixed DOM implementations.
   * @param feature The name of the feature requested (case-insensitive).
   * @param version  This is the version number of the feature to test. If
   *   the version is <code>null</code> or the empty string, supporting
   *   any version of the feature will cause the method to return an
   *   object that supports at least one version of the feature.
   * @return  Returns an object which implements the specialized APIs of
   *   the specified feature and version, if any, or <code>null</code> if
   *   there is no object which implements interfaces associated with that
   *   feature. If the <code>DOMObject</code> returned by this method
   *   implements the <code>Node</code> interface, it must delegate to the
   *   primary core <code>Node</code> and not return results inconsistent
   *   with the primary core <code>Node</code> such as attributes,
   *   childNodes, etc.
   * @since DOM Level 3
   */
  public Object
  getFeature(String feature, String version)
  {
    // we don't have any alternate node, either this node does the job
    // or we don't have anything that does
    return isSupported(feature, version) ? this : null;
  }

  /**
   * Tests whether two nodes are equal.
   * <br>This method tests for equality of nodes, not sameness (i.e.,
   * whether the two nodes are references to the same object) which can be
   * tested with <code>Node.isSameNode</code>. All nodes that are the same
   * will also be equal, though the reverse may not be true.
   * <br>Two nodes are equal if and only if the following conditions are
   * satisfied: The two nodes are of the same type.The following string
   * attributes are equal: <code>nodeName</code>, <code>localName</code>,
   * <code>namespaceURI</code>, <code>prefix</code>, <code>nodeValue</code>
   * , <code>baseURI</code>. This is: they are both <code>null</code>, or
   * they have the same length and are character for character identical.
   * The <code>attributes</code> <code>NamedNodeMaps</code> are equal.
   * This is: they are both <code>null</code>, or they have the same
   * length and for each node that exists in one map there is a node that
   * exists in the other map and is equal, although not necessarily at the
   * same index.The <code>childNodes</code> <code>NodeLists</code> are
   * equal. This is: they are both <code>null</code>, or they have the
   * same length and contain equal nodes at the same index. This is true
   * for <code>Attr</code> nodes as for any other type of node. Note that
   * normalization can affect equality; to avoid this, nodes should be
   * normalized before being compared.
   * <br>For two <code>DocumentType</code> nodes to be equal, the following
   * conditions must also be satisfied: The following string attributes
   * are equal: <code>publicId</code>, <code>systemId</code>,
   * <code>internalSubset</code>.The <code>entities</code>
   * <code>NamedNodeMaps</code> are equal.The <code>notations</code>
   * <code>NamedNodeMaps</code> are equal.
   * <br>On the other hand, the following do not affect equality: the
   * <code>ownerDocument</code> attribute, the <code>specified</code>
   * attribute for <code>Attr</code> nodes, the
   * <code>isWhitespaceInElementContent</code> attribute for
   * <code>Text</code> nodes, as well as any user data or event listeners
   * registered on the nodes.
   * @param arg The node to compare equality with.
   * @param deep If <code>true</code>, recursively compare the subtrees; if
   *   <code>false</code>, compare only the nodes themselves (and its
   *   attributes, if it is an <code>Element</code>).
   * @return If the nodes, and possibly subtrees are equal,
   *   <code>true</code> otherwise <code>false</code>.
   * @since DOM Level 3
   */
  public boolean
  isEqualNode(Node arg)
  {
    if (arg == this) {
      return true;
    }
    if (arg.getNodeType() != getNodeType()) {
      return false;
    }
    // in theory nodeName can't be null but better be careful
    // who knows what other implementations may be doing?...
    if (getNodeName() == null) {
      if (arg.getNodeName() != null) {
        return false;
      }
    } else if (!getNodeName().equals(arg.getNodeName())) {
      return false;
    }

    if (getLocalName() == null) {
      if (arg.getLocalName() != null) {
        return false;
      }
    } else if (!getLocalName().equals(arg.getLocalName())) {
      return false;
    }

    if (getNamespaceURI() == null) {
      if (arg.getNamespaceURI() != null) {
        return false;
      }
    } else if (!getNamespaceURI().equals(arg.getNamespaceURI())) {
      return false;
    }

    if (getPrefix() == null) {
      if (arg.getPrefix() != null) {
        return false;
      }
    } else if (!getPrefix().equals(arg.getPrefix())) {
      return false;
    }

    if (getNodeValue() == null) {
      if (arg.getNodeValue() != null) {
        return false;
      }
    } else if (!getNodeValue().equals(arg.getNodeValue())) {
      return false;
    }
    /*
        if (getBaseURI() == null) {
            if (((NodeImpl) arg).getBaseURI() != null) {
                return false;
            }
        }
        else if (!getBaseURI().equals(((NodeImpl) arg).getBaseURI())) {
            return false;
        }
    */

    return true;
  }

  /**
   * DOM Level 3 - Experimental:
   * Look up the namespace URI associated to the given prefix, starting from this node.
   * Use lookupNamespaceURI(null) to lookup the default namespace
   *
   * @param namespaceURI
   * @return th URI for the namespace
   * @since DOM Level 3
   */
  public String
  lookupNamespaceURI(String specifiedPrefix)
  {
    short type = this.getNodeType();
    switch (type) {
      case Node.ELEMENT_NODE : {

        String namespace = this.getNamespaceURI();
        String prefix = this.getPrefix();
        if (namespace != null) {
          // REVISIT: is it possible that prefix is empty string?
          if (specifiedPrefix == null && prefix == specifiedPrefix) {
            // looking for default namespace
            return namespace;
          } else if (prefix != null && prefix.equals(specifiedPrefix)) {
            // non default namespace
            return namespace;
          }
        }
        if (this.hasAttributes()) {
          NamedNodeMap map = this.getAttributes();
          int length = map.getLength();
          for (int i = 0; i < length; i++) {
            Node attr = map.item(i);
            String attrPrefix = attr.getPrefix();
            String value = attr.getNodeValue();
            namespace = attr.getNamespaceURI();
            if (namespace != null && namespace.equals("http://www.w3.org/2000/xmlns/")) {
              // at this point we are dealing with DOM Level 2 nodes only
              if (specifiedPrefix == null &&
                  attr.getNodeName().equals("xmlns")) {
                // default namespace
                return value;
              } else if (attrPrefix != null &&
                         attrPrefix.equals("xmlns") &&
                         attr.getLocalName().equals(specifiedPrefix)) {
                // non default namespace
                return value;
              }
            }
          }
        }
        /*
        NodeImpl ancestor = (NodeImpl)getElementAncestor(this);
        if (ancestor != null) {
            return ancestor.lookupNamespaceURI(specifiedPrefix);
        }
        */

        return null;


      }
      /*
              case Node.DOCUMENT_NODE : {
                      return((NodeImpl)((Document)this).getDocumentElement()).lookupNamespaceURI(specifiedPrefix) ;
                  }
      */
      case Node.ENTITY_NODE :
      case Node.NOTATION_NODE:
      case Node.DOCUMENT_FRAGMENT_NODE:
      case Node.DOCUMENT_TYPE_NODE:
        // type is unknown
        return null;
      case Node.ATTRIBUTE_NODE: {
        if (this.getOwnerElement().getNodeType() == Node.ELEMENT_NODE) {
          return getOwnerElement().lookupNamespaceURI(specifiedPrefix);

        }
        return null;
      }
      default: {
        /*
             NodeImpl ancestor = (NodeImpl)getElementAncestor(this);
             if (ancestor != null) {
                 return ancestor.lookupNamespaceURI(specifiedPrefix);
             }
          */
        return null;
      }

    }
  }

  /**
   *  DOM Level 3: Experimental
   *  This method checks if the specified <code>namespaceURI</code> is the
   *  default namespace or not.
   *  @param namespaceURI The namespace URI to look for.
   *  @return  <code>true</code> if the specified <code>namespaceURI</code>
   *   is the default namespace, <code>false</code> otherwise.
   * @since DOM Level 3
   */
  public boolean
  isDefaultNamespace(String namespaceURI)
  {
    /*
     // REVISIT: remove casts when DOM L3 becomes REC.
     short type = this.getNodeType();
     switch (type) {
     case Node.ELEMENT_NODE: {
         String namespace = this.getNamespaceURI();
         String prefix = this.getPrefix();

         // REVISIT: is it possible that prefix is empty string?
         if (prefix == null || prefix.length() == 0) {
             if (namespaceURI == null) {
                 return (namespace == namespaceURI);
             }
             return namespaceURI.equals(namespace);
         }
         if (this.hasAttributes()) {
             ElementImpl elem = (ElementImpl)this;
             NodeImpl attr = (NodeImpl)elem.getAttributeNodeNS("http://www.w3.org/2000/xmlns/", "xmlns");
             if (attr != null) {
                 String value = attr.getNodeValue();
                 if (namespaceURI == null) {
                     return (namespace == value);
                 }
                 return namespaceURI.equals(value);
             }
         }

         NodeImpl ancestor = (NodeImpl)getElementAncestor(this);
         if (ancestor != null) {
             return ancestor.isDefaultNamespace(namespaceURI);
         }
         return false;
     }
     case Node.DOCUMENT_NODE:{
             return((NodeImpl)((Document)this).getDocumentElement()).isDefaultNamespace(namespaceURI);
         }

     case Node.ENTITY_NODE :
       case Node.NOTATION_NODE:
     case Node.DOCUMENT_FRAGMENT_NODE:
     case Node.DOCUMENT_TYPE_NODE:
         // type is unknown
         return false;
     case Node.ATTRIBUTE_NODE:{
             if (this.ownerNode.getNodeType() == Node.ELEMENT_NODE) {
                 return ownerNode.isDefaultNamespace(namespaceURI);

             }
             return false;
         }
     default:{
             NodeImpl ancestor = (NodeImpl)getElementAncestor(this);
             if (ancestor != null) {
                 return ancestor.isDefaultNamespace(namespaceURI);
             }
             return false;
         }

     }
    */
    return false;


  }

  /**
   *
   * DOM Level 3 - Experimental:
   * Look up the prefix associated to the given namespace URI, starting from this node.
   *
   * @param namespaceURI
   * @return the prefix for the namespace
   */
  public String
  lookupPrefix(String namespaceURI)
  {

    // REVISIT: When Namespaces 1.1 comes out this may not be true
    // Prefix can't be bound to null namespace
    if (namespaceURI == null) {
      return null;
    }

    short type = this.getNodeType();

    switch (type) {
      /*
              case Node.ELEMENT_NODE: {

                      String namespace = this.getNamespaceURI(); // to flip out children
                      return lookupNamespacePrefix(namespaceURI, (ElementImpl)this);
                  }

              case Node.DOCUMENT_NODE:{
                      return((NodeImpl)((Document)this).getDocumentElement()).lookupPrefix(namespaceURI);
                  }
      */
      case Node.ENTITY_NODE :
      case Node.NOTATION_NODE:
      case Node.DOCUMENT_FRAGMENT_NODE:
      case Node.DOCUMENT_TYPE_NODE:
        // type is unknown
        return null;
      case Node.ATTRIBUTE_NODE: {
        if (this.getOwnerElement().getNodeType() == Node.ELEMENT_NODE) {
          return getOwnerElement().lookupPrefix(namespaceURI);

        }
        return null;
      }
      default: {
        /*
                        NodeImpl ancestor = (NodeImpl)getElementAncestor(this);
                        if (ancestor != null) {
                            return ancestor.lookupPrefix(namespaceURI);
                        }
        */
        return null;
      }
    }
  }

  /**
   * Returns whether this node is the same node as the given one.
   * <br>This method provides a way to determine whether two
   * <code>Node</code> references returned by the implementation reference
   * the same object. When two <code>Node</code> references are references
   * to the same object, even if through a proxy, the references may be
   * used completely interchangably, such that all attributes have the
   * same values and calling the same DOM method on either reference
   * always has exactly the same effect.
   * @param other The node to test against.
   * @return Returns <code>true</code> if the nodes are the same,
   *   <code>false</code> otherwise.
   * @since DOM Level 3
   */
  public boolean
  isSameNode(Node other)
  {
    // we do not use any wrapper so the answer is obvious
    return this == other;
  }

  /**
   * This attribute returns the text content of this node and its
   * descendants. When it is defined to be null, setting it has no effect.
   * When set, any possible children this node may have are removed and
   * replaced by a single <code>Text</code> node containing the string
   * this attribute is set to. On getting, no serialization is performed,
   * the returned string does not contain any markup. No whitespace
   * normalization is performed, the returned string does not contain the
   * element content whitespaces . Similarly, on setting, no parsing is
   * performed either, the input string is taken as pure textual content.
   * <br>The string returned is made of the text content of this node
   * depending on its type, as defined below:
   * <table border='1'>
   * <tr>
   * <th>Node type</th>
   * <th>Content</th>
   * </tr>
   * <tr>
   * <td valign='top' rowspan='1' colspan='1'>
   * ELEMENT_NODE, ENTITY_NODE, ENTITY_REFERENCE_NODE,
   * DOCUMENT_FRAGMENT_NODE</td>
   * <td valign='top' rowspan='1' colspan='1'>concatenation of the <code>textContent</code>
   * attribute value of every child node, excluding COMMENT_NODE and
   * PROCESSING_INSTRUCTION_NODE nodes</td>
   * </tr>
   * <tr>
   * <td valign='top' rowspan='1' colspan='1'>ATTRIBUTE_NODE, TEXT_NODE,
   * CDATA_SECTION_NODE, COMMENT_NODE, PROCESSING_INSTRUCTION_NODE</td>
   * <td valign='top' rowspan='1' colspan='1'>
   * <code>nodeValue</code></td>
   * </tr>
   * <tr>
   * <td valign='top' rowspan='1' colspan='1'>DOCUMENT_NODE, DOCUMENT_TYPE_NODE, NOTATION_NODE</td>
   * <td valign='top' rowspan='1' colspan='1'>
   * null</td>
   * </tr>
   * </table>
   * @exception DOMException
   *   NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly.
   * @exception DOMException
   *   DOMSTRING_SIZE_ERR: Raised when it would return more characters than
   *   fit in a <code>DOMString</code> variable on the implementation
   *   platform.
   * @since DOM Level 3
   */
  public void
  setTextContent(String textContent)
  throws DOMException
  {
    setNodeValue(textContent);
  }

  /**
   * This attribute returns the text content of this node and its
   * descendants. When it is defined to be null, setting it has no effect.
   * When set, any possible children this node may have are removed and
   * replaced by a single <code>Text</code> node containing the string
   * this attribute is set to. On getting, no serialization is performed,
   * the returned string does not contain any markup. No whitespace
   * normalization is performed, the returned string does not contain the
   * element content whitespaces . Similarly, on setting, no parsing is
   * performed either, the input string is taken as pure textual content.
   * <br>The string returned is made of the text content of this node
   * depending on its type, as defined below:
   * <table border='1'>
   * <tr>
   * <th>Node type</th>
   * <th>Content</th>
   * </tr>
   * <tr>
   * <td valign='top' rowspan='1' colspan='1'>
   * ELEMENT_NODE, ENTITY_NODE, ENTITY_REFERENCE_NODE,
   * DOCUMENT_FRAGMENT_NODE</td>
   * <td valign='top' rowspan='1' colspan='1'>concatenation of the <code>textContent</code>
   * attribute value of every child node, excluding COMMENT_NODE and
   * PROCESSING_INSTRUCTION_NODE nodes</td>
   * </tr>
   * <tr>
   * <td valign='top' rowspan='1' colspan='1'>ATTRIBUTE_NODE, TEXT_NODE,
   * CDATA_SECTION_NODE, COMMENT_NODE, PROCESSING_INSTRUCTION_NODE</td>
   * <td valign='top' rowspan='1' colspan='1'>
   * <code>nodeValue</code></td>
   * </tr>
   * <tr>
   * <td valign='top' rowspan='1' colspan='1'>DOCUMENT_NODE, DOCUMENT_TYPE_NODE, NOTATION_NODE</td>
   * <td valign='top' rowspan='1' colspan='1'>
   * null</td>
   * </tr>
   * </table>
   * @exception DOMException
   *   NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly.
   * @exception DOMException
   *   DOMSTRING_SIZE_ERR: Raised when it would return more characters than
   *   fit in a <code>DOMString</code> variable on the implementation
   *   platform.
   * @since DOM Level 3
   */
  public String
  getTextContent() throws DOMException
  {
    return getNodeValue();  // overriden in some subclasses
  }

  /**
   * Compares a node with this node with regard to their position in the
   * document.
   * @param other The node to compare against this node.
   * @return Returns how the given node is positioned relatively to this
   *   node.
   * @since DOM Level 3
   */
  public short
  compareDocumentPosition(Node other) throws DOMException
  {
    return 0;
  }

  /**
   * The absolute base URI of this node or <code>null</code> if undefined.
   * This value is computed according to . However, when the
   * <code>Document</code> supports the feature "HTML" , the base URI is
   * computed using first the value of the href attribute of the HTML BASE
   * element if any, and the value of the <code>documentURI</code>
   * attribute from the <code>Document</code> interface otherwise.
   * <br> When the node is an <code>Element</code>, a <code>Document</code>
   * or a a <code>ProcessingInstruction</code>, this attribute represents
   * the properties [base URI] defined in . When the node is a
   * <code>Notation</code>, an <code>Entity</code>, or an
   * <code>EntityReference</code>, this attribute represents the
   * properties [declaration base URI] in the . How will this be affected
   * by resolution of relative namespace URIs issue?It's not.Should this
   * only be on Document, Element, ProcessingInstruction, Entity, and
   * Notation nodes, according to the infoset? If not, what is it equal to
   * on other nodes? Null? An empty string? I think it should be the
   * parent's.No.Should this be read-only and computed or and actual
   * read-write attribute?Read-only and computed (F2F 19 Jun 2000 and
   * teleconference 30 May 2001).If the base HTML element is not yet
   * attached to a document, does the insert change the Document.baseURI?
   * Yes. (F2F 26 Sep 2001)
   * @since DOM Level 3
   */
  public String
  getBaseURI()
  {
    return null;
  }
}
