content: /*
   *  This file is part of AndroidIDE.
   *
   *  AndroidIDE is free software: you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation, either version 3 of the License, or
   *  (at your option) any later version.
   *
   *  AndroidIDE is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *   along with AndroidIDE.  If not, see <https://www.gnu.org/licenses/>.
   */
  
  /*
   * reserved comment block
   * DO NOT REMOVE OR ALTER!
   */
  /*
   * Copyright 1999-2002,2004 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.
   */
  
  package jaxp.sun.org.apache.xerces.internal.dom;
  
  import org.w3c.dom.Attr;
  import org.w3c.dom.DOMException;
  import org.w3c.dom.Element;
  import org.w3c.dom.NamedNodeMap;
  import org.w3c.dom.Node;
  import org.w3c.dom.NodeList;
  import org.w3c.dom.Text;
  
  import org.w3c.dom.TypeInfo;
  import jaxp.sun.org.apache.xerces.internal.util.URI;
  
  /**
   * Elements represent most of the "markup" and structure of the
   * document.  They contain both the data for the element itself
   * (element name and attributes), and any contained nodes, including
   * document text (as children).
   * <P>
   * Elements may have Attributes associated with them; the API for this is
   * defined in Node, but the function is implemented here. In general, XML
   * applications should retrive Attributes as Nodes, since they may contain
   * entity references and hence be a fairly complex sub-tree. HTML users will
   * be dealing with simple string values, and convenience methods are provided
   * to work in terms of Strings.
   * <P>
   * ElementImpl does not support Namespaces. ElementNSImpl, which inherits from
   * it, does.
   * @see ElementNSImpl
   *
   * @xerces.internal
   *
   * @author Arnaud  Le Hors, IBM
   * @author Joe Kesselman, IBM
   * @author Andy Clark, IBM
   * @author Ralf Pfeiffer, IBM
   * @since  PR-DOM-Level-1-19980818.
   */
  public class ElementImpl
      extends ParentNode
      implements Element, TypeInfo {
  
      //
      // Constants
      //
  
      /** Serialization version. */
      static final long serialVersionUID = 3717253516652722278L;
      //
      // Data
      //
  
      /** Element name. */
      protected String name;
  
      /** Attributes. */
      protected AttributeMap attributes;
  
      //
      // Constructors
      //
  
      /** Factory constructor. */
      public ElementImpl(CoreDocumentImpl ownerDoc, String name) {
          super(ownerDoc);
          this.name = name;
          needsSyncData(true);    // synchronizeData will initialize attributes
      }
  
      // for ElementNSImpl
      protected ElementImpl() {}
  
      // Support for DOM Level 3 renameNode method.
      // Note: This only deals with part of the pb. CoreDocumentImpl
      // does all the work.
      void rename(String name) {
          if (needsSyncData()) {
              synchronizeData();
          }
              this.name = name;
          reconcileDefaultAttributes();
      }
  
      //
      // Node methods
      //
  
  
      /**
       * A short integer indicating what type of node this is. The named
       * constants for this value are defined in the org.w3c.dom.Node interface.
       */
      public short getNodeType() {
          return Node.ELEMENT_NODE;
      }
  
      /**
       * Returns the element name
       */
      public String getNodeName() {
          if (needsSyncData()) {
              synchronizeData();
          }
          return name;
      }
  
      /**
       * Retrieve all the Attributes as a set. Note that this API is inherited
       * from Node rather than specified on Element; in fact only Elements will
       * ever have Attributes, but they want to allow folks to "blindly" operate
       * on the tree as a set of Nodes.
       */
      public NamedNodeMap getAttributes() {
  
          if (needsSyncData()) {
              synchronizeData();
          }
          if (attributes == null) {
              attributes = new AttributeMap(this, null);
          }
          return attributes;
  
      } // getAttributes():NamedNodeMap
  
      /**
       * Return a duplicate copy of this Element. Note that its children
       * will not be copied unless the "deep" flag is true, but Attributes
       * are <i>always</i> replicated.
       *
       * @see org.w3c.dom.Node#cloneNode(boolean)
       */
      public Node cloneNode(boolean deep) {
  
          ElementImpl newnode = (ElementImpl) super.cloneNode(deep);
          // Replicate NamedNodeMap rather than sharing it.
          if (attributes != null) {
              newnode.attributes = (AttributeMap) attributes.cloneMap(newnode);
          }
          return newnode;
  
      } // cloneNode(boolean):Node
  
     /**
       * DOM Level 3 WD - Experimental.
       * Retrieve baseURI
       */
      public String getBaseURI() {
  
          if (needsSyncData()) {
              synchronizeData();
          }
          // Absolute base URI is computed according to
          // XML Base (http://www.w3.org/TR/xmlbase/#granularity)
          // 1. The base URI specified by an xml:base attribute on the element,
          // if one exists
          if (attributes != null) {
              Attr attrNode = (Attr)attributes.getNamedItem("xml:base");
              if (attrNode != null) {
                  String uri =  attrNode.getNodeValue();
                  if (uri.length() != 0 ) {// attribute value is always empty string
                      try {
                         uri = new URI(uri).toString();
                      }
                      catch (URI.MalformedURIException e) {
                          // This may be a relative URI.
  
                          // Make any parentURI into a URI object to use with the URI(URI, String) constructor
                          String parentBaseURI = (this.ownerNode != null) ? this.ownerNode.getBaseURI() : null;
                          if (parentBaseURI != null){
                              try{
                                  uri = new URI(new URI(parentBaseURI), uri).toString();
                              }
                              catch (URI.MalformedURIException ex){
                                  // This should never happen: parent should have checked the URI and returned null if invalid.
                                  return null;
                              }
                              return uri;
                          }
                          return null;
                      }
                      return uri;
                  }
              }
          }
  
          // 2.the base URI of the element's parent element within the
          // document or external entity, if one exists
                  // 3. the base URI of the document entity or external entity
                  // containing the element
  
                  // ownerNode serves as a parent or as document
                  String baseURI = (this.ownerNode != null) ? this.ownerNode.getBaseURI() : null ;
          //base URI of parent element is not null
          if(baseURI != null){
              try {
                  //return valid absolute base URI
                 return new URI(baseURI).toString();
              }
              catch (URI.MalformedURIException e){
                  return null;
              }
          }
          return null;
      } //getBaseURI
  
  
  
      /**
       * NON-DOM
       * set the ownerDocument of this node, its children, and its attributes
       */
      void setOwnerDocument(CoreDocumentImpl doc) {
          super.setOwnerDocument(doc);
          if (attributes != null) {
              attributes.setOwnerDocument(doc);
          }
      }
  
      //
      // Element methods
      //
  
      /**
       * Look up a single Attribute by name. Returns the Attribute's
       * string value, or an empty string (NOT null!) to indicate that the
       * name did not map to a currently defined attribute.
       * <p>
       * Note: Attributes may contain complex node trees. This method
       * returns the "flattened" string obtained from Attribute.getValue().
       * If you need the structure information, see getAttributeNode().
       */
      public String getAttribute(String name) {
  
          if (needsSyncData()) {
              synchronizeData();
          }
          if (attributes == null) {
              return "";
          }
          Attr attr = (Attr)(attributes.getNamedItem(name));
          return (attr == null) ? "" : attr.getValue();
  
      } // getAttribute(String):String
  
  
      /**
       * Look up a single Attribute by name. Returns the Attribute Node,
       * so its complete child tree is available. This could be important in
       * XML, where the string rendering may not be sufficient information.
       * <p>
       * If no matching attribute is available, returns null.
       */
      public Attr getAttributeNode(String name) {
  
          if (needsSyncData()) {
              synchronizeData();
          }
          if (attributes == null) {
              return null;
          }
          return (Attr)attributes.getNamedItem(name);
  
      } // getAttributeNode(String):Attr
  
  
      /**
       * Returns a NodeList of all descendent nodes (children,
       * grandchildren, and so on) which are Elements and which have the
       * specified tag name.
       * <p>
       * Note: NodeList is a "live" view of the DOM. Its contents will
       * change as the DOM changes, and alterations made to the NodeList
       * will be reflected in the DOM.
       *
       * @param tagname The type of element to gather. To obtain a list of
       * all elements no matter what their names, use the wild-card tag
       * name "*".
       *
       * @see DeepNodeListImpl
       */
      public NodeList getElementsByTagName(String tagname) {
          return new DeepNodeListImpl(this,tagname);
      }
  
      /**
       * Returns the name of the Element. Note that Element.nodeName() is
       * defined to also return the tag name.
       * <p>
       * This is case-preserving in XML. HTML should uppercasify it on the
       * way in.
       */
      public String getTagName() {
          if (needsSyncData()) {
              synchronizeData();
          }
          return name;
      }
  
      /**
       * In "normal form" (as read from a source file), there will never be two
       * Text children in succession. But DOM users may create successive Text
       * nodes in the course of manipulating the document. Normalize walks the
       * sub-tree and merges adjacent Texts, as if the DOM had been written out
       * and read back in again. This simplifies implementation of higher-level
       * functions that may want to assume that the document is in standard form.
       * <p>
       * To normalize a Document, normalize its top-level Element child.
       * <p>
       * As of PR-DOM-Level-1-19980818, CDATA -- despite being a subclass of
       * Text -- is considered "markup" and will _not_ be merged either with
       * normal Text or with other CDATASections.
       */
      public void normalize() {
          // No need to normalize if already normalized.
          if (isNormalized()) {
              return;
          }
          if (needsSyncChildren()) {
              synchronizeChildren();
          }
          ChildNode kid, next;
          for (kid = firstChild; kid != null; kid = next) {
              next = kid.nextSibling;
  
              // If kid is a text node, we need to check for one of two
              // conditions:
              //   1) There is an adjacent text node
              //   2) There is no adjacent text node, but kid is
              //      an empty text node.
              if ( kid.getNodeType() == Node.TEXT_NODE )
              {
                  // If an adjacent text node, merge it with kid
                  if ( next!=null && next.getNodeType() == Node.TEXT_NODE )
                  {
                      ((Text)kid).appendData(next.getNodeValue());
                      removeChild( next );
                      next = kid; // Don't advance; there might be another.
                  }
                  else
                  {
                      // If kid is empty, remove it
                      if ( kid.getNodeValue() == null || kid.getNodeValue().length() == 0 ) {
                          removeChild( kid );
                      }
                  }
              }
  
              // Otherwise it might be an Element, which is handled recursively
              else if (kid.getNodeType() == Node.ELEMENT_NODE) {
                  kid.normalize();
              }
          }
  
          // We must also normalize all of the attributes
          if ( attributes!=null )
          {
              for( int i=0; i<attributes.getLength(); ++i )
              {
                  Node attr = attributes.item(i);
                  attr.normalize();
              }
          }
  
          // changed() will have occurred when the removeChild() was done,
          // so does not have to be reissued.
  
          isNormalized(true);
      } // normalize()
  
      /**
       * Remove the named attribute from this Element. If the removed
       * Attribute has a default value, it is immediately replaced thereby.
       * <P>
       * The default logic is actually implemented in NamedNodeMapImpl.
       * PR-DOM-Level-1-19980818 doesn't fully address the DTD, so some
       * of this behavior is likely to change in future versions. ?????
       * <P>
       * Note that this call "succeeds" even if no attribute by this name
       * existed -- unlike removeAttributeNode, which will throw a not-found
       * exception in that case.
       *
       * @throws DOMException(NO_MODIFICATION_ALLOWED_ERR) if the node is
       * readonly.
       */
      public void removeAttribute(String name) {
  
          if (ownerDocument.errorChecking && isReadOnly()) {
              String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NO_MODIFICATION_ALLOWED_ERR", null);
              throw new DOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR, msg);
          }
  
          if (needsSyncData()) {
              synchronizeData();
          }
  
          if (attributes == null) {
              return;
          }
  
          attributes.safeRemoveNamedItem(name);
  
      } // removeAttribute(String)
  
  
      /**
       * Remove the specified attribute/value pair. If the removed
       * Attribute has a default value, it is immediately replaced.
       * <p>
       * NOTE: Specifically removes THIS NODE -- not the node with this
       * name, nor the node with these contents. If the specific Attribute
       * object passed in is not stored in this Element, we throw a
       * DOMException.  If you really want to remove an attribute by name,
       * use removeAttribute().
       *
       * @return the Attribute object that was removed.
       * @throws DOMException(NOT_FOUND_ERR) if oldattr is not an attribute of
       * this Element.
       * @throws DOMException(NO_MODIFICATION_ALLOWED_ERR) if the node is
       * readonly.
       */
      public Attr removeAttributeNode(Attr oldAttr)
          throws DOMException {
  
          if (ownerDocument.errorChecking && isReadOnly()) {
              String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NO_MODIFICATION_ALLOWED_ERR", null);
              throw new DOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR, msg);
          }
  
          if (needsSyncData()) {
              synchronizeData();
          }
  
          if (attributes == null) {
              String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NOT_FOUND_ERR", null);
              throw new DOMException(DOMException.NOT_FOUND_ERR, msg);
          }
          return (Attr) attributes.removeItem(oldAttr, true);
  
      } // removeAttributeNode(Attr):Attr
  
  
      /**
       * Add a new name/value pair, or replace the value of the existing
       * attribute having that name.
       *
       * Note: this method supports only the simplest kind of Attribute,
       * one whose value is a string contained in a single Text node.
       * If you want to assert a more complex value (which XML permits,
       * though HTML doesn't), see setAttributeNode().
       *
       * The attribute is created with specified=true, meaning it's an
       * explicit value rather than inherited from the DTD as a default.
       * Again, setAttributeNode can be used to achieve other results.
       *
       * @throws DOMException(INVALID_NAME_ERR) if the name is not acceptable.
       * (Attribute factory will do that test for us.)
       *
       * @throws DOMException(NO_MODIFICATION_ALLOWED_ERR) if the node is
       * readonly.
       */
          public void setAttribute(String name, String value) {
  
                  if (ownerDocument.errorChecking && isReadOnly()) {
                          String msg =
                                  DOMMessageFormatter.formatMessage(
                                          DOMMessageFormatter.DOM_DOMAIN,
                                          "NO_MODIFICATION_ALLOWED_ERR",
                                          null);
                          throw new DOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR, msg);
                  }
  
                  if (needsSyncData()) {
                          synchronizeData();
                  }
  
                  Attr newAttr = getAttributeNode(name);
                  if (newAttr == null) {
                          newAttr = getOwnerDocument().createAttribute(name);
  
                          if (attributes == null) {
                                  attributes = new AttributeMap(this, null);
                          }
  
                          newAttr.setNodeValue(value);
                          attributes.setNamedItem(newAttr);
                  }
                  else {
                          newAttr.setNodeValue(value);
                  }
  
          } // setAttribute(String,String)
  
      /**
       * Add a new attribute/value pair, or replace the value of the
       * existing attribute with that name.
       * <P>
       * This method allows you to add an Attribute that has already been
       * constructed, and hence avoids the limitations of the simple
       * setAttribute() call. It can handle attribute values that have
       * arbitrarily complex tree structure -- in particular, those which
       * had entity references mixed into their text.
       *
       * @throws DOMException(INUSE_ATTRIBUTE_ERR) if the Attribute object
       * has already been assigned to another Element.
       */
      public Attr setAttributeNode(Attr newAttr)
          throws DOMException
          {
  
          if (needsSyncData()) {
              synchronizeData();
          }
  
          if (ownerDocument.errorChecking) {
              if (isReadOnly()) {
                  String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NO_MODIFICATION_ALLOWED_ERR", null);
                  throw new DOMException(
                                       DOMException.NO_MODIFICATION_ALLOWED_ERR,
                                       msg);
              }
  
              if (newAttr.getOwnerDocument() != ownerDocument) {
                  String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "WRONG_DOCUMENT_ERR", null);
                      throw new DOMException(DOMException.WRONG_DOCUMENT_ERR, msg);
              }
          }
  
          if (attributes == null) {
              attributes = new AttributeMap(this, null);
          }
          // This will throw INUSE if necessary
          return (Attr) attributes.setNamedItem(newAttr);
  
      } // setAttributeNode(Attr):Attr
  
      //
      // DOM2: Namespace methods
      //
  
      /**
       * Introduced in DOM Level 2. <p>
       *
       * Retrieves an attribute value by local name and namespace URI.
       *
       * @param namespaceURI
       *                      The namespace URI of the attribute to
       *                      retrieve.
       * @param localName     The local name of the attribute to retrieve.
       * @return String       The Attr value as a string, or empty string
       *                      if that attribute
       *                      does not have a specified or default value.
       * @since WD-DOM-Level-2-19990923
       */
      public String getAttributeNS(String namespaceURI, String localName) {
  
          if (needsSyncData()) {
              synchronizeData();
          }
  
          if (attributes == null) {
              return "";
          }
  
          Attr attr = (Attr)(attributes.getNamedItemNS(namespaceURI, localName));
          return (attr == null) ? "" : attr.getValue();
  
      } // getAttributeNS(String,String):String
  
      /**
       * Introduced in DOM Level 2. <p>
       *
       *  Adds a new attribute.
       *  If the given namespaceURI is null or an empty string and the
       *  qualifiedName has a prefix that is "xml", the new attribute is bound to
       *  the predefined namespace "http://www.w3.org/XML/1998/namespace"
       *  [Namespaces].  If an attribute with the same local name and namespace
       *  URI is already present on the element, its prefix is changed to be the
       *  prefix part of the qualifiedName, and its value is changed to be the
       *  value parameter. This value is a simple string, it is not parsed as it
       *  is being set. So any markup (such as syntax to be recognized as an
       *  entity reference) is treated as literal text, and needs to be
       *  appropriately escaped by the implementation when it is written out. In
       *  order to assign an attribute value that contains entity references, the
       *  user must create an Attr node plus any Text and EntityReference nodes,
       *  build the appropriate subtree, and use setAttributeNodeNS or
       *  setAttributeNode to assign it as the value of an attribute.
       *
       * @param namespaceURI      The namespace URI of the attribute to create
       *                          or alter.
       * @param qualifiedName     The qualified name of the attribute to create or
       *                          alter.
       * @param value             The value to set in string form.
       * @throws                  INVALID_CHARACTER_ERR: Raised if the specified
       *                          name contains an invalid character.
       *
       * @throws                  NO_MODIFICATION_ALLOWED_ERR: Raised if this
       *                          node is readonly.
       *
       * @throws                  NAMESPACE_ERR: Raised if the qualifiedName
       *                          has a prefix that is "xml" and the namespaceURI
       *                          is neither null nor an empty string nor
       *                          "http://www.w3.org/XML/1998/namespace", or if
       *                          the qualifiedName has a prefix that is "xmlns"
       *                          but the namespaceURI is neither null nor an
       *                          empty string, or if if the qualifiedName has a
       *                          prefix different from "xml" and "xmlns" and the
       *                          namespaceURI is null or an empty string.
       * @since WD-DOM-Level-2-19990923
       */
       public void setAttributeNS(String namespaceURI,String qualifiedName,
                                            String value) {
                  if (ownerDocument.errorChecking && isReadOnly()) {
                          String msg =
                                  DOMMessageFormatter.formatMessage(
                                          DOMMessageFormatter.DOM_DOMAIN,
                                          "NO_MODIFICATION_ALLOWED_ERR",
                                          null);
                          throw new DOMException(
                                  DOMException.NO_MODIFICATION_ALLOWED_ERR,
                                  msg);
                  }
                  if (needsSyncData()) {
                          synchronizeData();
                  }
                  int index = qualifiedName.indexOf(':');
                  String prefix, localName;
                  if (index < 0) {
                          prefix = null;
                          localName = qualifiedName;
                  }
                  else {
                          prefix = qualifiedName.substring(0, index);
                          localName = qualifiedName.substring(index + 1);
                  }
                  Attr newAttr = getAttributeNodeNS(namespaceURI, localName);
                  if (newAttr == null) {
              // REVISIT: this is not efficient, we are creating twice the same
              //          strings for prefix and localName.
                          newAttr = getOwnerDocument().createAttributeNS(
                                          namespaceURI,
                                          qualifiedName);
                          if (attributes == null) {
                                  attributes = new AttributeMap(this, null);
                          }
                          newAttr.setNodeValue(value);
                          attributes.setNamedItemNS(newAttr);
                  }
                  else {
              if (newAttr instanceof AttrNSImpl){
                  String origNodeName = ((AttrNSImpl) newAttr).name;
                  String newName = (prefix!=null) ? (prefix+":"+localName) : localName;
  
                  ((AttrNSImpl) newAttr).name = newName;
  
                  if (!newName.equals(origNodeName)) {
                      // Note: we can't just change the name of the attribute. Names have to be in sorted
                      // order in the attributes vector because a binary search is used to locate them.
                      // If the new name has a different prefix, the list may become unsorted.
                      // Maybe it would be better to resort the list, but the simplest
                      // fix seems to be to remove the old attribute and re-insert it.
                      // -- Norman.Walsh@Sun.COM, 2 Feb 2007
                      newAttr = (Attr) attributes.removeItem(newAttr, false);
                      attributes.addItem(newAttr);
                  }
              }
              else {
                  // This case may happen if user calls:
                  //      elem.setAttribute("name", "value");
                  //      elem.setAttributeNS(null, "name", "value");
                  // This case is not defined by the DOM spec, we choose
                  // to create a new attribute in this case and remove an old one from the tree
                  // note this might cause events to be propagated or user data to be lost
                  newAttr = new AttrNSImpl((CoreDocumentImpl)getOwnerDocument(), namespaceURI, qualifiedName, localName);
                  attributes.setNamedItemNS(newAttr);
              }
  
                          newAttr.setNodeValue(value);
                  }
  
      } // setAttributeNS(String,String,String)
  
  
      /**
       * Introduced in DOM Level 2. <p>
       *
       * Removes an attribute by local name and namespace URI. If the removed
       * attribute has a default value it is immediately replaced.
       * The replacing attribute has the same namespace URI and local name,
       * as well as the original prefix.<p>
       *
       * @param namespaceURI  The namespace URI of the attribute to remove.
       *
       * @param localName     The local name of the attribute to remove.
       * @throws                  NO_MODIFICATION_ALLOWED_ERR: Raised if this
       *                          node is readonly.
       * @since WD-DOM-Level-2-19990923
       */
      public void removeAttributeNS(String namespaceURI, String localName) {
  
          if (ownerDocument.errorChecking && isReadOnly()) {
              String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NO_MODIFICATION_ALLOWED_ERR", null);
              throw new DOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR, msg);
          }
  
          if (needsSyncData()) {
              synchronizeData();
          }
  
          if (attributes == null) {
              return;
          }
  
          attributes.safeRemoveNamedItemNS(namespaceURI, localName);
  
      } // removeAttributeNS(String,String)
  
      /**
       * Retrieves an Attr node by local name and namespace URI.
       *
       * @param namespaceURI  The namespace URI of the attribute to
       *                      retrieve.
       * @param localName     The local name of the attribute to retrieve.
       * @return Attr         The Attr node with the specified attribute
       *                      local name and namespace
       *                      URI or null if there is no such attribute.
       * @since WD-DOM-Level-2-19990923
       */
      public Attr getAttributeNodeNS(String namespaceURI, String localName){
  
          if (needsSyncData()) {
              synchronizeData();
          }
          if (attributes == null) {
              return null;
          }
          return (Attr)attributes.getNamedItemNS(namespaceURI, localName);
  
      } // getAttributeNodeNS(String,String):Attr
  
      /**
       * Introduced in DOM Level 2. <p>
       *
       * Adds a new attribute. If an attribute with that local name and
       * namespace URI is already present in the element, it is replaced
       * by the new one.
       *
       * @param Attr      The Attr node to add to the attribute list. When
       *                  the Node has no namespaceURI, this method behaves
       *                  like setAttributeNode.
       * @return Attr     If the newAttr attribute replaces an existing attribute
       *                  with the same local name and namespace URI, the *
       *                  previously existing Attr node is returned, otherwise
       *                  null is returned.
       * @throws          WRONG_DOCUMENT_ERR: Raised if newAttr
       *                  was created from a different document than the one that
       *                  created the element.
       *
       * @throws          NO_MODIFICATION_ALLOWED_ERR: Raised if
       *                  this node is readonly.
       *
       * @throws          INUSE_ATTRIBUTE_ERR: Raised if newAttr is
       *                  already an attribute of another Element object. The
       *                  DOM user must explicitly clone Attr nodes to re-use
       *                  them in other elements.
       * @since WD-DOM-Level-2-19990923
       */
      public Attr setAttributeNodeNS(Attr newAttr)
          throws DOMException
          {
  
          if (needsSyncData()) {
              synchronizeData();
          }
          if (ownerDocument.errorChecking) {
              if (isReadOnly()) {
                  String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NO_MODIFICATION_ALLOWED_ERR", null);
                      throw new DOMException(
                                       DOMException.NO_MODIFICATION_ALLOWED_ERR,
                                       msg);
              }
              if (newAttr.getOwnerDocument() != ownerDocument) {
                  String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "WRONG_DOCUMENT_ERR", null);
                  throw new DOMException(DOMException.WRONG_DOCUMENT_ERR, msg);
              }
          }
  
          if (attributes == null) {
              attributes = new AttributeMap(this, null);
          }
          // This will throw INUSE if necessary
          return (Attr) attributes.setNamedItemNS(newAttr);
  
      } // setAttributeNodeNS(Attr):Attr
  
      /**
        * NON-DOM: sets attribute node for this element
        */
      protected int setXercesAttributeNode (Attr attr){
  
          if (needsSyncData()) {
              synchronizeData();
          }
  
          if (attributes == null) {
              attributes = new AttributeMap(this, null);
          }
          return attributes.addItem(attr);
  
      }
  
      /**
        * NON-DOM: get inded of an attribute
        */
      protected int getXercesAttribute(String namespaceURI, String localName){
  
          if (needsSyncData()) {
              synchronizeData();
          }
          if (attributes == null) {
              return -1;
          }
          return attributes.getNamedItemIndex(namespaceURI, localName);
  
      }
  
      /**
       * Introduced in DOM Level 2.
       */
      public boolean hasAttributes() {
          if (needsSyncData()) {
              synchronizeData();
          }
          return (attributes != null && attributes.getLength() != 0);
      }
  
      /**
       * Introduced in DOM Level 2.
       */
      public boolean hasAttribute(String name) {
          return getAttributeNode(name) != null;
      }
  
      /**
       * Introduced in DOM Level 2.
       */
      public boolean hasAttributeNS(String namespaceURI, String localName) {
          return getAttributeNodeNS(namespaceURI, localName) != null;
      }
  
      /**
       * Introduced in DOM Level 2. <p>
       *
       * Returns a NodeList of all the Elements with a given local name and
       * namespace URI in the order in which they would be encountered in a
       * preorder traversal of the Document tree, starting from this node.
       *
       * @param namespaceURI The namespace URI of the elements to match
       *                     on. The special value "*" matches all
       *                     namespaces. When it is null or an empty
       *                     string, this method behaves like
       *                     getElementsByTagName.
       * @param localName    The local name of the elements to match on.
       *                     The special value "*" matches all local names.
       * @return NodeList    A new NodeList object containing all the matched
       *                     Elements.
       * @since WD-DOM-Level-2-19990923
       */
      public NodeList getElementsByTagNameNS(String namespaceURI,
                                             String localName) {
          return new DeepNodeListImpl(this, namespaceURI, localName);
      }
  
      /**
       * DOM Level 3 WD- Experimental.
       * Override inherited behavior from NodeImpl and ParentNode to check on
       * attributes
       */
      public boolean isEqualNode(Node arg) {
          if (!super.isEqualNode(arg)) {
              return false;
          }
          boolean hasAttrs = hasAttributes();
          if (hasAttrs != ((Element) arg).hasAttributes()) {
              return false;
          }
          if (hasAttrs) {
              NamedNodeMap map1 = getAttributes();
              NamedNodeMap map2 = ((Element) arg).getAttributes();
              int len = map1.getLength();
              if (len != map2.getLength()) {
                  return false;
              }
              for (int i = 0; i < len; i++) {
                  Node n1 = map1.item(i);
                  if (n1.getLocalName() == null) { // DOM Level 1 Node
                      Node n2 = map2.getNamedItem(n1.getNodeName());
                      if (n2 == null || !((NodeImpl) n1).isEqualNode(n2)) {
                          return false;
                      }
                  }
                  else {
                      Node n2 = map2.getNamedItemNS(n1.getNamespaceURI(),
                                                    n1.getLocalName());
                      if (n2 == null || !((NodeImpl) n1).isEqualNode(n2)) {
                          return false;
                      }
                  }
              }
          }
          return true;
      }
  
      /**
       * DOM Level 3: register the given attribute node as an ID attribute
       */
      public void setIdAttributeNode(Attr at, boolean makeId) {
          if (needsSyncData()) {
              synchronizeData();
          }
          if (ownerDocument.errorChecking) {
              if (isReadOnly()) {
                  String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NO_MODIFICATION_ALLOWED_ERR", null);
                  throw new DOMException(
                                       DOMException.NO_MODIFICATION_ALLOWED_ERR,
                                       msg);
              }
  
              if (at.getOwnerElement() != this) {
                  String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NOT_FOUND_ERR", null);
                  throw new DOMException(DOMException.NOT_FOUND_ERR, msg);
              }
          }
          ((AttrImpl) at).isIdAttribute(makeId);
          if (!makeId) {
              ownerDocument.removeIdentifier(at.getValue());
          }
          else {
              ownerDocument.putIdentifier(at.getValue(), this);
          }
      }
  
      /**
       * DOM Level 3: register the given attribute node as an ID attribute
       */
      public void setIdAttribute(String name, boolean makeId) {
          if (needsSyncData()) {
              synchronizeData();
          }
          Attr at = getAttributeNode(name);
  
                  if( at == null){
                  String msg = DOMMessageFormatter.formatMessage(
                                                                          DOMMessageFormatter.DOM_DOMAIN,
                                                                          "NOT_FOUND_ERR", null);
              throw new DOMException(DOMException.NOT_FOUND_ERR, msg);
                  }
  
                  if (ownerDocument.errorChecking) {
              if (isReadOnly()) {
                  String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NO_MODIFICATION_ALLOWED_ERR", null);
                  throw new DOMException(
                                       DOMException.NO_MODIFICATION_ALLOWED_ERR,
                                       msg);
              }
  
              if (at.getOwnerElement() != this) {
                  String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NOT_FOUND_ERR", null);
                  throw new DOMException(DOMException.NOT_FOUND_ERR, msg);
              }
          }
  
          ((AttrImpl) at).isIdAttribute(makeId);
          if (!makeId) {
              ownerDocument.removeIdentifier(at.getValue());
          }
          else {
              ownerDocument.putIdentifier(at.getValue(), this);
          }
      }
  
      /**
       * DOM Level 3: register the given attribute node as an ID attribute
       */
      public void setIdAttributeNS(String namespaceURI, String localName,
                                      boolean makeId) {
          if (needsSyncData()) {
              synchronizeData();
          }
          //if namespace uri is empty string, set it to 'null'
          if (namespaceURI != null) {
              namespaceURI = (namespaceURI.length() == 0)? null : namespaceURI;
          }
          Attr at = getAttributeNodeNS(namespaceURI, localName);
  
                  if( at == null){
                  String msg = DOMMessageFormatter.formatMessage(
                                                                          DOMMessageFormatter.DOM_DOMAIN,
                                                                          "NOT_FOUND_ERR", null);
              throw new DOMException(DOMException.NOT_FOUND_ERR, msg);
                  }
  
                  if (ownerDocument.errorChecking) {
              if (isReadOnly()) {
                  String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NO_MODIFICATION_ALLOWED_ERR", null);
                  throw new DOMException(
                                       DOMException.NO_MODIFICATION_ALLOWED_ERR,
                                       msg);
              }
  
              if (at.getOwnerElement() != this) {
                  String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NOT_FOUND_ERR", null);
                  throw new DOMException(DOMException.NOT_FOUND_ERR, msg);
              }
          }
          ((AttrImpl) at).isIdAttribute(makeId);
          if (!makeId) {
              ownerDocument.removeIdentifier(at.getValue());
          }
          else {
              ownerDocument.putIdentifier(at.getValue(), this);
          }
     }
  
      /**
       * @see org.w3c.dom.TypeInfo#getTypeName()
       */
       public String getTypeName() {
          return null;
       }
  
      /**
       * @see org.w3c.dom.TypeInfo#getTypeNamespace()
       */
      public String getTypeNamespace() {
          return null;
      }
  
      /**
       * Introduced in DOM Level 3. <p>
       * Checks if a type is derived from another by restriction. See:
       * http://www.w3.org/TR/DOM-Level-3-Core/core.html#TypeInfo-isDerivedFrom
       *
       * @param ancestorNS
       *        The namspace of the ancestor type declaration
       * @param ancestorName
       *        The name of the ancestor type declaration
       * @param type
       *        The reference type definition
       *
       * @return boolean True if the type is derived by restriciton for the
       *         reference type
       */
      public boolean isDerivedFrom(String typeNamespaceArg,
                                   String typeNameArg,
                                   int derivationMethod) {
  
          return false;
      }
  
          /**
           * Method getSchemaTypeInfo.
           * @return TypeInfo
           */
      public TypeInfo getSchemaTypeInfo(){
          if(needsSyncData()) {
              synchronizeData();
          }
          return this;
      }
  
      //
      // Public methods
      //
  
      /**
       * NON-DOM: Subclassed to flip the attributes' readonly switch as well.
       * @see NodeImpl#setReadOnly
       */
      public void setReadOnly(boolean readOnly, boolean deep) {
          super.setReadOnly(readOnly,deep);
          if (attributes != null) {
              attributes.setReadOnly(readOnly,true);
          }
      }
  
  
  
      //
      // Protected methods
      //
  
      /** Synchronizes the data (name and value) for fast nodes. */
      protected void synchronizeData() {
  
          // no need to sync in the future
          needsSyncData(false);
  
          // we don't want to generate any event for this so turn them off
          boolean orig = ownerDocument.getMutationEvents();
          ownerDocument.setMutationEvents(false);
  
          // attributes
          setupDefaultAttributes();
  
          // set mutation events flag back to its original value
          ownerDocument.setMutationEvents(orig);
  
      } // synchronizeData()
  
      // support for DOM Level 3 renameNode method
      // @param el The element from which to take the attributes
      void moveSpecifiedAttributes(ElementImpl el) {
          if (needsSyncData()) {
              synchronizeData();
          }
          if (el.hasAttributes()) {
              if (attributes == null) {
                  attributes = new AttributeMap(this, null);
              }
              attributes.moveSpecifiedAttributes(el.attributes);
          }
      }
  
      /** Setup the default attributes. */
      protected void setupDefaultAttributes() {
          NamedNodeMapImpl defaults = getDefaultAttributes();
          if (defaults != null) {
              attributes = new AttributeMap(this, defaults);
          }
      }
  
      /** Reconcile default attributes. */
      protected void reconcileDefaultAttributes() {
          if (attributes != null) {
              NamedNodeMapImpl defaults = getDefaultAttributes();
              attributes.reconcileDefaults(defaults);
          }
      }
  
      /** Get the default attributes. */
      protected NamedNodeMapImpl getDefaultAttributes() {
  
          DocumentTypeImpl doctype =
              (DocumentTypeImpl) ownerDocument.getDoctype();
          if (doctype == null) {
              return null;
          }
          ElementDefinitionImpl eldef =
              (ElementDefinitionImpl)doctype.getElements()
                                                 .getNamedItem(getNodeName());
          if (eldef == null) {
              return null;
          }
          return (NamedNodeMapImpl) eldef.getAttributes();
  
      } // getDefaultAttributes()
  
  } // class ElementImpl
  