/* (non-Javadoc)
  * @see org.xml.sax.ext.LexicalHandler#comment(char[], int, int)
  */
 public void comment(char[] ch, int start, int length) throws SAXException {
   if (inModification && charBuf.length() > 0) {
     final String normalized = charBuf.getNormalizedString(FastStringBuffer.SUPPRESS_BOTH);
     if (normalized.length() > 0) {
       final Text text = doc.createTextNode(normalized);
       if (stack.isEmpty()) {
         // LOG.debug("appending text to fragment: " + text.getData());
         contents.add(text);
       } else {
         final Element last = stack.peek();
         last.appendChild(text);
       }
     }
     charBuf.setLength(0);
   }
   if (inModification) {
     final Comment comment = doc.createComment(new String(ch, start, length));
     if (stack.isEmpty()) {
       contents.add(comment);
     } else {
       final Element last = stack.peek();
       last.appendChild(comment);
     }
   }
 }
  /** @see org.xml.sax.ContentHandler#processingInstruction(java.lang.String, java.lang.String) */
  public void processingInstruction(String target, String data) throws SAXException {
    if (inModification && charBuf.length() > 0) {
      final String normalized = charBuf.getNormalizedString(FastStringBuffer.SUPPRESS_BOTH);
      if (normalized.length() > 0) {
        final Text text = doc.createTextNode(normalized);
        if (stack.isEmpty()) {

          if (LOG.isDebugEnabled()) {
            LOG.debug("appending text to fragment: " + text.getData());
          }

          contents.add(text);
        } else {
          final Element last = stack.peek();
          last.appendChild(text);
        }
      }
      charBuf.setLength(0);
    }
    if (inModification) {
      final ProcessingInstruction pi = doc.createProcessingInstruction(target, data);
      if (stack.isEmpty()) {
        contents.add(pi);
      } else {
        final Element last = stack.peek();
        last.appendChild(pi);
      }
    }
  }
 /**
  * @see org.xml.sax.ContentHandler#endElement(java.lang.String, java.lang.String,
  *     java.lang.String)
  */
 public void endElement(String namespaceURI, String localName, String qName) throws SAXException {
   if (inModification && charBuf.length() > 0) {
     final String normalized =
         preserveWhitespace
             ? charBuf.toString()
             : charBuf.getNormalizedString(FastStringBuffer.SUPPRESS_BOTH);
     if (normalized.length() > 0) {
       final Text text = doc.createTextNode(charBuf.toString());
       if (stack.isEmpty()) {
         contents.add(text);
       } else {
         final Element last = stack.peek();
         last.appendChild(text);
       }
     }
     charBuf.setLength(0);
   }
   if (XUPDATE_NS.equals(namespaceURI)) {
     if (IF.equals(localName)) {
       final Conditional cond = conditionals.pop();
       modifications.add(cond);
     } else if (localName.equals(ELEMENT)) {
       this.resetWhitespaceHandling(stack.pop());
     } else if (localName.equals(ATTRIBUTE)) {
       inAttribute = false;
     } else if (localName.equals(APPEND)
         || localName.equals(UPDATE)
         || localName.equals(REMOVE)
         || localName.equals(RENAME)
         || localName.equals(REPLACE)
         || localName.equals(INSERT_BEFORE)
         || localName.equals(INSERT_AFTER)) {
       inModification = false;
       modification.setContent(contents);
       modification.setAccessContext(accessCtx);
       if (!conditionals.isEmpty()) {
         final Conditional cond = conditionals.peek();
         cond.addModification(modification);
       } else {
         modifications.add(modification);
       }
       modification = null;
     }
   } else if (inModification) {
     this.resetWhitespaceHandling(stack.pop());
   }
 }
  /**
   * @see org.xml.sax.ContentHandler#startElement(java.lang.String, java.lang.String,
   *     java.lang.String, org.xml.sax.Attributes)
   */
  public void startElement(String namespaceURI, String localName, String qName, Attributes atts)
      throws SAXException {
    // save accumulated character content
    if (inModification && charBuf.length() > 0) {
      //            String normalized = charBuf.toString();
      final String normalized =
          preserveWhitespace
              ? charBuf.toString()
              : charBuf.getNormalizedString(FastStringBuffer.SUPPRESS_BOTH);

      if (normalized.length() > 0) {
        final Text text = doc.createTextNode(charBuf.toString());
        if (stack.isEmpty()) {
          // LOG.debug("appending text to fragment: " + text.getData());
          contents.add(text);
        } else {
          final Element last = stack.peek();
          last.appendChild(text);
        }
      }
      charBuf.setLength(0);
    }
    if (namespaceURI.equals(XUPDATE_NS)) {
      String select = null;
      if (localName.equals(MODIFICATIONS)) {
        startModifications(atts);
        return;
      } else if (localName.equals(VARIABLE)) {
        // variable declaration
        startVariableDecl(atts);
        return;
      } else if (IF.equals(localName)) {
        if (inModification) {
          throw new SAXException("xupdate:if is not allowed inside a modification");
        }
        select = atts.getValue("test");
        final Conditional cond =
            new Conditional(broker, documentSet, select, namespaces, variables);
        cond.setAccessContext(accessCtx);
        conditionals.push(cond);
        return;
      } else if (VALUE_OF.equals(localName)) {
        if (!inModification) {
          throw new SAXException("xupdate:value-of is not allowed outside a modification");
        }

      } else if (APPEND.equals(localName)
          || INSERT_BEFORE.equals(localName)
          || INSERT_AFTER.equals(localName)
          || REMOVE.equals(localName)
          || RENAME.equals(localName)
          || UPDATE.equals(localName)
          || REPLACE.equals(localName)) {
        if (inModification) {
          throw new SAXException("nested modifications are not allowed");
        }
        select = atts.getValue("select");
        if (select == null) {
          throw new SAXException(localName + " requires a select attribute");
        }
        doc = builder.newDocument();
        contents = new NodeListImpl();
        inModification = true;
      } else if ((ELEMENT.equals(localName)
          || ATTRIBUTE.equals(localName)
          || TEXT.equals(localName)
          || PROCESSING_INSTRUCTION.equals(localName)
          || COMMENT.equals(localName))) {
        if (!inModification) {
          throw new SAXException("creation elements are only allowed inside " + "a modification");
        }
        charBuf.setLength(0);
      } else {
        throw new SAXException("Unknown XUpdate element: " + qName);
      }

      // start a new modification section
      if (APPEND.equals(localName)) {
        final String child = atts.getValue("child");
        modification = new Append(broker, documentSet, select, child, namespaces, variables);
      } else if (UPDATE.equals(localName)) {
        modification = new Update(broker, documentSet, select, namespaces, variables);
      } else if (INSERT_BEFORE.equals(localName)) {
        modification =
            new Insert(broker, documentSet, select, Insert.INSERT_BEFORE, namespaces, variables);
      } else if (INSERT_AFTER.equals(localName)) {
        modification =
            new Insert(broker, documentSet, select, Insert.INSERT_AFTER, namespaces, variables);
      } else if (REMOVE.equals(localName)) {
        modification = new Remove(broker, documentSet, select, namespaces, variables);
      } else if (RENAME.equals(localName)) {
        modification = new Rename(broker, documentSet, select, namespaces, variables);
      } else if (REPLACE.equals(localName)) {
        modification = new Replace(broker, documentSet, select, namespaces, variables);
      }

      // process commands for node creation
      else if (ELEMENT.equals(localName)) {
        String name = atts.getValue("name");
        if (name == null) {
          throw new SAXException("element requires a name attribute");
        }
        final int p = name.indexOf(':');
        String namespace = null;
        String prefix = "";
        if (p != Constants.STRING_NOT_FOUND) {
          prefix = name.substring(0, p);
          if (name.length() == p + 1) {
            throw new SAXException("illegal prefix in qname: " + name);
          }
          name = name.substring(p + 1);
          namespace = atts.getValue("namespace");
          if (namespace == null) {
            namespace = (String) namespaces.get(prefix);
          }
          if (namespace == null) {
            throw new SAXException("no namespace defined for prefix " + prefix);
          }
        }
        Element elem;
        if (namespace != null && namespace.length() > 0) {
          elem = doc.createElementNS(namespace, name);
          elem.setPrefix(prefix);
        } else {
          elem = doc.createElement(name);
        }

        if (stack.isEmpty()) {
          contents.add(elem);
        } else {
          final Element last = stack.peek();
          last.appendChild(elem);
        }
        this.setWhitespaceHandling((Element) stack.push(elem));
      } else if (ATTRIBUTE.equals(localName)) {
        final String name = atts.getValue("name");
        if (name == null) {
          throw new SAXException("attribute requires a name attribute");
        }
        final int p = name.indexOf(':');
        String namespace = null;
        if (p != Constants.STRING_NOT_FOUND) {
          final String prefix = name.substring(0, p);
          if (name.length() == p + 1) {
            throw new SAXException("illegal prefix in qname: " + name);
          }
          namespace = atts.getValue("namespace");
          if (namespace == null) {
            namespace = (String) namespaces.get(prefix);
          }
          if (namespace == null) {
            throw new SAXException("no namespace defined for prefix " + prefix);
          }
        }
        Attr attrib =
            namespace != null && namespace.length() > 0
                ? doc.createAttributeNS(namespace, name)
                : doc.createAttribute(name);
        if (stack.isEmpty()) {
          for (int i = 0; i < contents.getLength(); i++) {
            final Node n = contents.item(i);
            String ns = n.getNamespaceURI();
            final String nname = ns == null ? n.getNodeName() : n.getLocalName();
            if (ns == null) {
              ns = "";
            }
            // check for duplicate attributes
            if (n.getNodeType() == Node.ATTRIBUTE_NODE
                && nname.equals(name)
                && ns.equals(namespace)) {
              throw new SAXException(
                  "The attribute " + attrib.getNodeName() + " cannot be specified twice");
            }
          }
          contents.add(attrib);
        } else {
          final Element last = (Element) stack.peek();
          if (namespace != null && last.hasAttributeNS(namespace, name)
              || namespace == null && last.hasAttribute(name)) {
            throw new SAXException(
                "The attribute "
                    + attrib.getNodeName()
                    + " cannot be specified "
                    + "twice on the same element");
          }
          if (namespace != null) {
            last.setAttributeNodeNS(attrib);
          } else {
            last.setAttributeNode(attrib);
          }
        }
        inAttribute = true;
        currentNode = attrib;

        // process value-of
      } else if (VALUE_OF.equals(localName)) {
        select = atts.getValue("select");
        if (select == null) {
          throw new SAXException("value-of requires a select attribute");
        }
        final Sequence seq = processQuery(select);
        if (LOG.isDebugEnabled()) {
          LOG.debug("Found " + seq.getItemCount() + " items for value-of");
        }
        Item item;
        try {
          for (final SequenceIterator i = seq.iterate(); i.hasNext(); ) {
            item = i.nextItem();
            if (Type.subTypeOf(item.getType(), Type.NODE)) {
              final Node node = NodeSetHelper.copyNode(doc, ((NodeValue) item).getNode());
              if (stack.isEmpty()) {
                contents.add(node);
              } else {
                final Element last = (Element) stack.peek();
                last.appendChild(node);
              }
            } else {
              final String value = item.getStringValue();
              characters(value.toCharArray(), 0, value.length());
            }
          }
        } catch (final XPathException e) {
          throw new SAXException(e.getMessage(), e);
        }
      }
    } else if (inModification) {
      final Element elem =
          namespaceURI != null && namespaceURI.length() > 0
              ? doc.createElementNS(namespaceURI, qName)
              : doc.createElement(qName);
      Attr a;
      for (int i = 0; i < atts.getLength(); i++) {
        final String name = atts.getQName(i);
        final String nsURI = atts.getURI(i);
        if (name.startsWith("xmlns")) {
          // Why are these showing up? They are supposed to be stripped out?
        } else {
          a = nsURI != null ? doc.createAttributeNS(nsURI, name) : doc.createAttribute(name);
          a.setValue(atts.getValue(i));
          if (nsURI != null) {
            elem.setAttributeNodeNS(a);
          } else {
            elem.setAttributeNode(a);
          }
        }
      }
      if (stack.isEmpty()) {
        contents.add(elem);
      } else {
        final Element last = (Element) stack.peek();
        last.appendChild(elem);
      }
      this.setWhitespaceHandling((Element) stack.push(elem));
    }
  }