code: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements. See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership. The ASF licenses this file
   * to you 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.
   */
  /*
   * $Id$
   */
  package org.apache.xalan.templates;
  
  import javax.xml.transform.TransformerException;
  
  import org.apache.xalan.res.XSLTErrorResources;
  import org.apache.xalan.transformer.TransformerImpl;
  
  /**
   * Implement xsl:comment.
   * <pre>
   * <!ELEMENT xsl:comment %char-template;>
   * <!ATTLIST xsl:comment %space-att;>
   * </pre>
   * @see <a href="http://www.w3.org/TR/xslt#section-Creating-Comments">section-Creating-Comments in XSLT Specification</a>
   * @xsl.usage advanced
   */
  public class ElemComment extends ElemTemplateElement
  {
      static final long serialVersionUID = -8813199122875770142L;
  
    /**
     * Get an int constant identifying the type of element.
     * @see org.apache.xalan.templates.Constants
     *
     * @return The token ID for this element
     */
    public int getXSLToken()
    {
      return Constants.ELEMNAME_COMMENT;
    }
  
    /**
     * Return the node name.
     *
     * @return This element's name
     */
    public String getNodeName()
    {
      return Constants.ELEMNAME_COMMENT_STRING;
    }
  
    /**
     * Execute the xsl:comment transformation 
     *
     *
     * @param transformer non-null reference to the the current transform-time state.
     *
     * @throws TransformerException
     */
    public void execute(
            TransformerImpl transformer)
              throws TransformerException
    {
      if (transformer.getDebug())
        transformer.getTraceManager().fireTraceEvent(this);
      try
      {
        // Note the content model is:
        // <!ENTITY % instructions "
        // %char-instructions;
        // | xsl:processing-instruction
        // | xsl:comment
        // | xsl:element
        // | xsl:attribute
        // ">
        String data = transformer.transformToString(this);
  
        transformer.getResultTreeHandler().comment(data);
      }
      catch(org.xml.sax.SAXException se)
      {
        throw new TransformerException(se);
      }
      finally
      {
        if (transformer.getDebug())
          transformer.getTraceManager().fireTraceEndEvent(this);
      }
    }
  
    /**
     * Add a child to the child list.
     *
     * @param newChild Child to add to this node's child list
     *
     * @return Child that was just added to child list
     *
     * @throws DOMException
     */
    public ElemTemplateElement appendChild(ElemTemplateElement newChild)
    {
  
      int type = ((ElemTemplateElement) newChild).getXSLToken();
  
      switch (type)
      {
  
      // char-instructions 
      case Constants.ELEMNAME_TEXTLITERALRESULT :
      case Constants.ELEMNAME_APPLY_TEMPLATES :
      case Constants.ELEMNAME_APPLY_IMPORTS :
      case Constants.ELEMNAME_CALLTEMPLATE :
      case Constants.ELEMNAME_FOREACH :
      case Constants.ELEMNAME_VALUEOF :
      case Constants.ELEMNAME_COPY_OF :
      case Constants.ELEMNAME_NUMBER :
      case Constants.ELEMNAME_CHOOSE :
      case Constants.ELEMNAME_IF :
      case Constants.ELEMNAME_TEXT :
      case Constants.ELEMNAME_COPY :
      case Constants.ELEMNAME_VARIABLE :
      case Constants.ELEMNAME_MESSAGE :
  
        // instructions 
        // case Constants.ELEMNAME_PI:
        // case Constants.ELEMNAME_COMMENT:
        // case Constants.ELEMNAME_ELEMENT:
        // case Constants.ELEMNAME_ATTRIBUTE:
        break;
      default :
        error(XSLTErrorResources.ER_CANNOT_ADD,
              new Object[]{ newChild.getNodeName(),
                            this.getNodeName() });  //"Can not add " +((ElemTemplateElement)newChild).m_elemName +
  
      //" to " + this.m_elemName);
      }
  
      return super.appendChild(newChild);
    }
  }
  