001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements. See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership. The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the  "License");
007     * you may not use this file except in compliance with the License.
008     * You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    /*
019     * $Id: ElemComment.java 468643 2006-10-28 06:56:03Z minchau $
020     */
021    package org.apache.xalan.templates;
022    
023    import javax.xml.transform.TransformerException;
024    
025    import org.apache.xalan.res.XSLTErrorResources;
026    import org.apache.xalan.transformer.TransformerImpl;
027    
028    /**
029     * Implement xsl:comment.
030     * <pre>
031     * <!ELEMENT xsl:comment %char-template;>
032     * <!ATTLIST xsl:comment %space-att;>
033     * </pre>
034     * @see <a href="http://www.w3.org/TR/xslt#section-Creating-Comments">section-Creating-Comments in XSLT Specification</a>
035     * @xsl.usage advanced
036     */
037    public class ElemComment extends ElemTemplateElement
038    {
039        static final long serialVersionUID = -8813199122875770142L;
040    
041      /**
042       * Get an int constant identifying the type of element.
043       * @see org.apache.xalan.templates.Constants
044       *
045       * @return The token ID for this element
046       */
047      public int getXSLToken()
048      {
049        return Constants.ELEMNAME_COMMENT;
050      }
051    
052      /**
053       * Return the node name.
054       *
055       * @return This element's name
056       */
057      public String getNodeName()
058      {
059        return Constants.ELEMNAME_COMMENT_STRING;
060      }
061    
062      /**
063       * Execute the xsl:comment transformation 
064       *
065       *
066       * @param transformer non-null reference to the the current transform-time state.
067       *
068       * @throws TransformerException
069       */
070      public void execute(
071              TransformerImpl transformer)
072                throws TransformerException
073      {
074        if (transformer.getDebug())
075          transformer.getTraceManager().fireTraceEvent(this);
076        try
077        {
078          // Note the content model is:
079          // <!ENTITY % instructions "
080          // %char-instructions;
081          // | xsl:processing-instruction
082          // | xsl:comment
083          // | xsl:element
084          // | xsl:attribute
085          // ">
086          String data = transformer.transformToString(this);
087    
088          transformer.getResultTreeHandler().comment(data);
089        }
090        catch(org.xml.sax.SAXException se)
091        {
092          throw new TransformerException(se);
093        }
094        finally
095        {
096          if (transformer.getDebug())
097            transformer.getTraceManager().fireTraceEndEvent(this);
098        }
099      }
100    
101      /**
102       * Add a child to the child list.
103       *
104       * @param newChild Child to add to this node's child list
105       *
106       * @return Child that was just added to child list
107       *
108       * @throws DOMException
109       */
110      public ElemTemplateElement appendChild(ElemTemplateElement newChild)
111      {
112    
113        int type = ((ElemTemplateElement) newChild).getXSLToken();
114    
115        switch (type)
116        {
117    
118        // char-instructions 
119        case Constants.ELEMNAME_TEXTLITERALRESULT :
120        case Constants.ELEMNAME_APPLY_TEMPLATES :
121        case Constants.ELEMNAME_APPLY_IMPORTS :
122        case Constants.ELEMNAME_CALLTEMPLATE :
123        case Constants.ELEMNAME_FOREACH :
124        case Constants.ELEMNAME_VALUEOF :
125        case Constants.ELEMNAME_COPY_OF :
126        case Constants.ELEMNAME_NUMBER :
127        case Constants.ELEMNAME_CHOOSE :
128        case Constants.ELEMNAME_IF :
129        case Constants.ELEMNAME_TEXT :
130        case Constants.ELEMNAME_COPY :
131        case Constants.ELEMNAME_VARIABLE :
132        case Constants.ELEMNAME_MESSAGE :
133    
134          // instructions 
135          // case Constants.ELEMNAME_PI:
136          // case Constants.ELEMNAME_COMMENT:
137          // case Constants.ELEMNAME_ELEMENT:
138          // case Constants.ELEMNAME_ATTRIBUTE:
139          break;
140        default :
141          error(XSLTErrorResources.ER_CANNOT_ADD,
142                new Object[]{ newChild.getNodeName(),
143                              this.getNodeName() });  //"Can not add " +((ElemTemplateElement)newChild).m_elemName +
144    
145        //" to " + this.m_elemName);
146        }
147    
148        return super.appendChild(newChild);
149      }
150    }