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 org.apache.xpath.XPathVisitor;
  
  /**
   * A derivation from this class can be passed to a class that implements 
   * the XSLTVisitable interface, to have the appropriate method called 
   * for each component of an XSLT stylesheet.  Aside from possible other uses,
   * the main intention is to provide a reasonable means to perform expression 
   * rewriting.
   */
  public class XSLTVisitor extends XPathVisitor
  {
  	/**
  	 * Visit an XSLT instruction.  Any element that isn't called by one 
  	 * of the other visit methods, will be called by this method.
  	 * 
  	 * @param elem The xsl instruction element object.
  	 * @return true if the sub expressions should be traversed.
  	 */
  	public boolean visitInstruction(ElemTemplateElement elem)
  	{
  		return true;
  	}
  	
  	/**
  	 * Visit an XSLT stylesheet instruction.
  	 * 
  	 * @param elem The xsl instruction element object.
  	 * @return true if the sub expressions should be traversed.
  	 */
  	public boolean visitStylesheet(ElemTemplateElement elem)
  	{
  		return true;
  	}
  
  	
  	/**
  	 * Visit an XSLT top-level instruction.
  	 * 
  	 * @param elem The xsl instruction element object.
  	 * @return true if the sub expressions should be traversed.
  	 */
  	public boolean visitTopLevelInstruction(ElemTemplateElement elem)
  	{
  		return true;
  	}
  	
  	/**
  	 * Visit an XSLT top-level instruction.
  	 * 
  	 * @param elem The xsl instruction element object.
  	 * @return true if the sub expressions should be traversed.
  	 */
  	public boolean visitTopLevelVariableOrParamDecl(ElemTemplateElement elem)
  	{
  		return true;
  	}
  
  	
  	/**
  	 * Visit an XSLT variable or parameter declaration.
  	 * 
  	 * @param elem The xsl instruction element object.
  	 * @return true if the sub expressions should be traversed.
  	 */
  	public boolean visitVariableOrParamDecl(ElemVariable elem)
  	{
  		return true;
  	}
  	
  	/**
  	 * Visit a LiteralResultElement.
  	 * 
  	 * @param elem The literal result object.
  	 * @return true if the sub expressions should be traversed.
  	 */
  	public boolean visitLiteralResultElement(ElemLiteralResult elem)
  	{
  		return true;
  	}
  	
  	/**
  	 * Visit an Attribute Value Template (at the top level).
  	 * 
  	 * @param elem The attribute value template object.
  	 * @return true if the sub expressions should be traversed.
  	 */
  	public boolean visitAVT(AVT elem)
  	{
  		return true;
  	}
  
  
  	/**
  	 * Visit an extension element.
  	 * @param elem The extension object.
  	 * @return true if the sub expressions should be traversed.
  	 */
  	public boolean visitExtensionElement(ElemExtensionCall elem)
  	{
  		return true;
  	}
  
  }
  
  