/*
    * $Id$
    *
    * 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.
   */
  
  package org.apache.struts.tiles.xmlDefinition;
  
  import java.io.BufferedInputStream;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.URL;
  
  import org.apache.commons.digester.Digester;
  import org.xml.sax.SAXException;
  
  /**
   * Parse an XML definitions file.
   */
  public class XmlParser
  {
  
      /** Associated digester. */
    protected Digester digester;
      /**
       * Should we use a validating XML parser to read the configuration file.
       * Default is <code>false</code>.
       */
      protected boolean validating = false;
      /**
       * The set of public identifiers, and corresponding resource names for
       * the versions of the configuration file DTDs we know about.  There
       * <strong>MUST</strong> be an even number of Strings in this list!
       */
      protected String registrations[] = {
          "-//Apache Software Foundation//DTD Tiles Configuration 1.1//EN",
          "/org/apache/struts/resources/tiles-config_1_1.dtd",
          "-//Apache Software Foundation//DTD Tiles Configuration 1.3//EN",
          "/org/apache/struts/resources/tiles-config_1_3.dtd",
          "-//Apache Software Foundation//DTD Tiles Configuration 1.4//EN",
          "/org/apache/struts/resources/tiles-config_1_4.dtd"
      };
  
       /**
        * Constructor.
        * Creates a digester parser and initializes syntax rules.
        */
    public XmlParser()
    {
      digester = new Digester();
      digester.setValidating(validating);
      digester.setNamespaceAware(true);
      digester.setUseContextClassLoader(true);
      // Register our local copy of the DTDs that we can find
    for (int i = 0; i < registrations.length; i += 2) {
        URL url = this.getClass().getResource(registrations[i+1]);
        if (url != null)
            {
            digester.register(registrations[i], url.toString());
            }
    }
      // Init syntax rules
    initDigester( digester );
    }
  
      /**
       * Set digester validating flag.
       */
    public void setValidating( boolean validating )
      {
      digester.setValidating( validating);
      }
  
  
     /**
      * Init digester for components syntax.
      * This is an old set of rules, left for backward compatibility.
      * @param digester Digester instance to use.
      */
    private void initDigesterForComponentsDefinitionsSyntax( Digester digester )
    {
       // Common constants
    String PACKAGE_NAME = "org.apache.struts.tiles.xmlDefinition";
   String DEFINITION_TAG = "component-definitions/definition";
   String definitionHandlerClass = PACKAGE_NAME + ".XmlDefinition";
 
   String PUT_TAG  = DEFINITION_TAG + "/put";
   String putAttributeHandlerClass = PACKAGE_NAME + ".XmlAttribute";
 
   String LIST_TAG = DEFINITION_TAG + "/putList";
   String listHandlerClass     = PACKAGE_NAME + ".XmlListAttribute";
 
   String ADD_LIST_ELE_TAG = LIST_TAG + "/add";
 
     // syntax rules
     digester.addObjectCreate(  DEFINITION_TAG, definitionHandlerClass );
     digester.addSetProperties( DEFINITION_TAG);
     digester.addSetNext(       DEFINITION_TAG, "putDefinition", definitionHandlerClass);
     // put / putAttribute rules
     digester.addObjectCreate(  PUT_TAG, putAttributeHandlerClass);
     digester.addSetNext(       PUT_TAG, "addAttribute", putAttributeHandlerClass);
     digester.addSetProperties( PUT_TAG);
     digester.addCallMethod(    PUT_TAG, "setBody", 0);
     // list rules
     digester.addObjectCreate(  LIST_TAG, listHandlerClass);
     digester.addSetProperties( LIST_TAG);
     digester.addSetNext(       LIST_TAG, "addAttribute", putAttributeHandlerClass);
     // list elements rules
     // We use Attribute class to avoid rewriting a new class.
     // Name part can't be used in listElement attribute.
     digester.addObjectCreate(  ADD_LIST_ELE_TAG, putAttributeHandlerClass);
     digester.addSetNext(       ADD_LIST_ELE_TAG, "add", putAttributeHandlerClass);
     digester.addSetProperties( ADD_LIST_ELE_TAG);
     digester.addCallMethod(    ADD_LIST_ELE_TAG, "setBody", 0);
   }
 
    /**
     * Init digester for Tiles syntax.
     * Same as components, but with first element = tiles-definitions
     * @param digester Digester instance to use.
     */
   private void initDigesterForTilesDefinitionsSyntax( Digester digester )
   {
      // Common constants
   String PACKAGE_NAME = "org.apache.struts.tiles.xmlDefinition";
   String DEFINITION_TAG = "tiles-definitions/definition";
   String definitionHandlerClass = PACKAGE_NAME + ".XmlDefinition";
 
   String PUT_TAG  = DEFINITION_TAG + "/put";
   String putAttributeHandlerClass = PACKAGE_NAME + ".XmlAttribute";
 
   //String LIST_TAG = DEFINITION_TAG + "/putList";
     // List tag value
   String LIST_TAG = "putList";
   String DEF_LIST_TAG = DEFINITION_TAG + "/" + LIST_TAG;
   String listHandlerClass     = PACKAGE_NAME + ".XmlListAttribute";
     // Tag value for adding an element in a list
   String ADD_LIST_ELE_TAG = "*/" + LIST_TAG + "/add";
 
     // syntax rules
     digester.addObjectCreate(  DEFINITION_TAG, definitionHandlerClass );
     digester.addSetProperties( DEFINITION_TAG);
     digester.addSetNext(       DEFINITION_TAG, "putDefinition", definitionHandlerClass);
     // put / putAttribute rules
     // Rules for a same pattern are called in order, but rule.end() are called
     // in reverse order.
     // SetNext and CallMethod use rule.end() method. So, placing SetNext in
     // first position ensure it will be called last (sic).
     digester.addObjectCreate(  PUT_TAG, putAttributeHandlerClass);
     digester.addSetNext(       PUT_TAG, "addAttribute", putAttributeHandlerClass);
     digester.addSetProperties( PUT_TAG);
     digester.addCallMethod(    PUT_TAG, "setBody", 0);
     // Definition level list rules
     // This is rules for lists nested in a definition
     digester.addObjectCreate(  DEF_LIST_TAG, listHandlerClass);
     digester.addSetProperties( DEF_LIST_TAG);
     digester.addSetNext(       DEF_LIST_TAG, "addAttribute", putAttributeHandlerClass);
     // list elements rules
     // We use Attribute class to avoid rewriting a new class.
     // Name part can't be used in listElement attribute.
     digester.addObjectCreate(  ADD_LIST_ELE_TAG, putAttributeHandlerClass);
     digester.addSetNext(       ADD_LIST_ELE_TAG, "add", putAttributeHandlerClass);
     digester.addSetProperties( ADD_LIST_ELE_TAG);
     digester.addCallMethod(    ADD_LIST_ELE_TAG, "setBody", 0);
 
     // nested list elements rules
     // Create a list handler, and add it to parent list
   String NESTED_LIST = "*/" + LIST_TAG + "/" + LIST_TAG;
     digester.addObjectCreate(  NESTED_LIST, listHandlerClass);
     digester.addSetProperties( NESTED_LIST);
     digester.addSetNext(       NESTED_LIST, "add", putAttributeHandlerClass);
 
     // item elements rules
     // We use Attribute class to avoid rewriting a new class.
     // Name part can't be used in listElement attribute.
   //String ADD_WILDCARD = LIST_TAG + "/addItem";
   // non String ADD_WILDCARD = LIST_TAG + "/addx*";
   String ADD_WILDCARD = "*/item";
   String menuItemDefaultClass = "org.apache.struts.tiles.beans.SimpleMenuItem";
     digester.addObjectCreate(  ADD_WILDCARD, menuItemDefaultClass, "classtype");
     digester.addSetNext(       ADD_WILDCARD, "add", "java.lang.Object");
     digester.addSetProperties( ADD_WILDCARD);
 
     // bean elements rules
   String BEAN_TAG = "*/bean";
   String beanDefaultClass = "org.apache.struts.tiles.beans.SimpleMenuItem";
     digester.addObjectCreate(  BEAN_TAG, beanDefaultClass, "classtype");
     digester.addSetNext(       BEAN_TAG, "add", "java.lang.Object");
     digester.addSetProperties( BEAN_TAG);
 
     // Set properties to surrounding element
   digester.addSetProperty(BEAN_TAG+ "/set-property", "property", "value");
   }
 
    /**
     * Init digester in order to parse instances definition file syntax.
     * Instances is an old name for "definition". This method is left for
     * backwards compatibility.
     * @param digester Digester instance to use.
     */
   private void initDigesterForInstancesSyntax( Digester digester )
   {
         // Build a digester to process our configuration resource
   String PACKAGE_NAME = "org.apache.struts.tiles.xmlDefinition";
   String INSTANCE_TAG = "component-instances/instance";
   String instanceHandlerClass = PACKAGE_NAME + ".XmlDefinition";
 
   String PUT_TAG = INSTANCE_TAG + "/put";
   String PUTATTRIBUTE_TAG = INSTANCE_TAG + "/putAttribute";
   String putAttributeHandlerClass = PACKAGE_NAME + ".XmlAttribute";
 
   String LIST_TAG     = INSTANCE_TAG + "/putList";
   String listHandlerClass     = PACKAGE_NAME + ".XmlListAttribute";
 
   String ADD_LIST_ELE_TAG = LIST_TAG + "/add";
 
     // component instance rules
     digester.addObjectCreate(  INSTANCE_TAG, instanceHandlerClass );
     digester.addSetProperties( INSTANCE_TAG);
     digester.addSetNext(       INSTANCE_TAG, "putDefinition", instanceHandlerClass);
     // put / putAttribute rules
     digester.addObjectCreate(  PUTATTRIBUTE_TAG, putAttributeHandlerClass);
     digester.addSetProperties( PUTATTRIBUTE_TAG);
     digester.addSetNext(       PUTATTRIBUTE_TAG, "addAttribute", putAttributeHandlerClass);
     // put / putAttribute rules
     digester.addObjectCreate(  PUT_TAG, putAttributeHandlerClass);
     digester.addSetProperties( PUT_TAG);
     digester.addSetNext(       PUT_TAG, "addAttribute", putAttributeHandlerClass);
     // list rules
     digester.addObjectCreate(  LIST_TAG, listHandlerClass);
     digester.addSetProperties( LIST_TAG);
     digester.addSetNext(       LIST_TAG, "addAttribute", putAttributeHandlerClass);
     // list elements rules
     // We use Attribute class to avoid rewriting a new class.
     // Name part can't be used in listElement attribute.
     digester.addObjectCreate(  ADD_LIST_ELE_TAG, putAttributeHandlerClass);
     digester.addSetProperties( ADD_LIST_ELE_TAG);
     digester.addSetNext(       ADD_LIST_ELE_TAG, "add", putAttributeHandlerClass);
   }
 
    /**
     * Init digester.
     * @param digester Digester instance to use.
     */
   protected void initDigester( Digester digester )
   {
   initDigesterForTilesDefinitionsSyntax( digester );
   initDigesterForComponentsDefinitionsSyntax( digester );
   initDigesterForInstancesSyntax( digester );
   }
 
   /**
    * Parse input reader and add encountered definitions to definitions set.
    * @param in Input stream.
    * @param definitions Xml Definitions set to which encountered definition are added.
    * @throws IOException On errors during file parsing.
    * @throws SAXException On errors parsing XML.
    */
   public void parse( InputStream in, XmlDefinitionsSet definitions ) throws IOException, SAXException
   {
     try
     {
       // set first object in stack
     //digester.clear();
     digester.push(definitions);
       // parse
       digester.parse(in);
       in.close();
       }
   catch (SAXException e)
     {
       //throw new ServletException( "Error while parsing " + mappingConfig, e);
     throw e;
       }
 
   }
 
     /**
      * Main method to check file syntax.
      */
   public static void main(String[] args)
   {
   //String filename = "E:/programs/jakarta-tomcat/webapps/wtiles-struts/WEB-INF/tiles-examples-defs.xml";
   String filename = "E:/programs/jakarta-tomcat-4.0.3/webapps/wtiles-struts/WEB-INF/tiles-examples-defs.xml";
   //String filename = "E:/programs/jakarta-tomcat/webapps/wtiles-struts/WEB-INF/tilesDefinitions.xml";
   //String filename = "E:/programs/jakarta-tomcat/webapps/wtiles-channel/WEB-INF/componentDefinitions.xml";
   //String filename2 = "E:/programs/jakarta-tomcat/webapps/wtiles-tutorial/WEB-INF/componentDefinitions.xml";
 
 
     if( args.length > 1 )
       {
       filename = args[1];
       } // end if
 
   System.out.println( "Read file '" + filename  +"'" );
 
   InputStream input = null;
   // InputStream input2 = null;
     // Open file
     try
       {
         input = new BufferedInputStream(
                              new FileInputStream( filename) );
     //    input2 = new BufferedInputStream(
           //                   new FileInputStream( filename2) );
       }
      catch( IOException ex )
       {
       System.out.println( "can't open file '" + filename + "' : " + ex.getMessage() );
       }
     // Check file syntax
     try
       {
         XmlParser parser = new XmlParser();
       parser.setValidating(true);
       XmlDefinitionsSet definitions = new XmlDefinitionsSet();
         System.out.println( "  Parse file" );
       parser.parse( input, definitions);
       //  System.out.println( "  Check file 2" );
       //parser.parse( input2, definitions);
         System.out.println( "  done." );
       System.out.println( "  Result : " + definitions.toString() );
       }
      catch( Exception ex )
       {
       System.out.println( "Error during parsing '" + filename + "' : " + ex.getMessage() );
       ex.printStackTrace();
       }
   }
 
 }